USAP-DC

{"dp_type": "Project", "free_text": "MODELS"}

[{"awards": "2336354 Juarez Rivera, Marisol", "bounds_geometry": "POLYGON((160 -76.5,160.45 -76.5,160.9 -76.5,161.35 -76.5,161.8 -76.5,162.25 -76.5,162.7 -76.5,163.15 -76.5,163.6 -76.5,164.05 -76.5,164.5 -76.5,164.5 -76.7,164.5 -76.9,164.5 -77.1,164.5 -77.3,164.5 -77.5,164.5 -77.7,164.5 -77.9,164.5 -78.1,164.5 -78.3,164.5 -78.5,164.05 -78.5,163.6 -78.5,163.15 -78.5,162.7 -78.5,162.25 -78.5,161.8 -78.5,161.35 -78.5,160.9 -78.5,160.45 -78.5,160 -78.5,160 -78.3,160 -78.1,160 -77.9,160 -77.7,160 -77.5,160 -77.3,160 -77.1,160 -76.9,160 -76.7,160 -76.5))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Jul 2024 00:00:00 GMT", "description": "Perennially ice-covered lakes in the McMurdo Dry Valleys of Antarctica contain abundant microbial mats, and the export of this mat material can fertilize the surrounding polar desert ecosystems. These desert soils are one of the most organic-poor on earth yet host a community of microorganisms. Microbial mat material is exported from the shallow, gas-supersaturated regions of the lakes when gas bubbles form in the mats, lifting them to the ice cover. The perennial ice cover maintains gas supersaturation. These mats freeze in and are exported to the surrounding soils through ice ablation. The largest seasonal decrease and thinnest ice cover in the history of Lake Fryxell was recorded during the 2022-2023 Austral summer. In this thin ice year, the water column dissolved oxygen increased over prior observations, and the lake bottom surface area with bubble-disrupted mat was more than double that observed in 1980-1981 and 2006-2007. This work will constrain mat mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning to understand how future changing regional climate and predicted seasonal loss of lake ice cover will affect nutrient transport in the McMurdo Dry Valleys. Exceptional years of mat export are hypothesized to have the most significant impact on nutrient export to soil communities. Variability in mat liftoff may thus play a role in the McMurdo Dry Valleys ecosystem response to changing climate. The perennial ice cover of lakes in the McMurdo Dry Valleys of Antarctica modulates the transfer of gasses, organic and inorganic material, between the lakes and surrounding soils. The export of biomass in these lakes is driven by the supersaturation of atmospheric gasses in the shallow regions under perennial ice cover. Gas bubbles nucleate in the mats, producing buoyancy that lifts them to the bottom of the ice, where they freeze in and are exported to the surrounding soils through ice ablation. These mats represent a significant source of biomass and nutrients to the McMurdo Dry Valleys soils, which are among the most organic-poor on earth. Nevertheless, this biomass remains unaccounted for in organic carbon cycling models for the McMurdo Dry Valleys. Ice cover data from the McMurdo Dry Valleys Long Term Ecological Research Project shows that the ice thickness has undergone cyclical variation over the last 40 years, reaching the largest seasonal decrease and thinnest ice-cover in the recorded history of Lake Fryxell during the 2022-2023 austral summer. Preliminary work shows that the surface area with mat liftoff at Lake Fryxell is more than double that observed in 1980-1981 and 2006-2007, coinciding with this unprecedented thinning of the ice-cover and an increase in the water column dissolved O2. This research will constrain biomass mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning. The researchers hypothesize that a thinner ice cover promotes more biomass mobilization by 1) stimulating additional production of gas bubbles from the existing gas-supersaturated waters during summertime photosynthesis to create microbial mat liftoff and 2) promoting mat liftoff in deeper, thicker microbial mats, and 3) that this biomass can be traced into the soils by characterizing its chemistry and modeling the most likely depositional settings. This work will use microbial mat samples, lake dissolved oxygen and photosynthetically active radiation data and underwater drone footage documenting the depth distribution of liftoff mats in January 2023, and long-term ice cover thickness, photosynthetically active radiation, and lake level change data collected by the McMurdo Dry Valleys Long Term Ecological Research Project to test hypotheses 1-3. The dispersal of the liftoff mat exposed at Lake Fryxell surface will be modeled using a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Exceptional liftoff years like the present are hypothesized to have the most significant impact on the soil communities as the rates of soil respiration increase with the addition of carbon. However, continued warming in the next 10 - 40 years may result in seasonal loss of the ice cover and cessation of liftoff mat export.", "east": 164.5, "geometry": "POINT(162.25 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; MINERALS; LAKE/POND; ISOTOPES; Organic Matter; McMurdo Dry Valleys; SEDIMENTARY ROCKS", "locations": "McMurdo Dry Valleys", "north": -76.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Juarez Rivera, Marisol", "platforms": null, "repositories": null, "science_programs": null, "south": -78.5, "title": "RAPID: Is Biomass Mobilization at Ice-covered Lake Fryxell, Antarctica reaching a Critical Threshold?", "uid": "p0010467", "west": 160.0}, {"awards": "2301026 Amsler, Charles", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 May 2024 00:00:00 GMT", "description": "General abstract\u003cbr/\u003e\u003cbr/\u003eMost organisms alternate between life stages that vary in the number and arrangement of their chromosomes, in the number of cells they possess, and in the environmental conditions in which they are best adapted to live. Much of what we understand about these alternations comes from organisms like animals and land plants in which one of the two stages dominates the life cycle with the other small and short-lived. However, across the tree of life there are countless examples of organisms in which both stages are of long duration, multicellular, or both. These life cycles challenge common ideas used to explain ecological and evolutionary patterns we see in nature. Macroalgae (seaweeds) display a wide range of life cycle types and consequently are excellent models to test and expand ideas about how life cycles evolve. Undersea forests of seaweeds with a variety of life cycle types dominate the shallow waters of the western Antarctic Peninsula where they are ecologically important and, for most of the species, at the southern end of their geographic range. Using existing samples from previous expeditions to Antarctica, the investigators are uniquely positioned to test and expand knowledge of life cycle evolution and how this intersects with reproductive mode variation. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the public. The project will support a postdoctoral scholar as well as a faculty member new to US Antarctic research. The investigators will take advantage of an existing program to include high school or undergraduate students in the work which will also expand mentorship experience for the postdoc. All team members will contribute by writing for blogs produced by professional societies for the public. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eTechnical abstract\u003cbr/\u003e\u003cbr/\u003eExisting macroalgal taxa samples from across a latitudinal gradient in the western Antarctic Peninsula will be used to explore patterns of genetic diversity from the center to the southern latitudinal limits of their range. Not only will genetic diversity be documented for an understudied and critical group of Antarctic organisms, but how it changes with latitude, compounded by high levels of endemism, will be explored. This will be accomplished by (i) characterization of latitudinal gradients in genetic diversity of many species and (ii) determination of the reproductive system of five focal foundation species. At present, there are few genetic data for macroalgae, dominant primary producers in coastal ecosystems around the world. This gap is particularly acute along Antarctic coastlines that are experiencing rapid climate change. Furthermore, Antarctica is isolated by the Southern Ocean, decreasing the likelihood of regular migration from other land masses. Latitudinal reproductive system patterns are predicted to be largely driven by recolonization events that increase with latitude due to changes in iceberg scour and sea ice coverage. Thus, Antarctica is the best place to understand what processes underlie reproductive mode variation in populations that are isolated, including many endemic taxa, while simultaneously extending our knowledge about how marginal environments converge with complex life cycles.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MACROALGAE (SEAWEEDS); Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Amsler, Charles; Krueger-Hadfield, Stacy", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Historical and Contemporary Drivers of Macroalgal Reproductive System Variation along the Western Antarctic Peninsula", "uid": "p0010460", "west": null}, {"awards": "2423761 Blackburn, Terrence", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 14 May 2024 00:00:00 GMT", "description": "Non-technical abstract\u003cbr/\u003e\u003cbr/\u003eEarth\u2019s climatic changes have been recorded in the ice core collected from the Antarctic ice sheet. While these records provide a high resolution view of how polar temperatures changed through time, it is not always clear what Earth process influence Antarctic climate. One likely contributor to Antarctic temperature changes is the cyclic changes in Earth\u2019s orientation as it orbits the sun. These so-called Milankovitch cycles control the amount and pattern of sunlight reaching the polar regions, that in turn result in periods of climatic warming or cooling. While the orbital variations and control on incoming solar energy remain well understood, how they influence Antarctic climate remains unresolved. It is the goal of this project to determine how variations in Earth\u2019s orbit may be locally influencing Antarctic temperatures. The researchers on this project are pursing this goal by identifying periods of past ice melting on the surface of Antarctica using minerals that precipitate from the meltwaters that resulted from past warm periods. The timing of this past melting will be determined by radioisotopic dating of the minerals using the natural radioactive decay of uranium to thorium. By dating numerous samples, collected in past scientific expeditions throughout the Antarctic continent, these researchers aim to reconstruct the frequency and spatial pattern of past warming and in doing so, determine what aspect of Earth\u2019s orbital variations influences Antarctic ice loss.\u003cbr/\u003e\u003cbr/\u003eTechnical abstract\u003cbr/\u003e\u003cbr/\u003eAntarctic ice cores provide high resolution records of Pleistocene Southern Hemisphere temperatures that show an overall coherence with Northern Hemisphere temperature variations. One explanation for this bi-hemispheric temperature covariance relies on changes in atmospheric CO2 that result from varying northern hemisphere insolation. An alternative posits that the apparent coherence of polar temperatures is due to the misleading covariance between northern hemisphere summer insolation and, the southern hemisphere summer duration. At present there is an insufficient understanding of the role that local insolation plays in Antarctic climate. The goal of this research project is to identify the temporal spatial patterns of solar forcing in Antarctica. To reach this goal, the project team will: 1) develop a way to identify periods of past surface melt production in Antarctica using U-Th dating of pedogenic carbonates; and 2) utilize the evidence of past surface melting to calibrate energy balance models and interrogate past Antarctic surface temperatures and; 3) compare the timing of Antarctic warm periods to potential solar forcing mechanisms such as peak summer insolation or summer duration. A means of identifying the spatial and temporal pattern at which local insolation influences Antarctic temperature would provide a transformative solution to the contradiction in current climate records.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; PALEOCLIMATE RECONSTRUCTIONS", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "EAGER: Pedogenic Carbonates Record Insolation Driven Surface Melting in Antarctica", "uid": "p0010459", "west": -180.0}, {"awards": "2231230 Joughin, Ian", "bounds_geometry": "POLYGON((90 -65,93.5 -65,97 -65,100.5 -65,104 -65,107.5 -65,111 -65,114.5 -65,118 -65,121.5 -65,125 -65,125 -65.2,125 -65.4,125 -65.6,125 -65.8,125 -66,125 -66.2,125 -66.4,125 -66.6,125 -66.8,125 -67,121.5 -67,118 -67,114.5 -67,111 -67,107.5 -67,104 -67,100.5 -67,97 -67,93.5 -67,90 -67,90 -66.8,90 -66.6,90 -66.4,90 -66.2,90 -66,90 -65.8,90 -65.6,90 -65.4,90 -65.2,90 -65))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 29 Feb 2024 00:00:00 GMT", "description": "The snow that falls on Antarctica compresses to ice that flows toward the coast as a large sheet, returning it to the ocean over periods of centuries to millennia. In many places around Antarctica, the ice sheet extends from the land to over the ocean, forming floating ice shelves on the periphery. If this cycle is in balance, the ice sheets help maintain a stable sea level. When the climate cools or warms, however, sea level falls or rises as the ice sheet gains or loses ice. The peripheral ice shelves are important for regulating sea level because they help hold back the flow of ice to the ocean. Warming ocean waters thin ice shelves by melting their undersides, allowing ice to flow faster to the ocean, and raising sea level globally. Thus, an important question is how much sea level will rise in response to warming ocean temperatures over the next century(s) that further thin Antarctica?s ice shelves. Currently, West Antarctica produces the majority of the continent?s contribution to sea level. Albeit with large uncertainty, ice-sheet models indicate that Totten and Denman glaciers in East Antarctica could also produce substantial sea-level rise in the next century(s). This international study will focus on improving understanding of how much these glaciers will contribute to sea level under various warming scenarios. The project will use numerical models constrained by oceanographic and remote sensing observations to determine how Totten and Denman glaciers will respond to increased melting. Remote sensing data will provide updated and improved estimates of the melt rate for each ice shelf. Two float profilers will be deployed from aircraft by British and Australian partners in front of each ice shelf to repeatedly measure the temperature and salinity of the water column, with the results telemetered back via satellite link. The melt and oceanographic data will be used to constrain parameterized transfer functions for ice-shelf cavity melting in response to ocean temperature, improving on current parameterizations based on limited data. These melt functions will be used with ocean temperatures from climate models to force an open-source ice-flow numerical model for each glacier to determine the century-scale response for a variety of scenarios, helping to reduce uncertainty in sea level contributions from this part of Antarctica. Processes other than melt that might further alter the contribution to sea level over the next few centuries will also be examined. On the observational side, the demonstrated deployment of float profilers from a sonobuoy launch tube in polar settings would help raise the technology readiness of operational in-situ monitoring of the rapidly changing polar shelf seas, paving the way for an expansion of observations of ocean hydrographic properties from remote areas that currently are poorly understood. In addition to being of scientific value, reduced uncertainty in sea-level rise projections has strong societal benefit to coastal communities struggling with long-range planning to mitigate the effects of sea-level rise over the coming decades to centuries. Outreach activities by team members will help raise public awareness of Antarctica\u0027s dramatic changes and the resulting consequences. This is a project jointly funded by the National Science Foundation?s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.", "east": 125.0, "geometry": "POINT(107.5 -66)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE SHEETS", "locations": "Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Joughin, Ian; Shapero, Daniel; Smith, Benjamin E", "platforms": null, "repositories": null, "science_programs": null, "south": -67.0, "title": "NSFGEO-NERC: Understanding the Response to Ocean Melting for Two of East Antarctica\u0027s Most Vulnerable Glaciers: Totten and Denman", "uid": "p0010454", "west": 90.0}, {"awards": "1939146 Siddoway, Christine; 1939139 Scherer, Reed", "bounds_geometry": "POLYGON((-120 -66,-117.5 -66,-115 -66,-112.5 -66,-110 -66,-107.5 -66,-105 -66,-102.5 -66,-100 -66,-97.5 -66,-95 -66,-95 -67.1,-95 -68.2,-95 -69.3,-95 -70.4,-95 -71.5,-95 -72.6,-95 -73.7,-95 -74.8,-95 -75.9,-95 -77,-97.5 -77,-100 -77,-102.5 -77,-105 -77,-107.5 -77,-110 -77,-112.5 -77,-115 -77,-117.5 -77,-120 -77,-120 -75.9,-120 -74.8,-120 -73.7,-120 -72.6,-120 -71.5,-120 -70.4,-120 -69.3,-120 -68.2,-120 -67.1,-120 -66))", "dataset_titles": "Pliocene diatom abundance, IODP 379-U1532; Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature; U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "datasets": [{"dataset_uid": "601828", "doi": null, "keywords": "Amundsen Sea; Antarctica; Cryosphere; Geochronology; Marie Byrd Land; Subglacial Bedrock; Thermochronology", "people": "Siddoway, Christine", "repository": "USAP-DC", "science_program": null, "title": "U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "url": "https://www.usap-dc.org/view/dataset/601828"}, {"dataset_uid": "601804", "doi": "10.15784/601804", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Oceanography; Sabrina Coast; Sea Surface Temperature; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature", "url": "https://www.usap-dc.org/view/dataset/601804"}, {"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Scherer, Reed Paul; Furlong, Heather", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 379-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}], "date_created": "Tue, 20 Feb 2024 00:00:00 GMT", "description": "Part I, Non-technical Abstract \u003cbr/\u003eConcerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts.\u003cbr/\u003e\u003cbr/\u003ePart 2, Technical Abstract\u003cbr/\u003e\u003cbr/\u003eNew drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -71.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICEBERGS; SEA SURFACE TEMPERATURE; Amundsen Sea; MICROFOSSILS", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul; Siddoway, Christine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica", "uid": "p0010451", "west": -120.0}, {"awards": "1744989 LaRue, Michelle", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Detecting climate signals in populations: case of emperor penguin; Emperor penguin population trends (2009-2018); Landfast ice: a major driver of reproductive success in a polar seabird", "datasets": [{"dataset_uid": "601513", "doi": "10.15784/601513", "keywords": "Antarctica; Breeding Success; Emperor Penguin; Fast Sea Ice", "people": "Jenouvrier, Stephanie; Labrousse, Sara", "repository": "USAP-DC", "science_program": null, "title": "Landfast ice: a major driver of reproductive success in a polar seabird", "url": "https://www.usap-dc.org/view/dataset/601513"}, {"dataset_uid": "601491", "doi": "10.15784/601491", "keywords": "Antarctica", "people": "Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "Detecting climate signals in populations: case of emperor penguin", "url": "https://www.usap-dc.org/view/dataset/601491"}, {"dataset_uid": "200410", "doi": "10.5061/dryad.m63xsj48v", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Emperor penguin population trends (2009-2018)", "url": "https://doi.org/10.5061/dryad.m63xsj48v"}], "date_created": "Thu, 08 Feb 2024 00:00:00 GMT", "description": "This project on emperor penguin populations will quantify penguin presence/absence, and colony size and trajectory, across the entire Antarctic continent using high-resolution satellite imagery. For a subset of the colonies, population estimates derived from high-resolution satellite images will be compared with those determined by aerial surveys - these results have been uploaded to MAPPPD (penguinmap.com) and are freely available for use. This validated information will be used to determine population estimates for all emperor penguin colonies through iterations of supervised classification and maximum likelihood calculations on the high-resolution imagery. The effect of spatial, geophysical, and environmental variables on population size and decadal-scale trends will be assessed using generalized linear models. This research will result in a first ever empirical result for emperor penguin population trends and habitat suitability, and will leverage currently-funded NSF infrastructure and hosting sites to publish results in near-real time to the public.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "COMMUNITY DYNAMICS; USA/NSF; Amd/Us; USAP-DC; Antarctica; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "LaRue, Michelle; Ito, Emi; Jenouvrier, Stephanie", "platforms": null, "repo": "USAP-DC", "repositories": "Dryad; USAP-DC", "science_programs": null, "south": -90.0, "title": "A Multi-scale Approach to Understanding Spatial and Population Variability in Emperor Penguins", "uid": "p0010447", "west": -180.0}, {"awards": "1443522 Wannamaker, Philip", "bounds_geometry": "POLYGON((166 -77.15,166.34 -77.15,166.68 -77.15,167.02 -77.15,167.36 -77.15,167.7 -77.15,168.04 -77.15,168.38 -77.15,168.72 -77.15,169.06 -77.15,169.4 -77.15,169.4 -77.22500000000001,169.4 -77.30000000000001,169.4 -77.375,169.4 -77.45,169.4 -77.525,169.4 -77.60000000000001,169.4 -77.67500000000001,169.4 -77.75,169.4 -77.825,169.4 -77.9,169.06 -77.9,168.72 -77.9,168.38 -77.9,168.04 -77.9,167.7 -77.9,167.36 -77.9,167.02 -77.9,166.68 -77.9,166.34 -77.9,166 -77.9,166 -77.825,166 -77.75,166 -77.67500000000001,166 -77.60000000000001,166 -77.525,166 -77.45,166 -77.375,166 -77.30000000000001,166 -77.22500000000001,166 -77.15))", "dataset_titles": "Erebus volcano/Ross Island Magnetotelluric (MT) data", "datasets": [{"dataset_uid": "601493", "doi": "10.15784/601493", "keywords": "Antarctica; Mantle Melting; Mount Erebus", "people": "Wannamaker, Philip; Hill, Graham", "repository": "USAP-DC", "science_program": null, "title": "Erebus volcano/Ross Island Magnetotelluric (MT) data", "url": "https://www.usap-dc.org/view/dataset/601493"}], "date_created": "Mon, 05 Feb 2024 00:00:00 GMT", "description": "General Description:\u003cbr/\u003eThis project is intended to reveal the magma source regions, staging areas, and eruptive pathways within the active volcano Mount Erebus. This volcano is an end-member type known as phonolitic, which refers to the lava composition, and is almost purely carbon-dioxide-bearing and occurs in continental rift settings. It is in contrast to the better known water-bearing volcanoes which occur at plate boundary settings (such as Mount St Helens or Mount Fuji). Phonolitic volcanic eruptions elsewhere such as Tamboro or Vesuvius have caused more than 50,000 eruption related fatalities. Phonolites are also associated with rare earth element deposits, giving them economic interest. To illuminate the inner workings of Mount Erebus, we will cover the volcano with a dense network of geophysical probes based on magnetotelluric (MT) measurements. MT makes use of naturally occurring electromagnetic (EM) waves generated mainly by the sun as sources to provide images of the electrical conductivity structure of the Earth\u0027s interior. Conductivity is sensitive to the presence of fluids and melts in the Earth and so is well suited to understanding volcanic processes. The project is a cooperative effort between scientists from the United States, New Zealand, Japan and Canada. It implements new technology developed by the lead investigator and associates that allows such measurements to be taken on snow-covered terrains. This has applicability for frozen environments generally, such as resource exploration in the Arctic. The project supports a new post-doctoral researcher, and leverages imaging and measurement methods developed through support by other agencies and interfaced with commercial platforms.\u003cbr/\u003e\u003cbr/\u003eTechnical Description:\u003cbr/\u003eThe investigators propose to test magmatic evolution models for Mount Erebus volcano, Antarctica, using the magnetotelluric (MT) method. The phonolite lava flow compositions on Mount Erebus are uncommon, but provide a window into the range of upper mantle source compositions and melt differentiation paths. Explosive phonolite eruptions have been known worldwide for devastating eruptions such as Tambora and Vesuvius, and commonly host rare earth element deposits. In the MT method, temporal variations in the Earth\u0027s natural electromagnetic (EM) field are used as source fields to probe the electrical resistivity structure in the depth range of 1 to 100 kilometers. This effort will consist of approximately 100 MT sites, with some concentration in the summit area. Field acquisition will take place over two field seasons. The main goals are to 1) confirm the existence and the geometry of the uppermost magma chamber thought to reside at 5-10 kilometer depths; 2) attempt to identify, in the deeper resistivity structure, the magma staging area near the crust-mantle boundary; 3) image the steep, crustal-scale, near-vertical conduit carrying magma from the mantle; 4) infer the physical and chemical state from geophysical properties of a CO2-dominated mafic shield volcano; and 5) constrain the relationships between structural and magmatic/ hydrothermal activity related to the Terror Rift. Tomographic imaging of the interior resistivity will be performed using a new inversion platform developed at Utah, based on the deformable edge finite element method, that is the best available for accommodating the steep topography of the study area. The project is an international cooperation between University of Utah, GNS Science Wellington New Zealand (G. Hill, Co-I), and Tokyo Institute of Technology Japan (Y. Ogawa, Co-I), plus participation by University of Alberta (M. Unsworth) and Missouri State University (K. Mickus). Instrument deployments will be made exclusively by helicopter. The project implements new technology that allows MT measurements to be taken on snow-covered terrains. The project supports a new post-doctoral researcher, and leverages imaging and measurement methods developed through support by other agencies and interfaced with commercial platforms.", "east": 169.4, "geometry": "POINT(167.7 -77.525)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS", "is_usap_dc": true, "keywords": "MAGNETIC FIELD; FIELD SURVEYS; Ross Island; Magnetotelluric; Mount Erebus", "locations": "Ross Island; Mount Erebus", "north": -77.15, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wannamaker, Philip", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.9, "title": "Magma Sources, Residence and Pathways of Mount Erebus Phonolitic Volcano, Antarctica, from Magnetotelluric Resistivity Structure", "uid": "p0010444", "west": 166.0}, {"awards": "2333940 Zhong, Shijie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 08 Jan 2024 00:00:00 GMT", "description": "Satellite observations of Earth?s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth?s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth?s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS; CRUSTAL MOTION; COMPUTERS; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE", "locations": "WAIS", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Zhong, Shijie", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Investigating Effects of Transient and Non-Newtonian Mantle Viscosity on Glacial Isostatic Adjustment Process and their Implications for GPS Observations in Antarctica", "uid": "p0010441", "west": -180.0}, {"awards": "0944018 Lazzara, Matthew; 0943952 Cassano, John", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Automatic Weather Stations", "datasets": [{"dataset_uid": "200375", "doi": "https://doi.org/10.48567/1hn2-nw60", "keywords": null, "people": null, "repository": "Antarctic Meteorological Research and Data Center", "science_program": null, "title": "Antarctic Automatic Weather Stations", "url": "https://amrdcdata.ssec.wisc.edu/dataset?q=0944018+"}], "date_created": "Fri, 20 Oct 2023 00:00:00 GMT", "description": "The Antarctic Automatic Weather Station (AWS) network, first commenced in 1978, is the most extensive meteorological observing system on the Antarctic continent, approaching its 30th year at many of its key sites. Its prime focus as a long term observational record is vital to the measurement of the near surface climatology of the Antarctic atmosphere. AWS units measure air-temperature, pressure, wind speed and direction at a nominal surface height of 3m. Other parameters such as relative humidity and snow accumulation may also be taken. Observational data from the AWS are collected via the DCS Argos system aboard either NOAA or MetOp polar orbiting satellites and thus made available globally, in near real time via the GTS (Global Telecommunications System), to operational and synoptic weather forecasters. The surface observations from the AWS network also are often used to check on satellite and remote sensing observations, and the simulations of Global Climate Models (GCMs). Research instances of its use in this project include continued development of the climatology of the Antarctic atmosphere and surface wind studies of the Ross Ice Shelf. The AWS observations benefit the broader earth system science community, supporting research activities ranging from paleoclimate studies to penguin phenology.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; DATA COLLECTIONS; SURFACE PRESSURE; HUMIDITY; AIR TEMPERATURE; FIELD SITES; LAND-BASED PLATFORMS; SURFACE WINDS; WEATHER STATIONS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lazzara, Matthew; Cassano, John", "platforms": "LAND-BASED PLATFORMS; LAND-BASED PLATFORMS \u003e FIELD SITES; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e WEATHER STATIONS", "repo": "Antarctic Meteorological Research and Data Center", "repositories": "Antarctic Meteorological Research and Data Center", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Antarctic Automatic Weather Station Program", "uid": "p0010438", "west": -180.0}, {"awards": "1149085 Bassis, Jeremy", "bounds_geometry": "POLYGON((66 -68,66.9 -68,67.8 -68,68.7 -68,69.6 -68,70.5 -68,71.4 -68,72.3 -68,73.2 -68,74.1 -68,75 -68,75 -68.6,75 -69.2,75 -69.8,75 -70.4,75 -71,75 -71.6,75 -72.2,75 -72.8,75 -73.4,75 -74,74.1 -74,73.2 -74,72.3 -74,71.4 -74,70.5 -74,69.6 -74,68.7 -74,67.8 -74,66.9 -74,66 -74,66 -73.4,66 -72.8,66 -72.2,66 -71.6,66 -71,66 -70.4,66 -69.8,66 -69.2,66 -68.6,66 -68))", "dataset_titles": "Antarctic Ice Shelf Rift Propagation Rates", "datasets": [{"dataset_uid": "601740", "doi": "10.15784/601740", "keywords": "Amery Ice Shelf; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; MODIS", "people": "Walker, Catherine; Bassis, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Shelf Rift Propagation Rates", "url": "https://www.usap-dc.org/view/dataset/601740"}], "date_created": "Fri, 13 Oct 2023 00:00:00 GMT", "description": "This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbr\u00e4e, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.", "east": 75.0, "geometry": "POINT(70.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Amery Ice Shelf", "locations": "Amery Ice Shelf", "north": -68.0, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Bassis, Jeremy", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "CAREER: Bound to Improve - Improved Estimates of the Glaciological Contribution to Sea Level Rise", "uid": "p0010437", "west": 66.0}, {"awards": "2012958 Meyer, Colin", "bounds_geometry": null, "dataset_titles": "Frozen fringe friction ; Ring shear bed deformation measurements ", "datasets": [{"dataset_uid": "601757", "doi": "10.15784/601757", "keywords": "Antarctica", "people": "Zoet, Lucas", "repository": "USAP-DC", "science_program": null, "title": "Ring shear bed deformation measurements ", "url": "https://www.usap-dc.org/view/dataset/601757"}, {"dataset_uid": "601756", "doi": "10.15784/601756", "keywords": "Antarctica", "people": "Zoet, Lucas", "repository": "USAP-DC", "science_program": null, "title": "Frozen fringe friction ", "url": "https://www.usap-dc.org/view/dataset/601756"}], "date_created": "Wed, 13 Sep 2023 00:00:00 GMT", "description": "The fastest-changing regions of the Antarctic and Greenland Ice Sheets that contribute most to sea-level rise are underlain by soft sediments that facilitate glacier motion. Glacier ice can infiltrate several meters into these sediments, depending on the temperature and water pressure at the base of the glacier. To understand how ice infiltration into subglacial sediments affects glacier slip, the team will conduct laboratory experiments under relevant temperature and pressure conditions and compare the results to state-of-the-art mathematical models. Through an undergraduate research exchange between University of Wisconsin-Madison, Dartmouth College, and the College of Menominee Nation, Native American students will work on laboratory experiments in one summer and mathematical theory in the following summer.\u003cbr/\u003e\u003cbr/\u003eIce-sediment interactions are a central component of ice-sheet and landform-development models. Limited process understanding poses a key uncertainty for ice-sheet models that are used to forecast sea-level rise. This uncertainty underscores the importance of developing experimentally validated, theoretically robust descriptions of processes at the ice-sediment interface. To achieve this, the team aims to build on long-established theoretical, experimental, and field investigations that have elucidated the central role of premelting and surface-energy effects in controlling the dynamics of frost heave in soils. Project members will theoretically describe and experimentally test the role of premelting at the basal ice-sediment interface. The experiments are designed to provide quantitative insight into the impact of ice infiltration into sediments on glacier sliding, erosion, and subglacial landform evolution.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "BASAL SHEAR STRESS; GLACIER MOTION/ICE SHEET MOTION; GLACIERS/ICE SHEETS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Meyer, Colin; Rempel, Alan; Zoet, Lucas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Freeze-on of Subglacial Sediments in Experiments and Theory", "uid": "p0010434", "west": null}, {"awards": "2034874 Salesky, Scott; 2035078 Giometto, Marco", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "1. A non-technical explanation of the project\u0027s broader significance and importance, that serves as a public justification for NSF funding. This part should be understandable to an educated reader who is not a scientist or engineer.\r\n\r\nKatabatic or drainage winds, carry high-density air from a higher elevation down a slope under the force of gravity. Although katabatic flows are ubiquitous in alpine and polar regions, a surface-layer similarity theory is currently lacking for these flows, undermining the accuracy of numerical weather and climate prediction models. This project is interdisciplinary, and will give graduate and undergraduate students valuable experience interacting with researchers outside their core discipline. Furthermore, this project will broaden participating in science through recruitment of students from under-represented groups at OU and CU through established programs.\r\n\r\nThe Antarctic Ice Sheet drives many processes in the Earth system through its modulation of regional and global atmospheric and oceanic circulations, storage of fresh water, and effects on global albedo and climate. An understanding of the surface mass balance of the ice sheets is critical for predicting future sea level rise and for interpreting ice core records. Yet, the evolution of the ice sheets through snow deposition, erosion, and transport in katabatic winds (which are persistent across much of the Antarctic) remains poorly understood due to the lack of an overarching theoretical framework, scarcity of in situ observational datasets, and a lack of accurate numerical modeling tools. Advances in the fundamental understanding and modeling capabilities of katabatic transport processes are urgently needed in view of the future climatic and snowfall changes that are projected to occur within the Antarctic continent. This project will leverage the expertise of a multidisciplinary team of investigators (with backgrounds spanning cryospheric science, environmental fluid mechanics, and atmospheric science) to address these knowledge gaps.\r\n\r\n\r\n2. A technical description of the project that states the problem to be studied, the goals and scope of the research, and the methods and approaches to be used. In many cases, the technical project description may be a modified version of the project summary submitted with the proposal. \r\n\r\nUsing field observations and direct numerical simulations of katabatic flow, this project is expected--- for the first time---to lead to a surface-layer similarity theory for katabatic flows relating turbulent fluxes to mean vertical gradients. The similarity theory will be used to develop surface boundary conditions for large eddy simulations (LES), enabling the first accurate LES of katabatic flow.\r\n\r\nThe numerical tools that the PIs will develop will allow them to investigate how the partitioning between snow redistribution, transport, and sublimation depends on the environmental parameters typically encountered in Antarctica (e.g. atmospheric stratification, surface sloping angles, and humidity profiles), and to develop simple models to infer snow transport based on satellite remote sensing and regional climate models\r\n\r\nThis award reflects the NSF statutory mission and has been deemed worthy of support through evaluation using the intellectual merit of the Foundation and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "TURBULENCE; ATMOSPHERIC RADIATION; DATA COLLECTIONS; SNOW/ICE; SNOW; FIELD INVESTIGATION; AIR TEMPERATURE; HUMIDITY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Salesky, Scott; Giometto, Marco; Das, Indrani", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Snow Transport in Katabatic Winds and Implications for the Antarctic Surface Mass Balance: Observations, Theory, and Numerical Modeling", "uid": "p0010433", "west": null}, {"awards": "2317263 Cross, Andrew", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2023 00:00:00 GMT", "description": "The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding below, and internal viscous flow within, ice masses. The latter of these\u2014viscous flow\u2014is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a crystal orientation fabric (COF). Historically, ice flow has been modeled using a constitutive equation, termed \u201cGlen\u2019s law\u201d, that describes ice flow rate as a function of temperature and stress. Glen\u2019s law was constrained under relatively high-stress conditions, and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, \u201csuperplastic\u201d conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. In this project, the PI primarily seeks to measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models.\r\n\r\nPolycrystalline ice samples with grain sizes ranging from 5 \u00b5m to 1000 \u00b5m will be fabricated and deformed in the PI\u2019s laboratory at WHOI, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of \u221230\u00b0C to \u221210\u00b0C, and at a constant uniaxial strain rate of 10-7 s-1. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student within the MIT-WHOI Joint Program, one or more undergraduate summer students, and a junior faculty member (the PI). In addition, the PI will host a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; Rheology; ROCKS/MINERALS/CRYSTALS; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cross, Andrew", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Microstructural Evolution during Superplastic Ice Creep", "uid": "p0010430", "west": null}, {"awards": "2203176 Cimino, Megan; 2203177 Steinberg, Deborah", "bounds_geometry": "POLYGON((-80 -60,-77 -60,-74 -60,-71 -60,-68 -60,-65 -60,-62 -60,-59 -60,-56 -60,-53 -60,-50 -60,-50 -61,-50 -62,-50 -63,-50 -64,-50 -65,-50 -66,-50 -67,-50 -68,-50 -69,-50 -70,-53 -70,-56 -70,-59 -70,-62 -70,-65 -70,-68 -70,-71 -70,-74 -70,-77 -70,-80 -70,-80 -69,-80 -68,-80 -67,-80 -66,-80 -65,-80 -64,-80 -63,-80 -62,-80 -61,-80 -60))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 10 Aug 2023 00:00:00 GMT", "description": "Macrozooplankton are key contributors to marine ecosystem function, and combining empirical sampling and modeling will enable prediction of changing distribution patterns. Challenges in understanding alterations in distributions of these organisms are magnified in the Antarctic Peninsula (AP) ecosystem where ocean warming and sea-ice decline are assumed to drive range shifts in dominant taxa (e.g., krill, pteropods and salps), but functional relationships between zooplankton species distributions and environmental conditions remain uncertain. Therefore, we propose to leverage three decades of zooplankton abundance data and predator (seabird, whale and seal) sighting data from two main longterm survey programs to develop and evaluate predictive Zooplankton Distribution Models (ZDMs) along the AP (at least 60\u00b0 S to 70\u00b0 S, ~400,000 km2). To do this, we will adapt a successful machine learning modeling approach from the California Current ecosystem that utilizes bathymetric and oceanographic data to predict zooplankton species distributions. Our main outputs will be 1) a description of species spatiotemporal trends and abundance patterns, 2) a summary of overlap in zooplankton species and predator species distributions, and 3) the creation of a zooplankton mapping tool allowing for public viewing of past and future ZDM predictions.", "east": -50.0, "geometry": "POINT(-65 -65)", "instruments": null, "is_usap_dc": true, "keywords": "ANIMAL ECOLOGY AND BEHAVIOR; PELAGIC; BIRDS; SPECIES/POPULATION INTERACTIONS; ANIMALS/INVERTEBRATES; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cimino, Megan; Steinberg, Deborah", "platforms": null, "repositories": null, "science_programs": null, "south": -70.0, "title": "Collaborative Research: Harvesting Long-term Survey Data to Develop Zooplankton Distribution Models for the Antarctic Peninsula", "uid": "p0010429", "west": -80.0}, {"awards": "1847173 Duddu, Ravindra", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 07 Jul 2023 00:00:00 GMT", "description": "Iceberg calving is a complex natural fracture process and a dominant cause of mass loss from the floating ice shelves on the margins of the Antarctic ice sheet. There is concern that rapid changes at these ice shelves can destabilize parts of the ice sheet and accelerate their contribution to sea-level rise. The goal of this project is to understand and simulate the fracture mechanics of calving and to develop physically-consistent calving schemes for ice-sheet models. This would enable more reliable estimation of Antarctic mass loss by reducing the uncertainty in projections. The research plan is integrated with an education and outreach plan that aims to (1) enhance computational modeling skills of engineering and Earth science students through a cross-college course and a high-performance computing workshop and (2) increase participation and diversity in engineering and sciences by providing interdisciplinary research opportunities to undergraduates and by deploying new cyberlearning tools to engage local K-12 students in the Metro Nashville Public Schools in computational science and engineering, and glaciology.\u003cbr/\u003e\u003cbr/\u003eThis project aims to provide fundamental understanding of iceberg calving by advancing the frontiers in computational fracture mechanics and nonlinear continuum mechanics and translating it to glaciology. The project investigates crevasse propagation using poro-damage mechanics models for hydrofracture that are consistent with nonlinear viscous ice rheology, along with the thermodynamics of refreezing in narrow crevasses at meter length scales. It will develop a fracture-physics based scheme to better represent calving in ice-sheet models using a multiscale method. The effort will also address research questions related to calving behavior of floating ice shelves and glaciers, with the goal of enabling more reliable prediction of calving fronts in whole-Antarctic ice-sheet simulations over decadal-to-millennial time scales.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIER MOTION/ICE SHEET MOTION", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Duddu, Ravindra", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "CAREER: Fracture Mechanics of Antarctic Ice Shelves and Glaciers - Representing Iceberg Calving in Ice Sheet Models and Developing Cyberlearning Tools for Outreach", "uid": "p0010423", "west": null}, {"awards": "2021699 Trusel, Luke", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic ice sheet daily surface melt detection from ASCAT (2007-2022); ASCAT-ERA5 Antarctic Peninsula Daily Surface Meltwater Production (2007-2022); Trusel et al 2022, Geophysical Research Letters: Publication data and code", "datasets": [{"dataset_uid": "200363", "doi": "10.5281/zenodo.6374343", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Trusel et al 2022, Geophysical Research Letters: Publication data and code", "url": "https://zenodo.org/record/6374343"}, {"dataset_uid": "200364", "doi": "10.5281/zenodo.7995998", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Antarctic ice sheet daily surface melt detection from ASCAT (2007-2022)", "url": "https://zenodo.org/record/7995998"}, {"dataset_uid": "200362", "doi": "10.5281/zenodo.7995543", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "ASCAT-ERA5 Antarctic Peninsula Daily Surface Meltwater Production (2007-2022)", "url": "https://zenodo.org/record/7995543"}], "date_created": "Fri, 02 Jun 2023 00:00:00 GMT", "description": "Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. \r\n\r\nThis project used a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project supported the scientific training of a postdoctoral associate, a graduate student, and several undergraduate researchers. In addition, the project aimed to promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers.\r\n\r\nWe identified that surface lake drainages on East Antarctica\u2019s Amery Ice Shelf closely correspond to peaks in the daily amplitude of ocean tides. This research indicates that tidal-induced flexure inherent to the ice shelf grounding zone when combined with sufficient surface meltwater volumes can trigger ice shelf surface lake drainages (Trusel et al., 2022). In addition, we developed new estimates of surface melting across the Antarctic ice sheet using satellite and reanalysis data. First, we developed and implemented a pan-Antarctic ice sheet surface melt detection method applied to C-band Advanced Scatterometer (ASCAT) radar backscatter data. These binary melt presence/absence data were then combined with radar backscatter and ERA5 reanalysis outputs to estimate daily rates of surface meltwater production (in mm of water equivalence) across the Antarctic Peninsula region. These data therefore provide a new, observationally based dataset to investigate the intensity and drivers of surface melting in Antarctica\u2019s highest-melt region, and with which to evaluate climate model simulations. This method and an assessment of the resulting data are the subject of a forthcoming manuscript. \r\n\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctica; Surface Hydrology", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Trusel, Luke; Moussavi, Mahsa", "platforms": null, "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Water on the Antarctic Ice Sheet: Quantifying Surface Melt and Mapping Supraglacial Lakes", "uid": "p0010422", "west": -180.0}, {"awards": "1643575 Kanatous, Shane; 1644004 Trumble, Stephen; 1644256 Costa, Daniel", "bounds_geometry": "POLYGON((-66.534369 -52.962091,-65.3857434 -52.962091,-64.2371178 -52.962091,-63.0884922 -52.962091,-61.9398666 -52.962091,-60.791241 -52.962091,-59.6426154 -52.962091,-58.4939898 -52.962091,-57.3453642 -52.962091,-56.1967386 -52.962091,-55.048113 -52.962091,-55.048113 -54.530129,-55.048113 -56.098167000000004,-55.048113 -57.666205000000005,-55.048113 -59.234243,-55.048113 -60.802281,-55.048113 -62.370319,-55.048113 -63.938357,-55.048113 -65.506395,-55.048113 -67.074433,-55.048113 -68.642471,-56.1967386 -68.642471,-57.3453642 -68.642471,-58.4939898 -68.642471,-59.6426154 -68.642471,-60.791241 -68.642471,-61.9398666 -68.642471,-63.0884922 -68.642471,-64.2371178 -68.642471,-65.3857434 -68.642471,-66.534369 -68.642471,-66.534369 -67.074433,-66.534369 -65.506395,-66.534369 -63.938356999999996,-66.534369 -62.370319,-66.534369 -60.802281,-66.534369 -59.234243,-66.534369 -57.666205,-66.534369 -56.098167000000004,-66.534369 -54.530129,-66.534369 -52.962091))", "dataset_titles": "Data from: Whiskers provide time-series of toxic and essential trace elements, Se:Hg molar ratios, and stable isotope values of an apex Antarctic predator, the leopard seal; Leopard Seal Diving behavior data; Leopard Seal movement data", "datasets": [{"dataset_uid": "601690", "doi": "10.15784/601690", "keywords": "Antarctica; Antarctic Peninsula; Biota; Body Mass; Diving Behavior; Leopard Seal; Seals", "people": "Costa, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Leopard Seal Diving behavior data", "url": "https://www.usap-dc.org/view/dataset/601690"}, {"dataset_uid": "200361", "doi": "https://doi.org/10.5061/dryad.ksn02v75b", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Data from: Whiskers provide time-series of toxic and essential trace elements, Se:Hg molar ratios, and stable isotope values of an apex Antarctic predator, the leopard seal", "url": "https://datadryad.org/stash/dataset/doi:10.5061%2Fdryad.ksn02v75b"}, {"dataset_uid": "601689", "doi": "10.15784/601689", "keywords": "Antarctica; Antarctic Peninsula; Biota; Body Mass; Diving Behavior; Leopard Seal; Movement Data; Seals", "people": "Costa, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Leopard Seal movement data", "url": "https://www.usap-dc.org/view/dataset/601689"}], "date_created": "Fri, 12 May 2023 00:00:00 GMT", "description": "This research project is a multidisciplinary effort that brings together a diverse team of scientists from multiple institutions together to understand the foraging behavior and physiology of leopard seals and their role in the Southern Ocean food web. The project will examine the physiology and behavior of leopard seals to in an effort to determine their ability to respond to potential changes in their habitat and foraging areas. Using satellite tracking devices the team will examine the movement and diving behavior of leopard seals and couple this information with measurements of their physiological capacity. The project will determine whether leopard seals- who feed on diverse range of prey- are built differently than their deep diving relatives the Weddell and elephant seal who feed on fish and squid. The team will also determine whether leopard seals are operating at or near their physiological capability to determine how much, if any, ?reserve capacity? they might have to forage and live in changing environments. A better understanding of their home ranges, movement patterns, and general behavior will also be informative to help in managing human-leopard seal interactions. The highly visual nature of the data and analysis for this project lends itself to public and educational display and outreach, particularly as they relate to the changing Antarctic habitats. The project will use the research results to educate the public on the unique physiological and ecological adaptations to extreme environments seen in diving marine mammals, including adaptations to exercise under low oxygen conditions and energy utilization, which affect and dictate the lifestyle of these exceptional organisms. The results of the project will also contribute to the broader understanding that may enhance the aims of managing marine living resources.\u003cbr/\u003e\u003cbr/\u003eThe leopard seal is an apex predator in the Antarctic ecosystem. This project seeks to better understand the ability of the leopard seal to cope with a changing environment. The project will first examine the foraging behavior and habitat utilization of leopard seals using satellite telemetry. Specifically, satellite telemetry tags will be used to obtain dive profiles and movement data for individuals across multiple years. Diet and trophic level positions across multiple temporal scales will then be determined from physiological samples (e.g., blood, vibrissae, blubber fatty acids, stable isotopes, fecal matter). Oceanographic data will be integrated with these measures to develop habitat models that will be used to assess habitat type, habitat utilization, habitat preference, and home range areas for individual animals. Diet composition for individual seals will be evaluated to determine whether specific animals are generalists or specialists. Second, the team will investigate the physiological adaptations that allow leopard seals to be apex predators and determine to what extent leopard seals are working at or near their physiological limit. Diving behavior and physiology of leopard seals will be evaluated (for instance the aerobic dive limit for individual animals and skeletal muscle adaptations will be determined for diving under hypoxic conditions). Data from time-depth recorders will be used to determine foraging strategies for individual seals, and these diving characteristics will be related to physiological variables (e.g., blood volume, muscle oxygen stores) to better understand the link between foraging behavior and physiology. The team will compare myoglobin storage in swimming muscles associated with both forelimb and hind limb propulsion and the use of anaerobic versus aerobic metabolic systems while foraging.", "east": -55.048113, "geometry": "POINT(-60.791241 -60.802281)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; Diving Behavior; MAMMALS; MARINE ECOSYSTEMS; Movement Patterns; Leopard Seal", "locations": "Antarctic Peninsula", "north": -52.962091, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Costa, Daniel; Trumble, Stephen J; Kanatous, Shane", "platforms": null, "repo": "USAP-DC", "repositories": "Dryad; USAP-DC", "science_programs": null, "south": -68.642471, "title": "Collaborative Research: Foraging Ecology and Physiology of the Leopard Seal", "uid": "p0010419", "west": -66.534369}, {"awards": "2306186 Schroeder, Dustin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 05 Apr 2023 00:00:00 GMT", "description": "This project will develop a new ice-penetrating radar system that can simultaneously map glacier geometry and glacier flow along repeat profiles. Forecasting an ice-sheet\u2019s contribution to sea level requires an estimate for the initial ice-sheet geometry and the parameters that govern ice flow and slip across bedrock. Existing ice-sheet models cannot independently determine this information from conventional observations of ice-surface velocities and glacier geometry. This introduces substantial uncertainty into simulations of past and future ice-sheet behavior. Thus, this new radar capability is conceived to provide the needed data to support higher-fidelity simulations of past and future ice-sheet behavior and more accurate projections of future sea level.\r\n\r\nThe new radar system will integrate two existing radars (the multi-channel coherent radio-echo depth sounder and the accumulation radar) developed by the Center for the Remote Sensing of Ice Sheets, as well as adding new capabilities. An eight-element very high frequency (VHF; 140-215 MHz) array will have sufficient cross-track aperture to swath map internal layers and the ice-sheet base in three dimensions. A single ultra high frequency (UHF; 600-900 MHz) antenna will have the range and phase resolution to map internal layer displacement with 0.25-mm precision. The VHF array will create 3D mappings of layer geometry that enable measurements of vertical velocities by accounting for spatial offsets between repeat profiles and changing surface conditions. The vertical displacement measurement will then be made by determining the difference in radar phase response recorded by the UHF antenna for radar profiles collected at the same locations at different times. The UHF antenna will be dual-polarized and thus capable of isolating both components of complex internal reflections. This should enable inferences of ice crystal orientation fabric and widespread mapping of ice viscosity. Initial field testing of the radar will occur on the McMurdo Ice Shelf and then progress to Thwaites Glacier, Antarctica. The dual-band radar system technology and processing algorithms will be developed with versatile extensible hardware and user-friendly software so that this system will serve as a prototype for a future community radar system.\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Greenland", "locations": "Greenland", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Schroeder, Dustin", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "EAGER: Community-Driven Ice Penetrating Radar Systems for Observing Complex Ice-Sheet Thermal Structure and Flow", "uid": "p0010413", "west": -180.0}, {"awards": "2149070 Hawco, Nicholas", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 13 Mar 2023 00:00:00 GMT", "description": "This proposal represents collaborative research to explore manganese (Mn) limitation in Antarctic diatoms by two early career investigators. Diatoms are central players in the Southern Ocean carbon cycle, where the micronutrient chemistry is fundamentally different from other oceans. The Southern Ocean is characterized by widespread low Mn, coupled with high zinc (Zn). High Zn levels are potentially toxic to diatoms as Zn can competitively inhibit Mn uptake and metabolism, compromising the ability of building critical cellular components, thus impacting the biological pump. Using culture experiments with a matrix of micronutrient treatments (Mn, Zn, Fe) and irradiances, and using physiological and transcriptomic approaches, along with biochemical principles, the Principal Investigators will address the central hypothesis (that diatoms from the Southern Ocean possess unique physiological mechanisms to adapt to low Mn/high Zn) by quantifying rates of uptake and transporter binding constants. The transcriptomics approach will help to identify candidate genes that may provide Antarctic diatoms physiological mechanisms in low Mn/high Zn environment. The project does not require fieldwork but instead would make use of culture experiments with 4 diatom species (3 Antarctic, and 1 temperate). The proposed approach will also enable the goal of developing biomarker(s) for assessing Mn stress or Zn toxicity and results from the physiological experiments will help parameterize models of micronutrient limitation in the Southern Ocean.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; BIOGEOCHEMICAL CYCLES; TRACE ELEMENTS; DIATOMS; Iron; Phytoplankton", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hawco, Nicholas; Cohen, Natalie", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA: Collaborative Research: Adaptations of Southern Ocean Diatoms to Manganese Scarcity: Can Physiological Ingenuity Overcome Unfavorable Chemistry?", "uid": "p0010412", "west": -180.0}, {"awards": "1543445 Zhang, Jing", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "3-km Surface Mass and Energy Budget for the Larsen C Ice Shelf; Antarctic passive microwave Kmeans derived surface melt days, 1979-2020", "datasets": [{"dataset_uid": "601685", "doi": "10.15784/601685", "keywords": "Antarctica; Glaciology; Larsen C Ice Shelf; Model Data; Surface Energy Budget; Surface Mass Balance; WRF Model", "people": "Luo, Liping; Zhang, Jing", "repository": "USAP-DC", "science_program": null, "title": "3-km Surface Mass and Energy Budget for the Larsen C Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601685"}, {"dataset_uid": "601457", "doi": "10.15784/601457", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Melt Days; Passive Microwave; Snow/ice; Snow/Ice; Surface Melt", "people": "Johnson, Andrew; Fahnestock, Mark; Hock, Regine", "repository": "USAP-DC", "science_program": null, "title": "Antarctic passive microwave Kmeans derived surface melt days, 1979-2020", "url": "https://www.usap-dc.org/view/dataset/601457"}], "date_created": "Fri, 24 Feb 2023 00:00:00 GMT", "description": "Over the last half century the Antarctic Peninsula has been among the most rapidly warming regions in the world. This has led to increased glacier melt, widespread glacier retreat, ice-shelf collapses, and glacier speed-ups. Many of these changes are driven by changing precipitation and increased melt due to warmer air temperatures. This project will use a combination of two models - a regional atmospheric model and a model of processes at the glacier surface - to simulate future changes in temperature and snowfall, and the resulting changes in glacier mass. The combination of models will be tested against the observational record (since 1979 when satellite observations became available), to verify that it can reproduce observed change, and then run to the year 2100. Results will provide better estimates of the impacts of future climate changes over the Antarctic Pensinsula and the expected glacier mass changes driven by the evolving climate. \u003cbr/\u003e\u003cbr/\u003eThe project will use the large changes observed on the Peninsula to validate a model framework suitable for understanding the impact of these changes on the glaciers and ice shelves there, with the goal of developing optimally constrained future climate and surface mass change scenarios for the region. The framework will provide both a coherent picture of the impacts of past changes on the region\u0027s ice cover, and also the best available constraints on forcings that will determine ice mass loss from this region going forward under a standard scenario. The Weather Forecasting and Research (WRF) Model will be used over the domain of the Antarctic Peninsula and neighboring islands to quantify trends in spatio-temporal patterns of mass change with a focus on surface melt. The WRF model will be enhanced to account for the specific conditions of glacier surfaces, and the modified model will be used to simulate climate conditions and resulting surface mass budgets and melt over the period 1979-2100. Tying modeled past climate changes to the surface and satellite-based observational record will provide a foundation for interpreting projected future change. Results will be validated using available weather station observations, surface mass-balance data, and satellite-derived records of melt. The activity will foster partnerships through collaboration with colleagues in Spain, Germany and The Netherlands and will support an early-career postdoctoral researcher and two graduate students, introduce undergraduate and high-school students to original research and provide training of students through inclusion of data and results in course curriculums.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; MODELS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Zhang, Jing; Hock, Regine; Fahnestock, Mark", "platforms": "OTHER \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Present and Projected Future Forcings on Antarctic Peninsula Glaciers and Ice Shelves using the Weather Forecasting and Research (WRF) Model", "uid": "p0010408", "west": -180.0}, {"awards": "1543457 Munro, David; 1543511 Stephens, Britton", "bounds_geometry": "POLYGON((-73 -53,-71.2 -53,-69.4 -53,-67.6 -53,-65.8 -53,-64 -53,-62.2 -53,-60.4 -53,-58.6 -53,-56.8 -53,-55 -53,-55 -54.4,-55 -55.8,-55 -57.2,-55 -58.6,-55 -60,-55 -61.4,-55 -62.8,-55 -64.2,-55 -65.6,-55 -67,-56.8 -67,-58.6 -67,-60.4 -67,-62.2 -67,-64 -67,-65.8 -67,-67.6 -67,-69.4 -67,-71.2 -67,-73 -67,-73 -65.6,-73 -64.2,-73 -62.8,-73 -61.4,-73 -60,-73 -58.6,-73 -57.2,-73 -55.8,-73 -54.4,-73 -53))", "dataset_titles": "Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the Southern Ocean, Drake Passage and South Atlantic Ocean in 2018, processed by NOAA (NCEI Accession 0184338); Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, Drake Passage, South Atlantic Ocean in 2022 (NCEI Accession 0276577); Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, South Atlantic Ocean in 2021 (NCEI Accession 0246983); Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, South Pacific Ocean, Drake Passage and South Atlantic Ocean from 2019-02-16 to 2020-02-11 (NCEI Accession 0208838); Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, South Pacific Ocean, Drake Passage and South Atlantic Ocean in 2020 (NCEI Accession 0225445); Underway measurements of pCO2 in the Surface Waters and the Atmosphere During the ARSV Laurence M. Gould 2017 Expeditions processed by NOAA (NCEI Accession 0170337)", "datasets": [{"dataset_uid": "200353", "doi": "https://doi.org/10.25921/fq0a-7y11", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, Drake Passage, South Atlantic Ocean in 2022 (NCEI Accession 0276577)", "url": "https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/LM_gould.html"}, {"dataset_uid": "200348", "doi": "https://doi.org/10.7289/v5tq5zt1", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Underway measurements of pCO2 in the Surface Waters and the Atmosphere During the ARSV Laurence M. Gould 2017 Expeditions processed by NOAA (NCEI Accession 0170337)", "url": "https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/LM_gould.html"}, {"dataset_uid": "200349", "doi": "https://doi.org/10.25921/b4jn-ef56", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the Southern Ocean, Drake Passage and South Atlantic Ocean in 2018, processed by NOAA (NCEI Accession 0184338)", "url": "https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/LM_gould.html"}, {"dataset_uid": "200350", "doi": "https://doi.org/10.25921/3ysc-pm11", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, South Pacific Ocean, Drake Passage and South Atlantic Ocean from 2019-02-16 to 2020-02-11 (NCEI Accession 0208838)", "url": "https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/LM_gould.html"}, {"dataset_uid": "200351", "doi": "https://doi.org/10.25921/z0pk-pv81", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, South Pacific Ocean, Drake Passage and South Atlantic Ocean in 2020 (NCEI Accession 0225445)", "url": "https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/LM_gould.html"}, {"dataset_uid": "200352", "doi": "https://doi.org/10.25921/f94g-zp40", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Surface underway measurements of partial pressure of carbon dioxide (pCO2) during the Antarctic Research and Supply Vessel (ARSV) Laurence M. Gould expeditions in the the Southern Ocean, South Atlantic Ocean in 2021 (NCEI Accession 0246983)", "url": "https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/LM_gould.html"}], "date_created": "Wed, 22 Feb 2023 00:00:00 GMT", "description": "The Southern Ocean plays a key role in modulating the global carbon cycle, but the size and even the sign of the flux of carbon dioxide between the ocean and atmosphere in this region is still uncertain. This is in part due to the lack of measurements in this remote region of the world ocean. This project continues a multi-year time series of shipboard chemical measurements in the Drake Passage to detect changes in the ocean carbon cycle and to improve the understanding of mechanisms driving natural variability and long-term change in the Southern Ocean. More specifically, this project is a continuation of the collection of underway upper ocean measurements of the surface partial pressure of carbon dioxide during crossings of the Drake Passage by the Antarctic Research and Supply Vessel Laurence M. Gould. This project also includes collection and analysis of discrete samples relevant to ocean carbon cycle studies including macronutrient concentrations, total carbon dioxide concentrations, and the carbon isotopic composition of total carbon dioxide. The Drake Passage data are made readily available to the international science community and serve as both validation and constraints of remotely sensed observations and numerical coupled earth systems models.", "east": -55.0, "geometry": "POINT(-64 -60)", "instruments": null, "is_usap_dc": true, "keywords": "Drake Passage; NUTRIENTS; BIOGEOCHEMICAL CYCLES; DISSOLVED GASES; TRACE GASES/TRACE SPECIES", "locations": "Drake Passage", "north": -53.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Munro, David; Sweeney, Colm; Lovenduski, Nicole S; Stephens, Britton", "platforms": null, "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -67.0, "title": "Collaborative Research: Investigating Biogeochemical Fluxes and Linkages To Climate Change With Multi-Scale Observations In The Drake Passage", "uid": "p0010407", "west": -73.0}, {"awards": "2233016 Blanchard-Wrigglesworth, Edward", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 17 Feb 2023 00:00:00 GMT", "description": "In the austral winter of 2021/2022 a drastic decline in Antarctic sea ice extent (SIE) has taken place, and February 2022 marked the lowest SIE on record since consistent satellite sea ice observations began in 1979. Combined with the loss of SIE, the most extreme heat wave ever observed globally (as estimated by temperature anomalies from climatology) took place over East Antarctica in March 2022 as temperatures climbed over +40\u00b0C from climatology, an event that climate models struggle to replicate. Extreme events have an oversized footprint in socioeconomic impacts, but also serve as litmus tests for climate models and their predictive capabilities, and thus our understanding of extreme events and the ability of climate models in simulating such events is of key interest both in a scientific and social context. This project will use novel tools to diagnose the factors that led to the record low Antarctic SIE and heat wave focusing on the impact of winds and ocean temperatures. Currently (June 2022) Antarctic SIE remains at record low levels for the time of year, raising the prospect of a long-lasting period of low SIE, yet annual forecasts of Antarctic sea ice do not yet exist. To address this issue, this project will also create exploratory annual sea ice forecasts for the 2022-2024 period. \r\n\r\nThese extreme events have questioned our current understanding of Antarctic climate variability. Motivated by the timing of these events and our recent development of novel analysis tools, this project will address the following research questions:\r\n(R1) Can local winds account for the observed 2021/2022 sea ice loss, or are remote sea surface temperature (SST) anomalies a necessary ingredient?\r\n(R2) Are sea ice conditions over 2022-2024 likely to remain anomalously low?\r\n(R3) Can a state-of-the-art climate model simulate a heat wave of comparable magnitude to that observed if it follows the observed circulation that led to the heat wave?\r\nThe main approach will be to use a nudging technique with a climate model, in which one or several variables in a climate model are nudged toward observed values. The project authors used this tool to attribute Antarctic sea ice variability and trends over 1979-2018 to winds and SST anomalies. This project will apply this tool to the period 2019-2022 to address R1 and R3 by running two different model experiments over this time period in which the winds over Antarctica and SSTs in the Southern Ocean are nudged toward observed values. In addition, we will diagnose the relevant modes of atmospheric variability over 2019-2022 that are known to influence Antarctic sea ice to gain further insight into the 2022 loss of SIE. To address R2, we plan to extend the model simulations but without nudging, using the model as a forecast model (as its 2022 initial conditions will be taken from the end of the nudged simulations and capture important aspects of the observed state). We expect that if current upper ocean heat content is anomalously high, low SIE conditions may continue over 2022-2024, as happened over 2017-2019 following the previous record low of SIE in 2016/2017. To further address R3, we will compare observations and model simulations using novel atmospheric heat transport calculations developed by the project team. ", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; SURFACE TEMPERATURE", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Blanchard-Wrigglesworth, Edward", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "RAPID: What Caused the Record Warmth and Loss of Antarctic Sea ice in the Austral Summer of 2022, and will Sea Ice Remain Low Over 2022-2024?", "uid": "p0010405", "west": -180.0}, {"awards": "1542723 Alexander, Becky", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": "WAIS Divide ice core nitrate isotopes", "datasets": [{"dataset_uid": "601456", "doi": "10.15784/601456", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chemistry; Ice Core Records; Nitrate; Nitrate Isotopes; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide ice core nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601456"}], "date_created": "Mon, 13 Feb 2023 00:00:00 GMT", "description": "The Earth\u0027s atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate.\u003cbr/\u003e\u003cbr/\u003eThis award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "Nitrate Isotopes; ICE CORE RECORDS; WAIS Divide; LABORATORY", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.28, "title": "Measuring an Ice-core Proxy for Relative Oxidant Abundances over Glacial-interglacial and Rapid Climate changes in a West Antarctic Ice Core", "uid": "p0010403", "west": -112.05}, {"awards": "1841879 Aydin, Murat; 1841858 Twickler, Mark; 1841844 Steig, Eric", "bounds_geometry": "POINT(-105 -86)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 06 Feb 2023 00:00:00 GMT", "description": "The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth\u0027s last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities. \u003cbr/\u003e\u003cbr/\u003eHercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -105.0, "geometry": "POINT(-105 -86)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Hercules Dome; FIELD SURVEYS; AIR TEMPERATURE; SNOW/ICE CHEMISTRY; GLACIER ELEVATION/ICE SHEET ELEVATION; PALEOCLIMATE RECONSTRUCTIONS", "locations": "Hercules Dome", "north": -86.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Fudge, T. J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": "Hercules Dome Ice Core", "south": -86.0, "title": "Collaborative Research: An Ice Core from Hercules Dome, East Antarctica", "uid": "p0010401", "west": -105.0}, {"awards": "2152622 Morlighem, Mathieu", "bounds_geometry": "POLYGON((-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-103 -74,-102 -74,-101 -74,-100 -74,-100 -74.3,-100 -74.6,-100 -74.9,-100 -75.2,-100 -75.5,-100 -75.8,-100 -76.1,-100 -76.4,-100 -76.7,-100 -77,-101 -77,-102 -77,-103 -77,-104 -77,-105 -77,-106 -77,-107 -77,-108 -77,-109 -77,-110 -77,-110 -76.7,-110 -76.4,-110 -76.1,-110 -75.8,-110 -75.5,-110 -75.2,-110 -74.9,-110 -74.6,-110 -74.3,-110 -74))", "dataset_titles": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "datasets": [{"dataset_uid": "601658", "doi": "10.15784/601658", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites; Thwaites Glacier", "people": "Das, Indrani", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601658"}], "date_created": "Tue, 20 Dec 2022 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections.\r\n\r\nThe project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-105 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; Amundsen Sea; ICE SHEETS", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "NOT APPLICABLE", "persons": "Morlighem, Mathieu; Das, Indrani", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "NSF-NERC: PROcesses, drivers, Predictions: Modeling the response of Thwaites Glacier over the next Century using Ice/Ocean Coupled Models (PROPHET)", "uid": "p0010400", "west": -110.0}, {"awards": "1542756 Koutnik, Michelle", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.9,-175 -78.8,-175 -79.7,-175 -80.6,-175 -81.5,-175 -82.4,-175 -83.3,-175 -84.2,-175 -85.1,-175 -86,-175.5 -86,-176 -86,-176.5 -86,-177 -86,-177.5 -86,-178 -86,-178.5 -86,-179 -86,-179.5 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))", "dataset_titles": "Beardmore Glacier model in \u0027icepack\u0027", "datasets": [{"dataset_uid": "200339", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beardmore Glacier model in \u0027icepack\u0027", "url": "https://github.com/danshapero/beardmore"}], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "In this project we investigated glaciers that drain ice from the East Antarctic Ice Sheet through the Transantarctic Mountains into the present-day Ross Ice Shelf. The outlet glaciers that flow through the Transantarctic Mountains have thinned significantly over the past 15,000 years, especially as they retreated from Last Glacial Maximum highstands to their present-day grounding lines. At certain locations and for certain glaciers, rocks or bedrock have been sampled to provide constraints on the timing of when ice retreated from these locations. In the locations where geochronological data are available we can use these data as direct constraints on ice-flow models that simulate ice elevation change over time. The intellectual merit of this work is using ice-flow models to spatially and temporally extrapolate between these limited geochronological data points, which enables new understanding of glacier evolution. \r\n\r\nThe mountainous topography in this region is complex, and there are limited measurements of the topography beneath the ice of the Transantarctic outlet glaciers. Since the topography of the glacier bed is an important control on ice flow and is a necessary boundary condition in models we developed a new gridded bed product at Beardmore Glacier, the one location where sufficient data were available, and we compared this to continent-scale gridded bed products. We found that for this glacier, the BedMachine v1 product was reasonably similar to the Beardmore Glacier bed topography measurements; our limited evaluation suggests that the BedMachine product may be sufficient at other Transantarctic outlets where bed measurements are not available, but that other compilations of bed topography data that do not include information about ice flow directions do not provide reliable results. Using these data and available geochronological constraints we investigated Beardmore Glacier evolution since the Last Glacial Maximum using simplified (flowline) models of ice flow.\r\n\r\nIn addition to flowline modeling at Beardmore Glacier, we developed a flow-model setup using the open-source \u0027icepack\u0027 model that uses the shallow stream equations and resolves flow in both the x and y directions. The key value added over flowline (or parameterized flowband) models is that this can capture converging and diverging ice flow, variable side wall and bottom drag, and other geometric complexities. In these simulations we can evaluate the past accumulation, ice influx, and ice outflux to compare controls on deglaciation to data constraints on the chronology of deglaciation.\r\n\r\nWe also used a flowline model to investigate the Darwin-Hatherton Glacier System. Exposure ages and radiocarbon ages of glacial deposits at four locations alongside Hatherton and Darwin glaciers record several hundred meters of late Pleistocene to early Holocene thickening relative to present. Deglaciation was relatively complex at this site, and we also found that Byrd glacier likely contributed ice to the catchment of the Darwin-Hatherton glacier system during the last glacial maximum, and that subsequent convergent flow from Byrd and Mulock glaciers during deglaciation complicated the response of the Darwin-Hatherton system. These new insights can be used on their own to better understand local deglaciation, and can also be used to evaluate regional or continent-scale model calculations.\r\n\r\nSeparately, we investigated the general response of outlet glaciers to different sources of climate forcing. We found that outlet glaciers have a characteristically different response over time to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. Our models demonstrated that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. These insights contributed to our general understanding of how outlet glaciers may have evolved over time.\r\n\r\nOur new model investigations provide a framework that can be applied at other Transantarctic outlet glaciers where geochronological data are available. In particular, our \u0027icepack\u0027 setup is an archived and documented resource for the community. These tools are available for future investigations, including additional investigations at Beardmore Glacier and at other Transantarctic Mountain outlet glaciers. Scientific broader impacts include that this contributes to our understanding of the past behavior of East Antarctic ice, which provides an important constraint on the future evolution of Antarctica. Our team has engaged in public outreach and has engaged students in this research. Two graduate students led in aspects of this work, and have since gone on to research positions after their PhD.", "east": -175.0, "geometry": "POINT(170 -81.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS; Transantarctic Mountains; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Transantarctic Mountains", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Smith, Ben; Conway, Howard; Shapero, Daniel", "platforms": null, "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -86.0, "title": "Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers", "uid": "p0010398", "west": 155.0}, {"awards": "1644234 Phillips, Fred", "bounds_geometry": "POLYGON((166.17 -77.3,166.32799999999997 -77.3,166.486 -77.3,166.644 -77.3,166.802 -77.3,166.95999999999998 -77.3,167.118 -77.3,167.276 -77.3,167.434 -77.3,167.59199999999998 -77.3,167.75 -77.3,167.75 -77.34,167.75 -77.38,167.75 -77.42,167.75 -77.46,167.75 -77.5,167.75 -77.54,167.75 -77.58,167.75 -77.62,167.75 -77.66,167.75 -77.7,167.59199999999998 -77.7,167.434 -77.7,167.276 -77.7,167.118 -77.7,166.95999999999998 -77.7,166.802 -77.7,166.644 -77.7,166.486 -77.7,166.32799999999997 -77.7,166.17 -77.7,166.17 -77.66,166.17 -77.62,166.17 -77.58,166.17 -77.54,166.17 -77.5,166.17 -77.46,166.17 -77.42,166.17 -77.38,166.17 -77.34,166.17 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Nontechnical Description: The age of rocks and soils at the surface of the Earth can help answer multiple questions that are important for human welfare, including: when did volcanoes erupt and are they likely to erupt again? when did glaciers advance and what do they tell us about climate? what is the frequency of hazards such as landslides, floods, and debris flows? how long does it take soils to form and is erosion of soils going to make farming unsustainable? One method that is used thousands of times every year to address these questions is called \u0027cosmogenic surface-exposure dating\u0027. This method takes advantage of cosmic rays, which are powerful protons and neutrons produced by supernova that constantly bombard the Earth\u0027s atmosphere. Some cosmic rays reach Earth\u0027s surface and produce nuclear reactions that result in rare isotopes. Measuring the quantity of the rare isotopes enables the length of time that the rock or soil has been exposed to the atmosphere to be calculated. The distribution of cosmic rays around the globe depends on Earth\u0027s magnetic field, and this distribution must be accurately known if useful exposure ages are to be obtained. Currently there are two remaining theories, narrowed down from many, of how to calculate this distribution. Measurements from a site that is at both high altitude and high latitude (close to the poles) are needed to test the two theories. This study involves both field and lab research and includes a Ph.D. student and an undergraduate student. The research team will collect rocks from lava flows on an active volcano in Antarctica named Mount Erebus and measure the amounts of two rare isotopes: 36Cl and 3He. The age of eruption of the samples will be determined using a highly accurate method that does not depend on cosmic rays, called 40Ar/39Ar dating. The two cosmic-ray theories will be used to calculate the ages of the samples using the 36Cl and 3He concentrations and will then be compared to the ages calculated from the 40Ar/39Ar dating. The accurate cosmic-ray theory will be the one that gives the same ages as the 40Ar/39Ar dating. Identification of the accurate theory will enable use of the cosmogenic surface dating methods anywhere on earth. \u003cbr/\u003eTechnical Description: Nuclides produced by cosmic rays in rocks at the surface of the earth are widely used for Quaternary geochronology and geomorphic studies and their use is increasing every year. The recently completed CRONUS-Earth Project (Cosmic-Ray Produced Nuclides on Earth) has systematically evaluated the production rates and theoretical underpinnings of cosmogenic nuclides. However, the CRONUS-Earth Project was not able to discriminate between the two leading theoretical approaches: the original Lal model (St) and the new Lifton-Sato-Dunai model (LSD). Mathematical models used to scale the production of the nuclides as a function of location on the earth, elevation, and magnetic field configuration are an essential component of this dating method. The inability to distinguish between the two models was because the predicted production rates did not differ sufficiently at the location of the calibration sites. \u003cbr/\u003e\u003cbr/\u003eThe cosmogenic-nuclide production rates that are predicted by the two models differ significantly from each other at Erebus volcano, Antarctica. Mount Erebus is therefore an excellent site for testing which production model best describes actual cosmogenic-nuclide production variations over the globe. The research team recently measured 3He and 36Cl in mineral separates extracted from Erebus lava flows. The exposure ages for each nuclide were reproducible within each flow (~2% standard deviation) and in very good agreement between the 3He and the 36Cl ages. However, the ages calculated by the St and LSD scaling methods differ by ~15-25% due to the sensitivity of the production rate to the scaling at this latitude and elevation. These results lend confidence that Erebus qualifies as a suitable high- latitude/high-elevation calibration site. The remaining component that is still lacking is accurate and reliable independent (i.e., non-cosmogenic) ages, however, published 40Ar/39Ar ages are too imprecise and typically biased to older ages due to excess argon contained in melt inclusions.\u003cbr/\u003eThe research team\u0027s new 40Ar/39Ar data show that previous problems with Erebus anorthoclase geochronology are now overcome with modern mass spectrometry and better sample preparation. This indicates a high likelihood of success for this proposal in defining an accurate global scaling model. Although encouraging, much remains to be accomplished. This project will sample lava flows over 3 km in elevation and determine their 40Ar/39Ar and exposure ages. These combined data will discriminate between the two scaling methods, resulting in a preferred scaling model for global cosmogenic geochronology. The LSD method contains two sub-methods, the \u0027plain\u0027 LSD scales all nuclides the same, whereas LSDn scales each nuclide individually. The project can discriminate between these models using 3He and 36Cl data from lava flows at different elevations, because the first model predicts that the production ratio for these two nuclides will be invariant with elevation and the second that there should be ~10% difference over the range of elevations to be sampled. Finally, the project will provide a local, finite-age calibration site for cosmogenic-nuclide investigations in Antarctica.", "east": 167.75, "geometry": "POINT(166.95999999999998 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "AGE DETERMINATIONS; Mount Erebus; VOLCANO", "locations": "Mount Erebus", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Phillips, Fred; Kyle, Philip; Heizler, Matthew T", "platforms": null, "repositories": null, "science_programs": null, "south": -77.7, "title": "A Test of Global and Antarctic Models for Cosmogenic-nuclide Production Rates using High-precision Dating of 40Ar/39Ar Lava Flows from Mount Erebus", "uid": "p0010397", "west": 166.17}, {"awards": "1644004 Trumble, Stephen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Data from: Whiskers provide time-series of toxic and essential trace elements, Se:Hg molar ratios, and stable isotope values of an apex Antarctic predator, the leopard seal", "datasets": [{"dataset_uid": "200338", "doi": "doi:10.5061/dryad.ksn02v75b", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Data from: Whiskers provide time-series of toxic and essential trace elements, Se:Hg molar ratios, and stable isotope values of an apex Antarctic predator, the leopard seal", "url": "https://datadryad.org/stash/share/h6UwXvfhZG26jtPTtDqyXNMnx2UWknOqmv05EBz6A10"}], "date_created": "Tue, 06 Dec 2022 00:00:00 GMT", "description": "This research project is a multidisciplinary effort that brings together a diverse team of scientists from multiple institutions together to understand the foraging behavior and physiology of leopard seals and their role in the Southern Ocean food web. The project will examine the physiology and behavior of leopard seals to in an effort to determine their ability to respond to potential changes in their habitat and foraging areas. Using satellite tracking devices the team will examine the movement and diving behavior of leopard seals and couple this information with measurements of their physiological capacity. The project will determine whether leopard seals- who feed on diverse range of prey- are built differently than their deep diving relatives the Weddell and elephant seal who feed on fish and squid. The team will also determine whether leopard seals are operating at or near their physiological capability to determine how much, if any, ?reserve capacity? they might have to forage and live in changing environments. A better understanding of their home ranges, movement patterns, and general behavior will also be informative to help in managing human-leopard seal interactions. The highly visual nature of the data and analysis for this project lends itself to public and educational display and outreach, particularly as they relate to the changing Antarctic habitats. The project will use the research results to educate the public on the unique physiological and ecological adaptations to extreme environments seen in diving marine mammals, including adaptations to exercise under low oxygen conditions and energy utilization, which affect and dictate the lifestyle of these exceptional organisms. The results of the project will also contribute to the broader understanding that may enhance the aims of managing marine living resources.\u003cbr/\u003eThe leopard seal is an apex predator in the Antarctic ecosystem. This project seeks to better understand the ability of the leopard seal to cope with a changing environment. The project will first examine the foraging behavior and habitat utilization of leopard seals using satellite telemetry. Specifically, satellite telemetry tags will be used to obtain dive profiles and movement data for individuals across multiple years. Diet and trophic level positions across multiple temporal scales will then be determined from physiological samples (e.g., blood, vibrissae, blubber fatty acids, stable isotopes, fecal matter). Oceanographic data will be integrated with these measures to develop habitat models that will be used to assess habitat type, habitat utilization, habitat preference, and home range areas for individual animals. Diet composition for individual seals will be evaluated to determine whether specific animals are generalists or specialists. Second, the team will investigate the physiological adaptations that allow leopard seals to be apex predators and determine to what extent leopard seals are working at or near their physiological limit. Diving behavior and physiology of leopard seals will be evaluated (for instance the aerobic dive limit for individual animals and skeletal muscle adaptations will be determined for diving under hypoxic conditions). Data from time-depth recorders will be used to determine foraging strategies for individual seals, and these diving characteristics will be related to physiological variables (e.g., blood volume, muscle oxygen stores) to better understand the link between foraging behavior and physiology. The team will compare myoglobin storage in swimming muscles associated with both forelimb and hind limb propulsion and the use of anaerobic versus aerobic metabolic systems while foraging.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MAMMALS; Stable Isotopes; Livingston Island", "locations": "Livingston Island", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Trumble, Stephen J", "platforms": null, "repo": "Dryad", "repositories": "Dryad", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Foraging Ecology and Physiology of the Leopard Seal", "uid": "p0010394", "west": -180.0}, {"awards": "1643961 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-80 -83,-79.8 -83,-79.6 -83,-79.4 -83,-79.2 -83,-79 -83,-78.8 -83,-78.6 -83,-78.4 -83,-78.2 -83,-78 -83,-78 -83.2,-78 -83.4,-78 -83.6,-78 -83.8,-78 -84,-78 -84.2,-78 -84.4,-78 -84.6,-78 -84.8,-78 -85,-78.2 -85,-78.4 -85,-78.6 -85,-78.8 -85,-79 -85,-79.2 -85,-79.4 -85,-79.6 -85,-79.8 -85,-80 -85,-80 -84.8,-80 -84.6,-80 -84.4,-80 -84.2,-80 -84,-80 -83.8,-80 -83.6,-80 -83.4,-80 -83.2,-80 -83))", "dataset_titles": "Rutford Ice Stream short period data", "datasets": [{"dataset_uid": "200336", "doi": "https://doi.org/10.7914/SN/5B_2018", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Rutford Ice Stream short period data", "url": "http://fdsn.adc1.iris.edu/networks/detail/5B_2018/"}], "date_created": "Wed, 16 Nov 2022 00:00:00 GMT", "description": "Anandakrishnan/1643961\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. \u003cbr/\u003e\u003cbr/\u003eDuring this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in Antarctica.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -78.0, "geometry": "POINT(-79 -84)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Seismicity; Ice Dynamic; Rutford Ice Stream", "locations": "Rutford Ice Stream", "north": -83.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": null, "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -85.0, "title": "Rutford Ice Stream Cooperative Research Program with British Antarctic Survey", "uid": "p0010392", "west": -80.0}, {"awards": "2135696 Polito, Michael; 2135695 Emslie, Steven", "bounds_geometry": "POLYGON((-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70.8,-180 -71.6,-180 -72.4,-180 -73.2,-180 -74,-180 -74.8,-180 -75.6,-180 -76.4,-180 -77.2,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -77.2,160 -76.4,160 -75.6,160 -74.8,160 -74,160 -73.2,160 -72.4,160 -71.6,160 -70.8,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 28 Oct 2022 00:00:00 GMT", "description": "Stable isotope analyses of carbon and nitrogen (\u03b413C and \u03b415N) are commonly used to investigate animal migration, foraging locations and diet, especially in marine species that can travel over great distances. One other stable isotope, sulfur (\u03b434S), is not as commonly used but is increasingly being applied to refine and corroborate data obtained from carbon and nitrogen analyses. Collagen is one of the best tissues for these analyses as it is abundant in bone, preserves well, and can be easily extracted for analysis. In the Ross Sea region, the cold, dry environment has been conductive for the preservation of Ad\u00e9lie penguin (Pygoscelis adeliae) bones, feathers, eggshell and even mummified remains, at active and abandoned colonies that date from before the Last Glacial Maximum (\u003e45,000 yrs ago) through the Holocene. Most of these colonies are associated with one of three polynyas, or highly productive areas of open water surrounded by sea ice in the Ross Sea. Thus, this species is an excellent bioindicator for marine conditions, past and present, and its colonies have appeared and disappeared throughout this region with changing climate and sea ice regimes for millennia. Current warming trends are inducing relatively rapid ecological responses by this species and some of the largest colonies in the Ross Sea are likely to be abandoned in the next 50 years from rising sea level. The recently established Ross Sea Marine Protected Area aims to protect Ad\u00e9lie penguins and other species in this region from human impacts and knowledge on how this species responds to climate change, past and present, will support this goal. \r\n\r\nWe propose to investigate ecological responses in diet and foraging behavior of the Ad\u00e9lie penguin to known climatic events that occurred in the middle to late Holocene, specifically, before, during and after a warming period known as the penguin \u2018optimum\u2019 at 2000 - 4000 cal yr before present (BP). We will apply for the first time a suite of three stable isotope analyses (\u03b413C, \u03b415N, \u03b434S) on chick bones and feathers, as well as prey remains, from active and abandoned colonies in the Ross Sea. We will use existing tissue samples (~60-80 bones) collected by PI Emslie with NSF support since 2001 and supplement these with newly collected samples of bones and feathers in this project. We will conduct compound-specific isotope analyses of carbon on essential amino acids from collagen from a selected sample of 30-40 bones that span the past 5000 yrs to provide corroboratory information. We will apply three-dimensional Bayesian niche models and/or community metrics using R scripts in these analyses to identify isotopic \u2018signatures\u2019 of existing and past foraging grounds and polynyas used by Ad\u00e9lie penguins in the southern, central, and northern Ross Sea. This four-year study will the first of its kind to apply multiple stable isotope analyses to investigate a living species of seabird over millennia in a region where it still exists today. \r\n\r\nBroader Impacts:\r\nThe PIs are committed to public engagement and enhancement of K-12 education in the STEM sciences. Broader impacts of this research will include support and training for one Ph.D., two M.S., and eight undergraduate students in the Department of Biology and Marine Biology, and two M.A. students in the Watson School of Education at the University of North Carolina Wilmington (UNCW). The last two students will continue to expand on a detailed polar curriculum that was initiated in previous NSF grants for 2nd and 4th grade students, and most recently for 9-12th grade students now available on PI Emslie\u2019s website (www.uncw.edu/penguins). Additional curricula for K-12 students will be designed and tested in this project, which will include visitation to local K-12 schools. As in previous awards, we will focus on schools that serve historically under-represented groups in the sciences. We will work with the UNCW Center for Education in STEM Sciences to assess the efficacy of this new curricula. All curricula will be uploaded on the Educational Resource Commons website. Field work will include blogs and active question-answer sessions with students at these schools. We will continue to post project information and updates on PI Emslie\u2019s website and YouTube channel. Our partnership with tour ship companies will provide a platform for onboard lectures on the importance of scientific research as well as citizen science opportunities for another sector of the public. This proposal requires fieldwork in the Antarctic.\r\n", "east": -180.0, "geometry": "POINT(170 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Climate Change; Adelie Penguin; Foraging Ecology; Ross Sea; PENGUINS; Holocene; Stable Isotopes", "locations": "Ross Sea", "north": -70.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Emslie, Steven; Lane, Chad S; Polito, Michael", "platforms": null, "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative Research: Using Multiple Stable Isotopes to Investigate Middle to Late Holocene Ecological Responses by Adelie Penguins in the Ross Sea", "uid": "p0010388", "west": 160.0}, {"awards": "1543533 Johnson, Jesse; 1543530 van der Veen, Cornelis", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Van der Veen/1543530\u003cbr/\u003e\u003cbr/\u003eThe objective of this research is to gain better understanding of the West Antarctic ice flow in the transition region from grounded ice to floating ice shelves and investigate the conditions that can initiate and sustain major retreat of these glaciers. Several major Antarctic outlet glaciers and ice streams will be investigated using a suite of observational techniques and modeling tools. Glaciers include Thwaites Glacier, which has become a focal point in the discussion of West Antarctic retreat, Whillans Ice Stream as an example of the archetype ice stream, and Byrd Glacier, a major outlet glacier draining East Antarctica through the Transantarctic Mountains into the Ross Ice Shelf. This study will investigate whether the ongoing changes in these glaciers will lead to long-term mass loss (the onset of ice sheet collapse), or whether these glaciers will quickly stabilize with a new geometry. \u003cbr/\u003e\u003cbr/\u003eTo adequately incorporate the dynamic behavior of outlet glaciers and ice streams requires inclusion of the relevant physical processes, and the development of regional models that employ a numerical grid with a horizontal grid spacing sufficiently refined to capture smaller-scale bed topographic features that may control the flow of these glaciers. This award revisits the issue of stability of marine-terminating glaciers whose grounding line is located on a retrograded bed slope. In particular, an attempt will be made to resolve the question whether observed rapid changes are the result of perturbations at the terminus or grounding line, or whether these changes reflect ice-dynamical forcing over the grounded reaches. High-resolution satellite imagery will be used to investigate ice-flow perturbations on smaller spatial scales than has been done before, to evaluate the importance of localized sites of high basal resistance on grounding-line stability. This collaborative project involves a range of modeling strategies including force-budget analysis, flow-band modeling, Full Stokes modeling for local studies, and using the Ice Sheet System Model developed at JPL for regional modeling. Broader Impacts include training two graduate students in computer simulations and ice sheet modeling algorithms. The work will also expand on a web-based interactive flowline model, so that it includes more realistic grounding line dynamics.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Sheet Dynamics; MODELS; Iceberg Calving; GLACIERS/ICE SHEETS; Numerical Glacier Modeling; Basal Sliding; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "van der Veen, Cornelis; Stearns, Leigh; Paden, John", "platforms": "OTHER \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Stability and Dynamics of Antarctic Marine Outlet Glaciers", "uid": "p0010387", "west": -180.0}, {"awards": "1916982 Teyssier, Christian; 1917176 Siddoway, Christine; 1917009 Thomson, Stuart", "bounds_geometry": "POLYGON((-160.16 -67.15,-154.572 -67.15,-148.984 -67.15,-143.39600000000002 -67.15,-137.808 -67.15,-132.22 -67.15,-126.632 -67.15,-121.04400000000001 -67.15,-115.456 -67.15,-109.868 -67.15,-104.28 -67.15,-104.28 -68.165,-104.28 -69.18,-104.28 -70.19500000000001,-104.28 -71.21000000000001,-104.28 -72.225,-104.28 -73.24,-104.28 -74.255,-104.28 -75.27,-104.28 -76.285,-104.28 -77.3,-109.868 -77.3,-115.456 -77.3,-121.044 -77.3,-126.632 -77.3,-132.22 -77.3,-137.808 -77.3,-143.396 -77.3,-148.98399999999998 -77.3,-154.572 -77.3,-160.16 -77.3,-160.16 -76.285,-160.16 -75.27,-160.16 -74.255,-160.16 -73.24,-160.16 -72.225,-160.16 -71.21000000000001,-160.16 -70.19500000000001,-160.16 -69.18,-160.16 -68.165,-160.16 -67.15))", "dataset_titles": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock; U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "datasets": [{"dataset_uid": "200332", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "url": ""}, {"dataset_uid": "200333", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock", "url": ""}], "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) that display a significant temperature change as a function of rock depth. The strong geothermal gradient in the bedrock is favorable for determining when the bedrock became exhumed, or \"uncovered\" by action of the overriding icesheet or other processes. Our approach takes advantage of a reference horizon, or paleogeotherm, established when high-T mineral thermochronometers across Marie Byrd Land (MBL) cooled from temperatures of \u003e800\u00b0 C to 300\u00b0 C, due to rapid regional extension at ~100 Ma . The event imparted a signature through which the subsequent Cenozoic landscape history can be explored: MBL\u0027s elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision. \r\n\r\nAnalyzing the chemistry of minerals (zircon and apatite) within fragments of eroded rock will reveal the rate and timing of the bedrock erosion and development of topography in West Antarctica. This collaborative project addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incisionm which will clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. The collaborative project provides training for one graduate and 8 undergraduate students in STEM. These students, together with PIs, will refine West Antarctic ice sheet history and obtain results that pertain to the international societal response to contemporary ice sheet change and its global consequences. \r\n\r\nThe methods used for the research include: \r\n\u2022Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling, applied to the timing and characterizatio episodes of glacial erosional incision. \r\n\u2022Single-grain double- and triple-dating of zircon and apatite, to determine the detailed crustal thermal evolution of the region, enabling the research team to identify the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism. \r\n\r\nStudents and PIs employed state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data we acquired will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction we are testing through use of inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP\u0027s Gulf Coast Core Repository, and the OSU Marine and Geology Repository. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -104.28, "geometry": "POINT(-132.22 -72.225)", "instruments": null, "is_usap_dc": true, "keywords": "Marie Byrd Land; GLACIERS/ICE SHEETS; Zircon; Subglacial Topography; FIELD SURVEYS; TECTONICS; Ice Sheet; Thermochronology; Apatite; ROCKS/MINERALS/CRYSTALS; Erosion; United States Of America; LABORATORY", "locations": "United States Of America; Marie Byrd Land", "north": -67.15, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC", "persons": "Siddoway, Christine; Thomson, Stuart; Teyssier, Christian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "in progress", "repositories": "in progress", "science_programs": null, "south": -77.3, "title": "Collaborative Research: Ice sheet erosional interaction with hot geotherm in West Antarctica", "uid": "p0010386", "west": -160.16}, {"awards": "2037963 Smith, Heidi", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 11 Oct 2022 00:00:00 GMT", "description": "Glacial ice cores serve as a museum back in time, providing detailed records of past climatic conditions. In addition to chronological records such as temperature, chemistry and gas composition, ice provides a unique environment for preserving microbes and other biological materials through time. These microbes provide invaluable insight into the physiological capabilities necessary for survival in the Earths cryosphere and other icy planetary bodies, yet little is known about them. This award supports fundamental research into the activity of microbes in ice, and directly supports major research priorities regarding Antarctic biota identified in the 2015 National Academies of Sciences, Engineering, and Medicine report, A Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research. The broader impacts of this work are that it will be relevant to researchers across paleoclimate and biological fields. It will support two early career researchers, a graduate and an undergraduate student who will conduct laboratory analyses, participate in outreach activities, publish papers in scientific journals and present at conferences. \r\n\r\nThis work will use previously collected ice cores to investigate englacial microbial activity from the Holocene back to the Last Glacial Maximum from the blue ice area of Taylor Glacier, Antarctica. The proposal identified making significant contributions to 1) investing how Antarctic organisms evolve and adapt to changing environment, 2) understanding how microbes alter the preservation of paleorecord-relevant gas and trace element information in ice cores, and 3) identifying microbial life in cores and their activity in relation to dust depositional events. Two recently developed complementary techniques (bio-orthogonal noncanonical amino acid tagging and deuterium isotope probing) in combination with Raman Confocal Microspectroscopy will be used to assess and quantify microbial activity in ice. During phase one of the project, these methods will be optimized using deaccessioned ice cores available at the National Science Foundations Ice Core Facility. In phase two, ice cores in a time series from the Taylor Glacier will be analyzed for geochemistry and microbial activity. Research results will provide a comprehensive view of englacial microbial communities, including their metabolic diversity and activity, and the effect of geochemical parameters on microbial assemblages from different climate periods. Given the dearth of information available on englacial microbial communities, the results of this research will be of particular significance.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Microbial Activity; LABORATORY; Paleoclimate; CAMP; Taylor Glacier; Microbiology; Alaska; ICE CORE RECORDS", "locations": "CAMP; Alaska; Taylor Glacier", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Smith, Heidi; Foreman, Christine; Dieser, Markus", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Life in Ice: Probing Microbial Englacial Activity through Time", "uid": "p0010385", "west": null}, {"awards": "2011454 Veit, Richard; 2011285 Santora, Jarrod", "bounds_geometry": "POLYGON((-39 -53,-38.6 -53,-38.2 -53,-37.8 -53,-37.4 -53,-37 -53,-36.6 -53,-36.2 -53,-35.8 -53,-35.4 -53,-35 -53,-35 -53.2,-35 -53.4,-35 -53.6,-35 -53.8,-35 -54,-35 -54.2,-35 -54.4,-35 -54.6,-35 -54.8,-35 -55,-35.4 -55,-35.8 -55,-36.2 -55,-36.6 -55,-37 -55,-37.4 -55,-37.8 -55,-38.2 -55,-38.6 -55,-39 -55,-39 -54.8,-39 -54.6,-39 -54.4,-39 -54.2,-39 -54,-39 -53.8,-39 -53.6,-39 -53.4,-39 -53.2,-39 -53))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 06 Oct 2022 00:00:00 GMT", "description": "Part I: Non-technical description: \r\nOcean warming in the western Antarctic Peninsula and Scotia Sea in winter is among the highest worldwide. This project will quantify the impact of the climate warming on seabirds. The study area is in South Georgia in the South Atlantic with the largest and most diverse seabird colonies in the world. Detecting and understanding how physics and biology interact to bring positive or negative population changes to seabirds has long challenged scientists. The team in this project hypothesizes that 1) Cold water seabird species decline while warm water species increase due to ocean warming observed in the last 30 years; 2) All species decrease with ocean warming, affecting how they interact with each other and in doing so, decreasing their chances of survival; and 3) Species profiles can be predicted using multiple environmental variables and models. To collect present-day data to compare with observations done in 1985, 1991 and 1993, 2 cruises are planned in the austral winter; the personnel will include the three Principal Investigators, all experienced with sampling of seabirds, plankton and oceanography, with 2 graduate and 5 undergraduate students. Models will be developed based on the cruise data and the environmental change experienced in the last 30 years. The research will improve our understanding of seabird and marine mammal winter ecology, and how they interact with the environment. This project benefits NSF\u0027s goals to expand the fundamental knowledge of Antarctic systems, biota, and processes. The project will provide an exceptional opportunity to teach polar field skills to undergraduates by bringing 5 students to engage in the research cruises. To further increase polar literacy training and educational impacts, broader impacts include the production of an educational documentary that will be coupled to field surveys to assess public perceptions about climate change. \r\n\r\nPart II: Technical description: \r\nOcean warming in the western Antarctic Peninsula and Scotia Sea in winter is among the highest worldwide. Based on previous work, the Principal Investigators in this project want to test the hypothesis that warming would have decreased seabird abundance and species associations in the South Georgia region of the South Atlantic. A main premise of this proposal is that because of marine environmental change, the structure of the seabird communities has also changed, and potentially in a manner that has diminished the mutually beneficial dynamics of positive interactions, with subsequent consequences to fitness and population trends. The study is structured by 3 main objectives: 1) identify changes in krill, bird and mammal abundance that have occurred from previous sampling off both ends of South Georgia during winter in 1985, 1991 and 1993, 2) identify pairings of species that benefit each other in searching for prey, and quantify how such relationships have changed since 1985, and 3) make predictions about how these changes in species pairing might continue given predicted future changes in climate. The novelty of the approach is the conceptual model that inter-species associations inform birds of food availability and that the associations decrease if bird abundance decreases, thus warming could decrease overall population fitness. These studies will be essential to establish if behavioral patterns in seabird modulate their response to climate change. The project will provide exceptional educational opportunity to undergraduates by bringing 5 students to participate on the cruises. To further increase polar literacy training and educational impacts, broader impacts include the production of an educational documentary that will be coupled to field surveys to assess public perceptions about climate change.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -35.0, "geometry": "POINT(-37 -54)", "instruments": null, "is_usap_dc": true, "keywords": "Local Enhancement; South Georgia Island; Mutualism; Climate Change; Positive Interactions; Seabirds; COMMUNITY DYNAMICS; SPECIES/POPULATION INTERACTIONS; R/V NBP", "locations": "South Georgia Island", "north": -53.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Veit, Richard; Manne, Lisa; Santora, Jarrod", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repositories": null, "science_programs": null, "south": -55.0, "title": "Collaborative Research: Climate, Changing Abundance and Species Interactions of Marine Birds and Mammals at South Georgia in Winter", "uid": "p0010382", "west": -39.0}, {"awards": "1644118 Dunbar, Robert", "bounds_geometry": "POLYGON((-108 -73,-107.3 -73,-106.6 -73,-105.9 -73,-105.2 -73,-104.5 -73,-103.8 -73,-103.1 -73,-102.4 -73,-101.7 -73,-101 -73,-101 -73.3,-101 -73.6,-101 -73.9,-101 -74.2,-101 -74.5,-101 -74.8,-101 -75.1,-101 -75.4,-101 -75.7,-101 -76,-101.7 -76,-102.4 -76,-103.1 -76,-103.8 -76,-104.5 -76,-105.2 -76,-105.9 -76,-106.6 -76,-107.3 -76,-108 -76,-108 -75.7,-108 -75.4,-108 -75.1,-108 -74.8,-108 -74.5,-108 -74.2,-108 -73.9,-108 -73.6,-108 -73.3,-108 -73))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}], "date_created": "Wed, 21 Sep 2022 00:00:00 GMT", "description": "Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt.\u003cbr/\u003e\u003cbr/\u003eThis research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.", "east": -101.0, "geometry": "POINT(-104.5 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; WATER TEMPERATURE; SALINITY; Oxygen Isotope; Meltwater Inventory; Pine Island Bay; OCEAN CHEMISTRY", "locations": "Pine Island Bay", "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Dunbar, Robert", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater", "uid": "p0010380", "west": -108.0}, {"awards": "2218402 Fegyveresi, John", "bounds_geometry": "POLYGON((-115 -85.5,-113.5 -85.5,-112 -85.5,-110.5 -85.5,-109 -85.5,-107.5 -85.5,-106 -85.5,-104.5 -85.5,-103 -85.5,-101.5 -85.5,-100 -85.5,-100 -85.65,-100 -85.8,-100 -85.95,-100 -86.1,-100 -86.25,-100 -86.4,-100 -86.55,-100 -86.7,-100 -86.85,-100 -87,-101.5 -87,-103 -87,-104.5 -87,-106 -87,-107.5 -87,-109 -87,-110.5 -87,-112 -87,-113.5 -87,-115 -87,-115 -86.85,-115 -86.7,-115 -86.55,-115 -86.4,-115 -86.25,-115 -86.1,-115 -85.95,-115 -85.8,-115 -85.65,-115 -85.5))", "dataset_titles": "Multi-Site Brittle Ice Data and Measurements", "datasets": [{"dataset_uid": "601786", "doi": null, "keywords": "Antarctica; Brittle Ice; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Glaciology; Ice Core; Ice Core Records; Ice Core Records; Physical Properties; Simple Dome; Siple Dome; South Pole; SPICEcore; Subgrain Boundaries; WAIS Divide", "people": "Fegyveresi, John; Barnett, Samantha", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-Site Brittle Ice Data and Measurements", "url": "https://www.usap-dc.org/view/dataset/601786"}], "date_created": "Mon, 19 Sep 2022 00:00:00 GMT", "description": "Brittle ice has been a long-standing and consistent challenge for ice-coring projects, complicating sampling, and introducing the possibility of contamination. Several procedures have been tested to reduce brittle damage to recovered cores, but many come with high monetary and time costs. Our background research suggests that bubble size and c-axis fabric are primary drivers for brittleness and are predictable from site characteristics, enabling prediction of brittleness before coring. We propose to improve understanding of the mechanisms involved in brittle ice onset and behavior, through targeted investigations of various ice physical properties, in carefully selected samples across multiple ice-core sites, in order to guide the upcoming Hercules Dome ice-core drilling and science communities. This project will involve collaboration between Northern Arizona University, the National Science Foundation Ice Core Facility, and Pennsylvania State University, and will utilize new and existing ice-core physical properties data from several previously drilled sites. This is a high-risk, low-cost project that could yield important results, and thus is well-suited for EAGER funding. This proposal utilizes existing ice cores and does not require Antarctic fieldwork. ", "east": -100.0, "geometry": "POINT(-107.5 -86.25)", "instruments": null, "is_usap_dc": true, "keywords": "Hercules Dome Ice Core; West Antarctica; Grain Statistics; LABORATORY; Ice Core; ICE SHEETS; Physical Properties; Brittle Ice; C-Axis Fabric; Bubble; ICE CORE RECORDS", "locations": "West Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fegyveresi, John", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Hercules Dome Ice Core", "south": -87.0, "title": "EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site.", "uid": "p0010378", "west": -115.0}, {"awards": "2123333 Fitzsimmons, Jessica; 2123491 John, Seth; 2123354 Conway, Timothy", "bounds_geometry": "POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 08 Sep 2022 00:00:00 GMT", "description": "The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service.\r\n\r\nThe US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135\u00b0W) of the Antarctic Margin. The cruise will follow the Amundsen Sea \u2018conveyor belt\u2019 by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean?", "east": -100.0, "geometry": "POINT(-117.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "R/V NBP; Amundsen Sea; TRACE ELEMENTS; BIOGEOCHEMICAL CYCLES", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Chemical Oceanography; Chemical Oceanography; Chemical Oceanography", "paleo_time": null, "persons": "Conway, Timothy; Fitzsimmons, Jessica; John, Seth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repositories": null, "science_programs": null, "south": -76.0, "title": "Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals", "uid": "p0010374", "west": -135.0}, {"awards": "2220969 Manucharyan, Georgy; 2220968 Stewart, Andrew", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "The world ocean is continuously in motion, and a large fraction of this motion takes the form of \"eddies\", nearly-horizontal swirls of water spanning tens to hundreds of kilometers. These eddies affect the ocean by mediating large-scale currents, redistributing heat, and supplying nutrients to oceanic ecosystems. Consequently, the ocean science community has historically invested substantial effort in characterizing the properties and impact of these eddies. In polar regions, the sea ice cover inhibits observations of eddies, and the relatively small horizontal size of the eddies hampers computer simulations of their behavior. Nonetheless, previous studies have identified an active population of eddies beneath the Arctic sea ice and shown that these eddies play a crucial role in maintaining the large-scale circulation in the Arctic seas. However, there has been no systematic attempt to study such eddies under Antarctic sea ice, leaving a significant gap in our understanding of eddies and their contribution to the large-scale ocean circulation around Antarctica.\r\n\r\nThe proposed research combines multiple approaches to improve our understanding of the eddy dynamics. Statistical characterizations of the sub-sea ice eddy field will be derived using hydrographic observations under Antarctic sea ice from Argo floats and instrumented seals. High-resolution global ocean and sea ice models will be used to track the simulated eddies back to their formation sites to identify the eddy formation mechanisms. Theoretical calculations will be conducted to test the hypothesis that the eddies primarily originate from hydrodynamic instabilities associated with subsurface density gradients. These theoretical, modeling, and data analysis approaches will be combined to estimate the eddies\u0027 contribution to lateral tracer transports and their impact on mean circulations of the near-Antarctic ocean. The proposed work will facilitate future scientific endeavors by providing publicly-available databases of detected eddy properties. This project will support the research of several junior scientists: an undergraduate student, two graduate students, and an early-career faculty member.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; OCEAN CURRENTS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Stewart, Andrew; Bianchi, Daniele", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Characteristics and Origins of Eddies beneath Antarctic Sea Ice", "uid": "p0010366", "west": -180.0}, {"awards": "2205008 Walker, Catherine", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "The majority of mass loss from the Antarctic Ice Sheet, a major contributor to sea level rise, occurs at its margins, where ice meets the ocean. Glaciers and ice streams flow towards the coast and can go afloat over the water, forming ice shelves. Ice shelves make up almost half of the entire Antarctic coastline, and hold back the flow of inland ice in Antarctica continent; thus they are integral to the overall stability of the Antarctic Ice Sheet. Ice shelves lose mass by two main processes: iceberg calving and basal melting. Temporal and spatial fluctuations in both are driven by various processes; a major driver of ice shelf melt is the heat provided by the neighboring Southern Ocean. Ocean heat, in turn, is driven by various aspects of the ice shelf environment. One of the most significant contributors to changes in the ocean\u2019s heat content is the presence of sea ice. This research will focus on the effects of coastal polynyas (areas of open water amidst sea ice), how they modulate the local ocean environment, and how that environment drives ice shelf basal melting. To date, the relationship between polynyas and ice shelf melt has not been characterized on an Antarctic-wide scale. Understanding the feedbacks between polynya size and duration, ocean stratification, and ice shelf melt, and the strength of those feedbacks, will improve the ability to characterize influences on the long-term stability of ice shelves, and in turn, the Antarctic Ice Sheet as a whole. A critical aspect of this study is that it will provide a framework for understanding ice shelf-ocean interaction across a diverse range of geographic settings. This, together with improvements of various models, will help interpret the impacts of future climate change on these systems, as their responses are likely quite variable and, on the whole, different from the large-scale response of the ice sheet. This project will also provide a broader context to better design future observational studies of specific coastal polynya and ice shelf processes.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; ICE EXTENT; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Walker, Catherine; Zhang, Weifeng; Seroussi, Helene", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Investigating the Role of Coastal Polynya Variability in Modulating Antarctic Marine-Terminating Glacier Drawdown", "uid": "p0010364", "west": -180.0}, {"awards": "1744767 Sanders, Robert", "bounds_geometry": "POLYGON((-68 -64,-67.4 -64,-66.8 -64,-66.2 -64,-65.6 -64,-65 -64,-64.4 -64,-63.8 -64,-63.2 -64,-62.6 -64,-62 -64,-62 -64.5,-62 -65,-62 -65.5,-62 -66,-62 -66.5,-62 -67,-62 -67.5,-62 -68,-62 -68.5,-62 -69,-62.6 -69,-63.2 -69,-63.8 -69,-64.4 -69,-65 -69,-65.6 -69,-66.2 -69,-66.8 -69,-67.4 -69,-68 -69,-68 -68.5,-68 -68,-68 -67.5,-68 -67,-68 -66.5,-68 -66,-68 -65.5,-68 -65,-68 -64.5,-68 -64))", "dataset_titles": "Companion datasets to Diversity of microbial eukaryotes along the West Antarctic peninsula in austral spring.; Expedition Data of NBP1910; Expedition Data of NBP 2205; LMG1904 expedition data; NBP1910_protist_community_RNA Raw sequence reads; NBP2205_protist_community_RNA Raw sequence reads will be made available here after processing is completed", "datasets": [{"dataset_uid": "200365", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "NBP1910_protist_community_RNA Raw sequence reads; NBP2205_protist_community_RNA Raw sequence reads will be made available here after processing is completed", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=PRJNA807326"}, {"dataset_uid": "200147", "doi": "10.7284/908260", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG1904 expedition data", "url": "https://www.rvdata.us/search/cruise/LMG1904"}, {"dataset_uid": "200366", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP 2205", "url": "https://www.rvdata.us/search/cruise/NBP2205"}, {"dataset_uid": "200325", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1910", "url": "https://www.rvdata.us/search/cruise/NBP1910"}, {"dataset_uid": "200320", "doi": "10.6084/m9.figshare.19514110.v3", "keywords": null, "people": null, "repository": "Figshare", "science_program": null, "title": "Companion datasets to Diversity of microbial eukaryotes along the West Antarctic peninsula in austral spring.", "url": "https://doi.org/10.6084/m9.figshare.19514110.v3"}], "date_created": "Wed, 27 Jul 2022 00:00:00 GMT", "description": "Traditional models of oceanic food chains have consisted of photosynthetic algae (phytoplankton) being ingested by small animals (zooplankton), which were ingested by larger animals (fish). These traditional models changed as new methods allowed recognition of the importance of bacteria and other non-photosynthetic protozoa in more complex food webs. More recently, the wide-spread existence of mixotrophs (organisms that can both photosynthesize and ingest food particles) and their importance as microbial predators has been recognized in many oceanographic areas. In the Southern Ocean, the only two surveys of mixotrophs have suggested that there may be seasonal differences in their importance as predators. During the long polar night (winter), the ability of mixotrophs to ingest particulate food may aid in their survival thus ensuring a sufficient population in spring to support a phytoplankton bloom once photosynthesis rates can increase. Thus mixotrophs may provide a critical early food source upon which zooplankton and larger animals depend on for growth and reproduction. This project will advance understanding of mixotroph diversity and their ecological impact within the Southern Ocean microbial food web. Specifically, efforts will be focused on mixotrophy in the western Antarctica peninsula region during the austral spring and autumn when there are likely to be changes in the relative importance of photosynthesis and ingestion to mixotrophs. The project will provide research opportunities for undergraduate and graduate students and a post-doctoral researcher. There will be real-time outreach from the Southern Ocean to the public via blogs and interviews, and to high school art students through an established program that blends science and art education. Despite traditional views of protists as either \"phototrophic\" or \"heterotrophic,\" there are many photosynthetic protists that consume prey (mixotrophy). Mixotrophy is a widespread phenomenon in aquatic systems and phytoplankton groups with known mixotrophic species, notably chrysophytes, cryptophytes, prymnesiophytes, prasinophytes and dinoflagellates, are present and often abundant in Antarctic waters. However, in the Southern Ocean, the presence of mixotrophic phytoflagellates has been surveyed only twice prior to this project: in the Ross Sea during Austral spring 2008 and summer 2011. The primary goals of the project are to gain better understanding of mixotroph diversity and their ecological impact with respect to the Southern Ocean microbial food web. The contribution of mixotrophs to primary production and bacterial consumption is likely linked to the taxonomic composition of the community and the abundance of particular species. Abundances of novel mixotrophic species will be evaluated via qPCR, which will be coupled with assessments of rates of feeding and photosynthesis with the goal of describing how active mixotrophs direct the movement of carbon through food webs. These experiments will help the determination of how viable and widespread mixotrophy is as a nutritional strategy in polar waters and give direct information on the currently unknown diversity of mixotrophic taxa under different environmental conditions occurring in austral spring and autumn. Furthermore, the methods will simultaneously yield information on the whole communities of protists - mixotrophic, phototrophic and heterotrophic. In addition, a method to examine aspects of the taxonomic and functional diversities of the bacterivorous/mixotrophic community will be employed. A thymidine analog (BrdU) will be used to label DNA of eukaryotes feeding on bacteria. The BrdU-labeled eukaryotic DNA will be isolated using immunoprecipitation. High-throughput sequencing of the labeled DNA (bacterivores) versus unlabeled community DNA will determine the diversity of bacterivorous mixotrophs relative to other microeukaryotes. Flow cytometric sorting based on chlorophyll to focus on mixotrophic species. These approaches will elucidate a gap in current knowledge of the influence of microbial interactions in the Southern Ocean under different conditions. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-65 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; PLANKTON; COASTAL", "locations": "Antarctic Peninsula", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sanders, Robert; Gast, Rebecca; Jeffrey, Wade H.", "platforms": null, "repo": "NCBI", "repositories": "Figshare; NCBI; R2R", "science_programs": null, "south": -69.0, "title": "Collaborative Research: Diversity and ecological impacts of Antarctic mixotrophic phytoplankton", "uid": "p0010357", "west": -68.0}, {"awards": "1937595 Briggs, Brandon; 1937546 Morgan-Kiss, Rachael", "bounds_geometry": "POLYGON((162 -77.616667,162.1 -77.616667,162.2 -77.616667,162.3 -77.616667,162.4 -77.616667,162.5 -77.616667,162.6 -77.616667,162.7 -77.616667,162.8 -77.616667,162.9 -77.616667,163 -77.616667,163 -77.6283336,163 -77.6400002,163 -77.6516668,163 -77.6633334,163 -77.67500000000001,163 -77.68666660000001,163 -77.69833320000001,163 -77.7099998,163 -77.7216664,163 -77.733333,162.9 -77.733333,162.8 -77.733333,162.7 -77.733333,162.6 -77.733333,162.5 -77.733333,162.4 -77.733333,162.3 -77.733333,162.2 -77.733333,162.1 -77.733333,162 -77.733333,162 -77.7216664,162 -77.7099998,162 -77.69833320000001,162 -77.68666660000001,162 -77.67500000000001,162 -77.6633334,162 -77.6516668,162 -77.6400002,162 -77.6283336,162 -77.616667))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 27 Jul 2022 00:00:00 GMT", "description": " Microbial communities are of more than just a scientific curiosity. Microbes represent the single largest source of evolutionary and biochemical diversity on the planet. They are the major agents for cycling carbon, nitrogen, phosphorus, and other elements through the ecosystem. Despite their importance in ecosystem function, microbes are still generally overlooked in food web models and nutrient cycles. Moreover, microbes do not live in isolation: their growth and metabolism are influenced by complex interactions with other microorganisms. This project will focus on the ecology, activity and roles of microbial communities in Antarctic Lake ecosystems. The team will characterize the genetic underpinnings of microbial interactions and the influence of environmental gradients (e.g. light, nutrients, oxygen, sulfur) and seasons (e.g. summer vs. winter) on microbial networks in Lake Fryxell and Lake Bonney in the Taylor Valley within the McMurdo Dry Valley region. Finally, the project furthers the NSF goals of training new generations of scientists by including undergraduate and graduate students, a postdoctoral researcher and a middle school teacher in both lab and field research activities. This partnership will involve a number of other outreach training activities, including visits to classrooms and community events, participation in social media platforms, and webinars. \u003cbr/\u003e\u003cbr/\u003ePart II: Technical description: Ecosystem function in the extreme Antarctic Dry Valleys ecosystem is dependent on complex biogeochemical interactions between physiochemical environmental factors (e.g. light, nutrients, oxygen, sulfur), time of year (e.g. summer vs. winter) and microbes. Microbial network complexity can vary in relation to specific abiotic factors, which has important implications on the fragility and resilience of ecosystems under threat of environmental change. This project will evaluate the influence of biogeochemical factors on microbial interactions and network complexity in two Antarctic ice-covered lakes. The study will be structured by three main objectives: 1) infer positive and negative interactions from rich spatial and temporal datasets and investigate the influence of biogeochemical gradients on microbial network complexity using a variety of molecular approaches; 2) directly observe interactions among microbial eukaryotes and their partners using flow cytometry, single-cell sorting and microscopy; and 3) develop metabolic models of specific interactions using metagenomics. Outcomes from amplicon sequencing, meta-omics, and single-cell genomic approaches will be integrated to map specific microbial network complexity and define the role of interactions and metabolic activity onto trends in limnological biogeochemistry in different seasons. These studies will be essential to determine the relationship between network complexity and future climate conditions. Undergraduate researchers will be recruited from both an REU program with a track record of attracting underrepresented minorities and two minority-serving institutions. To further increase polar literacy training and educational impacts, the field team will include a teacher as part of a collaboration with the successful NSF-funded PolarTREC program and participation in activities designed for public outreach.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 163.0, "geometry": "POINT(162.5 -77.67500000000001)", "instruments": null, "is_usap_dc": true, "keywords": "MICROALGAE; AQUATIC ECOSYSTEMS; Antarctica; LAKE/POND; BACTERIA/ARCHAEA; COMMUNITY DYNAMICS", "locations": "Antarctica", "north": -77.616667, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Morgan-Kiss, Rachael; Briggs, Brandon", "platforms": null, "repositories": null, "science_programs": null, "south": -77.733333, "title": "ANT LIA: Collaborative Research: Genetic Underpinnings of Microbial Interactions in Chemically Stratified Antarctic Lakes", "uid": "p0010355", "west": 162.0}, {"awards": "2012365 Johnston, David; 2012444 Cimino, Megan; 2012247 Groff, Dulcinea", "bounds_geometry": "POLYGON((-65 -64.5,-64.8 -64.5,-64.6 -64.5,-64.4 -64.5,-64.2 -64.5,-64 -64.5,-63.8 -64.5,-63.6 -64.5,-63.4 -64.5,-63.2 -64.5,-63 -64.5,-63 -64.55,-63 -64.6,-63 -64.65,-63 -64.7,-63 -64.75,-63 -64.8,-63 -64.85,-63 -64.9,-63 -64.95,-63 -65,-63.2 -65,-63.4 -65,-63.6 -65,-63.8 -65,-64 -65,-64.2 -65,-64.4 -65,-64.6 -65,-64.8 -65,-65 -65,-65 -64.95,-65 -64.9,-65 -64.85,-65 -64.8,-65 -64.75,-65 -64.7,-65 -64.65,-65 -64.6,-65 -64.55,-65 -64.5))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 24 Jul 2022 00:00:00 GMT", "description": "This award is funded in whole or part under the American Rescue Plan Act of 2021 (Public Law 117-2). \r\nPart I: Non-technical description: \r\nAdlie penguin colonies are declining and disappearing from the western Antarctic Peninsula. However, not all colonies in a certain area decline or disappear at the same rate. This research project will evaluate the influence of terrestrial surface properties on Adlie penguin colonies, leveraging five decades of research on seabirds near Palmer Station where an Adlie colony on Litchfield Island became extinct in 2007 while other colonies nearby are still present. The researchers will combine information obtained from remote sensing, UAS (Unoccupied Aircraft System, or drones) high-resolution maps, reconstruction of past moss banks and modeling with machine learning tools to define suitable penguin and peatbank moss habitats and explore the influence of microclimate on their distributions. In particular, the researchers are asking if guano from penguin colonies could act as fertilizers of moss banks in the presence of localized wind patters that can carry airborne nitrogen to the mosses. Modeling will relate penguin and peatbank moss spatial patterns to environmental variables and provide a greater understanding of how continued environmental change could impact these communities. The project allows for documentation of terrestrial Antarctic ecosystems in support of seabirds and provisioning of such information to the broader science community that seeks to study penguins, educating graduate and undergraduate students and a post-doctoral researcher. The research team includes two young women as Principal Investigators, one of them from an under-represented ethnic minority, first time Antarctic Principal Investigator, from an EPSCoR state (Wyoming), broadening participation in Antarctic research. Researchers will serve as student mentors through the Duke Bass Connections program entitled Biogeographic Assessment of Antarctic Coastal Habitats. This program supports an interdisciplinary team of graduate and undergraduate students collaborating with project faculty and experts on cutting-edge research bridging the classroom and the real world.\r\n\r\nPart II: Technical description: \r\nThis research aims to understand the changes at the microclimate scale (meters) by analyzing present and past Adlie penguin colonies and moss peatbanks in islands around Palmer Station in the western Antarctic Peninsula interlinked systems that are typically considered in isolation. By integrating in situ and remote data, this project will synthesize the drivers of biogeomorphology on small islands of the Antarctic Peninsula, a region of rapid change where plants and animals often co-occur and animal presence often determines the habitation of plants. A multi-disciplinary approach combine field measurements, remote sensing, UAS (Unoccupied Aircraft Systems) maps, paleoecology and modeling with machine learning to define suitable habitats and the influence of microclimates on penguin and peatbank distributions. The link between the two aspects of this study, peatbanks and penguins, is the potential source of nutrients for peat mosses from penguin guano. Peatbank and penguin distribution will be modeled and all models will be validated using in situ information from moss samples that will identify mechanistic processes. This project leverages 5 decades of seabird research in the area and high-definition remote sensing provided by the Polar Geospatial center to study the microclimate of Litchfield Island where an Adlie colony became extinct in 2007 when other colonies nearby are still present. The research team includes two early career women as Principal Investigators, one of them from an under-represented ethnic minority, first time Antarctic Principal Investigator, from an EPSCoR state (Wyoming). Researchers will serve as mentors for students through the Duke Bass Connections program entitled Biogeogrpahic Assessment of Antarctic Coastal Habitats which bridges the classroom and the real world.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -63.0, "geometry": "POINT(-64 -64.75)", "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; Antarctic Peninsula; COASTAL; STABLE ISOTOPES; TOPOGRAPHIC EFFECTS; PALEOCLIMATE RECONSTRUCTIONS; MACROFOSSILS; PLANTS; PENGUINS; ISOTOPES; VISIBLE IMAGERY; RADIOCARBON; Anvers Island", "locations": "Antarctic Peninsula; Anvers Island; Palmer Station", "north": -64.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Groff, Dulcinea; Cimino, Megan; Johnston, David", "platforms": null, "repositories": null, "science_programs": null, "south": -65.0, "title": "Collaborative Research: Common Environmental Drivers Determine the Occupation Chronology of Ad\u00e9lie Penguins and Moss Peatbanks on the Western Antarctic Peninsula", "uid": "p0010354", "west": -65.0}, {"awards": "2114502 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 19 Jul 2022 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).\r\n\r\nAn important part of understanding future climate change is predicting changes in how fast the ice in Antarctica is moving. If ice flows more quickly towards the ocean, it will have a direct impact on sea level rise. One of the things that can influence the ice flow is the type of rock below the ice coverage in Antarctica. Sedimentary basins are large regions where sedimentary rocks accumulated in the past, often under ancient seas. It has been observed that where there are sediments below the ice, the ice can flow faster. This project seeks to understand what is below the ice and how the underlying rock influences the ice flow. Is it hard, crystalline rock? Is it a sedimentary basin? What is the relationship between sediments and ice flow? The answers to these questions will be addressed by using a combination of available data and geophysical methods. Information from well-known rock-types will be used to train the computer to recognize these features by using an application of artificial intelligence known as machine learning, which will help the characterization and identification of unknown sedimentary basins beneath the ice. The results of this project will be disseminated to a broad audience by holding workshops for teacher and students to explain our findings under the ice and to introduce the machine learning technique. Open-source codes used during this project will be made available for use in higher-level classrooms as well as in further studies.\r\n\r\nTo date, no comprehensive distribution of onshore and offshore sedimentary basins over Antarctica has been developed. A combination of large-scale datasets will be used to characterize known basins and identify new sedimentary basins to produce the first continent-wide mapping of sedimentary basins and provide improved basal parametrizations conditions that have the potential to support more realistic ice sheet models. Available geophysical compilations of data and the location of well-known sedimentary basins will be used to apply an ensemble machine learning algorithm. The machine learning algorithm will learn complex relationships by voting among a collection of randomized decision trees. The gravity signal related to sedimentary basins known from other (e.g. seismic) techniques will be evaluated and unknown basins from aerogravity data regression analyses will be proposed by calculating a gravity residual that reflects density inhomogeneities. The gravimetric sedimentary basins identified from the regression analyses will be compared with an independent method of identifying sedimentary distribution, the Werner deconvolution method of estimating depth to magnetic sources. The hypothesis, which is sedimentary basins are correlated to fast ice flow behavior, will be tested by comparing the location of the sedimentary basins with locations of high ice flow by using available ice velocity observations. A relationship between sedimentary basins and ice streams will be defined qualitatively and quantitatively, aiming to evaluate if there are ice streams where no sedimentary basins are reported, or sedimentary basins with no ice streams related. The findings of these project can confirm if the presence of abundant sediments is a pre-requisite for ice streaming. Analyzing previously known sedimentary basins and identifying new ones in Antarctica is central to evaluating the influence of subglacial sediments on the ice sheet flow.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GRAVITY ANOMALIES; ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Constantino, Renata", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Pan-Antarctic Assessment of Sedimentary Basins and the Onset of Streaming Ice Flow from Machine Learning and Aerogravity Regression Analyses", "uid": "p0010351", "west": -180.0}, {"awards": "1643431 Bitz, Cecilia", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Analysis code, processed observational data and climate model output required to produce figures for Roach et al (2022); Model output: CICE experiments with varying floe and wave physics described in Roach et al. (2019); Model output from experiments (FSD-M21) described in Cooper et al 2022.; Model output from experiments (IC4M1) described in Cooper et al 2022.; Model output from experiments (IC4M2) described in Cooper et al 2022.; Model output from experiments (IC4M3rad) described in Cooper et al 2022.; Model output from experiments (IC4M4) described in Cooper et al 2022.; Model output from experiments (IC4M5) described in Cooper et al 2022.; Model output from experiments (IC4M7) described in Cooper et al 2022.; Model output: NEMO-CICE with an emergent sea ice floe size distribution described in Roach et al (2018)", "datasets": [{"dataset_uid": "200310", "doi": "10.5281/zenodo.1193930", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output: NEMO-CICE with an emergent sea ice floe size distribution described in Roach et al (2018)", "url": "https://zenodo.org/record/1193930"}, {"dataset_uid": "200301", "doi": "10.5281/zenodo.6213441", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M1) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6213441"}, {"dataset_uid": "200302", "doi": "10.5281/zenodo.6213793", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M2) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6213793"}, {"dataset_uid": "200303", "doi": "10.5281/zenodo.6214364", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M3rad) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214364"}, {"dataset_uid": "200304", "doi": "10. 5281/zenodo.6214555", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M4) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214555"}, {"dataset_uid": "200305", "doi": "10.5281/zenodo.6214998", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M5) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214998"}, {"dataset_uid": "200306", "doi": "10.5281/zenodo.6212423", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M7) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6212423"}, {"dataset_uid": "200307", "doi": "10.5281/zenodo.6212232", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (FSD-M21) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6212232"}, {"dataset_uid": "200308", "doi": "10.5281/zenodo.5913959", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Analysis code, processed observational data and climate model output required to produce figures for Roach et al (2022)", "url": "https://zenodo.org/record/5913959"}, {"dataset_uid": "200309", "doi": "10.5281/zenodo.3463580", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output: CICE experiments with varying floe and wave physics described in Roach et al. (2019)", "url": "https://zenodo.org/record/3463580"}], "date_created": "Tue, 19 Jul 2022 00:00:00 GMT", "description": "Sea-ice coverage surrounding Antarctica has expanded during the era of satellite observations, in contrast to rapidly shrinking Arctic sea ice. Most climate models predict Antarctic sea ice loss, rather than growth, indicating that there is much to learn about Antarctic sea ice in terms of its natural variability, processes and interactions affecting annual growth and retreat, and the impact of atmospheric factors such increasing greenhouse gases and stratospheric ozone depletion. This project is designed to improve model simulations of sea ice and examine the role of wind and wave forcing on changes in sea ice around Antarctica.\u003cbr/\u003e\u003cbr/\u003eThis project seeks to explain basic interactions of the coupled atmosphere, ocean, and ice dynamics in the Antarctic climate system, especially in the region near the sea ice edge. The summer evolution of sea ice cover and the near surface heat exchange of atmosphere and ocean depend on the geometric distribution of floes and the open water surrounding them. The distribution of floes has the greatest impact on the sea ice state in the marginal seas, where the distribution itself can vary rapidly. This project would develop and implement a model of sea ice floes in the Los Alamos sea ice model, known as CICE5. This sea ice component would be coupled to the third generation WaveWatch model within the Community Climate System Model Version 2. The coupled model would be used to study sea ice-wave interactions and the role of modeling sea ice floes in the Antarctic. The broader impacts of this project include outreach, support of female scientists, and improvement of the sea-ice codes in widely used climate models.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE FLOES; Southern Ocean; SEA ICE", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bitz, Cecilia", "platforms": null, "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "The Role of Wave-sea Ice Floe Interactions in Recent Antarctic Sea Ice Change", "uid": "p0010350", "west": -180.0}, {"awards": "1644277 Aschwanden, Andy", "bounds_geometry": "POLYGON((-75 -60,-72 -60,-69 -60,-66 -60,-63 -60,-60 -60,-57 -60,-54 -60,-51 -60,-48 -60,-45 -60,-45 -61.5,-45 -63,-45 -64.5,-45 -66,-45 -67.5,-45 -69,-45 -70.5,-45 -72,-45 -73.5,-45 -75,-48 -75,-51 -75,-54 -75,-57 -75,-60 -75,-63 -75,-66 -75,-69 -75,-72 -75,-75 -75,-75 -73.5,-75 -72,-75 -70.5,-75 -69,-75 -67.5,-75 -66,-75 -64.5,-75 -63,-75 -61.5,-75 -60))", "dataset_titles": "Linear Theory of Orographic Precipitation QGIS Plugin; Parallel Ice Sheet Model (PISM) v2", "datasets": [{"dataset_uid": "601590", "doi": "10.15784/601590", "keywords": "Antarctica", "people": "Aschwanden, Andy", "repository": "USAP-DC", "science_program": null, "title": "Linear Theory of Orographic Precipitation QGIS Plugin", "url": "https://www.usap-dc.org/view/dataset/601590"}, {"dataset_uid": "601589", "doi": "10.15784/601589", "keywords": "Antarctica", "people": "Aschwanden, Andy", "repository": "USAP-DC", "science_program": null, "title": "Parallel Ice Sheet Model (PISM) v2", "url": "https://www.usap-dc.org/view/dataset/601589"}], "date_created": "Thu, 14 Jul 2022 00:00:00 GMT", "description": "Aschwanden/1644277\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the phenomenon of the rain shadow (technically called orographic precipitation) in the Antarctic Peninsula and its interaction with a mountain range covered in ice and snow. Orographic precipitation gives rise to the largest climatic and ecological gradients on Earth. Air ascending on the windward side of the mountain range expands and cools, condensing the water vapor it carries and producing heavy rain- or snow-fall. As the air descends on the leeward flank, the air warms and dries out, leaving little-to-no precipitation. This pattern of snowfall, caused by the interaction of winds and the landscape, is hypothesized to control the shape of the ice cap itself. The investigators hypothesize that feedbacks between precipitation and topography control ice flux and temperature, impacting basal conditions (frozen versus wet) and motion, which over long time scales can affect basal topography via erosion.\u003cbr/\u003e\u003cbr/\u003eThe authors propose to investigate the feedbacks between orographically driven precipitation, ice dynamics, thermodynamics, and basal erosion and uplift over the northern Antarctic Peninsula by coupling an orographic precipitation model to the Parallel Ice Sheet Model (PISM). Using idealized and more realistic geometries, they will begin with a 2-D flow band model, which will be expanded into three dimensions to determine the strength of the feedbacks as a function of bedrock geometry and the intensity of the orographic precipitation gradient. The Antarctic Peninsula is targeted as the ideal case study, in the context of its rapid modern and future change as well as its deflation since the Last Glacial Maximum. The broader impacts of the work include the strengthening of predictive models by capturing feedbacks related to orographic precipitation not included in current models. This is likely to provide a more realistic assessment of the impacts of orographic precipitation in a regime of changing climate. The project will support an early career scientist and a female mid-career scientist and will support one PhD student, and provide summer research experience for one undergraduate student as an REU supplement. The project does not require field work in the Antarctic.", "east": -45.0, "geometry": "POINT(-60 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctic Ice Sheet", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aschwanden, Andy; Pettit, Erin", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Collaborative Research: Feedbacks between Orographic Precipitation and Ice Dynamics", "uid": "p0010348", "west": -75.0}, {"awards": "1745018 Fraser, William; 1744884 Oliver, Matthew; 1745011 Klinck, John; 1745023 Hennon, Tyler; 1745081 Bernard, Kim; 1745009 Kohut, Josh", "bounds_geometry": "POLYGON((-75 -60,-73 -60,-71 -60,-69 -60,-67 -60,-65 -60,-63 -60,-61 -60,-59 -60,-57 -60,-55 -60,-55 -61,-55 -62,-55 -63,-55 -64,-55 -65,-55 -66,-55 -67,-55 -68,-55 -69,-55 -70,-57 -70,-59 -70,-61 -70,-63 -70,-65 -70,-67 -70,-69 -70,-71 -70,-73 -70,-75 -70,-75 -69,-75 -68,-75 -67,-75 -66,-75 -65,-75 -64,-75 -63,-75 -62,-75 -61,-75 -60))", "dataset_titles": "Antarctic ACROBAT data; CTD Data from IFCB Sampling; Finite Time Lyapunov Exponent Results, Calculated from High Frequency Radar Observed Surface Currents; High Frequency Radar, Palmer Deep; IFCB Image Data; Relative Particle Density; SWARM AMLR moorings - acoustic data; SWARM Glider Data near Palmer Deep; WAP model float data; Winds from Joubin and Wauwerman Islands", "datasets": [{"dataset_uid": "200396", "doi": "10.26008/1912/bco-dmo.867442.2", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "WAP model float data", "url": "https://www.bco-dmo.org/dataset/867442"}, {"dataset_uid": "200397", "doi": "10.26008/1912/bco-dmo.865098.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Winds from Joubin and Wauwerman Islands", "url": "https://www.bco-dmo.org/dataset/865098"}, {"dataset_uid": "200398", "doi": "", "keywords": null, "people": null, "repository": "IOOS Glider DAAC", "science_program": null, "title": "SWARM Glider Data near Palmer Deep", "url": "https://gliders.ioos.us/erddap/search/index.html?page=1\u0026itemsPerPage=1000\u0026searchFor=swarm"}, {"dataset_uid": "200389", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic ACROBAT data", "url": "https://www.bco-dmo.org/dataset/916046"}, {"dataset_uid": "200390", "doi": "10.26008/1912/bco-dmo.865030.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "CTD Data from IFCB Sampling", "url": "https://www.bco-dmo.org/dataset/865030"}, {"dataset_uid": "200391", "doi": "10.26008/1912/bco-dmo.917914.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Finite Time Lyapunov Exponent Results, Calculated from High Frequency Radar Observed Surface Currents", "url": "https://www.bco-dmo.org/dataset/917914"}, {"dataset_uid": "200392", "doi": "10.26008/1912/bco-dmo.917884.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "High Frequency Radar, Palmer Deep", "url": "https://www.bco-dmo.org/dataset/917884"}, {"dataset_uid": "200393", "doi": "10.26008/1912/bco-dmo.865002.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "IFCB Image Data", "url": "https://www.bco-dmo.org/dataset/865002"}, {"dataset_uid": "200394", "doi": "10.26008/1912/bco-dmo.917926.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Relative Particle Density", "url": "https://www.bco-dmo.org/dataset/917926"}, {"dataset_uid": "200395", "doi": "10.26008/1912/bco-dmo.872729.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "SWARM AMLR moorings - acoustic data", "url": "https://www.bco-dmo.org/dataset/872729"}], "date_created": "Tue, 05 Jul 2022 00:00:00 GMT", "description": "Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function.\u003cbr/\u003e \u003cbr/\u003e \u003cbr/\u003eTo understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -55.0, "geometry": "POINT(-65 -65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CONDUCTIVITY SENSORS \u003e CONDUCTIVITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e RADIATION SENSORS", "is_usap_dc": true, "keywords": "MOORED; WATER TEMPERATURE; CONDUCTIVITY; FLUORESCENCE; UNCREWED VEHICLES; Palmer Station; PHOTOSYNTHETICALLY ACTIVE RADIATION; PELAGIC; OCEAN MIXED LAYER; SURFACE; SALINITY; WATER PRESSURE; LIVING ORGANISM; MODELS; ACOUSTIC SCATTERING", "locations": "Palmer Station", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Instrumentation and Support; Antarctic Organisms and Ecosystems", "paleo_time": "NOT APPLICABLE", "persons": "Bernard, Kim; Oliver, Matthew; Kohut, Josh; Fraser, William; Klinck, John M.; Statcewich, Hank", "platforms": "LIVING ORGANISM-BASED PLATFORMS \u003e LIVING ORGANISM; OTHER \u003e MODELS; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE", "repo": "BCO-DMO", "repositories": "BCO-DMO; IOOS Glider DAAC", "science_programs": null, "south": -70.0, "title": "Collaborative Research: Physical Mechanisms Driving Food Web Focusing in Antarctic Biological Hotspots", "uid": "p0010346", "west": -75.0}, {"awards": "9981683 Costa, Daniel; 0003956 Burns, Jennifer", "bounds_geometry": "POLYGON((-70 -65,-69.5 -65,-69 -65,-68.5 -65,-68 -65,-67.5 -65,-67 -65,-66.5 -65,-66 -65,-65.5 -65,-65 -65,-65 -65.5,-65 -66,-65 -66.5,-65 -67,-65 -67.5,-65 -68,-65 -68.5,-65 -69,-65 -69.5,-65 -70,-65.5 -70,-66 -70,-66.5 -70,-67 -70,-67.5 -70,-68 -70,-68.5 -70,-69 -70,-69.5 -70,-70 -70,-70 -69.5,-70 -69,-70 -68.5,-70 -68,-70 -67.5,-70 -67,-70 -66.5,-70 -66,-70 -65.5,-70 -65))", "dataset_titles": "Crabeater seal oxygen stores", "datasets": [{"dataset_uid": "601583", "doi": "10.15784/601583", "keywords": "Antarctica; Crabeater Seal; GLOBEC; Hemoglobin; LMG0104; LMG0106; LMG0204; LMG0205; Marguerite Bay; Myoglobin; Oxygen Stores; Seals", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Crabeater seal oxygen stores", "url": "https://www.usap-dc.org/view/dataset/601583"}], "date_created": "Wed, 29 Jun 2022 00:00:00 GMT", "description": "This collaborative study between the University of California, Santa Cruz, Duke University, the University of South Florida, the University of Alaska-Anchorage, and the University of California, San Diego will examine the identification of biological and physical features associated with the abundance and distribution of individual Antarctic predators; the identification and characterization of biological \u0027hot spots\u0027 within the Western Antarctic Peninsula; and the development of temporally and spatially explicit models of krill consumption within the WAP by vertebrate predators. It is one of several data synthesis and modeling components that use the data obtained in the course of the field work of the Southern Ocean Global Ocean Ecosystems Dynamics (SO GLOBEC) experiment.\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with understanding how predators utilize \u0027hot spots\u0027, i.e. locally intense areas of biological productivity, and how \u0027hot spots\u0027 might temporally and spatially structure krill predation rates, and will be integrated with other synthesis and modeling studies that deal with the hydrography primary production, and krill dynamics.", "east": -65.0, "geometry": "POINT(-67.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "Marguerite Bay; MARINE ECOSYSTEMS", "locations": "Marguerite Bay", "north": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Burns, Jennifer; Costa, Daniel", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Foraging Ecology of Crabeater Seals (Lobodon Carcinophagus)", "uid": "p0010345", "west": -70.0}, {"awards": "2139497 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "This project will conduct basic research into geological dating techniques that are useful for determining the age of glacial deposits in polar regions, Antarctica in particular. These techniques are necessary for determining how large the polar ice sheets were in the geologic past, including during past periods of warm climate that likely resemble present and near-future conditions. Thus, they represent an important technical capability needed for estimating the response of polar ice sheets to climate warming. Because changes in the size of polar ice sheets are the largest potential contribution to future global sea-level change, this capability is also relevant to understanding likely sea-level impacts of future climate change. The research in this project comprises several observational and experimental approaches to improving the speed, efficiency, cost, and accuracy of these techniques, as well as a scientific outreach program aimed at making the resulting capabilities more broadly available to other researchers. The project supports a postdoctoral scholar and contributes to human resources development in polar and climate science.\r\n\r\nThe project focuses on several areas of cosmogenic-nuclide geochemistry, which is a geochemical dating method that relies on the production and decay of cosmic-ray-produced radionuclides in surface rocks. Measurements of these nuclides can be used to quantify the duration of surface exposure and ice cover at locations in Antarctica that are covered and uncovered by changes in the size of the Antarctic ice sheets, thus providing a means of reconstructing past ice-sheet change. The first proposed set of experiments are aimed at implementing a \u0027\u0027virtual mineral separation\u0027\u0027 approach to cosmogenic noble gas analysis that may allow measurement of nuclide concentrations in certain minerals without physically separating the minerals from the host rock. If feasible, this would realize significant speed and cost improvements for this type of analysis. A second set of experiments will focus on means of identifying and quantifying non-cosmogenic background inventories of some relevant nuclides, which is intended to improve the measurement sensitivity and precision for cosmic-ray-produced inventories of these nuclides. A third focus area aims to improve capabilities to measure multiple cosmic-ray-produced nuclides in the same sample, which has the potential to improve the accuracy of dating methods based on these nuclides and to expand the situations in which these methods can be applied. If successful, these experiments are likely to improve a number of applications of cosmogenic-nuclide geochemistry relevant to Antarctic research, including subglacial bedrock exposure dating, dating of multimillion-year-old glacial deposits, and surface-process studies useful in understanding landform evolution and ecosystem dynamics.\r\n\r\nThis award reflects NSF\u0027\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "California; LABORATORY; AMD; GEOCHEMISTRY; Amd/Us; USAP-DC; USA/NSF", "locations": "California", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Balco, Gregory", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -90.0, "title": "Targeted Basic Research to Enable Antarctic Science Applications of Cosmogenic-Nuclide Geochemistry", "uid": "p0010343", "west": -180.0}, {"awards": "1744771 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities; 5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "datasets": [{"dataset_uid": "601602", "doi": "10.15784/601602", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Balco, Gregory; Halberstadt, Anna Ruth; Buchband, Hannah", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601602"}, {"dataset_uid": "601601", "doi": "10.15784/601601", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Balco, Gregory; Halberstadt, Anna Ruth; Buchband, Hannah", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601601"}], "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "The purpose of this project is to use geological data that record past changes in the Antarctic ice sheets to test computer models for ice sheet change. The geologic data mainly consist of dated glacial deposits that are preserved above the level of the present ice sheet, and range in age from thousands to millions of years old. These provide information about the size, thickness, and rate of change of the ice sheets during past times when the ice sheets were larger than present. In addition, some of these data are from below the present ice surface and therefore also provide some information about past warm periods when ice sheets were most likely smaller than present. The primary purpose of the computer model is to predict future ice sheet changes, but because significant changes in the size of ice sheets are slow and likely occur over hundreds of years or longer, the only way to determine whether these models are accurate is to test their ability to reproduce past ice sheet changes. The primary purpose of this project is to carry out such a test. The research team will compile relevant geologic data, in some cases generate new data by dating additional deposits, and develop methods and software to compare data to model simulations. In addition, this project will (i) contribute to building and sustaining U.S. science capacity through postdoctoral training in geochronology, ice sheet modeling, and data science, and (ii) improve public access to geologic data and model simulations relevant to ice sheet change through online database and website development. \u003cbr/\u003e\u003cbr/\u003eTechnical aspects of this project are primarily focused on the field of cosmogenic-nuclide exposure-dating, which is a method that relies on the production of rare stable and radio-nuclides by cosmic-ray interactions with rocks and minerals exposed at the Earth\u0027s surface. Because the advance and retreat of ice sheets results in alternating cosmic-ray exposure and shielding of underlying bedrock and surficial deposits, this technique is commonly used to date and reconstruct past ice sheet changes. First, this project will contribute to compiling and systematizing a large amount of cosmogenic-nuclide exposure age data collected in Antarctica during the past three decades. Second, it will generate additional geochemical data needed to improve the extent and usefulness of measurements of stable cosmogenic nuclides, cosmogenic neon-21 in particular, that are useful for constraining ice-sheet behavior on million-year timescales. Third, it will develop a computational framework for comparison of the geologic data set with existing numerical model simulations of Antarctic ice sheet change during the past several million years, with particular emphasis on model simulations of past warm periods, for example the middle Pliocene ca. 3-3.3 million years ago, during which the Antarctic ice sheets are hypothesized to have been substantially smaller than present. Fourth, guided by the results of this comparison, it will generate new model simulations aimed at improving agreement between model simulations and geologic data, as well as diagnosing which processes or parameterizations in the models are or are not well constrained by the data.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "BERYLLIUM-10 ANALYSIS; AMD; ICE SHEETS; GLACIATION; Amd/Us; LABORATORY; USA/NSF; Antarctica; ALUMINUM-26 ANALYSIS; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Balco, Gregory", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Synoptic Evaluation of Long-Term Antarctic Ice Sheet Model Simulations using a Continent-Wide Database of Cosmogenic-Nuclide Measurements", "uid": "p0010342", "west": -180.0}, {"awards": "1543367 Shubin, Neil", "bounds_geometry": "POLYGON((158.3 -77.5,158.54000000000002 -77.5,158.78 -77.5,159.02 -77.5,159.26 -77.5,159.5 -77.5,159.74 -77.5,159.98 -77.5,160.22 -77.5,160.45999999999998 -77.5,160.7 -77.5,160.7 -77.605,160.7 -77.71,160.7 -77.815,160.7 -77.92,160.7 -78.025,160.7 -78.13,160.7 -78.235,160.7 -78.34,160.7 -78.445,160.7 -78.55,160.45999999999998 -78.55,160.22 -78.55,159.98 -78.55,159.74 -78.55,159.5 -78.55,159.26 -78.55,159.02 -78.55,158.78 -78.55,158.54000000000002 -78.55,158.3 -78.55,158.3 -78.445,158.3 -78.34,158.3 -78.235,158.3 -78.13,158.3 -78.025,158.3 -77.92,158.3 -77.815,158.3 -77.71,158.3 -77.605,158.3 -77.5))", "dataset_titles": "Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian); Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian) 2 (2018-2019)", "datasets": [{"dataset_uid": "601584", "doi": "10.15784/601584", "keywords": "Acanthodii; Antarctica; Chondrichthyes; Early Vertebrates; Osteolepiformes; Paleontology; Placodermi; Transantarctic Mountains; Vertebrate Evolution", "people": "Daeschler, Ted", "repository": "USAP-DC", "science_program": null, "title": "Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian) 2 (2018-2019)", "url": "https://www.usap-dc.org/view/dataset/601584"}, {"dataset_uid": "601580", "doi": "10.15784/601580", "keywords": "Acanthodii; Antarctica; Chondrichthyes; Early Vertebrates; Osteolepiformes; Paleontology; Placodermi; Transantarctic Mountains; Vertebrate Evolution", "people": "Daeschler, Ted", "repository": "USAP-DC", "science_program": null, "title": "Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian)", "url": "https://www.usap-dc.org/view/dataset/601580"}], "date_created": "Fri, 17 Jun 2022 00:00:00 GMT", "description": "This research will provide new insights into the relationships and history of sharks, fish and limbed animals. Understanding these relationships forms the backbone for both basic and applied science because fish often serve as models of human traits and diseases. Some of the main lines of evidence for these relationships come from fossils in rocks over 380 million years old that were originally deposited as ancient rivers and streams. Because rocks of this type and age are abundantly exposed along a number of the dry valleys and mountains of Antarctica, the investigation of these areas holds exceptional promise for discoveries that can have a broad impact. The fieldwork will involve geological mapping and assessment of the rocks with detailed reconnaissance for the fossils that they may hold. Fossil discoveries form the backbone for public communication of the methods and results of scientific research-- these studies will be used as vehicles for training of students at multiple levels as well as communication of science to the broader non-science citizen base.\u003cbr/\u003e\u003cbr/\u003eThe discovery, description, and analysis of Middle to Late Devonian (390-355 Million years ago) vertebrates and depositional environments provide important data on the emergence of novel anatomical structures, faunas, and habitats during a critical interval in the history of life and earth. Biological innovation during this time includes the early evolution of freshwater fish, the origins of major groups of vertebrates (e.g., sharks, lobe and ray-finned fish, tetrapods), and the expansion and elaboration of non-marine ecosystems. Accordingly, expanding our knowledge of vertebrate diversity during the Middle and Late Devonian will provide new evidence on the relationships of the major groups of vertebrates, the assembly of novelties that ultimately enabled tetrapods to invade land, the origin and early evolution of sharks and their relatives, and the assembly and expansion of non-marine ecosystems generally. The Aztec Siltstone of Antarctica Middle-Late Devonian; Givetian-Frasnian Stages) has exceptional potential to produce new paleontological evidence of these events and to illuminate the temporal, ecological, and geographic context in which they occurred. It is essentially fossiliferous throughout its known exposure range, something that is rare for Middle-Late Devonian non-marine rocks anywhere in the world. In addition, fine-grained meandering stream deposits are abundantly exposed in the Aztec Siltstone and are recognized as an important locus for the discovery of well-preserved Devonian fish, including stem tetrapods and their relatives. Given the exceedingly fossiliferous nature of the Aztec Siltstone, the large number of taxa known only from partial material, and the amount of promising exposure yet to be worked, a dedicated reconnaissance, collection, and research effort is designed to recover important new fossil material and embed it in a stratigraphic and sedimentological context. The first major objective of this study is the recovery, preparation, and description of Middle-Late Devonian fossil taxa. Ensuing investigation of the phylogenetic affinities, taphonomic occurrence, and stratigraphic position of fossil assemblages will allow both local and global comparisons of biotic diversity. These analyses will inform: 1) higher level phylogenetic hypotheses of jawed vertebrates, 2) biostratigraphic and biogeographic analysis of the distribution of the Middle-Late Devonian fish, and 3) paleobiological investigation of the elaboration of terrestrial and freshwater habitats. The broader impacts are derived from the utility of paleontology and Antarctic expeditionary science as educational tools with powerful narratives. Specific goals include affiliations with local urban secondary schools (using established relationships for broadening participation) and collegiate and graduate training. Wider dissemination of knowledge to the general public is a direct product of ongoing interactions with national and international media (print, television, internet).", "east": 160.7, "geometry": "POINT(159.5 -78.025)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; FIELD INVESTIGATION; Transantarctic Mountains; USA/NSF; MACROFOSSILS; Fossils; USAP-DC", "locations": "Transantarctic Mountains", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e PALEOZOIC \u003e DEVONIAN", "persons": "Shubin, Neil; Daeschler, Edward B", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.55, "title": "Middle-Late Devonian Vertebrates of Antarctica", "uid": "p0010340", "west": 158.3}, {"awards": "1643716 Buizert, Christo; 1643664 Severinghaus, Jeffrey; 1643669 Petrenko, Vasilii", "bounds_geometry": "POLYGON((112 -66,112.2 -66,112.4 -66,112.6 -66,112.8 -66,113 -66,113.2 -66,113.4 -66,113.6 -66,113.8 -66,114 -66,114 -66.1,114 -66.2,114 -66.3,114 -66.4,114 -66.5,114 -66.6,114 -66.7,114 -66.8,114 -66.9,114 -67,113.8 -67,113.6 -67,113.4 -67,113.2 -67,113 -67,112.8 -67,112.6 -67,112.4 -67,112.2 -67,112 -67,112 -66.9,112 -66.8,112 -66.7,112 -66.6,112 -66.5,112 -66.4,112 -66.3,112 -66.2,112 -66.1,112 -66))", "dataset_titles": "Concentration and isotopic composition of atmospheric N2O over the last century; Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2; Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy", "datasets": [{"dataset_uid": "601598", "doi": "10.15784/601598", "keywords": "Antarctica; Firn; Firn Density; Gravitational Settling; Inert Gases; Law Dome", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2", "url": "https://www.usap-dc.org/view/dataset/601598"}, {"dataset_uid": "601597", "doi": "10.15784/601597", "keywords": "Antarctica; Ice Core; Law Dome; Noble Gas", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy", "url": "https://www.usap-dc.org/view/dataset/601597"}, {"dataset_uid": "601693", "doi": "10.15784/601693", "keywords": "Antarctic; Antarctica; Anthropogenic Emission; Atmosphere; Greenhouse Gas; Greenland; Ice Core Data; Nitrification And Denitrification Processes; Nitrous Oxide; Site-Specific 15N Isotopomer; Styx Glacier", "people": "Toyoda, Sakae ; Yoshida, Naohiro ; Ahn, Jinho ; Joong Kim, Seong; Etheridge, David; Ghosh, Sambit; Langenfelds, Ray L ; Buizert, Christo ", "repository": "USAP-DC", "science_program": null, "title": "Concentration and isotopic composition of atmospheric N2O over the last century", "url": "https://www.usap-dc.org/view/dataset/601693"}], "date_created": "Fri, 17 Jun 2022 00:00:00 GMT", "description": "Hydroxyl radicals are responsible for removal of most atmospheric trace gases, including pollutants and important greenhouse gases. They have been called the \"detergent of the atmosphere\". Changes in hydroxyl radical concentration in response to large changes in reactive trace gas emissions, which may happen in the future, are uncertain. This project aims to provide the first estimates of the variability of atmospheric hydroxyl radicals since about 1880 AD when anthropogenic emissions of reactive trace gases were minimal. This will improve understanding of their stability in response to large changes in emissions. The project will also investigate whether ice cores record past changes in Southern Hemisphere westerly winds. These winds are a key component of the global climate system, and have an important influence on ocean circulation and possibly on atmospheric carbon dioxide concentrations. The project team will include three early career scientists, a postdoctoral researcher, and graduate and undergraduate students, working in collaboration with senior scientists and Australian collaborators. \u003cbr/\u003e \u003cbr/\u003eFirn air and shallow ice to a depth of about 233 m will be sampled at the Law Dome high-accumulation coastal site in East Antarctica. Trapped air will be extracted from the ice cores on site immediately after drilling. Carbon-14 of carbon monoxide (14CO) will be analyzed in firn and ice-core air samples. Corrections will be made for the in situ cosmogenic 14CO component in the ice, allowing for the atmospheric 14CO history to be reconstructed. This 14CO history will be interpreted with the aid of a chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere hydroxyl radical concentration after about 1880 AD. An additional component of the project will analyze Krypton-86 in the firn-air and ice-core samples. These measurements will explore whether ice-core Krypton-86 acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere westerly winds.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 114.0, "geometry": "POINT(113 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; TRACE GASES/TRACE SPECIES; Law Dome; Amd/Us; USAP-DC; LABORATORY; ICE CORE AIR BUBBLES; USA/NSF", "locations": "Law Dome", "north": -66.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Petrenko, Vasilii; Murray, Lee T; Buizert, Christo; Petrenko, Vasilii; Murray, Lee T", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "uid": "p0010341", "west": 112.0}, {"awards": "2201129 Fischer, Karen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 14 Jun 2022 00:00:00 GMT", "description": "The western portion of the Antarctic continent is active in terms of plate tectonic processes that can produce significant variations in the Earth\u0027s mantle temperature as well as partial melting of the mantle. In addition to these internal processes, the ice sheet in western Antarctica is melting due to Earth\u0027s warming climate and adding water to the ocean. These changes in ice mass cause adjustments in rocks within the Earth\u0027s crust, allowing the surface to rebound in some locations and fall in others, altering the geographical pattern of sea-level change. However, the solid Earth response depends strongly on the strength of the rocks at a wide range of timescales which is not well-known and varies with temperature and other rock properties. This project has three primary goals. (1) It will assess how processes such as rifting, mantle upwelling and lithospheric instability have altered the lithosphere and underlying asthenosphere of western Antarctica, contributing to a planet-wide understanding of these processes. (2) It will use new measurements of mantle and crust properties to estimate the rate at which heat from the solid Earth flows into the base of the ice, which is important for modeling the rates at which the ice melts and flows. (3) It will places bounds on mantle viscosity, which is key for modeling the interaction of the solid Earth with changing ice and water masses and their implications for sea-level rise. To accomplish these goals, new resolution of crust and mantle structure will be obtained by analyzing seismic waves from distant earthquakes that have been recorded at numerous seismic stations in Antarctica. These analyses will include new combinations of seismic wave data that provide complementary information about mantle temperature, heat flow and viscosity. \u003cbr\u003e\u003cbr\u003eTechnical Description: This research addresses key questions about mantle processes and properties in western Antarctica. What are the relative impacts of rifting, mantle plumes, and lithospheric delamination in the evolution of the lithosphere and asthenosphere? Where is topography isostatically compensated, and where are dynamic processes such as plate flexure or tractions from 3-D mantle flow required? What are the bounds on heat flow and mantle viscosity, which represent important inputs to models of ice sheet evolution and its feedback from the solid Earth? To address these questions, this project will measure mantle and crust properties using seismic tools that have not yet been applied in Antarctica: regional-scale measurement of mantle attenuation from surface waves; Sp body wave phases to image mantle velocity gradients such as the lithosphere-asthenosphere boundary; and surface wave amplification and ellipticity. The resulting models of seismic attenuation and velocity will be jointly interpreted to shed new light on temperature, bulk composition, volatile content, and partial melt, using a range of laboratory-derived constitutive laws, while considering data from mantle xenoliths. To test the relative roles of rifting, mantle plumes, and delamination, and to assess isostatic support for Antarctic topography, the predictions of these processes will be compared to the new models of crust and mantle properties. To improve bounds on western Antarctic heat flow, seismic attenuation and velocity will be used in empirical comparisons and in direct modeling of vertical temperature gradients. To better measure mantle viscosity at the timescales of glacial isostatic adjustment, frequency-dependent viscosity will be estimated from the inferred mantle conditions. \u003cbr\u003e\u003cbr\u003eThis project will contribute to the education and career development of a Brown University Ph.D. student, Brown undergraduates, and undergraduates from outside the university who will be involved through the Department of Earth, Environmental and Planetary Sciences (DEEPS) Leadership Alliance NSF Research Experience for Undergraduates (REU) Site which focuses on geoscience summer research experiences for underrepresented students. The project will be the basis for a seminar at Brown that explores the connections between the solid Earth and cryosphere in Antarctica and will contribute to outreach in local public elementary and high schools.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; West Antarctica; USA/NSF; SEISMIC SURFACE WAVES; AMD; PLATE TECTONICS; Amd/Us; GLACIERS/ICE SHEETS; FIELD INVESTIGATION", "locations": "West Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Fischer, Karen; Dalton, Colleen", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -90.0, "title": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity", "uid": "p0010339", "west": -180.0}, {"awards": "1643436 Donohoe, Aaron", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Partionining of CERES planetary albedo between atmospheric and surface reflection", "datasets": [{"dataset_uid": "601579", "doi": "10.15784/601579", "keywords": "Antarctica; Southern Ocean", "people": "Donohoe, Aaron", "repository": "USAP-DC", "science_program": null, "title": "Partionining of CERES planetary albedo between atmospheric and surface reflection", "url": "https://www.usap-dc.org/view/dataset/601579"}], "date_created": "Fri, 10 Jun 2022 00:00:00 GMT", "description": "The key scientific question of this project is: what mechanism is the dominant driver of Southern Ocean (SO) sea ice variability and long-term trends in nature? Our primary goal is to understand the processes that drive SO sea ice loss over the observational record and identify which models get the physics right. Although our primary focus is on mechanisms of long-term sea ice loss, the observational record includes rich information at shorter timescales which are better sampled and may elucidate the relevant physics. Thus, our analysis of mechanisms of sea ice variability spans time scales ranging from days (synoptic) to inter-annual variability to long-term trends to identify model biases in the physics that drive SO sea ice loss events.\r\n\r\nWe divided our work into explorations of 5 major topics \r\n1. Identifying model biases in high frequency sea ice variability in the Southern Ocean\r\n2. Identifying model biases in radiative impact of sea ice loss events\r\n3. Disentangling the roles of winds and sea surface temperature on the observational record of Southern Ocean sea ice\r\n4. Quantifying the degree to which Southern Ocean sea ice loss is remotely forced by the influence of the tropics and mid-latitudes and, conversely, how much much influence does the Southern Ocean have on the tropics \r\n5. Analyzing the impact of atmospheric heat transport on sea ice loss \r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; AMD; Amd/Us; SEA ICE; United States Of America; COMPUTERS; ATMOSPHERIC WINDS; ATMOSPHERIC RADIATION; NSF/USA", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Donohoe, Aaron; Schweiger, Axel", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "What Processes Drive Southern Ocean Sea Ice Variability and Trends? Insights from the Energy Budget of the Coupled Cryosphere-ocean-atmosphere System", "uid": "p0010336", "west": -180.0}, {"awards": "1947558 Leckie, Robert; 1947657 Dodd, Justin; 1947646 Shevenell, Amelia", "bounds_geometry": "POLYGON((-180 -72.5,-177.6 -72.5,-175.2 -72.5,-172.8 -72.5,-170.4 -72.5,-168 -72.5,-165.6 -72.5,-163.2 -72.5,-160.8 -72.5,-158.4 -72.5,-156 -72.5,-156 -73.15,-156 -73.8,-156 -74.45,-156 -75.1,-156 -75.75,-156 -76.4,-156 -77.05,-156 -77.7,-156 -78.35,-156 -79,-158.4 -79,-160.8 -79,-163.2 -79,-165.6 -79,-168 -79,-170.4 -79,-172.8 -79,-175.2 -79,-177.6 -79,180 -79,178.4 -79,176.8 -79,175.2 -79,173.6 -79,172 -79,170.4 -79,168.8 -79,167.2 -79,165.6 -79,164 -79,164 -78.35,164 -77.7,164 -77.05,164 -76.4,164 -75.75,164 -75.1,164 -74.45,164 -73.8,164 -73.15,164 -72.5,165.6 -72.5,167.2 -72.5,168.8 -72.5,170.4 -72.5,172 -72.5,173.6 -72.5,175.2 -72.5,176.8 -72.5,178.4 -72.5,-180 -72.5))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 08 Jun 2022 00:00:00 GMT", "description": "Presently, Antarctica\u0027s glaciers are melting as Earth\u0027s atmosphere and the Southern Ocean warm. Not much is known about how Antarctica\u0027s ice sheets might respond to ongoing and future warming, but such knowledge is important because Antarctica\u0027s ice sheets might raise global sea levels significantly with continued melting. Over time, mud accumulates on the sea floor around Antarctica that is composed of the skeletons and debris of microscopic marine organisms and sediment from the adjacent continent. As this mud is deposited, it creates a record of past environmental and ecological changes, including ocean depth, glacier advance and retreat, ocean temperature, ocean circulation, marine ecosystems, ocean chemistry, and continental weathering. Scientists interested in understanding how Antarctica\u0027s glaciers and ice sheets might respond to ongoing warming can use a variety of physical, biological, and chemical analyses of these mud archives to determine how long ago the mud was deposited and how the ice sheets, oceans, and marine ecosystems responded during intervals in the past when Earth\u0027s climate was warmer. In this project, researchers from the University of South Florida, University of Massachusetts, and Northern Illinois University will reconstruct the depth, ocean temperature, weathering and nutrient input, and marine ecosystems in the central Ross Sea from ~17 to 13 million years ago, when the warm Miocene Climate Optimum transitioned to a cooler interval with more extensive ice sheets. Record will be generated from new sediments recovered during the International Ocean Discovery Program (IODP) Expedition 374 and legacy sequences recovered in the 1970?s during the Deep Sea Drilling Program. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions. ", "east": -156.0, "geometry": "POINT(-176 -75.75)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; LABORATORY; AMD; PALEOCLIMATE RECONSTRUCTIONS; Ross Sea; USAP-DC; USA/NSF", "locations": "Ross Sea", "north": -72.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.0, "title": "Collaborative Proposal: Miocene Climate Extremes: A Ross Sea Perspective from IODP Expedition 374 and DSDP Leg 28 Marine Sediments", "uid": "p0010335", "west": 164.0}, {"awards": "2203487 Ben Mansour, Walid", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 06 Jun 2022 00:00:00 GMT", "description": "The thermochemical structure of the lithosphere beneath Antarctica is fundamental for understanding the geological evolution of the continent and its relationship to surrounding Gondwana continents. In addition, the thermal structure controls the solid earth response to glacial unloading, with important implications for ice sheet models and the future of the West Antarctic Ice Sheet. However, it is challenging to get an accurate picture of temperature and composition from only sparse petrological/geochemical analysis, and most previous attempts to solve this problem geophysically have relied on seismic or gravity data alone. Here, we propose to use a probabilistic joint inversion (high resolution regional seismic data, satellite gravity data, topography) and petrological modelling approach to determine the 3D thermochemical structure of the mantle. The inversion will be carried out using a Markov-chain Bayesian Monte Carlo methodology, providing quantitative estimates of uncertainties. Mapping the 3-D thermochemical structure (thermal and composition) will provide a comprehensive view of the horizontal (50-100 km resolution) and vertical (from the surface down to 380 km) variations. This new model will give us the temperature variation from the surface down to 380 km and the degree of depletion of the lithospheric mantle and the sub-lithospheric mantle. This new model will also be compared to recent models of Gondwana terranes 200 Myrs to build a new model of the thermochemical evolution of the cratonic mantle. The new thermal and chemical structures can be used to better understand the geothermal heat flux beneath the ice sheet as well as improve glacial isostatic adjustment and ice sheet models.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; GRAVITY FIELD; AMD; COMPUTERS; GEOCHEMISTRY; PLATE BOUNDARIES; Amd/Us; SEISMIC SURFACE WAVES; USA/NSF; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ben-Mansour, Walid; Wiens, Douglas", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Thermal and Compositional Structure of Antarctica from Probabilistic Joint Inversion of Seismic, Gravity, and Topography Data and Petrological Modelling", "uid": "p0010334", "west": -180.0}, {"awards": "2055455 Duhaime, Melissa", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Part 1: Non-technical description:\r\nIt is well known that the Southern Ocean plays an important role in global carbon cycling and also receives a disproportionately large influence of climate change. The role of marine viruses on ocean productivity is largely understudied, especially in this global region. This team proposes to use combination of genomics, flow cytometry, and network modeling to test the hypothesis that viral biogeography, infection networks, and viral impacts on microbial metabolism can explain variations in net community production (NCP) and carbon cycling in the Southern Ocean. The project includes the training of a postdoctoral scholar, graduate students and undergraduate students. It also includes the development of a new Polar Sci ReachOut program in partnership with the University of Michigan Museum of Natural History especially targeted to middle-school students and teachers and the general public. The team will also produce a Science for Tomorrow (SFT) program for use in middle schools in metro-Detroit communities and lead a summer Research Experience for Teachers (RET) fellows. \r\n\r\nPart 2: Technical description: \r\nThe study will leverage hundreds of existing samples collected for microbes and viruses from the Antarctic Circumpolar Expedition (ACE). These samples provide the first contiguous survey of viral diversity and microbial communities around Antarctica. Viral networks are being studied in the context of biogeochemical data to model community networks and predict net community production (NCP), which will provide a way to evaluate the role of viruses in Southern Ocean carbon cycling. Using cutting edge molecular and flow cytometry approaches, this project addresses the following questions: 1) How/why are Southern Ocean viral populations distributed across environmental gradients? 2a) Do viruses interfere with \"keystone\" metabolic pathways and biogeochemical processes of microbial communities in the Southern Ocean? 2b) Does nutrient availability or other environmental variables drive changes in virus-microbe infection networks in the Southern Ocean? Results will be used to develop and evaluate generative models of NCP predictions that incorporate the importance of viral traits and virus-host interactions.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; Amd/Us; AMD; FIELD INVESTIGATION; USA/NSF; AQUATIC SCIENCES; BACTERIA/ARCHAEA; MARINE ECOSYSTEMS; VIRUSES; USAP-DC", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Duhaime, Melissa; Zaman, Luis", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA - Viral Ecogenomics of the Southern Ocean: Unifying Omics and Ecological Networks to Advance our Understanding of Antarctic Microbial Ecosystem Function", "uid": "p0010333", "west": -180.0}, {"awards": "1951090 Stukel, Michael", "bounds_geometry": "POLYGON((-80 -63,-78.2 -63,-76.4 -63,-74.6 -63,-72.8 -63,-71 -63,-69.2 -63,-67.4 -63,-65.6 -63,-63.8 -63,-62 -63,-62 -63.7,-62 -64.4,-62 -65.1,-62 -65.8,-62 -66.5,-62 -67.2,-62 -67.9,-62 -68.6,-62 -69.3,-62 -70,-63.8 -70,-65.6 -70,-67.4 -70,-69.2 -70,-71 -70,-72.8 -70,-74.6 -70,-76.4 -70,-78.2 -70,-80 -70,-80 -69.3,-80 -68.6,-80 -67.9,-80 -67.2,-80 -66.5,-80 -65.8,-80 -65.1,-80 -64.4,-80 -63.7,-80 -63))", "dataset_titles": "BCO-DMO Project Page", "datasets": [{"dataset_uid": "200294", "doi": null, "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "BCO-DMO Project Page", "url": "https://www.bco-dmo.org/project/838048"}], "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Algae in the surface ocean convert carbon dioxide into organic carbon through photosynthesis. The biological carbon pump transports this organic carbon from the atmosphere to the deep ocean where it can be stored for tens to hundreds of years. Annually, the amount transported is similar to that humans are currently emitting by burning fossil fuels. However, at present we cannot predict how this important process will change with a warming ocean. These investigators plan to develop a 15+ year time-series of vertical carbon transfer for the Western Antarctic Peninsula; a highly productive Antarctic ecosystem. This region is also rapid transition to warmer temperatures leading to reduced sea ice coverage. This work will help researchers better understand how the carbon cycle in the Western Antarctic Peninsula will respond to climate change. The researchers will develop the first large-scale time-series of carbon flux anywhere in the ocean. This research will also support the education and training of a graduate student and support the integration of concepts in Antarctic research into two undergraduate courses designed for non-science majors and advanced earth science students. The researchers will also develop educational modules for introducing elementary and middle-school age students to important concepts such as gross and net primary productivity, feedbacks in the marine and atmospheric systems, and the differences between correlation and causation. Results from this proposal will also be incorporated into a children?s book, ?Plankton do the Strangest Things?, that is targeted at 5-7 year olds and is designed to introduce them to the incredible diversity and fascinating adaptations of microscopic marine organisms.\u003cbr/\u003e\u003cbr/\u003e This research seeks to leverage 6 years (2015-2020) of 234Th samples collected on Palmer LTER program, 5 years of prior measurements (2009-2010, 2012-2014), and upcoming cruises (2021-2023) to develop a time-series of summertime particle flux in the WAP that stretches for 15 years. The 238U-234Th disequilibrium approach utilizes changes in the activity of the particle-active radio-isotope 234Th relative to its parent nuclide 238U to quantify the flux of sinking carbon out of the surface ocean (over a time-scale of ~one month). This proposal will fund 234Th analyses from nine years? worth of cruises (2015-2023) and extensive analyses designed to investigate the processes driving inter-annual variability in the BCP. These include: 1) physical modeling to quantify the importance of advection and diffusion in the 234Th budget, 2) time-series analyses of particle flux, and 3) statistical modeling of the relationships between particle flux and multiple presumed drivers (biological, chemical, physical, and climate indices) measured by collaborators in the Palmer LTER program. This multi-faceted approach is critical for linking the measurements to models and for predicting responses to climate change. It will also test the hypothesis that export flux is decreasing in the northern WAP, increasing in the southern WAP, and increasing when integrated over the entire region as a result of earlier sea ice retreat and a larger ice-free zone. The project will also investigate relationships between carbon export and multiple potentially controlling factors including: primary productivity, algal biomass and taxonomic composition, biological oxygen saturation, zooplankton biomass and taxonomic composition, bacterial production, temperature, wintertime sea ice extent, date of sea ice retreat, and climate modes.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-71 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; FIELD INVESTIGATION; Palmer Station; USAP-DC; BIOGEOCHEMICAL CYCLES; USA/NSF", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Stukel, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -70.0, "title": "Quantifying Processes Driving Interannual Variability in the Biological Carbon Pump in the Western Antarctic Peninsula", "uid": "p0010332", "west": -80.0}, {"awards": "2019719 Brook, Edward", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "2019-2020 Allan Hills Field Report; 2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report; 2022-23 (CXA1) flight based HDF5/matlab format data; 2022-23 (CXA1) transect based (science organized) unfocused data; 2023-2024 Allan Hills End-of-Season Science Report; 2023-24 (CXA2) flight based data HDF5/matlab format; 2023-24 (CXA2) transect based (science organized) unfocused data; Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills I-188 Field Season Report 2022-2023; COLDEX Raw MARFA Ice Penetrating Radar data; Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland", "datasets": [{"dataset_uid": "200403", "doi": "https://doi.org/10.18738/T8/J38CO5", "keywords": null, "people": null, "repository": "OPR", "science_program": null, "title": "2022-23 (CXA1) flight based HDF5/matlab format data", "url": "https://data.cresis.ku.edu/data/rds/2022_Antarctica_BaslerMKB/"}, {"dataset_uid": "200406", "doi": "10.18738/T8/FV6VNT", "keywords": null, "people": null, "repository": "TDR", "science_program": null, "title": "2023-24 (CXA2) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/FV6VNT"}, {"dataset_uid": "200405", "doi": "10.18738/T8/XPMLCC", "keywords": null, "people": null, "repository": "TDR", "science_program": null, "title": "2022-23 (CXA1) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/XPMLCC"}, {"dataset_uid": "601826", "doi": "10.15784/601826", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Horlings, Annika; Shaya, Margot; Manos, John-Morgan; Conway, Howard; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills I-188 Field Season Report 2022-2023", "url": "https://www.usap-dc.org/view/dataset/601826"}, {"dataset_uid": "601824", "doi": "10.15784/601824", "keywords": "Allan Hills; Antarctica; Coldex; Cryosphere", "people": "Goverman, Ashley; Morton, Elizabeth; Marks Peterson, Julia; Hudak, Abigail; Mayo, Emalia; Epifanio, Jenna; Jayred, Michael; Manos, John-Morgan; Carter, Austin; Shackleton, Sarah; Banerjee, Asmita; Brook, Edward J.; Higgins, John", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2023-2024 Allan Hills End-of-Season Science Report", "url": "https://www.usap-dc.org/view/dataset/601824"}, {"dataset_uid": "601819", "doi": "10.15784/601819", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Morgan, Jacob; Higgins, John; Shackleton, Sarah; Epifanio, Jenna; Kuhl, Tanner; Morton, Elizabeth; Zajicek, Anna; Nesbitt, Ian; Carter, Austin", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2019-2020 Allan Hills Field Report", "url": "https://www.usap-dc.org/view/dataset/601819"}, {"dataset_uid": "200404", "doi": "10.18738/T8/J38CO5", "keywords": null, "people": null, "repository": "OPR", "science_program": null, "title": "2023-24 (CXA2) flight based data HDF5/matlab format", "url": "https://data.cresis.ku.edu/data/rds/2023_Antarctica_BaslerMKB/"}, {"dataset_uid": "601768", "doi": null, "keywords": "Antarctica; East Antarctic Plateau", "people": "Kempf, Scott D.; Ng, Gregory; Young, Duncan A.; Blankenship, Donald D.; Greenbaum, Jamin; Buhl, Dillon; Kerr, Megan; Chan, Kristian", "repository": "USAP-DC", "science_program": null, "title": "COLDEX Raw MARFA Ice Penetrating Radar data", "url": "https://www.usap-dc.org/view/dataset/601768"}, {"dataset_uid": "601697", "doi": "10.15784/601697", "keywords": "Allan Hills; Antarctica; Apres; Ice Core; Ice Penetrating Radar; Temperature Profiles", "people": "Conway, Howard; Brook, Edward J.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report", "url": "https://www.usap-dc.org/view/dataset/601697"}, {"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Shackleton, Sarah; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "601659", "doi": "10.15784/601659", "keywords": "Antarctica; Continuous Flow; Glaciology; Greenland; Ice Core Data; Laser Spectroscopy; Oxygen Isotope; Triple Oxygen Isotopes", "people": "Davidge, Lindsey", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland", "url": "https://www.usap-dc.org/view/dataset/601659"}], "date_created": "Sat, 21 May 2022 00:00:00 GMT", "description": "Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth\u2019s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth\u2019s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community.\r\n\r\nKnowledge of Earth\u2019s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth\u2019s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; Antarctica; Amd/Us; Coldex; USAP-DC; FIELD SURVEYS; ICE DEPTH/THICKNESS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Polar Special Initiatives", "paleo_time": null, "persons": "Brook, Edward J.; Neff, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "OPR", "repositories": "OPR; TDR; USAP-DC", "science_programs": "COLDEX", "south": -90.0, "title": "Center for Oldest Ice Exploration", "uid": "p0010321", "west": -180.0}, {"awards": "1744958 Wei, Yong; 1744759 Dunham, Eric; 1744856 Bromirski, Peter", "bounds_geometry": null, "dataset_titles": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves; Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "datasets": [{"dataset_uid": "601561", "doi": "10.15784/601561", "keywords": "Amundsen Sea; Antarctica; Glaciology", "people": "Dunham, Eric; Tazhimbetov, Nurbek; Almquist, Martin", "repository": "USAP-DC", "science_program": null, "title": "Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "url": "https://www.usap-dc.org/view/dataset/601561"}, {"dataset_uid": "200323", "doi": "10.25740/qy001dt7463", "keywords": null, "people": null, "repository": "Stanford Digital Repository", "science_program": null, "title": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves", "url": "https://doi.org/10.25740/qy001dt7463"}], "date_created": "Mon, 16 May 2022 00:00:00 GMT", "description": "Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences.\u003cbr/\u003e\u003cbr/\u003eThis project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; AMD; Amd/Us; SEA ICE; Amundsen Sea; USAP-DC; USA/NSF; MODELS", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Dunham, Eric; Bromirski, Peter", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "Stanford Digital Repository; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Do Ocean Wave Impacts Pose a Hazard to the Stability of West Antarctic Ice Shelves?", "uid": "p0010320", "west": null}, {"awards": "1643285 Joughin, Ian; 1643174 Padman, Laurence", "bounds_geometry": "POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73))", "dataset_titles": "Beta Version of Plume Model; Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier; icepack; Pine Island Basin Scale Model", "datasets": [{"dataset_uid": "200313", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beta Version of Plume Model", "url": "https://github.com/icepack/plumes"}, {"dataset_uid": "200315", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Pine Island Basin Scale Model", "url": "https://github.com/fastice/icesheetModels"}, {"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}, {"dataset_uid": "200290", "doi": "http://hdl.handle.net/1773/46687", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier", "url": "https://doi.org/10.6069/2MZZ-6B61"}], "date_created": "Fri, 13 May 2022 00:00:00 GMT", "description": "Overview: Several recent studies indicate continuing and increasing ice loss from the Amundsen Sea region of West Antarctica (chiefly Pine Island and Thwaites glaciers). This loss is initiated by thinning of the floating ice shelves by basal melting driven by circulation of relatively warm ocean water under the ice shelves. This thinning triggers ice-dynamics related feedbacks, which leads to loss of ice from the grounded ice sheet. Models suggest that, even though long-term committed ice loss might be governed by ice dynamics, the magnitude of ocean-driven melting at the base of the ice shelves plays a critical role in controlling the rate of ice loss. These conclusions, however, are based on simple parameterized models for melt rate that do not take into account how ocean circulation will change in future as large-scale climate forcing changes, and as the ice shelves thin and retreat through both excess melting and accelerated ice flow. Given that present global climate models struggle to resolve the modern ocean state close to the ice shelves around Antarctica, their projections of future impacts on basal melting and time scale of ice loss have large uncertainties.\r\nThis project is aimed at reducing these uncertainties though two approaches: (i) assessing, for a given ocean state, how the melt rates will change as ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of melt rates beneath the Pine Island and Thwaites ice shelves to changes in ocean state on the Amundsen Sea continental shelf. These studies will provide more realistic bounds on ice loss and sea level rise, and lay the groundwork for development of future fully-coupled ice sheet-ocean simulations.\r\nIntellectual Merit: Rather than pursue a strategy of using fully coupled models, this project adopts a simpler semi-coupled approach to understand the sensitivity of ice-shelf melting to future forcing. Specifically, the project focuses on using regional ocean circulation models to understand current and future patterns of melting in ice-shelf cavities. The project\u2019s preliminary stage will focus on developing high-resolution ice-shelf cavity-circulation models driven by modern observed regional ocean state and validated with current patterns of melt inferred from satellite observations. Next, an ice-flow model will be used to estimate the future grounding line at various stages of retreat. Using these results, an iterative process with the ocean-circulation and ice-flow models will be applied to determine melt rates at each stage of grounding line retreat. These results will help assess whether more physically constrained melt-rate estimates substantially alter the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway. Further, by multiple simulations with modified open-ocean boundary conditions, this study will provide a better understanding of the sensitivity of melt to future changes in regional forcing. For example, what is the sensitivity of melt to changes in Circumpolar Deep Water temperature and to changes in the thermocline height driven be changes in wind forcing? Finally, several semi-coupled ice-ocean simulations will be used to investigate the influence of the ocean-circulation driven distribution of melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.\r\nBroader Impacts: Planning within the current large range of uncertainty in future sea level change leads to high social and economic costs for governments and businesses worldwide. Thus, our project to reduce sea-level rise uncertainty has strong societal as well as scientific interest. The findings and methods will be applicable to ice shelf cavities in other parts of Antarctica and northern Greenland, and will set the stage for future studies with fully coupled models as computational resources improve. This interdisciplinary work combines expertise of glaciologists and oceanographers, and will contribute to the education of new researchers in this field, with participation of graduate students and postdocs. Through several outreach activities, team members will help make the public aware of the dramatic changes occurring in Antarctica along with the likely consequences.\r\n\r\nThis proposal does not require fieldwork in the Antarctic.\r\n", "east": -86.0, "geometry": "POINT(-95 -77)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; USA/NSF; ICE SHEETS; AMD; USAP-DC; MODELS; Amd/Us; Pine Island Glacier", "locations": "Pine Island Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica ", "uid": "p0010318", "west": -104.0}, {"awards": "2146791 Lai, Chung Kei Chris", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 06 May 2022 00:00:00 GMT", "description": "Melt from the Greenland and Antarctic ice sheets is increasingly contributing to sea-level rise. This ice sheet mass loss is primarily driven by the thinning, retreat, and acceleration of glaciers in contact with the ocean. Observations from the field and satellites indicate that glaciers are sensitive to changes at the ice-ocean interface and that the increase in submarine melting is likely to be driven by the discharge of meltwater from underneath the glacier known as subglacial meltwater plumes. The melting of glacier ice also directly adds a large volume of freshwater into the ocean, potentially causing significant changes in the circulation of ocean waters that regulate global heat transport, making ice-ocean interactions an important potential factor in climate change and variability. The ability to predict, and hence adequately respond to, climate change and sea-level rise therefore depends on our knowledge of the small-scale processes occurring in the vicinity of subglacial meltwater plumes at the ice-ocean interface. Currently, understanding of the underlying physics is incomplete; for example, different models of glacier-ocean interaction could yield melting rates that vary over a factor of five for the same heat supply from the ocean. It is then very difficult to assess the reliability of predictive models. This project will use comprehensive laboratory experiments to study how the melt rates of glaciers in the vicinity of plumes are affected by the ice roughness, ice geometry, ocean turbulence, and ocean density stratification at the ice-ocean interface. These experiments will then be used to develop new and improved predictive models of ice-sheet melting by the ocean. This project builds bridges between modern experimental fluid mechanics and glaciology with the goal of leading to advances in both fields. \r\n\r\nThis project consists of a comprehensive experimental program designed for studying the melt rates of glacier ice under the combined influences of (1) turbulence occurring near and at the ice-ocean interface, (2) density stratification in the ambient water column, (3) irregularities in the bottom topology of an ice shelf, and (4) differing spatial distributions of multiple meltwater plumes. The objective of the experiments is to obtain high-resolution data of the velocity, density, and temperature near/at the ice-ocean interface, which will then be used to improve understanding of melt processes down to scales of millimeters, and to devise new, more robust numerical models of glacier evolution and sea-level rise. Specially, laser-based, optical techniques in experimental fluid mechanics (particle image velocity and laser-induced fluorescence) will be used to gather the data, and the experiments will be conducted using refractive-index matching techniques to eliminate changes in refractive indices that could otherwise bias the measurements. The experiments will be run inside a climate-controlled cold room to mimic field conditions (ocean temperature from 0-10 degrees C). The project will use 3D-printing to create different casting molds for making ice blocks with different types of roughness. The goal is to investigate how ice melt rate changes as a function of the properties of the plume, the ambient ocean water, and the geometric properties of the ice interface. Based on the experimental findings, this project will develop and test a new integral-plume-model coupled to a regional circulation model (MITgcm) that can be used to predict the effects of glacial melt on ocean circulation and sea-level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Glacier-Ocean Boundary Layer; Alaska; USAP-DC; USA/NSF; ABLATION ZONES/ACCUMULATION ZONES; GLACIERS; AMD; Amd/Us; Antarctica; LABORATORY", "locations": "Antarctica; Alaska", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Lai, Chung; Robel, Alexander", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Revising Models of the Glacier-Ocean Boundary Layer with Novel Laboratory Experiments ", "uid": "p0010317", "west": null}, {"awards": "2045880 Sokol, Eric; 2046260 Salvatore, Mark", "bounds_geometry": "POLYGON((161.88 -77.47,162.075 -77.47,162.27 -77.47,162.465 -77.47,162.66 -77.47,162.855 -77.47,163.05 -77.47,163.245 -77.47,163.44 -77.47,163.635 -77.47,163.83 -77.47,163.83 -77.501,163.83 -77.532,163.83 -77.563,163.83 -77.594,163.83 -77.625,163.83 -77.656,163.83 -77.687,163.83 -77.718,163.83 -77.749,163.83 -77.78,163.635 -77.78,163.44 -77.78,163.245 -77.78,163.05 -77.78,162.855 -77.78,162.66 -77.78,162.465 -77.78,162.27 -77.78,162.075 -77.78,161.88 -77.78,161.88 -77.749,161.88 -77.718,161.88 -77.687,161.88 -77.656,161.88 -77.625,161.88 -77.594,161.88 -77.563,161.88 -77.532,161.88 -77.501,161.88 -77.47))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 21 Apr 2022 00:00:00 GMT", "description": "Part I: Non-technical description: \r\nWater is life and nowhere is it more notable than in deserts. Within the drylands on Earth, the Antarctic deserts, represented in this study by the McMurdo Dry Valleys, exemplify life in extreme environments with scarce water, low temperatures and long periods of darkness during the polar winter. There is a scarcity of methods to determine water availability, data necessary to predict which species are successful in the drylands, unless measurements are done manually or with field instruments. This project aims to develop a remote method of determining soil moisture and use the new data to identify locations suitable for life. Combining these habitats with known species distributions in the McMurdo Dry Valleys, results from this project will predict which species should be present, and also what is the expected species distribution in a changing environment. In this way the project takes advantage of a combination of methods, from recent remote sensing products, ecological models and 30 years of field collections to bring a prediction of how life might change in the McMurdo Dry Valleys in a warmer, and possibly, moister future climate. This project benefits the National Science Foundation goals of expanding fundamental knowledge of Antarctic biota and the processes that sustain life in extreme environments. The knowledge acquired in this project will be disseminated to other drylands through training in high-school curricular programming in Native American communities of the Southwest U.S. \r\nPart II: Technical description: \r\nTerrestrial environments in Antarctica are characterized by low liquid water supply, sub-zero temperatures and the polar night in winter months. During summer, melting of snow patches, seasonal steams from glacial melt and vicinity to lakes provide a variety of environments that maintain life, not yet studied at landscape-scale level for habitat suitability and the processes that drive them. This project proposes to integrate remote sensing, hydrological models and ecological models to establish habitat suitability for species in the McMurdo Dry Valleys based on water availability. The approach is at a landscape level in order to establish present-day and future scenarios of species distribution. There are four main objectives: remote sensing development of moisture levels in soils, combining biological and soil data, building and calibrating models of habitat suitability by combining species distribution and environmental variability and applying statistical species distribution model. The field data needed to develop habitat suitability and calibration of models will leverage a the 30-year dataset collected by the McMurdo Long-Term Ecological Research program. Mechanistic models developed will be essential to predict species distribution in future climate scenarios. Training of post-doctoral researchers and a graduate student will prepare for the next generation of Antarctic scientists. Results from this project will train high-school students from Native American communities in the Southwestern U.S., where similar desert conditions exist.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 163.83, "geometry": "POINT(162.855 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ACTIVE LAYER; Taylor Valley; USAP-DC; Amd/Us; AMD; MODELS; USA/NSF", "locations": "Taylor Valley", "north": -77.47, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Salvatore, Mark; Gooseff, Michael N.; Sokol, Eric; Barrett, John", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -77.78, "title": "Collaborative Research: Moving Beyond the Margins: Modeling Water Availability and Habitable Terrestrial Ecosystems in the Polar Desert of the McMurdo Dry Valleys", "uid": "p0010316", "west": 161.88}, {"awards": "2038145 Bernard, Kim", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 01 Apr 2022 00:00:00 GMT", "description": "Warming at the northern Antarctic Peninsula is causing fundamental changes in the marine ecosystem. Antarctic krill are small shrimp-like animals that are most abundant in that area. They are also an essential part of the marine food web of the waters surrounding Antarctica. Meanwhile, a rapidly growing international fishery has developed for krill. Understanding changes in krill populations is therefore critical both to the management of the fishery and the ability of scientists to predict changes in the Antarctic marine ecosystem. This project will have two broader societal impacts. First, the project will support the training of students for careers in oceanography. The students will be recruited from underrepresented groups in an effort to increase diversity, equity and inclusion in STEM. Second, results from this project will develop improved population models, which are essential for the effective management of the Antarctic krill fishery. In collaboration with US delegates on the Commission for the Conservation of Antarctic Marine Living Resources, the researchers will produce a report outlining the key findings from the study.\r\n\r\nEffective population modeling relies on empirical and theoretical understanding of how environment drives krill reproduction. There are two critical egg development stages in Antarctic krill that impact population growth. They are early egg development, and advanced egg development/spawning. The timing and duration of early egg development determines the number of eggs produced and the number of seasonal spawning events a female can undergo. The research team will use samples of Antarctic krill collected over the last 30 years in late winter/early spring, summer and early fall. The reproductive development stages of individual females in these samples will be assessed. These data will be modeled against climatological and oceanographic data to test three hypotheses. First, they will test if colder winter conditions correspond to early preparation for spawning. Second, they will test if favorable winter-summer conditions increase early spawning. Finally, they will test if favorable winter-summer conditions lengthen the spawning season. The study will advance current understanding of the environmental conditions that promote population increases in Antarctic krill and will fill an important gap in current knowledge of the reproductive development and output of Antarctic krill.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "FISHERIES; AMD; USAP-DC; Antarctic Peninsula; Amd/Us; USA/NSF; PELAGIC; LABORATORY", "locations": "Antarctic Peninsula", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bernard, Kim", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -90.0, "title": "Drivers of Antarctic Krill Reproductive Output", "uid": "p0010312", "west": -180.0}, {"awards": "2148517 Hancock, Cathrine", "bounds_geometry": "POLYGON((-60 -55,-51 -55,-42 -55,-33 -55,-24 -55,-15 -55,-6 -55,3 -55,12 -55,21 -55,30 -55,30 -57,30 -59,30 -61,30 -63,30 -65,30 -67,30 -69,30 -71,30 -73,30 -75,21 -75,12 -75,3 -75,-6 -75,-15 -75,-24 -75,-33 -75,-42 -75,-51 -75,-60 -75,-60 -73,-60 -71,-60 -69,-60 -67,-60 -65,-60 -63,-60 -61,-60 -59,-60 -57,-60 -55))", "dataset_titles": "Under ice trajectories for RAFOS enabled profiling floats in the Weddell Gyre", "datasets": [{"dataset_uid": "601652", "doi": "10.15784/601652", "keywords": "Antarctica; ANTXXIV/3; Argo Float; Artoa4argo; GPS Data; RAFOS; US Argo Program; Weddell Sea", "people": "Hancock, Cathrine", "repository": "USAP-DC", "science_program": null, "title": "Under ice trajectories for RAFOS enabled profiling floats in the Weddell Gyre", "url": "https://www.usap-dc.org/view/dataset/601652"}], "date_created": "Fri, 25 Mar 2022 00:00:00 GMT", "description": "The Weddell Gyre is one of the major components of the Southern Ocean circulation system, linking heat and carbon fluxes in the Antarctic Circumpolar Current to the continental margins. Water masses entering the Weddell Gyre are modified as they move in a great circular route around the gyre margin and change through processes involving air-sea-cryosphere interactions as well as through ocean eddies that mix properties across the gyre boundaries. Some of the denser water masses exit the gyre through pathways along the northern boundary, and ultimately ventilate the global deep ocean as Antarctic Bottom Water. While in-situ and satellite observations, as well as computer modeling efforts, provide estimates of the large-scale average flow within the gyre, details of the smaller-scale, or \"mesoscale\" eddy flow remain elusive. The proposed research will quantify mixing due to mesoscale eddies within the Weddell Gyre, as well as the transport of incoming deep water from the northeast, thought to be a result of transient eddies. Since the Weddell Gyre produces source water for about 40% of Antarctic Bottom Water formation, understanding the dynamics in this region helps to identify causes of documented changes in global bottom waters. This in turn, will give insight into how climate change is affecting global oceans, through modification of dense polar waters and Antarctic Bottom Water characteristics.\r\n\r\nThis project aims to track 153 RAFOS-enabled Argo floats in the ice-covered regions of the Weddell Gyre. The resultant tracks along with all available Argo and earlier float data will be used to calculate Eulerian and Lagrangian means and eddy statistics for the Weddell Gyre. The study will link RAFOS tracks with Argo profiles under ice, allowing one to characterize the importance of eddies in water column modification at critical ice-edge boundaries and leads. With RAFOS tracks near the northeastern limit of the gyre, the project will investigate the eddy-driven processes of incoming Circumpolar Deep Water, to understand better the mechanisms and volume fluxes involved. Previous work shows that a large fraction of the mean circulation in the southern and western limits of the gyre, where it contacts the Antarctic continent, occurs in a narrow boundary layer above the slope. The research here will integrate this flow structure into a complete interior and boundary layer mean circulation synthesis. The findings and products from the proposed work will improve the positioning of Argo profiles in the polar regions, which would allow for more accurate climatological maps and derived quantities. Estimates of meso-scale mixing may serve as a foundation for the development of new parameterization schemes employed in climate models, as well as local and global ocean circulation models in polar regions.", "east": 30.0, "geometry": "POINT(-15 -65)", "instruments": null, "is_usap_dc": true, "keywords": "OCEAN CURRENTS; WATER MASSES; BUOYS; USA/NSF; Weddell Sea; AMD; USAP-DC; Amd/Us", "locations": "Weddell Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Hancock, Cathrine; Speer, Kevin", "platforms": "WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e BUOYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Weddell Gyre Mean Circulation and Eddy Statistics from Floats", "uid": "p0010310", "west": -60.0}, {"awards": "2149500 Chambers, Don", "bounds_geometry": "POLYGON((-180 -30,-144 -30,-108 -30,-72 -30,-36 -30,0 -30,36 -30,72 -30,108 -30,144 -30,180 -30,180 -36,180 -42,180 -48,180 -54,180 -60,180 -66,180 -72,180 -78,180 -84,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84,-180 -78,-180 -72,-180 -66,-180 -60,-180 -54,-180 -48,-180 -42,-180 -36,-180 -30))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Mar 2022 00:00:00 GMT", "description": "The Southern Ocean accounts for ~40% of the total ocean uptake of anthropogenic CO2 despite covering only 20% of the global ocean surface, and is particularly rich in long-lived eddies. These eddies, or large ocean whirlpools which can be observed from space, can alter air-sea fluxes of CO2 in ways that are not yet fully understood. New observations from autonomous platforms measuring ocean carbon content suggest that there is significant heterogeneity in ocean carbon fluxes which can be linked to these dynamic eddy features. Due to computational and time limitations, ocean eddies are not explicitly represented in most climate models, limiting our ability to understand the role eddies play in the ocean carbon cycle. This work will explore the impact of eddies on ocean carbon content and air-sea CO2 fluxes in the Southern Ocean using both model- and observation-based strategies and the findings will improve our understanding of the ocean\u2019s role in the carbon cycle and in global climate. While this work will primarily be focused on the Southern Ocean, the results will be globally applicable. The researchers will also broaden interest in physical and chemical oceanography among middle school-age girls in the University of South Florida\u2019s Oceanography Camp for Girls by augmenting existing lessons with computational methods in oceanography. \r\n\r\nThis project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite SSH data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls (OCG), recognized by NSF as a \u201cModel STEM Program for Women and Girls\u201d focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography.\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Southern Ocean; PH; BIOGEOCHEMICAL CYCLES; AMD; OCEAN CHEMISTRY; OCEAN MIXED LAYER; USA/NSF; NITROGEN; OCEAN CURRENTS; SALINITY/DENSITY; USAP-DC; OCEAN TEMPERATURE; MODELS; CHLOROPHYLL; DISSOLVED GASES; NUTRIENTS", "locations": "Southern Ocean", "north": -30.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Williams, Nancy; Chambers, Don; Tamsitt, Veronica", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Diagnosing the Role of Ocean Eddies in Carbon Cycling from a High-resolution Data Assimilating Ocean Biogeochemical Model", "uid": "p0010309", "west": -180.0}, {"awards": "1823135 Bromwich, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "YOPP-SH Analysis and Forecast Results. ", "datasets": [{"dataset_uid": "200287", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "YOPP-SH Analysis and Forecast Results. ", "url": "http://polarmet.osu.edu/YOPP-SH/"}], "date_created": "Mon, 14 Mar 2022 00:00:00 GMT", "description": "This research will take advantage of the greater number of Antarctic weather observations collected as part of the World Meteorological Organization\u0027s \"Year of Polar Prediction\". Researchers will use these additional observations to study new ways of incorporating data into existing weather prediction models. The primary goal of this research is to improve the accuracy of weather forecasts in Antarctica. This work is important, as the harsh weather in Antarctica greatly impacts scientific research and the support of this research. Being able to accurately predict changing weather increases the safety and efficiency of Antarctic field science and operations. \r\nThe proposed effort seeks to advance goals of the World Meteorological Organization\u0027s Polar Prediction Project and its Year of Polar Prediction-Southern Hemisphere (YOPP-SH) effort. Researchers will investigate and demonstrate the forecast impact of enhanced atmospheric observations obtained from YOPP-SH\u0027s Special Observing Period on polar numerical weather prediction. This will be done by using the Antarctic Mesoscale Prediction System (AMPS). AMPS is the primary numerical weather prediction capability for the United States Antarctic Program (USAP). Modeling experimentation will assess the impact of Special Observing Period data on Antarctic forecasts and will serve as a vehicle for testing new data assimilation approaches for AMPS. The primary goal for this work is improved forecasting and numerical weather prediction tools. Outcomes will include quantification of the value of enhanced southern hemisphere atmospheric observations. This work will also help improve AMPS and its ability to support the USAP.\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "VERTICAL PROFILES; Antarctica; USA/NSF; WATER VAPOR PROFILES; USAP-DC; AMD; Amd/Us; COMPUTERS; WIND PROFILES", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bromwich, David; Powers, Jordan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -90.0, "title": "Application of Year of Polar Prediction- Southern Hemisphere (YOPP-SH) Observations for Improvement of Antarctic Numerical Weather Prediction", "uid": "p0010308", "west": -180.0}, {"awards": "2149501 Mazloff, Matthew", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 04 Mar 2022 00:00:00 GMT", "description": "This project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite SSH data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls (OCG), recognized by NSF as a \u201cModel STEM Program for Women and Girls\u201d focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; AMD; USA/NSF; USAP-DC; MODELS; BIOGEOCHEMICAL CYCLES; Amd/Us", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Mazloff, Matthew", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Diagnosing the role of ocean eddies in carbon cycling from a high- resolution data assimilating ocean biogeochemical model", "uid": "p0010304", "west": -180.0}, {"awards": "0944150 Hall, Brenda", "bounds_geometry": "POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Royal Society Range Headland Moraine Belt Radiocarbon Data; Salmon Valley Radiocarbon Data", "datasets": [{"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}, {"dataset_uid": "601555", "doi": "10.15784/601555", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Royal Society Range Headland Moraine Belt Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601555"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}, {"dataset_uid": "601556", "doi": "10.15784/601556", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Salmon Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601556"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth\u0027s climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. ", "east": 164.6, "geometry": "POINT(164.1 -77.85)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Amd/Us; AMD; USA/NSF; GLACIAL LANDFORMS; USAP-DC; Royal Society Range; GLACIER ELEVATION/ICE SHEET ELEVATION", "locations": "Royal Society Range", "north": -77.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.2, "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "uid": "p0010302", "west": 163.6}, {"awards": "1643534 Cassar, Nicolas", "bounds_geometry": "POLYGON((-83 -62,-80.3 -62,-77.6 -62,-74.9 -62,-72.2 -62,-69.5 -62,-66.8 -62,-64.1 -62,-61.4 -62,-58.7 -62,-56 -62,-56 -63.1,-56 -64.2,-56 -65.3,-56 -66.4,-56 -67.5,-56 -68.6,-56 -69.7,-56 -70.8,-56 -71.9,-56 -73,-58.7 -73,-61.4 -73,-64.1 -73,-66.8 -73,-69.5 -73,-72.2 -73,-74.9 -73,-77.6 -73,-80.3 -73,-83 -73,-83 -71.9,-83 -70.8,-83 -69.7,-83 -68.6,-83 -67.5,-83 -66.4,-83 -65.3,-83 -64.2,-83 -63.1,-83 -62))", "dataset_titles": "Palmer LTER 18S rRNA gene metabarcodin; rDNA amplicon sequencing of WAP microbial community", "datasets": [{"dataset_uid": "200285", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Palmer LTER 18S rRNA gene metabarcodin", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA508517"}, {"dataset_uid": "200286", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "rDNA amplicon sequencing of WAP microbial community", "url": "https://www.ncbi.nlm.nih.gov/sra/SRR6162326/"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This project seeks to make detailed measurements of the oxygen content of the surface ocean along the Western Antarctic Peninsula. Detailed maps of changes in net oxygen content will be combined with measurements of the surface water chemistry and phytoplankton distributions. The project will determine the extent to which on-shore or offshore phytoplankton blooms along the peninsula are likely to lead to different amounts of carbon being exported to the deeper ocean. \r\n\r\nThe project will analyze oxygen in relation to argon that will allow determination of the physical and biological contributions to surface ocean oxygen dynamics. These assessments will be combined with spatial and temporal distributions of nutrients (iron and macronutrients) and irradiances. This will allow the investigators to unravel the complex interplay between ice dynamics, iron and physical mixing dynamics as they relate to Net Community Production (NCP) in the region. NCP measurements will be normalized to Particulate Organic Carbon (POC) and be used to help identify area of \"High Biomass and Low NCP\" and those with \"Low Biomass and High NCP\" as a function of microbial plankton community composition. The team will use machine learning methods- including decision tree assemblages and genetic programming- to identify plankton groups key to facilitating biological carbon fluxes. Decomposing the oxygen signal along the West Antarctic Peninsula will also help elucidate biotic and abiotic drivers of the O2 saturation to further contextualize the growing inventory of oxygen measurements (e.g. by Argo floats) throughout the global oceans.", "east": -56.0, "geometry": "POINT(-69.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; USAP-DC; BIOGEOCHEMICAL CYCLES; AMD; USA/NSF; LABORATORY; Amd/Us", "locations": "West Antarctica", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cassar, Nicolas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NCBI", "repositories": "NCBI", "science_programs": null, "south": -73.0, "title": "Biological and Physical Drivers of Oxygen Saturation and Net Community Production Variability along the Western Antarctic Peninsula", "uid": "p0010303", "west": -83.0}, {"awards": "1643248 Hall, Brenda", "bounds_geometry": "POLYGON((163.3 -77.8,163.43 -77.8,163.56 -77.8,163.69 -77.8,163.82 -77.8,163.95 -77.8,164.08 -77.8,164.21 -77.8,164.34 -77.8,164.47 -77.8,164.6 -77.8,164.6 -77.85,164.6 -77.9,164.6 -77.95,164.6 -78,164.6 -78.05,164.6 -78.1,164.6 -78.15,164.6 -78.2,164.6 -78.25,164.6 -78.3,164.47 -78.3,164.34 -78.3,164.21 -78.3,164.08 -78.3,163.95 -78.3,163.82 -78.3,163.69 -78.3,163.56 -78.3,163.43 -78.3,163.3 -78.3,163.3 -78.25,163.3 -78.2,163.3 -78.15,163.3 -78.1,163.3 -78.05,163.3 -78,163.3 -77.95,163.3 -77.9,163.3 -77.85,163.3 -77.8))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Pyramid Trough Radiocarbon Data; Walcott Glacier area radiocarbon data; Walcott Glacier Exposure Data", "datasets": [{"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}, {"dataset_uid": "601614", "doi": "10.15784/601614", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pyramid Trough; Radiocarbon; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Pyramid Trough Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601614"}, {"dataset_uid": "601615", "doi": "10.15784/601615", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Howchin Glacier; Radiocarbon; Radiocarbon Dates; Ross Sea Drift; Royal Society Range; Walcott Glacier", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Walcott Glacier area radiocarbon data", "url": "https://www.usap-dc.org/view/dataset/601615"}, {"dataset_uid": "601616", "doi": "10.15784/601616", "keywords": "Antarctica; Beryllium-10; Exposure Age; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; McMurdo Sound; Royal Society Range; Walcott Glacier", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Walcott Glacier Exposure Data", "url": "https://www.usap-dc.org/view/dataset/601616"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "The Antarctic Ice Sheet is the greatest potential contributor to sea-level change. However, the future response of the ice sheet to warming climate is recognized as one of the greatest uncertainties in sea-level projections. An understanding of past ice fluctuations can afford insight into ice-sheet response to climate change and thus is critical for improving sea-level predictions. In this project, we will reconstruct the behavior of the Antarctic Ice Sheet in the western Ross Sea region during the great global warming that ended the last ice age. Fluctuations in ice volume during this time period will allow us to characterize the factors that cause the ice sheet to advance and retreat and will enable us to distinguish between models that suggest repeated episodes of ice-sheet collapse vs those that indicate ice-sheet growth during warming climate. An understanding of the cause(s) of changes in ice volume during the warming that ended the last ice age has important implications for the future of the Antarctic Ice Sheet. ", "east": 164.6, "geometry": "POINT(163.95 -78.05)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER ELEVATION/ICE SHEET ELEVATION; Royal Society Range; USA/NSF; USAP-DC; Amd/Us; AMD; LABORATORY; GLACIAL LANDFORMS", "locations": "Royal Society Range", "north": -77.8, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "Response of the Antarctic Ice Sheet to the last great global warming", "uid": "p0010301", "west": 163.3}, {"awards": "0342484 Harwood, David", "bounds_geometry": "POINT(167.083333 -77.888889)", "dataset_titles": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601451", "doi": "10.15784/601451", "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; McMurdo Sound; Miocene; Paleoclimate; Particle Size", "people": "Passchier, Sandra; Candice, Falk", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601451"}], "date_created": "Fri, 04 Feb 2022 00:00:00 GMT", "description": "ANDRILL is a scientific drilling program to investigate Antarctica\u0027s role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica\u0027s climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth\u0027s ocean-climate system. \u003cbr/\u003e\u003cbr/\u003eThis award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica\u0027s major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.\u003cbr/\u003e\u003cbr/\u003eThe South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area\u0027s complex tectonic history.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society\u0027s understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. \u003cbr/\u003e\u003cbr/\u003eAs key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica\u0027s ice sheets are important to society\u0027s understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth\u0027s climatic future.", "east": 167.083333, "geometry": "POINT(167.083333 -77.888889)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; FIELD SURVEYS; ICE SHEETS; USA/NSF; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; Ross Ice Shelf; SEDIMENTS", "locations": "Ross Ice Shelf", "north": -77.888889, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harwood, David; Levy, Richard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.888889, "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "uid": "p0010297", "west": 167.083333}, {"awards": "1744835 Wagner, Till; 1744800 Adcroft, Alistair", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Model of iceberg drift and decay including breakup", "datasets": [{"dataset_uid": "601510", "doi": "10.15784/601510", "keywords": "Antarctica; Footloose Mechanism; Iceberg Breakup; Iceberg Decay; Model; Southern Ocean", "people": "Wagner, Till; England, Mark", "repository": "USAP-DC", "science_program": null, "title": "Model of iceberg drift and decay including breakup", "url": "https://www.usap-dc.org/view/dataset/601510"}], "date_created": "Tue, 18 Jan 2022 00:00:00 GMT", "description": "Nearly half of the freshwater flux from the Antarctic Ice Sheet into the Southern Ocean occurs in the form of large tabular icebergs that calve off the continent\u2019s ice shelves. However, because of difficulties in adequately simulating their breakup, large Antarctic icebergs to date have either not been represented in models or represented but with no breakup scheme such that they consistently survive too long and travel too far compared with observations. Here, we introduce a representation of iceberg fracturing using a breakup scheme based on the \u201cfootloose mechanism.\u201d We optimize the parameters of this breakup scheme by forcing the iceberg model with an ocean state estimate and comparing the modeled iceberg trajectories and areas with the Antarctic Iceberg Tracking Database. We show that including large icebergs and a representation of their breakup substantially affects the iceberg meltwater distribution, with implications for the circulation and stratification of the Southern Ocean.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; ICEBERGS; USA/NSF; Southern Ocean; AMD; USAP-DC; COMPUTERS", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Wagner, Till; Eisenman, Ian", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Modeling Giant Icebergs and Their Decay", "uid": "p0010290", "west": -180.0}, {"awards": "2031554 Chartier, Alex; 2032421 Kim, Hyomin", "bounds_geometry": "POLYGON((-180 -75,-144 -75,-108 -75,-72 -75,-36 -75,0 -75,36 -75,72 -75,108 -75,144 -75,180 -75,180 -76.5,180 -78,180 -79.5,180 -81,180 -82.5,180 -84,180 -85.5,180 -87,180 -88.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88.5,-180 -87,-180 -85.5,-180 -84,-180 -82.5,-180 -81,-180 -79.5,-180 -78,-180 -76.5,-180 -75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 31 Dec 2021 00:00:00 GMT", "description": "The deep polar cap is unique in that it contains \"open\" magnetic field lines connecting directly to the interplanetary magnetic field (IMF). These provide a direct pathway for solar wind energy into the ionosphere and upper atmosphere. Important on large scales is the spatial extent of the polar cap, controlled by ionospheric convection and demarcated by the OCB. Observations of that boundary serve the important role of validating magnetic field models. In addition, ULF waves in the polar cap may be related to direct penetration of solar wind. Ionospheric density enhancement, tongue of ionization (TOI), and irregularities causing RF signal scintillations in the polar cap are very important and yet underexplored areas of studies. Motivated by the compelling science in the underexplored polar region, we propose to investigate M-I coupling processes, ionospheric irregularities inside the polar cap and their space weather impacts by establishing a new ground-based network that will be deployed in the Antarctic polar cap region. The goal of this investigation is to establish a spatially extensive ground-based observational record of coupled Magnetosphere-Ionosphere (M-I) dynamics in the deep polar cap. This is to be achieved using three new Autonomous Geophysical Observatories (AGOs) along the Jang Bogo \u2013 Dome C supply route (deployment and maintenance paid for by Korea Polar Research Institute \u2013 KOPRI). ", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USA/NSF; Jang Bogo Station; Jang Bogo Station And A Traverse Route On The Antarctic Plateau; USAP-DC; FIELD SURVEYS; MAGNETIC FIELDS/MAGNETIC CURRENTS; AURORAE; AMD", "locations": "Jang Bogo Station And A Traverse Route On The Antarctic Plateau; Jang Bogo Station", "north": -75.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Kim, Hyomin; Perry, Gareth; Chartier, Alex", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Investigation of Deep Polar Cap Dynamics Using an Autonomous Instrument Network", "uid": "p0010288", "west": -180.0}, {"awards": "2037561 Jenouvrier, Stephanie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Code for \u015een et al. 2023; Detecting climate signals in populations: case of emperor penguin", "datasets": [{"dataset_uid": "200373", "doi": "https://doi.org/10.5281/zenodo.7803266", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Code for \u015een et al. 2023", "url": "https://zenodo.org/record/7803266"}, {"dataset_uid": "601491", "doi": "10.15784/601491", "keywords": "Antarctica", "people": "Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "Detecting climate signals in populations: case of emperor penguin", "url": "https://www.usap-dc.org/view/dataset/601491"}], "date_created": "Wed, 08 Dec 2021 00:00:00 GMT", "description": "Overview: We aim to provide the most detailed investigation to date of the factors that influence predictability of Antarctic climate, the coupling of climate to penguins populations, and the integration of the two to optimize ecological forecasts. This integrated understanding is critical for guiding future ecological and climate research, prioritizing bio-physical monitoring efforts, and informing conservation decision-making. Our study will reveal the influence of climate system dynamics on ecological predictability across a range of scales and will examine how this role differs among ecological processes, species and regions of Antarctica. \r\n\r\nIntellectual Merit: Many biophysical processes will change in the coming century. Yet, the mechanisms controlling the predictability of many climate processes are still poorly understood, limiting progress in climate forecasting. In parallel, ecological forecasting remains a nascent discipline. In particular, comparative assessments of predictability, both within and among species, are critically needed to understand the factors that allow (or prevent) useful ecological forecasts. While important for ecological science generally, this need is particularly pressing in Antarctica where the environment is highly dynamic, strongly coupled to biological processes, and likely to change in the future. Improved ecological forecasting therefore requires interdisciplinary efforts to understand the causes of predictability in climate, and in tandem, how climate influences the predictability of natural populations.\r\nThis proposed research will examine the predictability of Antarctic climate and its influence on penguin demographic response predictability at various temporal and spatial scales using the longest datasets available for two penguin species. Specifically, the PI will 1) identify the physical mechanisms giving rise to climate predictability in Antarctica, 2) identify the relationships between climate and ecological processes at a range of scales, and 3) reveal the factors controlling ecological predictability across a range of scales (e.g., those relevant for short-term adaptive management versus those relevant at end-of-century timescales). These objectives will be achieved using the analysis of existing climate data and Atmosphere-Ocean Global Circulation Models (AGOCMs), with coupled analysis of existing long-term demographic data for multiple seabird species that span a range of ecological niches, life histories, and study sites across the continent.\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ECOLOGICAL DYNAMICS; PENGUINS; Amd/Us; Antarctica; USA/NSF; SEA ICE; NOT APPLICABLE; USAP-DC; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jenouvrier, Stephanie; Holland, Marika", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "Zenodo", "repositories": "USAP-DC; Zenodo", "science_programs": null, "south": -90.0, "title": "Integrating Antarctic Environmental and Biological Predictability to Obtain Optimal Forecasts", "uid": "p0010282", "west": -180.0}, {"awards": "1951500 Jenouvrier, Stephanie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "The impact of boldness on demographic rates and lifehistory outcomes in the wandering albatross", "datasets": [{"dataset_uid": "601770", "doi": "10.15784/601770", "keywords": "Antarctica; Cryosphere; Demography; Sub-Antarctic", "people": "Joanie, Van de Walle; Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "The impact of boldness on demographic rates and lifehistory outcomes in the wandering albatross", "url": "https://www.usap-dc.org/view/dataset/601770"}], "date_created": "Wed, 08 Dec 2021 00:00:00 GMT", "description": "Overview: To date, studies that have addressed the impacts of global changes have mainly focused on linking climate variability and/or human disturbances to individual life history traits, population dynamics or distribution. However, individual behavior and plasticity mediate these responses. The goal of this project is to understand mechanisms linking environmental changes (climate \u0026 fisheries)- behavioral personality type \u2013 plasticity in foraging behaviors- life history traits \u2013 population dynamics for a seabird breeding in the southern ocean: the wandering albatross. This project will also forecast the population structure and growth rate using the most detailed mechanistic model to date for any wild species incorporating behaviors in an eco-evolutionary context. Specifically, the investigators will (1) characterize the life history strategies along the shy-bold continuum of personalities and across environmental conditions; (2) understand the link between phenotypic plasticity in foraging effort and personality; (3) characterize the heritability of personality and foraging behaviors; (4) develop a stochastic eco-evolutionary model to understand and forecast the distribution of bold and shy individuals within the population and the resulting effect on population growth rate in a changing environment by integrating processes from goals 1, 2 and 3. To date, this has been hampered by the lack of long-term data on personality and life histories in any long-lived species in the wild. For the first time ever, we have tested in a controlled environment the response to a novel situation for ~1800 individuals for more than a decade to define individual personality variation along the shy-bold continuum that we can relate to the life history traits over the entire species life cycle using unique long-term individual mark-recapture data sets for this iconic polar species. The novelty of this project thus lies in the combination of personality, foraging and demographic data to understand and forecast population responses to global change using state-of-the-art statistical analysis and eco-evolutionary modeling approaches. \r\nIntellectual Merit: While there is ubiquitous evidence of personality differences across taxa, the implications for life-history are less clear, and the consequences for population dynamics virtually unexplored empirically. How the phenotypic distributions of personality and foraging behaviors types within a population is created and maintained by ecological (demographic and phenotypic plasticity) and evolutionary (heritability) processes remain an open question. Personality traits are a crucial link between how individuals acquire resources, and how they allocate these to reproduction and survival, and this trade-off drives population dynamics. However, although some studies have found different foraging behaviors or breeding performances between personality types, none have established the link between personality- foraging behaviors \u2013 life histories (both reproduction and survival, and their covariations) in the context of climate change. Furthermore plasticity in foraging behaviors is not considered in the pace-of-life syndrome, which has potentially hampered our ability to find covariation between personality and life history trade-off. Research into the heritability of personality traits has revealed a strong heritable component, but studies looking at the heritability of foraging behaviors are lacking. For the first time ever, this project will fill these knowledge gaps and integrate in an eco-evolutionary model the complex interaction among individual personality and foraging plasticity, heritability of personality and foraging behaviors, life history strategies, population dynamics in a changing environment (fisheries and climate). Furthermore, this project will provide for the first time projections of population size and structure under future global change using state-of-the-art climate projections from IPCC-class atmospheric-oceanic global circulation models.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE; AMD; ECOLOGICAL DYNAMICS; OCEAN TEMPERATURE; USA/NSF; Antarctica; SPECIES/POPULATION INTERACTIONS; PENGUINS; Amd/Us", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jenouvrier, Stephanie; Patrick, Samantha", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "NSFGEO-NERC: Integrating Individual Personality Differences in the Evolutionary Ecology of a Seabird in the Rapidly Changing Polar Environment", "uid": "p0010283", "west": -180.0}, {"awards": "1644094 Caffee, Marc; 1644128 Welten, Kees", "bounds_geometry": "POINT(-112.12 -79.48)", "dataset_titles": "WAIS Divide Core 10Be data, 2850-3240 m", "datasets": [{"dataset_uid": "601692", "doi": "10.15784/601692", "keywords": "10Be; Antarctica; Beryllium; Cosmogenic Radionuclides; Ice Core Data; WAIS Divide", "people": "Caffee, Marc; Welten, Kees; Woodruff, Thomas", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Core 10Be data, 2850-3240 m", "url": "https://www.usap-dc.org/view/dataset/601692"}], "date_created": "Mon, 15 Nov 2021 00:00:00 GMT", "description": "The award supports a project to use existing samples from the West Antarctic Ice Sheet (WAIS) Divide ice core to align its timescale with that of the Greenland ice cores using common chronological markers. The upper 2850 m of the WAIS Divide core, which was drilled to a depth of 3405 m, has been dated with high precision. The timescale of the remaining (bottom) 550 m of the core has larger uncertainties, limiting our understanding of the timing of abrupt climate events in Antarctica relative to those in Greenland during the last ice age. The intellectual merit of this project is to further constrain the relative timing of these abrupt climate events in Greenland and Antarctica to obtain crucial insight into the underlying mechanism. The main objective of this project is to improve the current timescale of the WAIS Divide core from 31,000 to 65,000 years ago by synchronizing this core with the Greenland ice cores using common signals in Beryllium-10, a radioactive isotope of Be that is produced in the atmosphere by cosmic rays and is deposited onto the snow within 1-2 years of its production. The 10Be flux is largely independent of climate signals since its production varies with solar activity and the geomagnetic field. This project will further strengthen collaborations between the PI\u2019s in Berkeley and Purdue with ice core researchers in the US and Europe, involve undergraduate students in many aspects of its research, and continue out-reach to under-represented students.\r\n\r\nThe direct ice-to-ice synchronization of the WAIS Divide ice core with the Greenland Ice Core Chronology (GICC05) using cosmogenic 10Be is expected to reduce the uncertainty in the relative timing of more than 20 abrupt climate events in Greenland and Antarctica to a few decades. To achieve this goal we will obtain a continuous high-resolution record of 10Be in the WAIS Divide core from 2850 to 3390 m depth, and compare the obtained 10Be record with existing 10Be records of the Greenland ice cores, including GISP2 and NGRIP. We will separate 10Be from ~1000 ice samples of the WAIS Divide core and measure the 10Be concentration in each sample using accelerator mass spectrometry (AMS). Broader impacts of the 10Be measurements are that they will also provide information on the Laschamp event, a ~2000 year long period of low geomagnetic field strength around 41,000 years ago, and improve the calibration of the 14C dating method for organic samples older than 30,000 years. The broader impacts of the project include (1) the involvement and training of undergraduate students in ice core research and accelerator mass spectrometry measurements, (2) the incorporation of ice core and climate research into ongoing outreach programs at Purdue University and Berkeley SSL, (3) better understanding of abrupt climate changes in the past will improve our ability to predict future climate change, (4) evaluating the possible threat of a future geomagnetic excursion in the next few hundred years. This award does not require support in Antarctica.\r\n", "east": -112.12, "geometry": "POINT(-112.12 -79.48)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; LABORATORY; Amd/Us; WAIS Divide; AMD; USAP-DC; DEPTH AT SPECIFIC AGES", "locations": "WAIS Divide", "north": -79.48, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Welten, Kees; Caffee, Marc", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.48, "title": "Synchronizing the WAIS Divide and Greenland Ice Cores from 30-65 ka BP using high-resolution 10Be measurements", "uid": "p0010280", "west": -112.12}, {"awards": "1643394 Buizert, Christo", "bounds_geometry": "POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65))", "dataset_titles": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "200257", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/34133"}, {"dataset_uid": "200256", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/24530"}, {"dataset_uid": "200255", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/32632"}], "date_created": "Wed, 10 Nov 2021 00:00:00 GMT", "description": "This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles.\r\n\r\nThe project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ISOTOPES; Antarctica; USA/NSF; AMD; ICE CORE RECORDS; USAP-DC; VOLCANIC DEPOSITS; MODELS; Amd/Us", "locations": "Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Buizert, Christo; Wettstein, Justin", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw in Antarctica from Synchronized Ice Cores", "uid": "p0010279", "west": -180.0}, {"awards": "2138556 Halberstadt, Anna Ruth", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 09 Nov 2021 00:00:00 GMT", "description": "This project combines numerical simulations and geologic data to explore fundamental knowledge gaps regarding the interpretation and use of marine and terrestrial datasets. This work will produce an ensemble of continent-wide coupled ice sheet and glacial isostatic adjustment simulations, constrained with comprehensive existing geologic data, to reproduce a history of deglacial Antarctic Ice Sheet evolution that is compatible with the geologic record as well as glaciologically and gravitationally self-consistent. Comparison between simulations and data is improved through high-resolution nested ice sheet modeling techniques, which provide unprecedented context for exposure age data generally located in regions of complex topography. Numerical simulations will be performed with systematically varied parameters and boundary conditions, and can thus support an investigation of (1) chronological mismatches between terrestrial thinning and marine ice sheet retreat during the mid-Holocene, and (2) how marine grounding-line dynamics are propagated upstream to coastal outlet glaciers and further interior under a variety of different scenarios.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; GLACIERS/ICE SHEETS; USAP-DC; USA/NSF; MODELS; AMD; Amd/Us", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Halberstadt, Anna Ruth", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "OPP-PRF: High-resolution Nested Antarctic Ice Sheet Modeling to Reconcile Marine and Terrestrial Geologic Data", "uid": "p0010278", "west": -180.0}, {"awards": "2136940 Newman, Dava; 2136938 Tedesco, Marco; 2136939 Cervone, Guido", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 08 Nov 2021 00:00:00 GMT", "description": "Surface melting and the evolution of the surface hydrological system on Antarctica ice shelves modulate the ice sheet mass balance. Despite its importance, limitations still exist that preclude the scientific community from mapping the spatio-temporal evolution of the surface hydrological system at the required resolutions to make the necessary leap forward to address the current and future evolution of ice shelves in Antarctica (Kingslake et al., 2019). Differently from Greenland, surface melting in Antarctica does not exhibit a dependency from elevation, with most of it occurring over ice shelves, at the sea level and where little elevation gradients exist. Therefore, statistical downscaling techniques using digital elevation models - as in the case of Greenland or other mountain regions - cannot be used. Machine learning (ML) tools can help in this regard. In this project, we address this issue and propose a novel method to map the spatio-temporal evolution of surface meltwater in Antarctica on a daily basis at high spatial (30 - 100 m) resolution using a combination of remote sensing, numerical modeling and machine learning. The final product of this project will consist of daily maps of surface meltwater at resolutions of the order of 100 m for the period 2000 - 2021 that will satisfy the following constraints: a) to be physically consistent with the model prediction and with the underlying governing dynamics for the melt processes; b) to capture the temporal dynamics of the model predictions, which include the temporal sequence of a set of past time steps which lead to the target prediction time, but could also include model predictions valid for a set of future time steps; c) to reconcile the higher spatial resolution of the input satellite measurements with the lower spatial resolution of the numerical model; d) to be consistent with previously generated surface melt products, so that temporal time series can be analyzed; e) to provide a measure of uncertainty to help with testing and validation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; Amd/Us; AMD; USA/NSF; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; USAP-DC; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Polar Cyberinfrastructure; Polar Cyberinfrastructure", "paleo_time": null, "persons": "Tedesco, Marco", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: EAGER: Generation of high resolution surface melting maps over Antarctica using regional climate models, remote sensing and machine learning", "uid": "p0010277", "west": -180.0}, {"awards": "2139051 Guitard, Michelle", "bounds_geometry": "POLYGON((-45 -57,-44.3 -57,-43.6 -57,-42.9 -57,-42.2 -57,-41.5 -57,-40.8 -57,-40.1 -57,-39.4 -57,-38.7 -57,-38 -57,-38 -57.5,-38 -58,-38 -58.5,-38 -59,-38 -59.5,-38 -60,-38 -60.5,-38 -61,-38 -61.5,-38 -62,-38.7 -62,-39.4 -62,-40.1 -62,-40.8 -62,-41.5 -62,-42.2 -62,-42.9 -62,-43.6 -62,-44.3 -62,-45 -62,-45 -61.5,-45 -61,-45 -60.5,-45 -60,-45 -59.5,-45 -59,-45 -58.5,-45 -58,-45 -57.5,-45 -57))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "The Mid-Pleistocene Transition (MPT; ~1.25\u20130.7 Ma) marks the shift from glacial-interglacial cycles paced by obliquity (~41 kyr cycles) to those paced by eccentricity (~100-kyr cycles). This transition occurred despite little variation in Earth\u2019s orbital parameters, suggesting a role for internal climate feedbacks. The MPT was accompanied by decreasing atmospheric pCO2, increasing deep ocean carbon storage, and changes in deep water formation and distribution, all of which are linked to Antarctic margin atmosphere-ice-ocean interactions. However, Pleistocene records that document such interactions are rarely preserved on the shelf due to repeated Antarctic Ice Sheet (AIS) advance; instead, they are preserved in deep Southern Ocean basins. This project takes advantage of the excellent preservation and recovery of continuous Pleistocene sediment sequences collected from the Scotia Sea during International Ocean Discovery Program Expedition 382 to test the following hypotheses: 1) Southern Ocean upper ocean temperatures vary on orbital timescales during the early to middle Pleistocene (2.6\u20130.7 Ma), and 2) Southern Ocean temperatures co-vary with AIS advance/retreat cycles. Paleotemperatures will be reconstructed using the TetraEther indeX of tetraethers containing 86 carbons (TEX86), a proxy that utilizes marine archaeal biomarkers. The Scotia Sea TEX86-based paleotemperature record will be compared to records of AIS variability, including ice rafted debris. Expedition 382 records will be compared to orbitally paced climatic time series and the benthic oxygen isotope record of global ice volume and bottom water temperature to determine if a correlation exists between upper ocean temperature, AIS retreat/advance, and orbital climate forcing. ", "east": -38.0, "geometry": "POINT(-41.5 -59.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; SEA SURFACE TEMPERATURE; USAP-DC; USA/NSF; LABORATORY; AMD; Scotia Sea", "locations": "Scotia Sea", "north": -57.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Michelle, Guitard", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -62.0, "title": "Investigating the influence of ocean temperature on Antarctic Ice Sheet evolution during the early to middle Pleistocene ", "uid": "p0010275", "west": -45.0}, {"awards": "1936530 Carbotte, Suzanne; 2230824 Nitsche, Frank", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Samples and data obtained by researchers working in Antarctica are valuable, unique assets which typically require a substantial and expensive logistical effort to acquire. Preservation of these data increases the return on the significant public investment for acquisition, enabling future re-use for new analyses, and ensure that data behind scientific publications are available for others to review. The US Antarctic Program Data Center (USAP-DC) will provide an open-disciplinary hybrid repository for project metadata and the diverse research data obtained from the Antarctic region by NSF funded researchers for which other data repositories do not exist. In addition, a Project Catalog will provide a single online resource for the US Antarctic scientific community to manage information about their research activities and will link project metadata to the various distributed repositories where Antarctic data resides. In doing so, the USAP-DC will follow community best practices and standards to ensure data are citable, shareable, and discoverable. It will also facilitate registration of data descriptions into the Antarctic Master Directory to meet US goals for data sharing under the International Antarctic Treaty.\r\n\r\nWith full open access to interfaces to search for and download data, USAP-DC will make a wide range of data products resulting from NSF funded research in Antarctica available not only to the research community but also to the broader public. The data center is operated using community standards for metadata and data access which helps ensure data re-usability into the future. The new Project catalog, which is designed to support consolidation of information on research products of USAP awards over the lifetime of a project, will make it simpler for NSF program managers, but also for individual researchers and especially larger collaborative research groups to keep track of datasets and related information produced as part of their projects. Through tutorials and meetings at conferences USAP-DC will contribute to raise awareness and inform the research community, especially new investigators about data management best practices.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; Antarctica; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; GLACIERS/ICE SHEETS; COMPUTERS; ICE CORE RECORDS; SNOW/ICE; Database; ECOLOGICAL DYNAMICS; USAP-DC; OCEAN CHEMISTRY; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Polar Cyberinfrastructure", "paleo_time": null, "persons": "Carbotte, Suzanne; Tinto, Kirsty; Nitsche, Frank O.", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Supporting Antarctic Research with Ongoing Operations and Development of the USAP-DC Project Catalog and Data Repository", "uid": "p0010274", "west": -180.0}, {"awards": "2139002 Huth, Alexander", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Simulations of ice-shelf rifting on Larsen C Ice Shelf", "datasets": [{"dataset_uid": "601718", "doi": "10.15784/601718", "keywords": "Antarctica; Glaciology; Iceberg; Ice Shelf Dynamics; Larsen C Ice Shelf; Model Data; Modeling", "people": "Huth, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Simulations of ice-shelf rifting on Larsen C Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601718"}], "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models.\r\n\r\nIn this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; ICEBERGS; AMD; Antarctic Ice Sheet; USA/NSF; GLACIERS/ICE SHEETS; Amd/Us; MODELS", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Huth, Alex", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "OPP-PRF Calving, Icebergs, and Climate", "uid": "p0010276", "west": -180.0}, {"awards": "1745015 Zimmerer, Matthew; 1744949 Campbell, Seth; 1744927 Mitrovica, Jerry", "bounds_geometry": "POLYGON((-145 -74,-141.6 -74,-138.2 -74,-134.8 -74,-131.4 -74,-128 -74,-124.6 -74,-121.2 -74,-117.8 -74,-114.4 -74,-111 -74,-111 -74.6,-111 -75.2,-111 -75.8,-111 -76.4,-111 -77,-111 -77.6,-111 -78.2,-111 -78.8,-111 -79.4,-111 -80,-114.4 -80,-117.8 -80,-121.2 -80,-124.6 -80,-128 -80,-131.4 -80,-134.8 -80,-138.2 -80,-141.6 -80,-145 -80,-145 -79.4,-145 -78.8,-145 -78.2,-145 -77.6,-145 -77,-145 -76.4,-145 -75.8,-145 -75.2,-145 -74.6,-145 -74))", "dataset_titles": "Mt. Waesche ground-penetrating radar data 2018-2019", "datasets": [{"dataset_uid": "601490", "doi": "10.15784/601490", "keywords": "Antarctica; GPR; Mt. Waesche", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": null, "title": "Mt. Waesche ground-penetrating radar data 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601490"}], "date_created": "Fri, 22 Oct 2021 00:00:00 GMT", "description": "Projecting future changes in West Antarctic Ice Sheet (WAIS) volume and global sea level rise in response to anthropogenic climate warming requires dynamic ice sheet models, which are enhanced by testing and calibrating with geologic evidence. Successfully modeling WAIS behavior during past collapse events \r\nprovides a basis for predictions of future sea level change. Exposure ages of erratics and bedrock throughout west Antarctica constrain higher-than-present WAIS geometry during the LGM and the last deglaciation. Quantifying the past surface elevation from the interior of the ice sheet is especially useful as it directly constrains ice thickness and volume where most of the mass is located. Data that determines WAIS geometry during the last interglacial, the last time that climate was warmer than present and when global sea level was 3-6 m higher, is critical for empirically constraining changes in WAIS volume and its contribution to sea level, as well as, to calibrate ice sheet models. These datasets are essentially non-\r\nexistent, as such evidence is now covered by the WAIS. Initial results from ground-penetrating radar surveys indicate ice depths around 1200 m. ", "east": -111.0, "geometry": "POINT(-128 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Mt. Waesche; USA/NSF; SNOW/ICE; GLACIER THICKNESS/ICE SHEET THICKNESS; PALEOCLIMATE RECONSTRUCTIONS; LABORATORY; LAVA COMPOSITION/TEXTURE; Amd/Us; AMD; USAP-DC", "locations": "Mt. Waesche", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Braddock, Scott; Campbell, Seth; Ackert, Robert; Zimmerer, Matthew; Mitrovica, Jerry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial", "uid": "p0010272", "west": -145.0}, {"awards": "1921418 Yan, Stephen", "bounds_geometry": null, "dataset_titles": "2019 initial L-band radar data for Dome Concordia; 2019 initial L-band radar data for EGRIP", "datasets": [{"dataset_uid": "601489", "doi": "10.15784/601489", "keywords": "Antarctica", "people": "Taylor, Ryan; Gogineni, Prasad; O\u0027Neill, Charles; Taylor, Drew", "repository": "USAP-DC", "science_program": null, "title": "2019 initial L-band radar data for Dome Concordia", "url": "https://www.usap-dc.org/view/dataset/601489"}, {"dataset_uid": "601488", "doi": "10.15784/601488", "keywords": "Antarctica; Greenland", "people": "Taylor, Drew; Gogineni, Prasad; O\u0027Neill, Charles; Taylor, Ryan", "repository": "USAP-DC", "science_program": null, "title": "2019 initial L-band radar data for EGRIP", "url": "https://www.usap-dc.org/view/dataset/601488"}], "date_created": "Mon, 11 Oct 2021 00:00:00 GMT", "description": "Predicting the response of ice sheets to changing climate and their contribution to sea level requires accurate representation in numerical models of basal conditions under the ice. There remain large data gaps for these basal boundary conditions under the East Antarctic Ice Sheet as well as in West Antarctica, including basal melt rates under ice shelves. This project developed and tested a prototype ground-based radar system to sound and image ice more than 4km thick, detect thin water films at the ice bed, and determine basal melt rates under ice shelves. The team worked with European partners (France, Italy, Germany) at Dome C to conduct deep-field Antarctic testing of the new radar.\r\n\r\nThe project built and tested an L-band radar system (1.2-1.4GHz) with peak transmit power of 2kW. In addition to sounding and imaging thick ice, detection goals included resolving thin water films (\u003e0.5mm). Such a system targets glaciological problems including site selection for ice in the 1.5-million-year age range, basal stress boundary conditions under grounded ice, and melt rates under floating shelves. By demonstrating feasibility, the project aims to influence sensor selection for satellite missions.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; GLACIER THICKNESS/ICE SHEET THICKNESS; Amd/Us; USAP-DC; AMD; Greenland; USA/NSF; FIELD SURVEYS; Antarctica", "locations": "Antarctica; Greenland", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology", "paleo_time": null, "persons": "Gogineni, Prasad; O\u0027Neill, Charles; Yan, Stephen; Taylor, Drew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "EAGER: L-Band Radar Ice Sounder for Measuring Ice Basal Conditions and Ice-Shelf Melt Rate", "uid": "p0010271", "west": null}, {"awards": "1745055 Stearns, Leigh; 1745043 Simkins, Lauren", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Circum-Antarctic grounding-line sinuosity; Elevation transects from Pine Island Bay; Pennell Trough, Ross Sea bathymetry and glacial landforms", "datasets": [{"dataset_uid": "601474", "doi": "10.15784/601474", "keywords": "Antarctica; Bathymetry; Elevation; Geomorphology; Glacial History; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; NBP1502; Pennell Trough; Ross Sea; R/v Nathaniel B. Palmer", "people": "Eareckson, Elizabeth; Prothro, Lindsay; Simkins, Lauren; Greenwood, Sarah; Anderson, John; Munevar Garcia, Santiago", "repository": "USAP-DC", "science_program": null, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "url": "https://www.usap-dc.org/view/dataset/601474"}, {"dataset_uid": "601774", "doi": "10.15784/601774", "keywords": "Antarctica; Bed Roughness; Cryosphere; Geomorphology; Pine Island Bay", "people": "Munevar Garcia, Santiago", "repository": "USAP-DC", "science_program": null, "title": "Elevation transects from Pine Island Bay", "url": "https://www.usap-dc.org/view/dataset/601774"}, {"dataset_uid": "601484", "doi": "10.15784/601484", "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "people": "Stearns, Leigh; Simkins, Lauren; Riverman, Kiya", "repository": "USAP-DC", "science_program": null, "title": "Circum-Antarctic grounding-line sinuosity", "url": "https://www.usap-dc.org/view/dataset/601484"}], "date_created": "Tue, 28 Sep 2021 00:00:00 GMT", "description": "The goals of this collaborative project are to merge empirical observations from the deglaciated Antarctic continental shelf and 1-D and 3-D numerical model experiments to test the sensitivity of marine-based ice sheets to subglacial topography with collaborators at the University of Kansas (L. Stearns, C. van der Veen). We focus on five glacial systems (i.e., flowlines) across the Amundsen Sea, Ross Sea, and George V Coast of Wilkes Land that extended to/near the continental shelf break at the Last Glacial Maximum \u2013 with a range of bed characteristics, topographic features, oceanographic and climatic conditions, and patterns of past ice flow and grounding line retreat. Specifically, at the University of Virginia, we (L. Simkins, S. Munevar Garcia) are: (ongoing) exploring bed roughness across the flowlines to determine the sensitivity of ice flow and grounding line behavior to different scales and wavelengths of bed topography/roughness; (upcoming) developing an empirical relationship between ice-marginal landform sediment volume and grounding line occupation time, and combining this with sedimentological analyses and new absolute age constraints to produce more comprehensive timelines of grounding line retreat, influential boundary conditions and processes, and determine the presence/absence of ice shelves; (ongoing) integrating quantitative and qualitative paleo- and offshore data to be incorporated into and/or validate 1-D and 3-D model experiments further testing the sensitivity of the five glacial systems to bed topography; and (completed) co-developing community engagement and education materials that focus on merging paleo-observations and model information of the Antarctic Ice Sheet from the LGM to the present \r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE SEDIMENTS; USAP-DC; Amd/Us; GLACIERS; BATHYMETRY; GLACIAL LANDFORMS; Antarctica; AMD; USA/NSF; R/V NBP", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Simkins, Lauren; Stearns, Leigh; Anderson, John; van der Veen, Cornelis", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations", "uid": "p0010269", "west": -180.0}, {"awards": "2046240 Khan, Alia", "bounds_geometry": "POLYGON((-75 -62,-73.5 -62,-72 -62,-70.5 -62,-69 -62,-67.5 -62,-66 -62,-64.5 -62,-63 -62,-61.5 -62,-60 -62,-60 -62.85,-60 -63.7,-60 -64.55,-60 -65.4,-60 -66.25,-60 -67.1,-60 -67.95,-60 -68.8,-60 -69.65,-60 -70.5,-61.5 -70.5,-63 -70.5,-64.5 -70.5,-66 -70.5,-67.5 -70.5,-69 -70.5,-70.5 -70.5,-72 -70.5,-73.5 -70.5,-75 -70.5,-75 -69.65,-75 -68.8,-75 -67.95,-75 -67.1,-75 -66.25,-75 -65.4,-75 -64.55,-75 -63.7,-75 -62.85,-75 -62))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 10 Sep 2021 00:00:00 GMT", "description": "Rapid and persistent climate warming in the Western Antarctic Peninsula is likely resulting in intensified snow-algae growth and an extended bloom season in coastal areas. Similarly, deposition of light absorbing particles (LAPs) onto Antarctica cryosphere surfaces, such as black carbon from intensifying Southern Hemisphere wildfire seasons, and dust from the expansion of ice-free regions in the Antarctic Peninsula, may be increasing. The presence of snow algae blooms and LAPs enhance the absorption of solar radiation by snow and ice surfaces. This positive feedback creates a measurable radiative forcing, which can have immediate local and long-term regional impacts on albedo, snow melt and downstream ecosystems. This project will investigate the spatial and temporal distribution of snow algae, black carbon and dust across the Western Antarctica Peninsula region, their response to climate warming, and their role in regional snow and ice melt. Data will be collected across multiple spatial scales from in situ field measurements and sample collection to imagery from ground-based photos and high resolution multi-spectral satellite sensors. Ground measurements will inform development and application of novel algorithms to map algal bloom extent through time using 0.5-3m spatial resolution multi-spectral satellite imagery. Results will be used to improve snow algae parameterization in a new version of the Snow Ice Aerosol Radiation model (SNICARv3) that includes bio-albedo feedbacks, eventually informing models of ice-free area expansion through incorporation of SNICARv3 in the Community Earth System Model. Citizen scientists will be mentored and engaged in the research through an active partnership with the International Association of Antarctic Tour Operators that frequently visits the region. The cruise ship association will facilitate sampling to develop a unique snow algae observing network to validate remote sensing algorithms that map snow algae with high-resolution multi-spectral satellite imagery from space. These time-series will inform instantaneous and interannual radiative forcing calculations to assess impacts of snow algae and LAPs on regional snow melt. Quantifying the spatio-temporal growing season of snow algae and impacts from black carbon and dust will increase our ability to model their impact on snow melt, regional climate warming and ice-free expansion in the Antarctic Peninsula region.", "east": -60.0, "geometry": "POINT(-67.5 -66.25)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Antarctic Peninsula; Amd/Us; AMD; SNOW/ICE CHEMISTRY; USA/NSF; USAP-DC; SNOW", "locations": "Antarctic Peninsula", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Khan, Alia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -70.5, "title": "CAREER: Coastal Antarctic Snow Algae and Light Absorbing Particles: Snowmelt, Climate and Ecosystem Impacts", "uid": "p0010263", "west": -75.0}, {"awards": "2103032 Schmittner, Andreas", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The Antarctic ice sheet is an important component of Earth\u2019s climate system, as it interacts with the atmosphere, the surrounding Southern Ocean, and the underlaying solid Earth. It is also the largest potential contributor to future sea level rise and a major uncertainty in climate projections. Climate change may trigger instabilities, which may lead to fast and irreversible collapse of parts of the ice sheet. However, very little is known about how interactions between the Antarctic ice sheet and the rest of the climate system affect its behavior, climate, and sea level, partly because most climate models currently do not have fully-interactive ice sheet components. This project investigates Antarctic ice-ocean interactions of the last 20,000 years. A novel numerical climate model will be constructed that includes an interactive Antarctic ice sheet, improving computational infrastructure for research. The model code will be made freely available to the public on a code-sharing site. Paleoclimate data will be synthesized and compared with simulations of the model. The model-data comparison will address three scientific hypotheses regarding past changes in deep ocean circulation, ice sheet, carbon, and sea level. The project will contribute to a better understanding of ice-ocean interactions and past climate variability.\r\n\r\nThis project will test suggestions that ice-ocean interactions have been important for setting deep ocean circulation and carbon storage during the Last Glacial Maximum and subsequent deglaciation. The new model will consist of three existing and well-tested components: (1) an isotope-enabled climate-carbon cycle model of intermediate complexity, (2) a model of the combined Antarctic ice sheet, solid Earth and sea level, and (3) an iceberg model. The coupling will include ocean temperature effects on basal melting of ice shelves, freshwater fluxes from the ice sheet to the ocean, and calving, transport and melting of icebergs. Once constructed and optimized, the model will be applied to simulate the Last Glacial Maximum and subsequent deglaciation. Differences between model versions with full, partial or no coupling will be used to investigate the effects of ice-ocean interactions on the Meridional Overturning Circulation, deep ocean carbon storage and ice sheet fluctuations. Paleoclimate data synthesis will include temperature, carbon and nitrogen isotopes, radiocarbon ages, protactinium-thorium ratios, neodymium isotopes, carbonate ion, dissolved oxygen, relative sea level and terrestrial cosmogenic ages into one multi-proxy database with a consistent updated chronology. The project will support an early-career scientist, one graduate student, undergraduate students, and new and ongoing national and international collaborations. Outreach activities in collaboration with a local science museum will benefit rural communities in Oregon by improving their climate literacy.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE CORE RECORDS; Amd/Us; USA/NSF; OCEAN TEMPERATURE; GLACIERS/ICE SHEETS; BIOGEOCHEMICAL CYCLES; MODELS; AMD; United States Of America; OCEAN CURRENTS; ICEBERGS; PALEOCLIMATE RECONSTRUCTIONS", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Schmittner, Andreas; Haight, Andrew ; Clark, Peter", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Investigating Antarctic Ice Sheet-Ocean-Carbon Cycle Interactions During the Last Deglaciation", "uid": "p0010256", "west": -180.0}, {"awards": "1542976 Balco, Gregory; 1542936 Goehring, Brent", "bounds_geometry": "POLYGON((-145.7 -64.195,-113.988 -64.195,-82.276 -64.195,-50.564 -64.195,-18.852 -64.195,12.86 -64.195,44.572 -64.195,76.284 -64.195,107.996 -64.195,139.708 -64.195,171.42 -64.195,171.42 -66.2096,171.42 -68.2242,171.42 -70.2388,171.42 -72.2534,171.42 -74.268,171.42 -76.2826,171.42 -78.2972,171.42 -80.3118,171.42 -82.3264,171.42 -84.341,139.708 -84.341,107.996 -84.341,76.284 -84.341,44.572 -84.341,12.86 -84.341,-18.852 -84.341,-50.564 -84.341,-82.276 -84.341,-113.988 -84.341,-145.7 -84.341,-145.7 -82.3264,-145.7 -80.3118,-145.7 -78.2972,-145.7 -76.2826,-145.7 -74.268,-145.7 -72.2534,-145.7 -70.2388,-145.7 -68.2242,-145.7 -66.2096,-145.7 -64.195))", "dataset_titles": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "datasets": [{"dataset_uid": "200199", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Fri, 03 Sep 2021 00:00:00 GMT", "description": "This project focused on geochemical measurements on rock samples from Antarctica that can be used to reconstruct changes in the size and thickness of the Antarctic ice sheets during the past several thousand years. It applied relatively newly developed technology for measurement of cosmic-ray-produced carbon-14 in quartz to gather new and better information on past ice sheet change from rock samples previously collected in past research in Antarctica. Specifically, it aimed to address a lack of information on past ice sheet change from the Weddell Sea embayment, and the primary result of the project is an improved understanding of ice volume change in this sector of Antarctica during the past ca. 15,000 years. This, in turn, is important in understanding the contribution of the Antarctic ice sheets to global sea level change during this time period. ", "east": 171.42, "geometry": "POINT(12.86 -74.268)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Cosmogenic Dating; GLACIER THICKNESS/ICE SHEET THICKNESS; AMD; USAP-DC; GLACIER ELEVATION/ICE SHEET ELEVATION; GLACIERS/ICE SHEETS; Carbon-14; USA/NSF; Weddell Sea Embayment; LABORATORY; FIELD SURVEYS; GLACIATION", "locations": "Weddell Sea Embayment", "north": -64.195, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Goehring, Brent; Balco, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -84.341, "title": "COLLABORATIVE RESEARCH: Resolving Ambiguous Exposure-Age Chronologies of Antarctic Deglaciation with Measurements of In-Situ-Produced Cosmogenic Carbon-14", "uid": "p0010254", "west": -145.7}, {"awards": "1744993 Higgins, John; 1745007 Mayewski, Paul; 1744832 Severinghaus, Jeffrey; 0838843 Kurbatov, Andrei; 1745006 Brook, Edward J.", "bounds_geometry": "POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))", "dataset_titles": "Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills Stable Water Isotopes; I-165-M GPR Field Report 2019-2020", "datasets": [{"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Shackleton, Sarah; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Brook, Edward J.; Nesbitt, Ian", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}, {"dataset_uid": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.; Spaulding, Nicole", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}], "date_created": "Fri, 27 Aug 2021 00:00:00 GMT", "description": " Between about 2.8-0.9 Ma, Earth\u2019s climate was characterized by 40 kyr cycles, driven or paced by changes in the tilt of Earth\u2019s spin axis. Much is known about the 40k world from studies of deep-sea sediments, but our understanding of climate change during this period and the transition between the 40kyr glacial cycles from 2.8-0.9 Ma and the 100kyr glacial cycles of the last 0.9 Myr is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of \u003e1 Ma ice discovered in shallow ice cores in the Allan Hills Blue Ice Area (BIA), Antarctica. During the 2015-2016 field season we recovered ice from two nearby drill cores that dates to \u003e 2 million years in age using the 40Ar/38Ar ratio of the trapped gases. Our discovery of ice of this antiquity in two cores demonstrates that there is gas-record quality ice from the 40k world in the Allan Hills BIA. To further characterize the composition of Earth\u2019s atmosphere and Antarctic climate during the 40k world we request support for two field seasons to drill new large-volume (4\u201d or 9\u201d diameter) ice cores at sites where we have previously identified \u003e1 Ma ice and nearby sites where ground penetrating radar has identified bedrock features conducive to the preservation of old ice. ", "east": 159.41667, "geometry": "POINT(159.29167 -76.7)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; SNOW/ICE; Allan Hills; FIELD SURVEYS; USA/NSF; Amd/Us; LABORATORY", "locations": "Allan Hills", "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Brook, Edward J.; Severinghaus, Jeffrey P.; Higgins, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area ", "uid": "p0010253", "west": 159.16667}, {"awards": "1740239 Johnson, Leah; 1341649 Johnson, Leah", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": "Albatrosses (family Diomedeidae) are among the most threatened of bird species. Of the 22 species that are currently recognized, all are considered at least Threatened or Near-Threatened, and 9 are listed as Endangered or Critically Endangered. Because of the decline in albatross populations and the birds\u0027 role as a top predator in the pelagic ecosystem, it is vitally important to understand the factors affecting the population dynamics of these birds to better inform strategies for conservation and mitigating environmental change. The goal of this project is to answer the question: What are the population consequences of albatross bioenergetics and foraging strategies? The project took a two pronged approach: 1) constructing, parameterizing, and validating a Dynamic Energy Budget model to understand growth and constraints on foraging; and 2) undertaking an in-depth meta-analysis of existing individual tracking and life history data from multiple albatross species across successive life stages. This theoretical work will be grounded with a unique and extensive data set on albatrosses provided by collaborator Richard Phillips from the British Antarctic Survey. Bioenergetics constrain a variety of behaviors. A more complete understanding of how individuals use energy can give insight into how behaviors from foraging to breeding and survival, and resulting population attributes, might change with environmental factors, due to anthropogenic and other drivers. This work will further a general understanding of how bioenergetics shapes behavior and drives population level processes, while providing an approach that can be used to guide conservation strategies for endangered populations. The research findings and activities were made accessible to public audiences through websites and a blog maintained for the project by a postdoctoral researcher. The project involved undergraduate researchers in the project, within formal laboratory groups and also through in-classroom presentations and activities. This project also involved public outreach through twitter and other venues. All project publications are open access, the resulting open source software was released to the public, and metadata and analyses are fully documented to promote further collaborative exploration of this system.\r\n\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "BIRDS; Amd/Us; USAP-DC; AMD; USA/NSF; MODELS; United States Of America", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Johnson, Leah; Ryan, Sadie", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Quantifying how Bioenergetics and Foraging Determine Population Dynamics in Threatened Antarctic Albatrosses", "uid": "p0010242", "west": -180.0}, {"awards": "1644171 Blackburn, Terrence", "bounds_geometry": "POLYGON((162 -77.5,162.2 -77.5,162.4 -77.5,162.6 -77.5,162.8 -77.5,163 -77.5,163.2 -77.5,163.4 -77.5,163.6 -77.5,163.8 -77.5,164 -77.5,164 -77.525,164 -77.55,164 -77.575,164 -77.6,164 -77.625,164 -77.65,164 -77.675,164 -77.7,164 -77.725,164 -77.75,163.8 -77.75,163.6 -77.75,163.4 -77.75,163.2 -77.75,163 -77.75,162.8 -77.75,162.6 -77.75,162.4 -77.75,162.2 -77.75,162 -77.75,162 -77.725,162 -77.7,162 -77.675,162 -77.65,162 -77.625,162 -77.6,162 -77.575,162 -77.55,162 -77.525,162 -77.5))", "dataset_titles": "Isotopic ratios for subglacial precipitates from East Antarctica; U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "200240", "doi": "10.26022/IEDA/111548 ", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Isotopic ratios for subglacial precipitates from East Antarctica", "url": "https://doi.org/10.26022/IEDA/111548"}, {"dataset_uid": "601806", "doi": "10.15784/601806", "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "people": "Tulaczyk, Slawek; Blackburn, Terrence; Piccione, Gavin; Edwards, Graham", "repository": "USAP-DC", "science_program": null, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601806"}], "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": "The primary scientific goal of the proposed project is to test whether Taylor Valley, Antarctica has experienced glacial incision in the last ~1 million years in spite of cold climate conditions. One of the Dry Valleys of the Transantarctic Mountains, Taylor Valley exhibits over 2000 m of relief from sub sea-level troughs to high polar peaks. The Dry Valleys are characterized by low mean annual temperatures, paucity of precipitation and erosion that has allowed fragile glacial landforms, now subaerially exposed at high elevations, to be preserved for as long as 15 Ma. Two end member models can explain the timing of glacial incision and the observation that Quaternary advances of Taylor Glacier have left deposits at lower valley elevations with each advance. In the first scenario, all Valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen fluvial channels more so than peaks. In this case, Quaternary drift deposits record advances of cold-based glaciers of decreasing ice volume. Limited glacial erosion and silt generation results in drift deposits composed primarily of recycled sediments. In the second scenario, selective erosion of the valley floor continues to deepen Taylor Valley over the last 2 Ma while high elevation peaks remain uneroded in polar conditions. The \u2018bathtub rings\u2019 of Quaternary drifts reaching a progressively lower elevation through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of silt which is now incorporated into these drifts. While either scenario would result in the present day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. Here we propose to distinguish between these two models, by placing time constrains on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss (\u003c50 \uf0ecm). The timing of comminution and particle size controls the magnitude of 234U loss, up to 10% in silt-sized particles comminuted over 1.5 million years ago. And while this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that our preliminary modeling and measured data show is readily resolved.", "east": 164.0, "geometry": "POINT(163 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Taylor Valley", "locations": "Taylor Valley", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence; Tulaczyk, Slawek", "platforms": null, "repo": "EarthChem", "repositories": "EarthChem; USAP-DC", "science_programs": null, "south": -77.75, "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion", "uid": "p0010243", "west": 162.0}, {"awards": "1927709 Friedlaender, Ari; 1927742 Fleming, Alyson; 1947453 Hunt, Kathleen", "bounds_geometry": "POLYGON((150 -60,153 -60,156 -60,159 -60,162 -60,165 -60,168 -60,171 -60,174 -60,177 -60,180 -60,180 -61.5,180 -63,180 -64.5,180 -66,180 -67.5,180 -69,180 -70.5,180 -72,180 -73.5,180 -75,177 -75,174 -75,171 -75,168 -75,165 -75,162 -75,159 -75,156 -75,153 -75,150 -75,150 -73.5,150 -72,150 -70.5,150 -69,150 -67.5,150 -66,150 -64.5,150 -63,150 -61.5,150 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 10 Aug 2021 00:00:00 GMT", "description": "An archive of baleen plates from 800 Antarctic blue and fin whales harvested between 1946 and 1948 was recently rediscovered in the Smithsonian\u2019s National Museum of Natural History. As baleen grows, it incorporates compounds from the whale\u2019s diet and surroundings, recording continuous biological and oceanographic information across multiple years. The baleen record forms an ideal experimental platform for studying bottom-up, top-down and anthropogenic impacts on blue and fin whales. Such insights are likely impossible to obtain through any other means as blue and fin whales now number ~1 and 4% of their pre-whaling abundances. The baleen archive includes years with strong climate and temperature anomalies allowing the influence of climate variability on predators and the ecosystems that support them to be examined. Additionally, the impact of whaling on whale stress levels will be investigated by comparing years of intensive whaling with the non-whaling years of WWII, both of which are captured in the time series. We will use 1) bulk stable isotopes to examine the trophic dynamics of Antarctic blue and fin whales, 2) compound-specific stable isotope analysis (CSIA-AA) to characterize the biogeochemistry of the base of the Antarctic food web and 3) hormone analyses to examine the population biology of these species. These investigations will fill major gaps in our understanding of the largest krill predators, their response to disturbance and environmental change, and the impact that commercial whaling has had on the structure and function of the Antarctic marine ecosystem.", "east": 180.0, "geometry": "POINT(165 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; PELAGIC; MAMMALS; LABORATORY; AMD; Amd/Us; Southern Ocean; USAP-DC; USA/NSF", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Fleming, Alyson; Friedlaender, Ari; McCarthy, Matthew; Hunt, Kathleen", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -75.0, "title": "Collaborative Research: A New Baseline for Antarctic Blue and Fin Whales", "uid": "p0010240", "west": 150.0}, {"awards": "1644155 Twining, Benjamin", "bounds_geometry": "POLYGON((78 -68.4,78.05 -68.4,78.1 -68.4,78.15 -68.4,78.2 -68.4,78.25 -68.4,78.3 -68.4,78.35 -68.4,78.4 -68.4,78.45 -68.4,78.5 -68.4,78.5 -68.419,78.5 -68.438,78.5 -68.457,78.5 -68.476,78.5 -68.495,78.5 -68.514,78.5 -68.533,78.5 -68.552,78.5 -68.571,78.5 -68.59,78.45 -68.59,78.4 -68.59,78.35 -68.59,78.3 -68.59,78.25 -68.59,78.2 -68.59,78.15 -68.59,78.1 -68.59,78.05 -68.59,78 -68.59,78 -68.571,78 -68.552,78 -68.533,78 -68.514,78 -68.495,78 -68.476,78 -68.457,78 -68.438,78 -68.419,78 -68.4))", "dataset_titles": "Flow cytometry enumeration of virus-like and bacteria-like abundance in Ace, Deep, \u0026 Organic lakes (Antarctica)", "datasets": [{"dataset_uid": "601626", "doi": "10.15784/601626", "keywords": "Ace Lake; Antarctica; Deep Lake; Organic Lake; Vestfold Hills", "people": "Martinez-Martinez, Joaquin; Twining, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "Flow cytometry enumeration of virus-like and bacteria-like abundance in Ace, Deep, \u0026 Organic lakes (Antarctica)", "url": "https://www.usap-dc.org/view/dataset/601626"}], "date_created": "Fri, 06 Aug 2021 00:00:00 GMT", "description": "Viruses are prevalent in aquatic environments where they reach up to five hundred million virus particles in a teaspoon of water. Ongoing discovery of viruses seems to confirm current understanding that all forms of life can host and be infected by viruses and that viruses are one of the largest reservoirs of unexplored genetic diversity on Earth. This study aims to better understand interactions between specific viruses and phytoplankton hosts and determine how these viruses may affect different algal groups present within lakes of the Vestfold Hills, Antarctica. These lakes (Ace, Organic and Deep)were originally derived from the ocean and contain a broad range of saline conditions with a similarly broad range of physicochemical characteristics resulting from isolation and low external influence for thousands of years. These natural laboratories allow examination of microbial processes and interactions that would be difficult to characterize elsewhere on earth. The project will generate extensive genomic information that will be made freely available. The project will also leverage the study of viruses and the genomic approaches employed to advance the training of undergraduate students and to engage and foster an understanding of Antarctic science and studies of microbes during a structured informal education program in Maine for the benefit of high school students.\r\n\r\nBy establishing the dynamics and interactions of (primarily) specific dsDNA virus groups in different habitats with different redox conditions throughout seasonal and inter annual cycles the project will learn about the biotic and abiotic factors that influence microbial community dynamics. This project does not require fieldwork in Antarctica. Instead, the investigators will leverage already collected and archived samples from three lakes that have concurrent measures of physicochemical information. Approximately 2 terabyte of Next Generation Sequencing (NGS) (including metagenomes, SSU rRNA amplicons and single virus genomes) will be generated from selected available samples through a Community Science Program (CSP) funded by the Joint Genome Institute. The investigators will employ bioinformatics to interrogate those sequence databases. In particular, they will focus on investigating the presence, phylogeny and co-occurrence of polintons, polinton-like viruses, virophages and large dsDNA phytoplankton viruses as well as of their putative eukaryotic microbial hosts. Bioinformatic analyses will be complemented with quantitative digital PCR and microbial association network analysis to detect specific virus-host interactions from co-occurrence spatial and temporal patterns. Multivariate analysis and network analyses will also be performed to investigate which abiotic factors most closely correlate with phytoplankton and virus abundances, temporal dynamics, and observed virus-phytoplankton associations within the three lakes. The results of this project will improve understanding of phytoplankton and their viruses as vital components of the carbon cycle in Antarctic, marine-derived aquatic environments, and likely in any other aquatic environment. Overall, this work will advance understanding of the genetic underpinnings of adaptations in unique Antarctic environments.", "east": 78.5, "geometry": "POINT(78.25 -68.495)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; AMD; USAP-DC; VIRUSES; Vestfold Hills; Amd/Us; FIELD SURVEYS; USA/NSF", "locations": "Vestfold Hills", "north": -68.4, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Twining, Benjamin; Martinez-Martinez, Joaquin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -68.59, "title": "Viral control of microbial communities in Antarctic lakes", "uid": "p0010237", "west": 78.0}, {"awards": "1745080 Gillikin, David; 1745057 Walker, Sally; 1745064 Perez-Huerta, Alberto", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails; Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails; Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "datasets": [{"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}, {"dataset_uid": "601469", "doi": "10.15784/601469", "keywords": "Adamussium Colbecki; Antarctica; McMurdo", "people": "Cronin, Kelly; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601469"}, {"dataset_uid": "601468", "doi": "10.15784/601468", "keywords": "Adamussium Colbecki; Antarctica; Growth; McMurdo Sound; Shell Fish", "people": "Cronin, Kelly; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601468"}, {"dataset_uid": "601764", "doi": null, "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Walker, Sally; Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "601761", "doi": "10.15784/601761", "keywords": "Adamussium Colbecki; Antarctica; Bay Of Sails; Carbon; Explorers Cove; McMurdo Sound; Oxygen; Stable Isotopes", "people": "Cronin, Kelly; Walker, Sally; Perez-Huerta, Alberto; Verheyden, Anouk; Bowser, Samuel S.; Andrus, Fred; Camarra, Steve; Puhalski, Emma; Gillikin, David", "repository": "USAP-DC", "science_program": null, "title": "Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601761"}], "date_created": "Fri, 06 Aug 2021 00:00:00 GMT", "description": "The goal of this project is to discover whether the Antarctic scallop, Adamussium colbecki, provides a guide to sea-ice conditions in nearshore Antarctica today and in the past. Scallops may grow slower and live longer in habitats where sea ice persists for many years, limited by food, compared to habitats where sea ice melts out annually. Also, the chemicals retained in the shell during growth may provide crucial habitat information related to not only changing sea-ice conditions but also the type of food, whether it is recycled from the seafloor or produced by algae blooming when sea ice has melted. Unlocking the ecological imprint captured within the shell of the Antarctic Scallop will increase our understanding of changing sea-ice conditions in Antarctica. Further, because the Antarctic scallop had relatives living at the time when the Antarctic ice sheet first appeared, the scallop shell record may contain information on the stability of the ice sheet and the history of Antarctic shallow seas. Funding will also be integral for training a new generation of geoscientists in fossil and chemical forensics related to shallow sea habitats in Antarctica.\r\n\r\nScallops are worldwide in distribution, are integral for structuring marine communities have an extensive fossil record dating to the late Devonian, and are increasingly recognized as important paleoenvironmental proxies because they are generally well preserved in the sediment and rock record. The primary goal of this project is to assess the differences in growth, lifespan, and chemistry (stable isotopes, trace elements) archived in the shell of the Antarctic scallop that may be indicative of two ice states: persistent (multiannual) sea ice at Explorers Cove (EC) and annual sea ice (that melts out every year) at Bay of Sails (BOS), western McMurdo Sound, Antarctica. This project will investigate growth and lifespan proxies (physical and geochemical) and will use high-resolution records of stable oxygen isotopes to determine if a melt-water signal is archived in A. colbecki shells and whether that signal captures the differing ice behavior at two sites (EC versus BOS). Stable isotopes of carbon and nitrogen in association with trace elements will be used to examine subannual productivity spikes indicative of phytoplankton blooms, which are predicted to be more pronounced during open ocean conditions. Small growth increments in the outer calcite layer will be assessed to determine if they represent fortnightly growth, if so, they could provide a high-resolution proxy for monthly environmental processes. Unlocking the environmental archive preserved in A. colbecki shells may prove to be an important proxy for understanding changing sea-ice conditions in Antarctica\u0027s past. Funding will support a Ph.D. student and undergraduates from multiple institutions working on independent research projects. Web content focused on Antarctic marine communities will be designed for museum outreach, reaching thousands of middle-school children each year.\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; AMD; Dry Valleys; USAP-DC; LABORATORY; USA/NSF", "locations": "Dry Valleys", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Gillikin, David; Perez-Huerta, Alberto; Andrus, Fred", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past", "uid": "p0010238", "west": -180.0}, {"awards": "1744871 Robinson, Rebecca", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Diatom assemblage from IODP Site U1357; Diatom-bound and bulk sedimentary N isotopes from ODP Site 1098, Western Antarctic Peninsula; Diatom-bound and bulk sedimentary nitrogen isotopes from IODP Site U1357; Dissolved nutrients, cell counts, and nitrogen isotope measurements from Chaetoceros socialis culture experiments; ODP Site 1098 deglacial diatom assemblage; Sediment chemistry of ODP Site 1098", "datasets": [{"dataset_uid": "601817", "doi": "10.15784/601817", "keywords": "Antarctica; Cryosphere; Wilkes Land", "people": "Dove, Isabel; Robinson, Rebecca; Kelly, Roger", "repository": "USAP-DC", "science_program": null, "title": "Diatom-bound and bulk sedimentary nitrogen isotopes from IODP Site U1357", "url": "https://www.usap-dc.org/view/dataset/601817"}, {"dataset_uid": "601727", "doi": "10.15784/601727", "keywords": "Antarctica", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Dissolved nutrients, cell counts, and nitrogen isotope measurements from Chaetoceros socialis culture experiments", "url": "https://www.usap-dc.org/view/dataset/601727"}, {"dataset_uid": "601778", "doi": "10.15784/601778", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Sediment chemistry of ODP Site 1098", "url": "https://www.usap-dc.org/view/dataset/601778"}, {"dataset_uid": "601818", "doi": "10.15784/601818", "keywords": "Antarctica; Cryosphere; Geochemistry; Sediment; Wilkes Land", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblage from IODP Site U1357", "url": "https://www.usap-dc.org/view/dataset/601818"}, {"dataset_uid": "601777", "doi": "10.15784/601777", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Sediment Core Data", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "ODP Site 1098 deglacial diatom assemblage", "url": "https://www.usap-dc.org/view/dataset/601777"}, {"dataset_uid": "601816", "doi": "10.15784/601816", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Geochemistry; Sediment", "people": "Robinson, Rebecca; Dove, Isabel; Jones, Colin; Kelly, Roger", "repository": "USAP-DC", "science_program": null, "title": "Diatom-bound and bulk sedimentary N isotopes from ODP Site 1098, Western Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601816"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "The chemical composition of diatom fossils in the Southern Ocean provides information about the environmental history of Antarctica, including sea ice extent, biological production, and ocean nutrient distribution. The sea ice zone is an important habitat for a group of diatoms, largely from the genus Chaetoceros, that have a unique life cycle stage under environmental stress, when they produce a structure called a resting spore. Resting spores are meant to reseed the surface ocean when conditions are more favorable. The production of these heavy resting spores tends to remove significant amounts of carbon and silicon, essential nutrients, out of the surface ocean. As a result, this group has the potential to remove carbon from the surface ocean and can impact the sedimentary record scientists use to reconstruct environmental change. \r\n\r\nThis project explores the role of resting spores and nutrients in the sedimentary record using the nitrogen isotopic signature of these fossils and how those measurements are used to estimate carbon cycle changes. Measurements of nitrogen stable isotopes of nitrate, biomass, and diatom-bound nitrogen and silicon-to-nitrogen ratios of individual species grown in the laboratory are used to quantify how resting spores record nutrient drawdown in the water column and to what degree their signature is biased toward low nutrient conditions. Laboratory incubations were conducted with surface sediment containing Chaetoceros spp.. The emergence of vegetative cells and subsequent formation of resting spores is manipulated with the addition of nutrients, primarily nitrate. The resulting samples, both of vegetative cells and resting spores were measured for diatom-bound d15N. Resting spore d15N values are consistently lower than the vegetative d15N \r\n from the same incubations. The incubation results will be used to quantify nutrient drawdown in sea ice environments during two contrasting intervals in earth history, the last ice age and the warm Pliocene. The project provided training and research opportunities for undergraduate and graduate students. Research efforts in Antarctic earth sciences are disseminated through an interactive display at the home institution and during university sponsored events.\r\n\r\nThis work addresses uncertainties in how Chaetoceros resting spores record surface nutrient conditions in their nitrogen stable isotopic composition, the relative impact of their specific signal with respect to the full sedimentary assemblage, and their potential to bias or enhance environmental reconstructions in the sea ice zone. \r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USAP-DC; Antarctica; ISOTOPES; MARINE SEDIMENTS; LABORATORY; USA/NSF; NITROGEN; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Rebecca", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The nitrogen isotopic composition of diatom resting spores in Southern Ocean sediments: A source of bias and/or paleoenvironmental information?", "uid": "p0010234", "west": -180.0}, {"awards": "1952199 Datta, Rajashree", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Variable-resolution CESM2 over Antarctica (ANTSI): Monthly outputs used for evaluation", "datasets": [{"dataset_uid": "200417", "doi": "10.5281/zenodo.7335891", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Variable-resolution CESM2 over Antarctica (ANTSI): Monthly outputs used for evaluation", "url": "https://zenodo.org/records/7335892"}], "date_created": "Wed, 21 Jul 2021 00:00:00 GMT", "description": "The Antarctic Ice Sheet (AIS) is sensitive to and an indicator of climate change. While dynamic ice loss is largely driven by ocean forcing, this ice loss might be mitigated by enhanced snowfall on the ice sheet. By developing and understanding of the processes governing snowfall variability and change on the AIS, this project will contribute to the objective of understanding the long-term role of the AIS as a contributor to sea level rise. This project is strongly embedded in the collaborative, open-source framework of the Community Earth System Model version 2 (CESM2) and will deliver new datasets of Antarctic precipitation for the community to use. The project will help to build a diverse geoscience workforce by recruiting and training a SOARs student to be directly involved in the research. A graduate student will also be recruited, and they will play a pivotal role in the proposed work. \r\n\r\nIn this project, we propose to leverage the Climate Model Intercomparison Project 6 (CMIP6) climate model ensemble as a whole, and CESM2 in particular, to disentangle the major sources of uncertainty and to elucidate the underlying mechanisms of Antarctic precipitation change, with a particular focus on the role of atmospheric circulation changes relative to that of atmospheric warming. Using the variable resolution capabilities of CESM2, we will provide the community with precipitation estimates at a very high horizontal resolution. The proposed analyses will also use a forthcoming 100-member large ensemble. The project seeks to answer the following questions: 1) How well does the CESM2 represent the present-day Antarctic surface climate, precipitation, and surface mass balance (SMB), including the mean and its variability? 2) What is the sensitivity of simulated Antarctic precipitation to model resolution in present-day and future climates? 3) What are the roles of thermodynamics (warming atmosphere and ocean) and dynamics (changes in atmospheric circulation) in observed and projected snowfall changes? How do these break down into forced and internal variability? In particular, is there a significant forced precipitation trend due to circulation changes driven by stratospheric ozone depletion and recovery and increases in greenhouse gas concentration? 4) What processes and boundary conditions drive the ensemble spread of AIS precipitation in single-model and multi-model ensembles? How does the spread driven by initial surface conditions (including sea ice cover, surface fluxes, inversion strength) compare with the irreducible uncertainty due to internal climate system variability?\r\n\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; ICE SHEETS; Amd/Us; Antarctica; AMD; SNOW; MODELS; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Schneider, David; Datta, Rajashree Tri", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Uncertainty and Mechanisms of Antarctica\u2019s Changing Snowfall and its Role in Sea Level Change", "uid": "p0010233", "west": -180.0}, {"awards": "1943550 McDonald, Birgitte", "bounds_geometry": "POLYGON((168 -77,168.3 -77,168.6 -77,168.9 -77,169.2 -77,169.5 -77,169.8 -77,170.1 -77,170.4 -77,170.7 -77,171 -77,171 -77.1,171 -77.2,171 -77.3,171 -77.4,171 -77.5,171 -77.6,171 -77.7,171 -77.8,171 -77.9,171 -78,170.7 -78,170.4 -78,170.1 -78,169.8 -78,169.5 -78,169.2 -78,168.9 -78,168.6 -78,168.3 -78,168 -78,168 -77.9,168 -77.8,168 -77.7,168 -77.6,168 -77.5,168 -77.4,168 -77.3,168 -77.2,168 -77.1,168 -77))", "dataset_titles": "Late chick-rearing foraging ecology of emperor penguins from the Cape Crozier colony; Post-molt emperor penguin foraging ecology", "datasets": [{"dataset_uid": "601686", "doi": "10.15784/601686", "keywords": "Antarctica; Biota; Emperor Penguin; NBP2302; Post-Molt; Ross Sea", "people": "McDonald, Birgitte", "repository": "USAP-DC", "science_program": null, "title": "Post-molt emperor penguin foraging ecology", "url": "https://www.usap-dc.org/view/dataset/601686"}, {"dataset_uid": "601688", "doi": "10.15784/601688", "keywords": "Animal Tracking; Antarctica; Biota; Emperor Penguin; GPS; Late Chick Rearing; Ross Sea", "people": "McDonald, Birgitte", "repository": "USAP-DC", "science_program": null, "title": "Late chick-rearing foraging ecology of emperor penguins from the Cape Crozier colony", "url": "https://www.usap-dc.org/view/dataset/601688"}], "date_created": "Tue, 20 Jul 2021 00:00:00 GMT", "description": "This project will identify behavioral and physiological variability in foraging Emperor Penguins that can be directly linked to individual success in the marine environment using an optimal foraging theory framework during two critical life history stages. First, this project will investigate the foraging energetics, ecology, and habitat use of Emperor Penguins at Cape Crozier using fine-scale movement and video data loggers during late chick-rearing, an energetically demanding life history phase. Specifically, this study will 1) Estimate the foraging efficiency and examine its relationship to foraging behavior and diet using an optimal foraging theory framework to identify what environmental or physiological constraints influence foraging behavior; 2) Investigate the inter- and intra-individual behavioral variability exhibited by emperor penguins, which is essential to predict how resilient they will be to climate change; and 3) Integrate penguin foraging efficiency data with environmental data to identify important habitat. Next the researchers will study the ecology and habitat preference after the molt and through early reproduction using satellite-linked data loggers. The researchers will: 1) Investigate the inter- and intra-individual behavioral variability exhibited by Emperor Penguins during the three-month post-molt and early winter foraging trips; and 2) Integrate penguin behavioral data with environmental data to identify which environmental features are indicative of habitat preference when penguins are not constrained to returning to the colony to feed a chick. These fine- and coarse-scale data will be combined with climate predictions to create predictive habitat models. The education objectives of this CAREER project are designed to inspire, engage, and train the next generation of scientists using the data and video generated while investigating Emperor Penguins in the Antarctic ecosystem. This includes development of two courses (general education and advanced techniques), training of undergraduate and graduate students, and a collaboration with the NSF funded \u201cPolar Literacy: A model for youth engagement and learning\u201d program to develop afterschool and camp curriculum that target underserved and underrepresented groups.\r\n\r\n", "east": 171.0, "geometry": "POINT(169.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; PENGUINS; MARINE ECOSYSTEMS; USA/NSF; Ross Sea; FIELD SURVEYS; USAP-DC; AMD", "locations": "Ross Sea", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "McDonald, Birgitte", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "CAREER: Foraging Ecology and Physiology of Emperor Penguins in the Ross Sea", "uid": "p0010232", "west": 168.0}, {"awards": "1744794 Jenouvrier, Stephanie; 1744989 LaRue, Michelle", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Detecting climate signals in populations: case of emperor penguin; Emperor penguin population trends (2009-2018); Landfast ice: a major driver of reproductive success in a polar seabird", "datasets": [{"dataset_uid": "601513", "doi": "10.15784/601513", "keywords": "Antarctica; Breeding Success; Emperor Penguin; Fast Sea Ice", "people": "Jenouvrier, Stephanie; Labrousse, Sara", "repository": "USAP-DC", "science_program": null, "title": "Landfast ice: a major driver of reproductive success in a polar seabird", "url": "https://www.usap-dc.org/view/dataset/601513"}, {"dataset_uid": "601491", "doi": "10.15784/601491", "keywords": "Antarctica", "people": "Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "Detecting climate signals in populations: case of emperor penguin", "url": "https://www.usap-dc.org/view/dataset/601491"}, {"dataset_uid": "200388", "doi": "", "keywords": null, "people": null, "repository": "Github", "science_program": null, "title": "Emperor penguin population trends (2009-2018)", "url": "https://github.com/davidiles/EMPE_Global"}], "date_created": "Wed, 14 Jul 2021 00:00:00 GMT", "description": "This project on emperor penguin populations will quantify penguin presence/absence, and colony size and trajectory, across the entire Antarctic continent using high-resolution satellite imagery. For a subset of the colonies, population estimates derived from high-resolution satellite images will be compared with those determined by aerial surveys - these results have been uploaded to MAPPPD (penguinmap.com) and are freely available for use. This validated information will be used to determine population estimates for all emperor penguin colonies through iterations of supervised classification and maximum likelihood calculations on the high-resolution imagery. The effect of spatial, geophysical, and environmental variables on population size and decadal-scale trends will be assessed using generalized linear models. This research will result in a first ever empirical result for emperor penguin population trends and habitat suitability, and will leverage currently-funded NSF infrastructure and hosting sites to publish results in near-real time to the public.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; Ross Sea; USAP-DC; AMD; COMMUNITY DYNAMICS; Amd/Us", "locations": "Ross Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "LaRue, Michelle; Ito, Emi; Jenouvrier, Stephanie", "platforms": null, "repo": "USAP-DC", "repositories": "Github; USAP-DC", "science_programs": null, "south": -90.0, "title": "A Multi-scale Approach to Understanding Spatial and Population Variability in Emperor Penguins", "uid": "p0010229", "west": -180.0}, {"awards": "2000992 Romans, Brian", "bounds_geometry": "POINT(-172.873074 -74.274008)", "dataset_titles": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "datasets": [{"dataset_uid": "601807", "doi": "10.15784/601807", "keywords": "Antarctica; Cryosphere; Grain Size; Ross Sea", "people": "Varela, Natalia; Romans, Brian W.", "repository": "USAP-DC", "science_program": null, "title": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601807"}], "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. We hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, we plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. \r\n\r\nTo test our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) We will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. We will integrate these data with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene.\r\n", "east": -172.873074, "geometry": "POINT(-172.873074 -74.274008)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; LABORATORY; AMD; USA/NSF; SEDIMENTS; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.274008, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.274008, "title": "COLLABORATIVE RESEARCH: Orbital-scale Variability of the West Antarctic Ice Sheet and the Formation of Bottom Water in the Ross Sea during the Pliocene-Pleistocene", "uid": "p0010227", "west": -172.873074}, {"awards": "1745097 Cassano, John; 1744878 Lazzara, Matthew", "bounds_geometry": "POLYGON((-115 -79,-114.4 -79,-113.8 -79,-113.2 -79,-112.6 -79,-112 -79,-111.4 -79,-110.8 -79,-110.2 -79,-109.6 -79,-109 -79,-109 -79.1,-109 -79.2,-109 -79.3,-109 -79.4,-109 -79.5,-109 -79.6,-109 -79.7,-109 -79.8,-109 -79.9,-109 -80,-109.6 -80,-110.2 -80,-110.8 -80,-111.4 -80,-112 -80,-112.6 -80,-113.2 -80,-113.8 -80,-114.4 -80,-115 -80,-115 -79.9,-115 -79.8,-115 -79.7,-115 -79.6,-115 -79.5,-115 -79.4,-115 -79.3,-115 -79.2,-115 -79.1,-115 -79))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "An observational campaign, focused on the atmospheric boundary layer over the West Antarctic ice sheet (WAIS), is planned. A robust set of year-round, autonomous, atmospheric and surface measurements, will be made using an instrumented 30-m tall tower (TT) at the WAIS divide field camp (WAIS TT). An unmanned aerial system (UAS) field campaign will be conducted and will supplement the WAIS TT observations by sampling the entire depth of the boundary layer.\r\nThe proposed work will create a unique dataset of year-round atmospheric boundary layer measurements from a portion of the Antarctic continent that has not previously been observed in this manner. The newly acquired dataset will be used to elucidate the processes that modulate the exchange of energy between the ice sheet surface and the overlying atmosphere, to assess the relationships\r\nbetween near surface stability, winds, and radiative forcing, and to compare these relationships observed at the WAIS TT to those described for other portions of the Antarctic continent. The dataset will also be used to assess the ability of the Antarctic Mesoscale Prediction System (AMPS) operational weather forecasting model and current generation reanalyses to accurately represent surface and boundary layer processes in this region of Antarctica.\r\nIntellectual Merit\r\nThe near surface atmosphere over West Antarctica is one of the fastest warming locations on the planet and this atmospheric warming, along with oceanic forcing, is contributing to ice sheet melt and rising sea levels. Recent reports from the National Research Council and the Scientific Committee on Antarctic Research have highlighted the critical nature of these aspects of the West Antarctic climate system.\r\nThe proposed research will advance our understanding of how the atmosphere exchanges heat, moisture, and momentum with the ice sheet surface in West Antarctica and will assess our ability to represent these processes in current generation numerical weather prediction and reanalysis products, by addressing the following scientific questions:\r\n- How does the surface layer and lower portion of the atmospheric boundary layer in West Antarctica compare to that over the low elevation ice shelves and the high elevation East Antarctic plateau?\r\n- What are the dominant factors that lead to warm episodes, and potentially periods of melt, over the West Antarctic ice sheet?\r\n- How well do operational forecast models (AMPS) and reanalyses reproduce the observed near surface stability in West Antarctica?\r\n- What are the sources of errors in the modeled near surface atmospheric stability of West Antarctica?\r\nBroader Impacts:\r\nAtmospheric warming and associated melting of the West Antarctic ice sheet has the potential to raise sea level by many meters. The proposed research will explore the processes that control this warming, and as such has broad societal relevance by providing improved understanding of the processes that could lead to large sea level rise.\r\nEducational outreach activities will include classroom visits to K-12 schools and Skype sessions from Antarctica with students at these schools. Photographs, videos, and instrumentation used during this project will be brought to the classrooms. At the college and university level data from the project will be used in classes being developed as part of a new undergraduate atmospheric and oceanic science major at the University of Colorado and a graduate student will be support on this project.\r\nPublic outreach will be in the form of field blogs, media interviews, and either an article for a general interest scientific magazine, such as Scientific American, or as an electronically published book of Antarctic fieldwork photographs.", "east": -109.0, "geometry": "POINT(-112 -79.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Amd/Us; HUMIDITY; ATMOSPHERIC TEMPERATURE; West Antarctic Ice Sheet; BOUNDARY LAYER TEMPERATURE; USAP-DC; ATMOSPHERIC PRESSURE MEASUREMENTS; FIELD SURVEYS; BOUNDARY LAYER WINDS; USA/NSF", "locations": "West Antarctic Ice Sheet", "north": -79.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Cassano, John; Lazzara, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -80.0, "title": "Collaborative Research: Observing the Atmospheric Boundary over the West Antarctic Ice Sheet", "uid": "p0010225", "west": -115.0}, {"awards": "2023303 Purkey, Sarah; 2023259 Thompson, Andrew; 2023244 Stewart, Andrew", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Ocean CFC reconstructed data product", "datasets": [{"dataset_uid": "601752", "doi": "10.15784/601752", "keywords": "Antarctica; CFCs; GLODAP; Ocean Model; Ocean Ventilation; Southern Ocean", "people": "Cimoli, Laura; Gebbie, Jack; Purkey, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Ocean CFC reconstructed data product", "url": "https://www.usap-dc.org/view/dataset/601752"}], "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "The formation of dense Antarctic Bottom Water (AABW) and its export northward from the Antarctic continent is one of the key components of the global ocean overturning circulation, and plays a critical role in regulating Earth\u0027s climate on multi-decadal-to-millennial time scales. Recent studies of the global ocean overturning circulation have increasingly emphasized its three-dimensional structure: AABW is produced in a handful of distinct sites around the Antarctic continent, and there is a pronounced asymmetry in the allocation of AABW transports into the Atlantic, Indian and Pacific basins. The connectivity of AABW between the Antarctic continental shelf and the northern basins is mediated by the Antarctic Circumpolar Current (ACC), a circumpolar eastward flow that also serves as the primary route for inter-basin exchange.\r\n\r\nThe mapping from different shelf AABW sources to the northern basins dictates the response of the global MOC to localized variability or shifts in the state of the Antarctic shelf, for example due to major glacier calving events or modified inputs of freshwater from the Antarctic ice sheet. At present this mapping is not well constrained, with conflicting conclusions drawn in previous studies: at one extreme the ACC has been suggested to be a ``conduit\u0027\u0027 that simply allows each variety of AABW to transit directly northward; at the other extreme, it has been suggested that the ACC ``blends\u0027\u0027 all shelf AABW sources together before they reach the northern basins. Such conflicts arise, in part, because little is understood about the physics that determines AABW\u0027s pathways across the ACC.\r\n\r\nTo close this gap in understanding, this collaborative project draws on three complementary analytical tools: process-oriented modeling of AABW export across the ACC, a high-resolution global ocean model, and an observationally-constrained estimate of the global circulation. The PIs will first identify and quantify the pathways of AABW across the ACC by using these tools to propagate passive tracers that identify each of the four major AABW formation sites. They will then use a suite of process model sensitivity experiments to develop a theory for what controls meridional versus inter-basin transport of AABW in the ACC, and transfer this theory to interpret the AABW pathways simulated in the global model. Finally, they will combine the process model, global model and the observationally-constrained circulation product to map the rates at which AABW is transformed into lighter waters, and relate these transformation rates to the diagnosed pathways of AABW across the ACC. This combination of approaches allow the PIs to not only constrain the three-dimensional circulation of AABW from Antarctica to the northern basins, but also provides a mechanistic understanding of the circulation that can be transferred to past or future climates.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "AMD; MODELS; USAP-DC; WATER MASSES; Southern Ocean; Amd/Us; OCEAN CURRENTS; COMPUTERS; Antarctic Circumpolar Current; USA/NSF", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Stewart, Andrew; Thompson, Andrew; Purkey, Sarah", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters?", "uid": "p0010220", "west": -180.0}, {"awards": "1947882 Robel, Alexander", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "Uncertainty in projections of future sea level rise comes, in part, from ice sheet melting under the influence of unpredictable variations in ocean and atmospheric temperature near ice sheets. The Antarctic Ice Sheet Large Ensemble (AISLENS) Project will estimate the range of possible Antarctic Ice Sheet melt during the recent past and over the next several centuries that could result from such climate variations. The graduate student will develop computational methods using statistical and machine learning approaches to generate plausible realizations of Antarctic climate forcing from output from the Energy Exascale Earth System Model (E3SM) developed by the Department of Energy, under past and future emissions scenarios. These realizations of variable climate will be used to force the MPAS Albany Land Ice (MALI) model, a state-of-the-art model of ice flow in the Antarctic Ice Sheet. Ultimately, the AISLENS Project will include hundreds of simulations of Antarctic ice sheet evolution from 1950 to 2300 forced by these realizations of climate, including snowfall on the ice sheet and surface melt from fluctuating oceanic and atmospheric temperatures. The graduate student will then use these simulations to analyze the evolution of uncertainty in the future evolution of the Antarctic Ice Sheet. Such analyses provide a range of plausible estimates of the ice sheet contribution to future sea level rise and are used by coastal communities to plan infrastructure and development which accounts for these changes in their coastline and water table.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctica; Antarctic Ice Sheet; AMD; USAP-DC; USA/NSF; MODELS; Amd/Us", "locations": "Antarctic Ice Sheet; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology", "paleo_time": null, "persons": "Robel, Alexander", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": null, "title": "The Antarctic Ice Sheet Large Ensemble (AISLENS) Project: Assessing the Role of Climate Variability in Past and Future Ice Sheet Mass Loss", "uid": "p0010223", "west": null}, {"awards": "2027615 Paden, John", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "This project will develop a new ice-penetrating radar system that can simultaneously map glacier geometry (three-dimensional ice-sheet internal architecture and subglacial topography) and glacier flow (vertical velocity of ice) along repeat profiles. Forecasting ice-sheet contribution to sea level requires an estimate for the initial ice-sheet geometry and the parameters that govern ice flow (ice rheology) and slip across bedrock (bed friction). Existing ice-sheet models cannot independently initialize ice rheology and bed friction from conventional observations of surface velocities and glacier geometry. These non-unique solutions for ice-sheet initial state introduce substantial uncertainty into ice-sheet model simulations of past and future ice-sheet behavior. \r\nSpatially-distributed vertical velocities of ice measured by this radar system can be directly compared to simulated vertical velocities produced by glacier models. Thus, this radar technology will allow ice rheology to be constrained independently from bed friction, leading to higher fidelity simulations of past and future ice-sheet behavior and more accurate projections of future sea level.\r\n\r\nThe new radar system will integrate two existing radars (the multi-channel coherent radio-echo depth sounder and the accumulation radar) developed by the Center for the Remote Sensing of Ice Sheets, but also includes new capabilities. An eight-element very high frequency (VHF; 140-215 MHz) array will have sufficient cross-track aperture to swath map internal layers and the ice-sheet base in three dimensions. A single ultra high frequency (UHF; 600-900 MHz) antenna will have the range and phase resolution to map internal layer displacement with 0.25 mm precision. The VHF array will create 3D mappings of layer geometry that enable measurements of vertical velocities by accounting for spatial offsets between repeat profiles and changing surface conditions. The vertical displacement measurement will then be made by determining the difference in radar phase response recorded by the UHF antenna for radar profiles collected at the same locations at different times. The UHF antenna will be dual-polarized and thus capable of isolating both components of complex internal reflections, which should enable inferences of ice crystal orientation fabric and widespread mapping of ice viscosity. Initial deployment of the radar will occur on the McMurdo Ice Shelf and Thwaites Glacier, Antarctica. The dual-band radar system technology and processing algorithms will be developed with versatile extensible hardware and user-friendly software, so that this system will serve as a prototype for a future community radar system.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS", "is_usap_dc": true, "keywords": "Amd/Us; USA/NSF; Airborne Radar; AMD; ICE SHEETS; Thwaites Glacier; USAP-DC", "locations": "Thwaites Glacier", "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Paden, John; Rodriguez-Morales, Fernando ", "platforms": null, "repositories": null, "science_programs": "Thwaites (ITGC)", "south": null, "title": "Collaborative Research: EAGER: A Dual-Band Radar for Measuring Internal Ice Deformation: a Multipass Ice-Penetrating Radar Experiment on Thwaites Glacier and the McMurdo Ice Shelf", "uid": "p0010215", "west": null}, {"awards": "1643445 Eisenman, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Model code, model output fields, etc", "datasets": [{"dataset_uid": "200226", "doi": null, "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Model code, model output fields, etc", "url": "https://eisenman-group.github.io/"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "Satellite observations show expanding Antarctic sea ice over the last three decades. Increasing Antarctic sea ice seems unexpected when compared to observations of rising global temperatures or shrinking Arctic sea ice. Computer models of global climate also predict Antarctic sea ice to shrink instead of grow. Several hypotheses have been suggested to explain the contradiction between what scientists expect to see based on computer models and physical intuition and the growth that is recorded in observations. This study will examine the hypothesis that sea ice expansion can be explained by sea ice motion, where sea ice moves in such a way as to promote an increase in overall coverage. Researchers will use several different types of computer models, ranging in complexity, to better understand the physical processes of sea ice motion and how the sea ice motion interacts with the larger atmosphere-ocean system. The team will transfer their research to the classroom by hosting a week-long teacher workshop. Teachers will learn how scientists use computer models to test hypotheses and then develop and test tools for use in the classroom. Five middle and high school teachers will participate and become part of the UC San Diego STEM Success Initiative master science teacher network. The project will support a graduate student and a postdoctoral researcher.\r\n\r\nSea ice motion has recently emerged as one of the candidates to explain the Antarctic sea ice expansion but a systematic investigation of how sea ice motion influences sea ice concentration has not been presented to date. Researchers will conduct a process-oriented study of the relationship between sea ice motion and Antarctic sea ice extent using a hierarchy of models. The hierarchy will consist of (i) an idealized single-column model of sea ice evolution, (ii) an idealized latitudinally-varying global model of sea ice and climate, (iii) an atmospheric global climate model (GCM) above a slab ocean that includes sea ice motion, (iv) a comprehensive GCM, and (v) model output from the suite of current comprehensive GCMs. The range of model complexities will help researchers better understand the relationship between sea ice motion and sea ice extent by allowing them to identify important processes that are robust across the model hierarchy.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; Southern Ocean; USAP-DC; USA/NSF; ICE EXTENT; COMPUTERS; Sea Ice; GCM", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Eisenman, Ian; Wagner, Till", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "The Influence of Sea Ice Motion on Antarctic Sea Ice Expansion", "uid": "p0010216", "west": -180.0}, {"awards": "2032473 Kurbatov, Andrei; 2032463 Talghader, Joseph", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "datasets": [{"dataset_uid": "601753", "doi": "10.15784/601753", "keywords": "Antarctica; Sampling", "people": "Talghader, Joseph; Mah, Merlin; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": null, "title": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "url": "https://www.usap-dc.org/view/dataset/601753"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "Overview\u003c/br\u003e\nIt is proposed that laser cutting technology can be used to rapidly extract high quality ice samples from borehole walls. The technology applies to both existing boreholes and newly drilled ones, even enabling scientists to obtain samples using non\u2010coring mechanical drills. Since the instrumentation is highly portable, a field team of three persons might take no longer than a few days in the field to extract ice, and samples from a critical time period could be extracted from multiple locations in a single field season.\n\nThis pilot program will investigate and validate the technology of laser sampling. It is beneficial to use fiber optics to convey light in borehole instrumentation rather than attempting to package a complete laser system for travel down a borehole, so the cutting laser and wavelength (1.07Pm) are chosen with such engineering in mind. The primary scientific goals of the program are to: 1) determine optimum cutting conditions in terms of laser power and operating conditions, 2) quantifying the effects of residual meltwater that remain in the cut slot after a cut so that re-cutting needs can be predicted or mitigated, 3) designing and testing mechanical structures to retract samples from blocks of ice once cut, and 4) analyzing the composition and crystal structure of ice near a cut slot to determine the impacted volume (if any) of ice and temperatures where scientific readings might be affected by the sampling process.\n\u003c/br\u003e\u003c/br\u003e\nIntellectual Merits\u003c/br\u003e\nThe collection of deep ice from the Polar Ice Sheets involves large amounts of time, effort, and expense. Often, the most important information is held in very small volumes of core, and while replicate coring can supplement this core, there is often a need to retrieve additional ice samples based on recent scientific findings or borehole logging at a site. In addition, there is currently no easy method of extracting ice from boreholes drilled by non\u2010coring mechanical drills, which are often much faster, lighter, and less expensive to operate. There are numerous specific projects that could immediately benefit from laser sampling including sampling ice overlaying buried impact craters and bolides, filling critical gaps in the chemical record in damaged core sections from Siple Dome, obtaining oldest ice cores from brittle sections near the surface of the Allan Hills blue ice area, where coring drills apply stresses that may fracture the ice, and replacing core whose value has degraded due to time and depressurization. This program builds on a prior engineering advances in optical fiber\u2010based logging technology, developed previously for Siple Dome borehole logging.\n\u003c/br\u003e\u003c/br\u003e\nBroader Impact\u003c/br\u003e\nLaser sampling would advance numerous fields interfaced with glaciology and ice core studies. These include climate and paleoenvironmental science, volcanology, and human history where large volumes of ice are crucial to extract ultra\u2010high resolution records of natural and anthropogenic emissions. Potentially the principle of laser sampling could be used to directly sample and study ice on other planets or their satellites.\nThis program encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training postdoctoral scientists, graduate students, and advanced undergraduates. The program will include a research opportunity for one or more middle school teachers through a Research Experience for Teachers program with one of the local school districts of the Twin Cities area. The teacher(s) will assist the investigators in the analysis of scattered laser light in glacier ice, and will set up a small experiment at various visible wavelengths to measure scattering constants. These experiments have been chosen because they can easily translate into classroom demonstrations and hands\u2010on activities using eye-safe visible- light LED sources and large samples of artificial ice. The teacher(s) will also produce a lesson plan on basic optics, glacial ice, or polar science as a deliverable.\nThis proposal does not involve field work.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Laser Cutting; Ice Core; USA/NSF; AMD; SULFATE; FIELD SURVEYS; OXYGEN COMPOUNDS; USAP-DC; LABORATORY; Sulfate", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Talghader, Joseph; Kurbatov, Andrei V.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Laser Cutting Technology for Borehole Sampling", "uid": "p0010218", "west": -180.0}, {"awards": "1744965 Diao, Minghui; 1744946 Gettelman, Andrew", "bounds_geometry": "POINT(166.7 -77.8)", "dataset_titles": "AWARE_Campaign_Data; Diao, M. (2020). VCSEL 1 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign; Diao, M. (2020). VCSEL 25 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign", "datasets": [{"dataset_uid": "200225", "doi": "10.26023/V925-2H41-SD0F", "keywords": null, "people": null, "repository": "UCAR", "science_program": null, "title": "Diao, M. (2020). VCSEL 25 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign", "url": "https://data.eol.ucar.edu/dataset/290779"}, {"dataset_uid": "200223", "doi": "10.17632/x6n4r3yxb2.1", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "AWARE_Campaign_Data", "url": "http://dx.doi.org/10.17632/x6n4r3yxb2.1"}, {"dataset_uid": "200224", "doi": "10.26023/KFSD-Y8DQ-YC0D", "keywords": null, "people": null, "repository": "UCAR", "science_program": null, "title": "Diao, M. (2020). VCSEL 1 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign", "url": "https://data.eol.ucar.edu/dataset/552.051"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "Ice supersaturation plays a key role in cloud formation and evolution, and it determines the partitioning among ice, liquid and vapor phases. Over the Southern Ocean and Antarctica, the transition between mixed-phase and ice clouds significantly impacts the radiative effects of clouds. Remote regions such as the Antarctica and Southern Ocean historically have been under-sampled by in-situ observations, especially by airborne observations. Even though more attention has been given to the cloud microphysical properties over these regions, the distribution and characteristics of ice supersaturation and its role in the current and future climate have not been fully investigated at the higher latitudes in the Southern Hemisphere. One of the main objectives of this study is to analyze observations from three recent major field campaigns sponsored by NSF and DOE, which provide intensive in-situ, airborne measurements over the Southern Ocean and ground-based observations at McMurdo station in Antarctica.\r\n\r\nThis project will analyze aircraft-based and ground-based observations over the Southern Ocean and Antarctica, and compare the observations with the Community Earth System Model Version 2 (CESM2) simulations. The focus will be on the observations of ice supersaturation and the relative humidity distribution in mixed-phase and ice clouds, as well as their relationship with cloud micro- and macrophysical properties. Observations will be compared to CESM2 simulations to elucidate model biases. Surface radiation and the precipitation budget at the McMurdo station will be quantified and compared against the CESM2 simulations to improve the fidelity of the representation of Antarctic climate (and climate prediction over Antarctica). Results from our research will be released to the community for improving the understanding of cloud radiative effects and the mass transport of water in the high southern latitudes. Comparisons between the simulations and observations will provide valuable information for improving the next generation CESM model. Two education/outreach projects will be carried out by PI Diao at San Jose State University (SJSU), including a unique undergraduate student research project with hands-on laboratory work on an airborne instrument, and an outreach program that uses social media to broadcast news on polar research to the public.", "east": 166.7, "geometry": "POINT(166.7 -77.8)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; CLIMATE MODELS; USA/NSF; SNOW; Amd/Us; USAP-DC; Chile; ATMOSPHERIC WATER VAPOR; ATMOSPHERIC TEMPERATURE; Antarctica; Southern Ocean; AMD", "locations": "Antarctica; Southern Ocean; Chile", "north": -77.8, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Diao, Minghui; Gettelman, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e CLIMATE MODELS", "repo": "UCAR", "repositories": "Publication; UCAR", "science_programs": null, "south": -77.8, "title": "Collaborative Research: Ice Supersaturation over the Southern Ocean and Antarctica, and its Role in Climate", "uid": "p0010209", "west": 166.7}, {"awards": "1851022 Fudge, Tyler; 1851094 Baker, Ian", "bounds_geometry": null, "dataset_titles": "EPICA Dome C Sulfate Data 7-3190m", "datasets": [{"dataset_uid": "601759", "doi": "10.15784/601759", "keywords": "Antarctica", "people": "Fudge, T. J.; Severi, Mirko", "repository": "USAP-DC", "science_program": "COLDEX", "title": "EPICA Dome C Sulfate Data 7-3190m", "url": "https://www.usap-dc.org/view/dataset/601759"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "An accurate constitutive relationship for ice is fundamental to ice-flow models and ice-core interpretations. While Glen\u2019s flow law describes well the overall deformation of ice when subjected to stress, many details remain poorly constrained. In particular, the effect of impurities on the strain rate both directly and through the development of ice fabric is not well understood. Variations in impurity concentrations are associated with variations in deformation rates as observed in both Greenland and Antarctica. The impact of uncertainties on the deformation of ice is most acutely observed in the interpretation of ice cores where the inference of past accumulation rate depends on the cumulative vertical thinning. Thus, many ice-core climate reconstructions, such as the gas-age ice-age difference, surface temperature histories, and aerosol fluxes, are also affected. Given the complexities of the possible impacts of sulfuric acid on the flow of ice and the interaction between these impacts, it seems almost impossible to examine an ice core and understand the impacts of impurities on the microstructural evolution and creep behavior. Our research seeks to understand the effects of sulfuric acid at concentrations applicable to polar ice sheets and relate these results to the flow of polar ice both through experiments and through modeling. Our results have shown that the presence of sulfuric acid in the grain boundaries of polar ice increases its strength in shear, while sulfuric acid in the whole matrix of polar ice reduces its strength. We have also found that sulfuric acid causes an initial increase in average grain sizes and then a subsequent decrease, a trend that differs from the continuous increase in average grain sizes observed in freshwater ice. We are also determining the role of stress state, i.e. simple compression versus shear, on the microstructural evolution and how sulfuric acid impacts this.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; Polycrystalline Ice; LABORATORY; Epica Dome C; SNOW/ICE; USA/NSF; USAP-DC; Ice Core; Amd/Us", "locations": "Epica Dome C", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology; Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "uid": "p0010211", "west": null}, {"awards": "1906015 Kelley, Joanna", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Data, Code, and Results for the Zoarcoidei Phylogeny (Hotaling et al.)", "datasets": [{"dataset_uid": "200221", "doi": "10.5281/zenodo.4306092).", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Data, Code, and Results for the Zoarcoidei Phylogeny (Hotaling et al.)", "url": "https://doi.org/10.5281/zenodo.4306092"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Fish that reside in the harsh, subfreezing waters of the Antarctic and Arctic provide fascinating examples of adaptation to extreme environments. Species at both poles have independently evolved ways to deal with constant cold temperature, including the evolution of antifreeze proteins. Under freezing conditions, these compounds attach to ice crystals and prevent their growth. This lowers the tissue freezing point and reduces the chance the animal will be injured or killed. While it might seem that the need for unique adaptations to survive in polar waters would reduce species diversity in these habitats, recent evidence showed higher speciation rates in fishes from polar environments as compared to those found in warmer waters. This is despite the fact cold temperatures slow cellular processes, which had been expected to lower rates of molecular evolution in these species. To determine how rates of speciation and molecular evolution are linked in marine fishes, this project will compare the genomes of multiple polar and non-polar fishes. By doing so, it will (1) clarify how rates of evolution vary in polar environments, (2) identify general trends that shape the adaptive trajectories of polar fishes, and (3) determine how functional differences shape the evolution of novel compounds such as the antifreeze proteins some polar fishes rely upon to survive. In addition to training a new generation of scientists, the project will develop curriculum and outreach activities for elementary and undergraduate science courses. Materials will be delivered in classrooms across the western United States, with a focus on rural schools as part of a network for promoting evolutionary education in rural communities.\r\n\r\nTo better understand the biology of polar fishes and the evolution of antifreeze proteins (AFPs), this research will compare the evolutionary histories of cold-adapted organisms to those of related non-polar species from both a genotypic and phenotypic context. In doing so, this research will test whether evolutionary rates are slowed in polar environments, perhaps due to constraints on cellular processes. It will also evaluate the effects of positive selection and the relaxation of selection on genes and pathways, both of which appear to be key adaptive strategies involved in the adaptation to polar environments. To address specific mechanisms by which extreme adaptation occurs, researchers will determine how global gradients of temperature and dissolved oxygen shape genome variation and influence adaptive trajectories among multiple species of eelpouts (family Zoarcidae). An in-vitro experimental approach will then be used to test functional hypotheses about the role of copy number variation in AFP evolution, and how and why multiple antifreeze protein isoforms have evolved. By comparing the genomes of multiple polar and non-polar fishes, the project will clarify how rates of evolution vary in polar environments, identify general trends that shape the adaptive trajectories of cold-adapted marine fishes, and determine how functional differences shape the evolution of novel proteins. This project addresses the strategic programmatic aim to provide a better understanding of the genetic underpinnings of organismal adaptations to their current environment and ways in which polar fishes may respond to changing conditions over different evolutionary time scales. The project is jointly funded by the Antarctic Organisms and Ecosystems Program in the Office of Polar Programs of the Geosciences Directorate, and the Molecular Biophysics Program of the Division of Molecular and Cellular Biosciences in the Biological Sciences Directorate.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; FISH; MARINE ECOSYSTEMS; LABORATORY; AMD; USAP-DC; Amd/Us; USA/NSF", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Kelley, Joanna", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Genome Evolution in Polar Fishes", "uid": "p0010200", "west": -180.0}, {"awards": "1846837 Bowman, Jeff", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "The coastal Antarctic is undergoing great environmental change. Physical changes in the environment, such as altered sea ice duration and extent, have a direct impact on the phytoplankton and bacteria species which form the base of the marine foodweb. Photosynthetic phytoplankton are the ocean\u0027s primary producers, transforming (fixing) CO2 into organic carbon molecules and providing a source of food for zooplankton and larger predators. When phytoplankton are consumed by zooplankton, or killed by viral attack, they release large amounts of organic carbon and nutrients into the environment. Heterotrophic bacteria must eat other things, and function as \"master recyclers\", consuming these materials and converting them to bacterial biomass which can feed larger organisms such as protists. Some protists are heterotrophs, but others are mixotrophs, able to grow by photosynthesis or heterotrophy. Previous work suggests that by killing and eating bacteria, protists and viruses may regulate bacterial populations, but how these processes are regulated in Antarctic waters is poorly understood. This project will use experiments to determine the rate at which Antarctic protists consume bacteria, and field studies to identify the major bacterial taxa involved in carbon uptake and recycling. In addition, this project will use new sequencing technology to obtain completed genomes for many Antarctic marine bacteria. To place this work in an ecosystem context this project will use microbial diversity data to inform rates associated with key microbial processes within the PALMER ecosystem model.\r\n\r\nThis project addresses critical unknowns regarding the ecological role of heterotrophic marine bacteria in the coastal Antarctic and the top-down controls on bacterial populations. Previous work suggests that at certain times of the year grazing by heterotrophic and mixotrophic protists may meet or exceed bacterial production rates. Similarly, in more temperate waters bacteriophages (viruses) are thought to contribute significantly to bacterial mortality during the spring and summer. These different top-down controls have implications for carbon flow through the marine foodweb, because protists are grazed more efficiently by higher trophic levels than are bacteria. This project uses a combination of grazing experiments and field observations to assess the temporal dynamics of mortality due to temperate bacteriophage and protists. Although many heterotrophic bacterial strains observed in the coastal Antarctic are taxonomically similar to strains from other regions, recent work suggest that they are phylogenetically and genetically distinct. To better understand the ecological function and evolutionary trajectories of key Antarctic marine bacteria, their genomes will be isolated and sequenced. Then, these genomes will be used to improve the predictions of the paprica metabolic inference pipeline, and our understanding of the relationship between heterotrophic bacteria and their major predators in the Antarctic marine environment. Finally, the research team will modify the Regional Test-Bed Model model to enable microbial diversity data to be used to optimize the starting conditions of key parameters, and to constrain the model\u0027s data assimilation methods.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Magmatic Volatiles; BACTERIA/ARCHAEA; VIRUSES; USA/NSF; Palmer Station; ECOSYSTEM FUNCTIONS; COMMUNITY DYNAMICS; LABORATORY; Amd/Us; PROTISTS; AMD; USAP-DC", "locations": "Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bowman, Jeff; Connors, Elizabeth", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "CAREER: Understanding microbial heterotrophic processes in coastal Antarctic waters", "uid": "p0010201", "west": null}, {"awards": "1914698 Hansen, Samantha; 1914743 Becker, Thorsten; 1914668 Aschwanden, Andy; 1914767 Winberry, Paul", "bounds_geometry": "POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))", "dataset_titles": "East Antarctic Seismicity from different Automated Event Detection Algorithms; Full Waveform Ambient Noise Tomography for East Antarctica", "datasets": [{"dataset_uid": "601763", "doi": "10.15784/601763", "keywords": "Ambient Noise; Antarctica; East Antarctica; Geoscientificinformation; Seismic Tomography; Seismology", "people": "Emry, Erica; Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Full Waveform Ambient Noise Tomography for East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601763"}, {"dataset_uid": "601762", "doi": "10.15784/601762", "keywords": "Antarctica; Geoscientificinformation; Machine Learning; Seismic Event Detection; Seismology; Seismometer", "people": "Hansen, Samantha; Ho, Long; Walter, Jacob", "repository": "USAP-DC", "science_program": null, "title": "East Antarctic Seismicity from different Automated Event Detection Algorithms", "url": "https://www.usap-dc.org/view/dataset/601762"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Part I: Nontechnical \u003cbr/\u003eEarths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California\u0027s Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica\u0027s potential for future sea-level. \u003cbr/\u003e\u003cbr/\u003e Part II: Technical Description \u003cbr/\u003eIn polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments.", "east": 180.0, "geometry": "POINT(135 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "TECTONICS; AMD; Wilkes Subglacial Basin; ICE SHEETS; USA/NSF; Amd/Us; SEISMOLOGICAL STATIONS; SEISMIC SURFACE WAVES; East Antarctica; USAP-DC", "locations": "East Antarctica; Wilkes Subglacial Basin", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Becker, Thorsten; Binder, April; Hansen, Samantha; Aschwanden, Andy; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)", "uid": "p0010204", "west": 90.0}, {"awards": "1644159 Jacobs, Stanley", "bounds_geometry": "POLYGON((-180 -72.5,-177 -72.5,-174 -72.5,-171 -72.5,-168 -72.5,-165 -72.5,-162 -72.5,-159 -72.5,-156 -72.5,-153 -72.5,-150 -72.5,-150 -73.15,-150 -73.8,-150 -74.45,-150 -75.1,-150 -75.75,-150 -76.4,-150 -77.05,-150 -77.7,-150 -78.35,-150 -79,-153 -79,-156 -79,-159 -79,-162 -79,-165 -79,-168 -79,-171 -79,-174 -79,-177 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.35,162 -77.7,162 -77.05,162 -76.4,162 -75.75,162 -75.1,162 -74.45,162 -73.8,162 -73.15,162 -72.5,163.8 -72.5,165.6 -72.5,167.4 -72.5,169.2 -72.5,171 -72.5,172.8 -72.5,174.6 -72.5,176.4 -72.5,178.2 -72.5,-180 -72.5))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020; Ross Island area salinity and temperature records 1956 to 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}, {"dataset_uid": "601458", "doi": "10.15784/601458", "keywords": "Antarctica; CTD; Oceans; Physical Oceanography; Ross Island; Ross Sea; Salinity; Temperature", "people": "Jacobs, Stanley; Giulivi, Claudia F.", "repository": "USAP-DC", "science_program": null, "title": "Ross Island area salinity and temperature records 1956 to 2020", "url": "https://www.usap-dc.org/view/dataset/601458"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "This project extended and combined historical and recent ocean data sets to investigate ice-ocean-interactions along the Pacific continental margin of the West Antarctic Ice Sheet. The synthesis focused on the strikingly different environments on and near the cold Ross Sea and warm Amundsen Sea continental shelves, where available measurements reach back to 1911 and 1994, respectively. On the more extensively covered Ross Sea continental shelf, multiple reoccupations of ocean stations and transects since the 1950s were used to extend our knowledge of ocean thermohaline change and variability. The more rugged Amundsen Sea continental shelf contains the earth\u0027s fastest melting ice shelves, which Holland et al (2019) show can be linked to decadal-scale variability in the tropical Pacific, and Jacobs et al. (2021) document as being the primary influence on freshening downstream in the Ross Sea. Recent and potential future rates of sea level rise are the primary broad-scale impacts revealed by the observations of ice and ocean changes in these study areas. More regionally, freshening also influences the properties of slope front and coastal currents, and abyssal water mass formation. The overriding question in such work is whether their contributions to global and regional sea levels will continue to increase ~linearly, perhaps allowing greenhouse gas reductions to head off the worst consequences, or accelerate and contribute to major social and economic upheavals. The compiled ocean station profile data has been derived from measurements made from 16 ships operated by 6 countries, from 5 projects using holes through fast and glacier ice, and from 3 studies using drifting floats. We are grateful to the many individuals who have acquired, processed and provided the data, along with their supporting agencies, and welcome corrections and updates to this archive.\n\n", "east": -150.0, "geometry": "POINT(-174 -75.75)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; USA/NSF; COMPUTERS; Ross Sea; SHIPS; USAP-DC; SALINITY/DENSITY; OCEAN TEMPERATURE", "locations": "Ross Sea", "north": -72.5, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "West Antarctic Ice Shelf- Ocean Interactions ", "uid": "p0010208", "west": 162.0}, {"awards": "1840927 Weissburg, Marc; 1840949 Fields, David; 1840941 Murphy, David", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Overview: This project has two goals. The first is to investigate the responses of Antarctic krill Euphasia superba to flow and chemical stimuli indicating food and predation risk, the interaction of these cues, and how krill responses to these cues depend on the photic environment. This project will will determine threshold responses, the ability of krill to orient to horizontal and vertical flows, whether chemical cues polarize responses to flow and whether this differs with attractive vs. aversive cues, and how these responses are affected by light intensity. This will determine how and under what specific conditions the flow, chemical and light environment can either attract or repel krill, and whether krill can use flows to transport themselves towards beneficial environments and away from risky ones. The second goal is to examine whether the behavioral responses of individual krill can be scaled up to predict the properties of aggregations such as density, coherence, swimming speed and direction. This project will use a modeling approach to determine properties of krill aggregations in defined oceanographic conditions characteristic of the southern ocean to examine links between individual behavior and aggregation properties in physically realistic scenarios.\r\n\r\nIntellectual Merit:\r\nKrill are an ecologically important component of all high latitude food webs and constitute a growing fishery yet we know very little about their behavior in response to environmentally relevant chemical, flow and photic conditions. Understanding krill demography can be enabled by examining individual responses to light, attractive (food related) and aversive (predator related) chemical cues, flow, light and their interactions. This analysis can be used to define/predict preferred environments, define the capacity of krill to detect and move to them (and away from unfavorable ones), better parameterize models of DVM, and krill energetics. Linking individual behavior to aggregations will improve our ability to use passive acoustic sampling of krill to understand their biology by providing insight into what krill are doing in aggregations that display particular features, and help define useful properties to characterize aggregations. The role of biology vs. physical forcing in determining zooplankton distributions, and the relationship between individual behavior and emergent group properties are fundamental questions.\r\n\r\nBroader Impacts:\r\nAntarctic krill (Eupahusia superba) are dominant members of the Southern Ocean. They are a critical resource for higher predators, are considered an ecosystem engineer, are the most highly linked species in Antarctic food webs, exert top down control on phytoplankton abundance and represent the largest Antarctic fishery. This project will therefore impact our understanding of the ecology of high latitude systems, their capacity to respond to environmental perturbations (like climate change), and krill fisheries management. Project PIs will engage conservation and management experts to vet and use the developed software tools, as well as to share results. The project will support one post-doctoral associate to be trained in a highly interdisciplinary environment, and provide graduate and undergraduate research opportunities in ocean sciences, biology and engineering. Products will include open source code for behavioral modeling, K12 curricular materials based on these models as well as digital archives of krill behavior, and a variety of public engagement activities.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ANIMAL ECOLOGY AND BEHAVIOR; AMD; FIELD INVESTIGATION; Amd/Us; USAP-DC; Palmer Station; USA/NSF", "locations": "Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Fields, David; Record, Nicholas ; Weissburg, Marc", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Individual Based Approaches to Understanding Krill Distributions and Aggregations", "uid": "p0010202", "west": null}, {"awards": "1844793 Aksoy, Mustafa", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Firn Brightness Temperatures Measured by AMSR2 and SSMIS (Concordia, Vostok, and the Entire Ice Sheet)); In-Situ Density, Temperature, Grain Size, and Layer Thickness data for the Antarctic Ice Sheet", "datasets": [{"dataset_uid": "601551", "doi": "10.15784/601551", "keywords": "Antarctica; Antarctic Ice Sheet", "people": "Kar, Rahul; Kaurejo, Dua; Aksoy, Mustafa", "repository": "USAP-DC", "science_program": null, "title": "In-Situ Density, Temperature, Grain Size, and Layer Thickness data for the Antarctic Ice Sheet", "url": "https://www.usap-dc.org/view/dataset/601551"}, {"dataset_uid": "601550", "doi": "10.15784/601550", "keywords": "Antarctica; Antarctic Ice Sheet; Satellite; Vostok", "people": "Kar, Rahul; Kaurejo, Dua; Aksoy, Mustafa", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Firn Brightness Temperatures Measured by AMSR2 and SSMIS (Concordia, Vostok, and the Entire Ice Sheet))", "url": "https://www.usap-dc.org/view/dataset/601550"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "This project will test the hypothesis that physical and thermal properties of Antarctic firn--partially compacted granular snow in an intermediate stage between snow and glacier ice--can be remotely measured from space. Although these properties, such as internal temperature, density, grain size, and layer thickness, are highly relevant to studies of Antarctic climate, ice-sheet dynamics, and mass balance, their measurement currently relies on sparse in-situ surveys under challenging weather conditions. Sensors on polar-orbiting satellites can observe the entire Antarctic every few days during their years-long lifetime. Consequently, the approaches developed in this study, when coupled with the advancing technologies of small and low-cost CubeSats, aim to contribute to Antarctic science and lead to cost-effective, convenient, and accurate long-term analyses of the Antarctic system while reducing the human footprint on the continent. Moreover, the project will be solely based on publicly-available datasets; thus, while contributing to interdisciplinary undergraduate and graduate research and education at the grantee\u0027s institution, the project will also encourage engagement of citizen scientists through its website.\r\n\r\nThe overarching goal of this project is to characterize Antarctic firn layers in terms of their thickness, physical temperature, density, and grain size through multi-frequency microwave radiometer measurements from space. Electromagnetic penetration depth changes with frequency in ice; thus, multi-frequency radiometers are able to profile firn layer properties versus depth. To achieve its objective, the project will utilize the Global Precipitation Measurement (GPM) satellite constellation as a single multi-frequency microwave radiometer system with 11 frequency channels observing the Antarctic Ice Sheet. Archived in-situ measurements of Antarctic firn density, grain size, temperature, and layer thickness will be collected and separated into training and test datasets. Microwave emissions simulated using the training data will be compared to GPM constellation measurements to evaluate and improve state-of-the-art forward microwave emission models. Based on these models, the project will develop numerical retrieval algorithms for the thermal and physical properties of Antarctic firn. Results of retrievals will be validated using the test dataset, and uncertainty and error analyses will be conducted. Lastly, changes in the thermal and physical characteristics of Antarctic firn will be examined through long-term retrieval studies exploiting GPM constellation measurements.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIRN; Amd/Us; USA/NSF; ICE SHEETS; SNOW DENSITY; Multi-Frequency Passive Remote Sensing; University At Albany; USAP-DC; SNOW/ICE TEMPERATURE; SATELLITES; SNOW/ICE", "locations": "University At Albany", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aksoy, Mustafa", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Characterization of Antarctic Firn by Multi-Frequency Passive Remote Sensing from Space", "uid": "p0010206", "west": -180.0}, {"awards": "1739027 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((-125 -73,-122.1 -73,-119.2 -73,-116.3 -73,-113.4 -73,-110.5 -73,-107.6 -73,-104.7 -73,-101.8 -73,-98.9 -73,-96 -73,-96 -73.7,-96 -74.4,-96 -75.1,-96 -75.8,-96 -76.5,-96 -77.2,-96 -77.9,-96 -78.6,-96 -79.3,-96 -80,-98.9 -80,-101.8 -80,-104.7 -80,-107.6 -80,-110.5 -80,-113.4 -80,-116.3 -80,-119.2 -80,-122.1 -80,-125 -80,-125 -79.3,-125 -78.6,-125 -77.9,-125 -77.2,-125 -76.5,-125 -75.8,-125 -75.1,-125 -74.4,-125 -73.7,-125 -73))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 24 Jun 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Collapse of the West Antarctic Ice Sheet (WAIS) could raise the global sea level by about 5 meters (16 feet) and the scientific community considers it the most significant risk for coastal environments and cities. The risk arises from the deep, marine setting of WAIS. Although scientists have been aware of the precarious setting of this ice sheet since the early 1970s, it is only now that the flow of ice in several large drainage basins is undergoing dynamic change consistent with a potentially irreversible disintegration. Understanding WAIS stability and enabling more accurate prediction of sea-level rise through computer simulation are two of the key objectives facing the polar science community today. This project will directly address both objectives by: (1) using state-of-the-art technologies to observe rapidly deforming parts of Thwaites Glacier that may have significant control over the future evolution of WAIS, and (2) using these new observations to improve ice-sheet models used to predict future sea-level rise. This project brings together a multidisciplinary team of UK and US scientists. This international collaboration will result in new understanding of natural processes that may lead to the collapse of the WAIS and will boost infrastructure for research and education by creating a multidisciplinary network of scientists. This team will mentor three postdoctoral researchers, train four Ph.D. students and integrate undergraduate students in this research project.\r\n\r\nThe project will test the overarching hypothesis that shear-margin dynamics may exert powerful control on the future evolution of ice flow in Thwaites Drainage Basin. To test the hypothesis, the team will set up an ice observatory at two sites on the eastern shear margin of Thwaites Glacier. The team argues that weak topographic control makes this shear margin susceptible to outward migration and, possibly, sudden jumps in response to the drawdown of inland ice when the grounding line of Thwaites retreats. The ice observatory is designed to produce new and comprehensive constraints on englacial properties, including ice deformation rates, ice crystal fabric, ice viscosity, ice temperature, ice water content and basal melt rates. The ice observatory will also establish basal conditions, including thickness and porosity of the till layer and the deeper marine sediments, if any. Furthermore, the team will develop new knowledge with an emphasis on physical processes, including direct assessment of the spatial and temporal scales on which these processes operate. Seismic surveys will be carried out in 2D and 3D using wireless geophones. A network of broadband seismometers will identify icequakes produced by crevassing and basal sliding. Autonomous radar systems with phased arrays will produce sequential images of rapidly deforming internal layers in 3D while potentially also revealing the geometry of a basal water system. Datasets will be incorporated into numerical models developed on different spatial scales. One will focus specifically on shear-margin dynamics, the other on how shear-margin dynamics can influence ice flow in the whole drainage basin. Upon completion, the project aims to have confirmed whether the eastern shear margin of Thwaites Glacier can migrate rapidly, as hypothesized, and if so what the impacts will be in terms of sea-level rise in this century and beyond.\r\n", "east": -96.0, "geometry": "POINT(-110.5 -76.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; Thwaites Glacier; USAP-DC; USA/NSF; Magmatic Volatiles; AMD; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; ICE SHEETS; Amd/Us", "locations": "Thwaites Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Tulaczyk, Slawek", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": "Thwaites (ITGC)", "south": -80.0, "title": "NSF-NERC: Thwaites Interdisciplinary Margin Evolution (TIME): The Role of Shear Margin Dynamics in the Future Evolution of the Thwaites Drainage Basin", "uid": "p0010199", "west": -125.0}, {"awards": "1643120 Iverson, Neal", "bounds_geometry": null, "dataset_titles": "Ice permeameter experimental parameters and results; Softening of temperate ice by interstitial water; Tertiary creep rates if temperate ice containing greater than 0.7% liquid water", "datasets": [{"dataset_uid": "601833", "doi": null, "keywords": "Antarctica; Cryosphere", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Tertiary creep rates if temperate ice containing greater than 0.7% liquid water", "url": "https://www.usap-dc.org/view/dataset/601833"}, {"dataset_uid": "601460", "doi": "10.15784/601460", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Stream; Lab Experiment; Rheology; Snow/ice; Snow/Ice; Water Content", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Softening of temperate ice by interstitial water", "url": "https://www.usap-dc.org/view/dataset/601460"}, {"dataset_uid": "601515", "doi": "10.15784/601515", "keywords": "Antarctica; Glacier Flow; Glacier Hydrology; Glaciological Instruments And Methods; Glaciology; Ice Physics; Ice Stream; Snow/ice; Snow/Ice", "people": "Iverson, Neal; Fowler, Jacob", "repository": "USAP-DC", "science_program": null, "title": "Ice permeameter experimental parameters and results", "url": "https://www.usap-dc.org/view/dataset/601515"}], "date_created": "Wed, 23 Jun 2021 00:00:00 GMT", "description": "This award supports a project to study the effect of liquid, intercrystalline water on the flow resistance of ice and the mobility of this water within ice. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is \"temperate,\u201d meaning that it is at its pressure-melting temperature with relatively thick water films at grain boundaries that significantly soften the ice. The amount of water in ice depends sensitively on its permeability, values of which are too poorly known to estimate the water contents of ice-stream shear margins or associated ice viscosities.\r\n \r\n\r\nThis award stems from the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University and Oxford University in the United Kingdom. The experimental part of the project is executed at Iowa State University and is the focus herein because it has been supported by NSF. Two sets of experiments are conducted. In one set, a large ring-shear device is used to shear ice in confined compression and at its melting temperature to study the sensitivity of ice viscosity to water content. Ice is sheared at stresses and strain rates comparable to those of ice-stream margins, and water content is varied through twice the range explored in the only previous set of experiments that investigated ice softening by water. The second set of experiments required the design, fabrication, and testing of a laboratory ice permeameter that allows the permeability of temperate ice to be measured. Experiments are conducted to study the dependence of ice permeability on ice grain size and water content--the two dependencies required to model grain-scale water flow through temperate ice.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; Rheology; Antarctica; LABORATORY; Ice Stream; USA/NSF; USAP-DC; Lab Experiment; Water Content", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Iverson, Neal; Zoet, Lucas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice", "uid": "p0010197", "west": null}, {"awards": "1643494 Saal, Alberto", "bounds_geometry": "POLYGON((-68.074 -57.345,-66.6033 -57.345,-65.1326 -57.345,-63.6619 -57.345,-62.1912 -57.345,-60.7205 -57.345,-59.2498 -57.345,-57.7791 -57.345,-56.3084 -57.345,-54.8377 -57.345,-53.367 -57.345,-53.367 -58.12517,-53.367 -58.90534,-53.367 -59.68551,-53.367 -60.46568,-53.367 -61.24585,-53.367 -62.02602,-53.367 -62.80619,-53.367 -63.58636,-53.367 -64.36653,-53.367 -65.1467,-54.8377 -65.1467,-56.3084 -65.1467,-57.7791 -65.1467,-59.2498 -65.1467,-60.7205 -65.1467,-62.1912 -65.1467,-63.6619 -65.1467,-65.1326 -65.1467,-66.6033 -65.1467,-68.074 -65.1467,-68.074 -64.36653,-68.074 -63.58636,-68.074 -62.80619,-68.074 -62.02602,-68.074 -61.24585,-68.074 -60.46568,-68.074 -59.68551,-68.074 -58.90534,-68.074 -58.12517,-68.074 -57.345))", "dataset_titles": "Major, trace elements contents and radiogenic isotopes of erupted lavas Antarctic Peninsula and Phoenix Ridge", "datasets": [{"dataset_uid": "601519", "doi": "10.15784/601519", "keywords": "Antarctica; Antarctic Peninsula; Chemical Composition; Chemistry:rock; Chemistry:Rock; Geochemistry; Isotope Data; Trace Elements", "people": "Saal, Alberto", "repository": "USAP-DC", "science_program": null, "title": "Major, trace elements contents and radiogenic isotopes of erupted lavas Antarctic Peninsula and Phoenix Ridge", "url": "https://www.usap-dc.org/view/dataset/601519"}], "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "The focus of our research is to examine the regional geochemical variations of well-characterized Pliocene-recent basalt samples along a transect from the Phoenix-Antarctic ridge to James Ross Island (through the South Shetland Islands, Bransfield Strait and the Antarctic Peninsula). The goal is to understand 1) the processes responsible for the generation of chemically diverse basalts in close spatial and temporal proximity within the Antarctic Peninsula and 2) the nature (lithology, composition and temperature) of the heterogeneous mantle source beneath the region.", "east": -53.367, "geometry": "POINT(-60.7205 -61.24585)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; USA/NSF; USAP-DC; TRACE ELEMENTS; MAJOR ELEMENTS; Amd/Us; LABORATORY; ROCKS/MINERALS/CRYSTALS; Magmatic Volatiles; AMD", "locations": "Antarctic Peninsula", "north": -57.345, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Saal, Alberto", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.1467, "title": "Magmatic Volatiles, Unraveling the Reservoirs and Processes of the Volcanism in the Antarctic Peninsula", "uid": "p0010196", "west": -68.074}, {"awards": "1744970 Shevenell, Amelia", "bounds_geometry": "POLYGON((120 -66,120.1 -66,120.2 -66,120.3 -66,120.4 -66,120.5 -66,120.6 -66,120.7 -66,120.8 -66,120.9 -66,121 -66,121 -66.1,121 -66.2,121 -66.3,121 -66.4,121 -66.5,121 -66.6,121 -66.7,121 -66.8,121 -66.9,121 -67,120.9 -67,120.8 -67,120.7 -67,120.6 -67,120.5 -67,120.4 -67,120.3 -67,120.2 -67,120.1 -67,120 -67,120 -66.9,120 -66.8,120 -66.7,120 -66.6,120 -66.5,120 -66.4,120 -66.3,120 -66.2,120 -66.1,120 -66))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "At present, Antarctica\u2019s glaciers are melting as the Southern Ocean warms. While glacial retreat in West Antarctica is linked to ocean warming, less is known about the response of East Antarctica\u2019s glaciers. Totten Glacier, located on the Sabrina Coast, East Antarctica is presently retreating. Totten\u2019s retreat is important because it is associated with warm ocean waters and because the glacier drains part of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels ~3.5 meters. Mud accumulating on the seafloor around Antarctica is composed of sediment from the adjacent continent, as well as the skeletons and debris from microscopic marine organisms. As mud accumulates, so does a record of past environmental changes, including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers from the University of South Florida will refine and test new geochemical thermometers to better understand the influence of ocean temperatures on East Antarctic glacier extent over the last ~16,000 years. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions.", "east": 121.0, "geometry": "POINT(120.5 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; FIELD INVESTIGATION; USA/NSF; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; AMD; Amd/Us", "locations": "Sabrina Coast", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -67.0, "title": "Deglacial to Recent Paleoceanography of the Sabrina Coast, East Antarctica: A Multi-proxy Study of Ice-ocean Interactions at the Outlet of the Aurora Subglacial Basin", "uid": "p0010194", "west": 120.0}, {"awards": "1750888 Aronson, Richard; 1750630 Smith, Craig; 1750903 Ingels, Jeroen", "bounds_geometry": "POLYGON((-64 -66,-63.3 -66,-62.6 -66,-61.9 -66,-61.2 -66,-60.5 -66,-59.8 -66,-59.1 -66,-58.4 -66,-57.7 -66,-57 -66,-57 -66.3,-57 -66.6,-57 -66.9,-57 -67.2,-57 -67.5,-57 -67.8,-57 -68.1,-57 -68.4,-57 -68.7,-57 -69,-57.7 -69,-58.4 -69,-59.1 -69,-59.8 -69,-60.5 -69,-61.2 -69,-61.9 -69,-62.6 -69,-63.3 -69,-64 -69,-64 -68.7,-64 -68.4,-64 -68.1,-64 -67.8,-64 -67.5,-64 -67.2,-64 -66.9,-64 -66.6,-64 -66.3,-64 -66))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. Major outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline. The latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological, geological and cryospheric processes associated with ice-shelf collapse and its ecosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting: 1) Cryospheric dynamics and ice-shelf collapse \u2013 past and future (M. Truffer, University of Alaska, Fairbanks) 2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer) 3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer) 4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sr\u0161en, Ann Vanreusel) 5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James McClintock, Kathryn Smith, Brittany Steffel) 6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the future (Huw Griffiths) 7) Feedback on the workshop \u201cClimate change impacts on marine ecosystems: implications for management of living resources and conservation\u201d held 19-22 September 2017, Cambridge, UK (Alex Rogers) 8) Past research activities and plans for Larsen field work by the Alfred Wegener Institute, Germany (Charlotte Havermans, Dieter Piepenburg. One of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem consequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team\u2014Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels\u2014initiated AntICE: \"Antarctic Influences of Climate Change on Ecosystems\" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to make the children aware of climatic changes in the Antarctic and their effect on ecosystems so they, in turn, can spread this knowledge to their communities, family and friends \u2013 acting as \u2018Polar Ambassadors\u2019. We collaborated with the Polar-ICE project, an NSF-funded educational project that established the Polar Literacy Initiative. This program developed the Polar Literacy Principles, which outline essential concepts to improve public understanding of Antarctic and Arctic ecosystems. In the Polar Academy work, we used the Polar Literacy principles, the Polar Academy Team\u2019s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will change further with climate change. Using general presentations, case studies, scientific methodology, individual experiences, interactive discussions and Q\u0026A sessions, the children were guided through the many issues Antarctic ecosystems are facing. Over 300 \u0027\u0027Polar ambassadors\u0027\u0027 attended the interactive lectures and afterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/\n\nFurther concrete products of the workshop: 1) a position-paper focusing on ideas, hypotheses and priorities for investigating the ecological impacts of ice-shelf collapse along the Antarctic Peninsula (Ingels et al., 2018; \u201cThe scientific response to Antarctic ice-shelf loss; Nature Climate Change 8, 848-851), and 2) a publication reviewing what is known and unknown about ecological responses to ice-shelf melt and collapse, outlining expected ecological outcomes of ice-shelf disintegration along the Antarctic Peninsula (Ingels et al., 2020; \u201cAntarctic ecosystem responses following ice\u2010shelf collapse and iceberg calving: Science review and future research\u201d, WIREs Climate Change, e682). The second publication was covered in the The Scientist and by a press-release in Germany, see https://www.altmetric.com/details/91826381. Other products included a poster presentation at the MEASO2018 conference in Hobart, Australia in 2018, and the above-mentioned visits to schools and institutes to talk about the research in invited seminars. We also conducted and active online outreach campaign, with dissemination of our work in various news outlets, blogs, and social media (e.g. reaching \u003e750k total followers on twitter with the publications alone).\u0027", "east": -57.0, "geometry": "POINT(-60.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE ECOSYSTEMS; USAP-DC; LABORATORY; AMD; Weddell Sea; GLACIERS/ICE SHEETS; ECOLOGICAL DYNAMICS; USA/NSF; SEA ICE; Amd/Us; Antarctica", "locations": "Antarctica; Weddell Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ingels, Jeroen; Aronson, Richard; Smith, Craig", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: RAPID/Workshop - Antarctic Ecosystem Research following Ice Shelf Collapse and Iceberg Calving Events", "uid": "p0010189", "west": -64.0}, {"awards": "1443342 Licht, Kathy; 1443556 Thomson, Stuart", "bounds_geometry": null, "dataset_titles": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "datasets": [{"dataset_uid": "601462", "doi": "10.15784/601462", "keywords": "Antarctica; Beardmore Glacier; Erosion; Landscape Evolution; Shackleton Glacier; Transantarctic Mountains; (U-Th)/He", "people": "Licht, Kathy; Hemming, Sidney R.; He, John; Thomson, Stuart; Reiners, Peter", "repository": "USAP-DC", "science_program": null, "title": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601462"}], "date_created": "Wed, 09 Jun 2021 00:00:00 GMT", "description": "Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth\u0027s last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media.\r\n\r\n\r\nThe main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100\u00b0E-160\u00b0E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; LANDSCAPE; AGE DETERMINATIONS; FIELD INVESTIGATION; GLACIAL PROCESSES; Transantarctic Mountains; USA/NSF; Thermochronology; Amd/Us; USAP-DC; TRACE ELEMENTS; Provenance Analysis; AMD; LANDFORMS; GLACIAL LANDFORMS", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Thomson, Stuart; Reiners, Peter; Licht, Kathy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: East Antarctic Glacial Landscape Evolution (EAGLE): A Study using Combined Thermochronology, Geochronology and Provenance Analysis", "uid": "p0010188", "west": null}, {"awards": "1245871 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": "Dataset for Tidal modulation of ice streams: Effect of periodic sliding velocity on ice friction and healing; Rate-state friction parameters for ice-on-rock oscillation experiments; RSFitOSC", "datasets": [{"dataset_uid": "200237", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "RSFitOSC", "url": "https://github.com/rmskarbek/RSFitOSC"}, {"dataset_uid": "601497", "doi": "10.15784/601497", "keywords": "Antarctica", "people": "McCarthy, Christine M.; Savage, Heather; Skarbek, Rob", "repository": "USAP-DC", "science_program": null, "title": "Dataset for Tidal modulation of ice streams: Effect of periodic sliding velocity on ice friction and healing", "url": "https://www.usap-dc.org/view/dataset/601497"}, {"dataset_uid": "601467", "doi": "10.15784/601467", "keywords": "Antarctica", "people": "Savage, Heather; Skarbek, Rob; McCarthy, Christine M.", "repository": "USAP-DC", "science_program": null, "title": "Rate-state friction parameters for ice-on-rock oscillation experiments", "url": "https://www.usap-dc.org/view/dataset/601467"}], "date_created": "Fri, 04 Jun 2021 00:00:00 GMT", "description": "This award supports a project to conduct laboratory experiments with a new, custom-fabricated cryo-friction apparatus to explore ice deformation oscillatory stresses like those experienced by tidewater glaciers in nature. The experimental design will explore the dynamic frictional properties of periodically loaded ice sliding on rock. Although the frictional strength of ice has been studied in the past these studies have all focused on constant rates of loading and sliding. The results of this work will advance understanding of ice stream dynamics by improving constraints on key material and frictional properties and allowing physics-based predictions of the amplitude and phase of glacier strain due to tidally induced stress variations. The intellectual merit of this work is that it will result in a better understanding of dynamic rheological parameters and will provide better predictive tools for dynamic glacier flow. The proposed experiments will provide dynamic material properties of ice and rock deformation at realistic frequencies experienced by Antarctic glaciers. The PIs will measure the full spectrum of material response from elastic to anelastic to viscous. The study will provide better constraints to improve predictive capability for glacier and ice-stream response to external forcing. The broader impacts of the work include providing estimates of material properties that can be used to broaden our understanding of glacier flow and that will ultimately be used for models of sea level rise and ice sheet stability. The ability to predict sea level in the near future is contingent on understanding of the processes responsible for flow of Antarctic ice streams and glaciers. Modulation of glacier flow by ocean tides represents a natural experiment that can be used to improve knowledge of ice and bed properties, and of the way in which these properties depend on time-varying forcings. Presently, the influence of tidal forcing on glacier movement is poorly understood, and knowledge of ice properties under tidal loading conditions is limited. The study will generate results of interest beyond polar science by examining phenomena that are of interest to seismology, glaciology and general materials science. The project will provide valuable research and laboratory experience for two undergraduate interns and will provide experience for the PI (currently a postdoc) in leading a scientific project. The three PIs are early career scientists. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Amd/Us; AMD; Ice Deformation; LABORATORY; BASAL SHEAR STRESS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McCarthy, Christine M.; Savage, Heather", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "GitHub", "repositories": "GitHub; USAP-DC", "science_programs": null, "south": null, "title": "Laboratory Study of Ice Deformation under Tidal Loading Conditions with Application to Antarctic Glaciers", "uid": "p0010186", "west": null}, {"awards": "1935438 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 03 Jun 2021 00:00:00 GMT", "description": "The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change the quantity relevant for estimating the ice sheets sea-level contribution requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores.\r\n\r\nThis project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (\u003e 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; LABORATORY; USA/NSF; COMPUTERS; USAP-DC; FIRN; Antarctic Ice Sheet; Amd/Us", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "McCarthy, Christine M.; Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Understanding Firn Rheology Through Laboratory Compaction Experiments and Radar Data", "uid": "p0010185", "west": null}, {"awards": "1743310 Kingslake, Jonathan", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Vulnerability of Antarctica\u2019s ice shelves to meltwater-driven fracture", "datasets": [{"dataset_uid": "601395", "doi": "10.15784/601395", "keywords": "Antarctica; Computer Model; Fractures; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meltwater; Model Data", "people": "Lai, Ching-Yao", "repository": "USAP-DC", "science_program": null, "title": "Vulnerability of Antarctica\u2019s ice shelves to meltwater-driven fracture", "url": "https://www.usap-dc.org/view/dataset/601395"}], "date_created": "Wed, 02 Jun 2021 00:00:00 GMT", "description": "Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets loose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project.\r\n\r\nThe team will develop and test physics-based mathematical models of water flow and ice-shelf fracture, closely informed by remote sensing observations, to examine (1) how do surface drainage systems respond to inter-annual changes in surface melting, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) developing and testing simple models of ice-shelf fracture. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity.\r\n\r\nThree aspects of the project will produce data and code that will be archived in USAP-DC:\r\n1. Mapped ice-shelf drainage system characteristics.\r\n2. Computed continent-wide fields of ice-shelf vulnerability to hydrofracture.\r\n3. An open source augmented reality ice sheet app.\r\n\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; USAP-DC; Antarctica; ICE SHEETS; Amd/Us; Ice Shelf; COMPUTERS; Surface Meltwater", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Satellite observations and modelling of surface meltwater flow and its impact on ice shelves", "uid": "p0010184", "west": -180.0}, {"awards": "1543501 Howat, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "The Reference Model of Antarctica", "datasets": [{"dataset_uid": "200218", "doi": "", "keywords": null, "people": null, "repository": "PGC", "science_program": null, "title": "The Reference Model of Antarctica", "url": "https://www.pgc.umn.edu/data/rema/"}], "date_created": "Tue, 18 May 2021 00:00:00 GMT", "description": "The Reference Elevation Model of Antarctica (REMA) is the first continental-scale digital elevation model (DEM) at a resolution of less than 10\u2009m. REMA is created from stereophotogrammetry with submeter resolution optical, commercial satellite imagery. The higher spatial and radiometric resolutions of this imagery enable high-quality surface extraction over the low-contrast ice sheet surface. The DEMs are registered to satellite radar and laser altimetry and are mosaicked to provide a continuous surface covering nearly 95\u2009% the entire continent. The mosaic includes an error estimate and a time stamp, enabling change measurement. Typical elevation errors are less than 1\u2009m, as validated by the comparison to airborne laser altimetry. REMA provides a powerful new resource for Antarctic science and provides a proof of concept for generating accurate high-resolution repeat topography at continental scales.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Topography; AMD; USA/NSF; Amd/Us; USAP-DC; Antarctica; ICE SHEETS; COMPUTERS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Howat, Ian; Myoung-Jong Noh, ", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "PGC", "repositories": "PGC", "science_programs": null, "south": -90.0, "title": "The Reference Elevation Model of Antarctica", "uid": "p0010180", "west": -180.0}, {"awards": "1834986 Ballard, Grant", "bounds_geometry": "POLYGON((165 -77,165.5 -77,166 -77,166.5 -77,167 -77,167.5 -77,168 -77,168.5 -77,169 -77,169.5 -77,170 -77,170 -77.1,170 -77.2,170 -77.3,170 -77.4,170 -77.5,170 -77.6,170 -77.7,170 -77.8,170 -77.9,170 -78,169.5 -78,169 -78,168.5 -78,168 -78,167.5 -78,167 -78,166.5 -78,166 -78,165.5 -78,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5,165 -77.4,165 -77.3,165 -77.2,165 -77.1,165 -77))", "dataset_titles": "Orthomosaics of Ross Island Penguin Colonies 2019 - 2021", "datasets": [{"dataset_uid": "601612", "doi": "10.15784/601612", "keywords": "Aerial Imagery; Aerial Survey; Antarctica; Biota; Geotiff; Penguin; Photo/video; Photo/Video; Population Count; Ross Island; UAV", "people": "Shah, Kunal; Schmidt, Annie; Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Orthomosaics of Ross Island Penguin Colonies 2019 - 2021", "url": "https://www.usap-dc.org/view/dataset/601612"}], "date_created": "Wed, 12 May 2021 00:00:00 GMT", "description": "New methodologies for the deployment of coordinated unmanned aerial vehicles will be developed with the aim of attaining whole-colony imagery that can be used to characterize nesting habitats of Adelie penguins at Cape Crozier, on Ross Island, Antarctica. This information will be used to test hypotheses regarding relationships between terrain characteristics, nesting density, and breeding success. This population, potentially the largest in the world and at the southern limit of the species\u0027 range, has doubled in size over the past 20 years while most other colonies in the region have remained stable or declined. New information gained from this project will be useful in understanding the potential of climate-driven changes in terrestrial nesting habitats for impacting Adelie penguins in the future. The project will produce, and document, open-source software tools to help automate image processing for automated counting of Adelie penguins. The project will train graduate and undergraduate students and contribute materials to ongoing educational outreach programs based on related penguin science projects. Information gained from this project will contribute towards building robust, cost-effective protocols for monitoring Adelie penguin populations, a key ecosystem indicator identified in the draft Ross Sea Marine Protected Area Research and Monitoring Plan.\r\n\r\nAdelie penguins are important indicators of ecosystem function and change in the Southern Ocean. In addition to facing rapid changes in sea ice and other factors in their pelagic environment, their terrestrial nesting habitat is also changing. Understanding the species\u0027 response to such changes is critical for assessing its ability to adapt to the changing climate. The objective of this project is to test several hypotheses about the influence of fine-scale nesting habitat, nest density, and breeding success of Adelie penguins in the Ross Sea region. To accomplish this, the project will develop algorithms to improve efficiency and safety of surveys by unmanned aerial systems and develop and disseminate an automated image processing workflow. Images collected during several UAV surveys will be used to estimate the number of nesting adults and chicks produced, as well as estimate nesting density in different parts of two colonies on Ross Island, Antarctica, that differ in size by two orders of magnitude. Imagery will be used to generate high resolution digital surface/elevation models that will allow terrain variables like flood risk and terrain complexity to be derived. Combining the surface model with the nest and chick counts at the two colonies will provide relationships between habitat covariates, nest density, and breeding success. The approaches developed will enable Adelie penguin population sizes and potentially several other indicators in the Ross Sea Marine Protected Area Research and Monitoring Plan to be determined and evaluated. The flight control algorithms developed have the potential to be used for many types of surveys, especially when large areas need to be covered in a short period with extreme weather potential and difficult landing options. Aerial images and video will be used to create useable materials to be included in outreach and educational programs. The automated image processing workflow and classification models will be developed as open source software and will be made freely available for others addressing similar wildlife monitoring challenges.", "east": 170.0, "geometry": "POINT(167.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "UAS; Ross Island; USA/NSF; FIELD INVESTIGATION; AMD; UAV; MARINE ECOSYSTEMS; USAP-DC; Amd/Us; Penguin", "locations": "Ross Island", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ballard, Grant; Schmidt, Annie; Schwager, Mac; McKown, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Does Nest Density Matter? Using Novel Technology to Collect Whole-colony Data on Adelie Penguins.", "uid": "p0010178", "west": 165.0}, {"awards": "1852617 Carlstrom, John", "bounds_geometry": "POINT(0 -90)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 11 May 2021 00:00:00 GMT", "description": "The South Pole Telescope Operations and Data Products award supports the maintenance and operation of the 10-meter South Pole Tele- scope (SPT) equipped with the current third-generation instrument, SPT-3G. The proposed operations plan includes five years of survey observations to obtain ultra-deep measurements of a 1500 square degree field with SPT-3G, as well as the production and public archiving of essential data products from the survey. The data products from SPT-3G as well as the previous SPTpol survey will be released to the public at regular and timely intervals over the project period. The operations also support SPT\u2019s critical role in the Event Horizon Telescope (EHT), a global array of telescopes to image the event horizon around the black hole at the center of our Galaxy.\r\n\r\nThe SPT-3G instrument, first deployed in the 2016-17 Austral summer, is a major upgrade in capabilities over previous generations of SPT cameras, with over 16,000 detectors configured for polarization-sensitive observations in three frequency bands. The SPT-3G maps of the temperature, polarization, and lensing potential of the CMB will have an unprecedented combination of depth, resolution and sky coverage (1500 square degrees). This unique data set will enable broad and impactful science, from sensitive constraints on inflationary models to the formation and evolution of galaxies.\r\n\r\nWorking in collaboration with the BICEP/Keck team, we will use the high-resolution SPT-3G data to remove the gravitational lensing signal from BICEP Array maps to enable a deep search for primordial gravitational waves (PGW). The full SPT-3G data set funded by this proposal will allow delensing of BICEP Array data that could improve constraints on PGW by more than a factor of two. \r\nThe SPT-3G temperature and polarization power spectrum measurements will play a central role in probing the nature of current tensions among cosmological parameter estimations from different data sets and determining if their explanation requires physics beyond the standard cosmological model (LCDM). One of the most well-motivated extensions to LCDM in light of these tensions is the existence of new light particles in the early Universe: SPT-3G will improve sensitivity to such particles by at least a factor of two over current CMB experiments.\r\n\r\nSPT-3G data will be used to constrain the properties of dark energy from its effect on the growth of structure through both CMB lensing and the abundance of galaxy clusters. These two observables will also be used to place nearly independent constraints on the sum of the neutrino masses. The unique catalogs of high-redshift galaxy clusters and early star-forming galaxies produced by SPT-3G will be used to understand cluster formation and trace massive galaxy evolution from the epoch of reionization to the peak of star formation.\r\n\r\nPublic data products will include temperature and polarization maps in all three SPT-3G frequency bands, CMB angular power spectra, gravitational lensing maps and power spectra, a catalog of distant massive galaxy clusters, and catalogs of mm-wave-bright galaxies.\r\n\r\nThis project is designed to provide calibrated, uniform, and publicly archived data products that will enable scientific breakthroughs in multiple areas. The public SPT data products will impact the larger community by enabling a broad range of studies that address some of the most compelling questions in cosmology and astrophysics. The sharing of the spirit of scientific inquiry will be extended beyond the research community through a well-established education network at all levels of the education continuum, from early childhood through graduate school. Summer Schools on CMB Instrumentation will be taught by the Co-I\u2019s and senior personnel on this proposal. For our proposed First Discoveries program, we will partner with The University of Chicago\u2019s Neighborhood Schools Program to work with students and teachers in less-advantaged classrooms to foster scientific reasoning through inquiry-based learning.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "SOLAR/SPACE OBSERVING INSTRUMENTS \u003e RADIO WAVE DETECTORS \u003e RADIO TELESCOPES", "is_usap_dc": true, "keywords": "USAP-DC; AMD; Adelie Penguin; THERMAL INFRARED; South Pole Station; Amd/Us; OBSERVATORIES", "locations": "South Pole Station", "north": -90.0, "nsf_funding_programs": "Polar Special Initiatives; Antarctic Astrophysics and Geospace Sciences; Antarctic Science and Technology", "paleo_time": null, "persons": "Carlstrom, John; Holzapfel, William; Benson, Bradford", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e OBSERVATORIES", "repositories": null, "science_programs": null, "south": -90.0, "title": "South Pole Telescope Operations and Data Products", "uid": "p0010176", "west": 0.0}, {"awards": "1643652 Hofmann, Eileen; 1643618 Arrigo, Kevin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic biological model output; Antarctic dFe model dyes", "datasets": [{"dataset_uid": "200211", "doi": "10.26008/1912/bco-dmo.858663.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic biological model output", "url": "https://www.bco-dmo.org/dataset/858663"}, {"dataset_uid": "200210", "doi": "10.26008/1912/bco-dmo.782848.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic dFe model dyes", "url": "https://www.bco-dmo.org/dataset/782848"}], "date_created": "Thu, 29 Apr 2021 00:00:00 GMT", "description": "Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail.\r\nThis project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings.\r\nThe project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts.\r\n\r\nPolynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers.\r\nIn this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for \u003e50% of the total Antarctic polynya production.\r\nThe research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent?\r\nThe Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Trace Metal; AMD; PELAGIC; POLYNYAS; PHYTOPLANKTON; MODELS; Amd/Us; USAP-DC; MICROALGAE; USA/NSF; Polynya; TRACE ELEMENTS; ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula", "uid": "p0010175", "west": -180.0}, {"awards": "1638957 Kovac, John", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "BICEP/Keck data products", "datasets": [{"dataset_uid": "200205", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "BICEP/Keck data products", "url": "http://bicepkeck.org"}], "date_created": "Wed, 31 Mar 2021 00:00:00 GMT", "description": "The theory of the \"Big Bang\" provides a well-established cosmological model for the Universe from its earliest known periods through its subsequent large-scale evolution. The model traces the expansion of the Universe, starting from initial conditions of a very high density and temperature state which is almost but not perfectly smooth, and it offers a comprehensive explanation for a broad range of now-known phenomena, including the abundance of light elements, the cosmic microwave background radiation, and the distribution of large scale structures. While the established \"Big Bang\" theory leaves open the question of explaining the initial conditions, current evidence is consistent with the entire observable Universe being spawned in a dramatic, exponential \"inflation\" of a sub-nuclear volume that lasted about one trillionth of a trillionth of a trillionth of a second. Following this short inflationary period, the Universe continues to expand, but at a less rapid rate. While the basic \"inflationary paradigm\" is accepted by most scientists, the detailed particle physics mechanism responsible for inflation is still not known. It is believed that this violent space-time expansion would have produced primordial gravitational waves now propagating through the expanding universe, thus forming a cosmic gravitational-wave background (CGB) the amplitude of which measures the energy scale of inflation. The CGB imprints a faint signature in the polarization of the Cosmic Microwave Background (CMB), and detecting this polarization signature is arguably the most important goal in cosmology today. This award will address one of the oldest questions ever posed by mankind, \"How did the Universe begin?\", and it does so via observations made at one of the most intriguing places on Earth, South Pole Station in Antarctica.\u003cbr/\u003e \u003cbr/\u003eThe community-driven Astro2010 Decadal Survey described the search for the CGB as \"the most exciting quest of all\", emphasizing that \"mid-term investment is needed for systems aimed at detecting the (B-mode) polarization of the CMB\". In 2005, the NASA/DOE/NSF Task Force on CMB Research identified this topic as the highest priority for the field and established a target sensitivity for the ratio of gravitational waves to density fluctuations of r ~ 0.01. Such measurements promise a definitive test of slow-roll models of inflation, which generally predict a gravitational-wave signal around r~0.01 or above, producing CMB B-modes fluctuations that peak on degree angular scales. The ongoing BICEP series of experiments is dedicated to this science goal. The experiment began operating at South Pole in 2006 and has been relentlessly mapping an 800 square degree region of the sky in a region of low in Galactic foregrounds known as the Southern Hole. This award will support science observations and analysis for the CMB \"Stage 3\" science with the BICEP Array program that will measure the polarized sky in five frequency bands. It is projected to reach an ultimate sensitivity to the amplitude of inflationary gravitational waves of \"sigma r\" \u003c 0.005, extrapolating from achieved performance and after conservatively accounting for the Galactic dust, Galactic synchrotron radiation, and CMB lensing foregrounds. This measurement will offer a definitive test of most slow-roll models of Inflation, and will realize or exceed the goals set by the Task Force in 2005 for sensitivity. The project will continue to provide excellent training for undergraduate and graduate students and postdoctoral fellows (including those from underrepresented groups) in laboratories that have exceptional track records in this regard. Cosmology and research in Antarctica both capture the public imagination, making this combination a remarkably effective vehicle for stimulating interest in science.", "east": 0.0, "geometry": "POINT(-180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "THERMAL INFRARED; NOT APPLICABLE; South Pole Station", "locations": "South Pole Station", "north": -90.0, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Kovac, John; Pryke, Clem", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "Project website", "repositories": "Project website", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Imaging the Beginning of Time from the South Pole: The next Stage of the BICEP Program", "uid": "p0010167", "west": 0.0}, {"awards": "1744755 Ito, Takamitsu", "bounds_geometry": "POLYGON((-80 -45,-75 -45,-70 -45,-65 -45,-60 -45,-55 -45,-50 -45,-45 -45,-40 -45,-35 -45,-30 -45,-30 -47.5,-30 -50,-30 -52.5,-30 -55,-30 -57.5,-30 -60,-30 -62.5,-30 -65,-30 -67.5,-30 -70,-35 -70,-40 -70,-45 -70,-50 -70,-55 -70,-60 -70,-65 -70,-70 -70,-75 -70,-80 -70,-80 -67.5,-80 -65,-80 -62.5,-80 -60,-80 -57.5,-80 -55,-80 -52.5,-80 -50,-80 -47.5,-80 -45))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 23 Mar 2021 00:00:00 GMT", "description": "Current generation of coupled climate models, that are used to make climate projections, lack the resolution to adequately resolve ocean mesoscale (10 - 100km) processes, exhibiting significant biases in the ocean carbon uptake. Mesoscale processes include many features including jets, fronts and eddies that are crucial for bio-physical interactions, air-sea CO2 exchange and the supply of iron to the surface ocean. This modeling project will support the eddy resolving regional simulations to understand the mechanisms that drives bio-physical interaction and air-sea exchange of carbon dioxide. ", "east": -30.0, "geometry": "POINT(-55 -57.5)", "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; OCEAN CHEMISTRY; Drake Passage; AMD; USA/NSF; USAP-DC; Air-Sea Carbon Transfer; Amd/Us", "locations": "Drake Passage", "north": -45.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Ito, Takamitsu", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -70.0, "title": "A mechanistic study of bio-physical interaction and air-sea carbon transfer in the Southern Ocean", "uid": "p0010166", "west": -80.0}, {"awards": "1738989 Venturelli, Ryan; 2317097 Venturelli, Ryan", "bounds_geometry": "POLYGON((-114 -74,-112.2 -74,-110.4 -74,-108.6 -74,-106.8 -74,-105 -74,-103.2 -74,-101.4 -74,-99.6 -74,-97.8 -74,-96 -74,-96 -74.2,-96 -74.4,-96 -74.6,-96 -74.8,-96 -75,-96 -75.2,-96 -75.4,-96 -75.6,-96 -75.8,-96 -76,-97.8 -76,-99.6 -76,-101.4 -76,-103.2 -76,-105 -76,-106.8 -76,-108.6 -76,-110.4 -76,-112.2 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica; Cosmogenic-Nuclide data at ICE-D; In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers; NBP1902 Expedition data; Pine Island Bay Relative Sea-Level Data", "datasets": [{"dataset_uid": "601677", "doi": "10.15784/601677", "keywords": "Antarctica; Ice Penetrating Radar; Pine Island Glacier; Subglacial Bedrock", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601677"}, {"dataset_uid": "200296", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}, {"dataset_uid": "601705", "doi": "10.15784/601705", "keywords": "Antarctica; Cosmogenic Radionuclides; Mount Murphy; Subglacial Bedrock", "people": "Venturelli, Ryan; Goehring, Brent; Balco, Gregory", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers", "url": "https://www.usap-dc.org/view/dataset/601705"}, {"dataset_uid": "601554", "doi": "10.15784/601554", "keywords": "Antarctica; Pine Island Bay; Radiocarbon; Raised Beaches", "people": "Braddock, Scott; Hall, Brenda", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Pine Island Bay Relative Sea-Level Data", "url": "https://www.usap-dc.org/view/dataset/601554"}], "date_created": "Tue, 16 Mar 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Thwaites Glacier system dominates the contribution to sea-level rise from Antarctica. Predicting how this system will evolve in coming decades, and thereby its likely contribution to sea level, requires detailed understanding of how it has responded to changes in climate and oceanographic conditions in the past. This project will provide a record of regional sea-level change by establishing chronologies for raised marine beaches as well as the timing and duration of periods of retreat of Thwaites Glacier during the past 10,000 years by sampling and dating bedrock presently covered by Thwaites Glacier via subglacial drilling. Together with climatic and oceanographic conditions from other records, these will provide boundary conditions for past-to-present model simulations as well as those used to predict future glacier changes under a range of climate scenarios. Specifically, the project will test the hypothesis--implied by existing geological evidence from the region--that present rapid retreat of the Thwaites Glacier system is reversible. \r\n\r\nThe team aims to utilize two approaches: 1. To reconstruct relative sea level during the Holocene, it will map and date raised marine and shoreline deposits throughout Pine Island Bay. Chronological constraints on sea-level change will be provided by radiocarbon dating of organic material in landforms and sediments that are genetically related to past sea level, such as shell fragments, bones of marine fauna, and penguin guano. 2. To obtain geological evidence for past episodes of grounding-line retreat, the team will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed for subglacial bedrock recovery, the team will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding-line position in the Thwaites system (specifically in the Hudson Mountains, and near Mount Murphy). Observation of significant cosmogenic-nuclide concentrations--the team will primarily measure Beryllium-10 and in situ Carbon-14--in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding-line retreat as well as constraints on their timing and duration.", "east": -96.0, "geometry": "POINT(-105 -75)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; GLACIERS/ICE SHEETS; GLACIAL LANDFORMS; LABORATORY; Amd/Us; USAP-DC; GLACIATION; Amundsen Sea; USA/NSF", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Goehring, Brent; Hall, Brenda; Campbell, Seth; Venturelli, Ryan A; Balco, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "ICE-D; R2R; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "uid": "p0010165", "west": -114.0}, {"awards": "2002346 Tinto, Kirsteen; 2001714 Muto, Atsuhiro", "bounds_geometry": "POLYGON((-115 -70,-113 -70,-111 -70,-109 -70,-107 -70,-105 -70,-103 -70,-101 -70,-99 -70,-97 -70,-95 -70,-95 -70.8,-95 -71.6,-95 -72.4,-95 -73.2,-95 -74,-95 -74.8,-95 -75.6,-95 -76.4,-95 -77.2,-95 -78,-97 -78,-99 -78,-101 -78,-103 -78,-105 -78,-107 -78,-109 -78,-111 -78,-113 -78,-115 -78,-115 -77.2,-115 -76.4,-115 -75.6,-115 -74.8,-115 -74,-115 -73.2,-115 -72.4,-115 -71.6,-115 -70.8,-115 -70))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 02 Mar 2021 00:00:00 GMT", "description": "Predictions of future changes of the Antarctic ice sheet are essential for understanding changes in the global sea level expected for the coming centuries. These predictions rely on models of ice-sheet flow that in turn rely on knowledge of the physical conditions of the Antarctic continent beneath the ice. Exploration of Antarctica by land, sea, and air has advanced our understanding of the geological material under the Antarctic ice sheet, but this information has not yet been fully integrated into ice-sheet models. This project will take advantage of existing data from decades of US and international investment in geophysical surveys to create a new understanding of the geology underlying the Amundsen Sea and the adjacent areas of the West Antarctic Ice Sheet?a portion of Antarctica that is considered particularly vulnerable to collapse. A series of new datasets called ?Bed Classes? will be developed that will translate the geological properties of the Antarctic continent in ways that can be incorporated into ice-sheet models. \u003cbr/\u003e\u003cbr/\u003eThis project will develop a new regional geologic/tectonic framework for the Amundsen Sea Embayment and its ice catchments using extensive marine and airborne geophysical data together with ground-based onshore geophysical and geological constraints to delineate sedimentary basins, bedrock ridges, faults, and volcanic structures. Using this new geologic interpretation of the region, several key issues regarding the geologic influence on ice-sheet stability will be addressed: whether the regional heat flow is dominated by localization along the faults or lithology; the role of geology on the sources, sinks, and flow-paths of subglacial water; the distribution of sediments that determine bed-character variability; and the extent of geologic control on the current Thwaites Glacier grounding line. The impact of improved geological knowledge on ice-sheet models will be tested with the development of a set of ?Bed Class? grids to capture these new insights for use in the models. Bed Classes will be tested within the Parallel Ice Sheet Model framework with initial experiments to identify the sensitivity of model simulations to geological parameterizations. Through a series of workshops with ice-sheet modelers, the Bed Classes will be refined and made accessible to the broader modelling community. This work aims to ensure that the Bed-Class concept can be applied more broadly to ice-sheet models working in different geographic areas and on different timescales.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-105 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Amundsen Sea; COMPUTERS; GRAVITY ANOMALIES; Amd/Us; GLACIERS/ICE SHEETS; AMD; USA/NSF; USAP-DC", "locations": "Amundsen Sea", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Integrated System Science; Antarctic Glaciology", "paleo_time": null, "persons": "Tinto, Kirsty; Bell, Robin; Porter, David; Muto, Atsu", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative Research: Building Geologically Informed Bed Classes to Improve Projections of Ice Sheet Change", "uid": "p0010164", "west": -115.0}, {"awards": "2048351 Lindow, Julia", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 26 Feb 2021 00:00:00 GMT", "description": "Measurements of in-situ produced cosmogenic nuclides in Antarctic surficial rock samples provide unique time scales for glacial and landscape evolution processes. However, due to analytical challenges, pyroxene-bearing and widely distributed lithologies like the Ferrar dolerite of the Transantarctic Mountains, are underutilized. This proposal aims to changes this and to improve the cosmogenic nuclide methodologies for stable isotopes (21Ne and 3He) and radioactive nuclides (10Be) in pyroxenes. Proposed methodological improvements will be directly applicable to erosion rates and deposition ages of important glacial deposits, such as the controversial Sirius Group tills, and also to younger glacial features. Bennett Platform is the focus of this study because it is one of the southern-most Sirius Group outcrops along the Transantarctic Mountains, where cosmogenic ages are sparse.\r\n\r\nPreliminary measurements demonstrate large discrepancies between 3He and 21Ne age determinations in Sirius Group pyroxenes. One possible explanation is composition dependence of the 21Ne production rates. Coupled measurements of 3He, 21Ne, and 10Be in well-characterized pyroxene mineral separates from Ferrar dolerite will be used to better constrain the production rates, major element and trace element dependencies, the assumptions of the method, and ultimately advance the application of cosmogenic nuclides to mafic Antarctic lithologies.\r\n\r\nThe main goals of this study are to improve measurement protocols for 10Be in pyroxene, and the determination of the composition dependence of 21Ne production rates by measuring mineral compositions (by electron microprobe), and nuclide concentrations in mineral pairs from young lava flows. Further aims are the validation of the nucleogenic contributions and the effects of helium diffusive loss through measurements of 3He/21Ne production ratios, combined with measurements of shielded samples of the Ferrar dolerite. Combined measurements of 3He, 21Ne and 10Be in pyroxenes have rarely been published for individual samples in Antarctica. The new and unique measurements of this study will advance the applicability of in-situ produced cosmogenic nuclides to both young and ancient Antarctic surfaces. The study will be performed using existing samples: no field work is requested.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; FIELD INVESTIGATION; LABORATORY; Transantarctic Mountains; USAP-DC; GLACIAL LANDFORMS; Amd/Us", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lindow, Julia; Kurz, Mark D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "New Cosmogenic 21Ne and 10Be Measurements in the Transantarctic Mountains", "uid": "p0010163", "west": null}, {"awards": "1443144 Steig, Eric; 1443448 Schaefer, Joerg", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Simulations of 10Be over Antarctica; South Pole ice Core 10Be CE", "datasets": [{"dataset_uid": "601431", "doi": "10.15784/601431", "keywords": "Antarctica; South Pole", "people": "Schaefer, Joerg; Steig, Eric J.; Ding, Qinghua", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Simulations of 10Be over Antarctica", "url": "https://www.usap-dc.org/view/dataset/601431"}, {"dataset_uid": "601535", "doi": "10.15784/601535", "keywords": "Antarctica; South Pole", "people": "Schaefer, Joerg", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice Core 10Be CE", "url": "https://www.usap-dc.org/view/dataset/601535"}], "date_created": "Thu, 04 Feb 2021 00:00:00 GMT", "description": "This project acquired measurements of the concentration of beryllium-10 (10Be) from an ice core from the South Pole, Antarctica. An isotope of the element beryllium, 10Be, is produced in the atmosphere by high-energy protons (cosmic rays) that enter Earth\u0027s atmosphere from space. It is removed from the atmosphere by settling or by scavenging by rain or snowfall. Hence, concentrations of 10Be in snow at the South Pole reflect the production rate of 10Be in the atmosphere. Because the rate of production of 10Be over Antarctica depends primarily on the strength of the Sun\u0027s magnetic field, measurements of 10Be in the South Pole ice core provide a record of changes in solar activity. To ain interpretation of the South Pole 10Be record, a climate model that can simulate the production of 10Be in the atmosphere, it\u0027s transport through the atmosphere, and its deposition at the snow surface in Antarctica is used to quantify the impact of climate noise on the 10Be signal.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "COSMIC RAYS; LABORATORY; BERYLLIUM-10 ANALYSIS; SNOW/ICE; South Pole; GLACIERS; ICE CORE RECORDS", "locations": "South Pole", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Schaefer, Joerg; Steig, Eric J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A High-sensitivity Beryllium-10 Record from an Ice Core at South Pole", "uid": "p0010158", "west": -180.0}, {"awards": "1842059 Huber, Matthew; 1842049 Kim, Sora; 1842176 Bizimis, Michael; 1842115 Jahn, Alexandra", "bounds_geometry": "POLYGON((-56.693516 -64.209061,-56.6823452 -64.209061,-56.6711744 -64.209061,-56.6600036 -64.209061,-56.6488328 -64.209061,-56.637662 -64.209061,-56.6264912 -64.209061,-56.6153204 -64.209061,-56.6041496 -64.209061,-56.5929788 -64.209061,-56.581808 -64.209061,-56.581808 -64.2143344,-56.581808 -64.2196078,-56.581808 -64.2248812,-56.581808 -64.2301546,-56.581808 -64.235428,-56.581808 -64.2407014,-56.581808 -64.2459748,-56.581808 -64.2512482,-56.581808 -64.2565216,-56.581808 -64.261795,-56.5929788 -64.261795,-56.6041496 -64.261795,-56.6153204 -64.261795,-56.6264912 -64.261795,-56.637662 -64.261795,-56.6488328 -64.261795,-56.6600036 -64.261795,-56.6711744 -64.261795,-56.6823452 -64.261795,-56.693516 -64.261795,-56.693516 -64.2565216,-56.693516 -64.2512482,-56.693516 -64.2459748,-56.693516 -64.2407014,-56.693516 -64.235428,-56.693516 -64.2301546,-56.693516 -64.2248812,-56.693516 -64.2196078,-56.693516 -64.2143344,-56.693516 -64.209061))", "dataset_titles": "Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota", "datasets": [{"dataset_uid": "200183", "doi": "https://doi.org/10.6071/M34T1Z", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota", "url": "https://datadryad.org/stash/dataset/doi:10.6071/M34T1Z"}], "date_created": "Tue, 15 Dec 2020 00:00:00 GMT", "description": "The Earth\u0027s climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from \u0027greenhouse\u0027 to \u0027icehouse\u0027 conditions. During the Eocene, a shift to cooler temperatures at high latitudes resulted in the inception of polar glaciation. This in turn affected the environment for living organisms. This project looks to uncover the interaction between biological, oceanographic, and climate systems for the Eocene in Antarctica using chemical analysis of fossil shark teeth collected during past expeditions. The combination of paleontological and geochemical analyses will provide insight to the past ecology and ocean conditions; climate models will be applied to test the role of tectonics, greenhouse gas concentration and ocean circulation on environmental change during this time period. The study contributes to understanding the interaction of increased atmospheric carbon dioxide and ocean circulation. This project also seeks to improve diversity, equity, and inclusion within the geosciences workforce with efforts targeted to undergraduate, graduate, postdoctoral, and early career faculty.\u003cbr/\u003e\u003cbr/\u003eThe research goal is to elucidate the processes leading from the Eocene greenhouse to Oligocene icehouse conditions. Previous explanations for this climate shift centers on Antarctica, where tectonic configurations influenced oceanic gateways, ocean circulation reduced heat transport, and/or greenhouse gas declines prompted glaciation. The team will reconstruct watermass, current, and climate fluctuations proximal to the Antarctic Peninsula using geochemical indicators (oxygen and neodymium isotope composition) from fossil shark teeth collected from Seymour Island. The approach builds on previous shark paleontological studies, incorporates geochemical analyses for environmental reconstruction (i.e., temperature gradients and ocean circulation), and tests hypotheses on Earth System dynamics using novel global climate model simulations with geochemical tracers. This project will advance global climate modeling capabilities with experiments that consider Eocene tectonic configuration within isotope-enabled climate model simulations. A comparison of geochemical results from Eocene climate simulations and empirical records of shark teeth will reveal processes and mechanisms central to the Eocene Antarctic climatic shift.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -56.581808, "geometry": "POINT(-56.637662 -64.235428)", "instruments": null, "is_usap_dc": true, "keywords": "FISH; USA/NSF; OXYGEN ISOTOPE ANALYSIS; WATER MASSES; Amd/Us; AMD; USAP-DC; OXYGEN ISOTOPES; LABORATORY; Seymour Island; Sharks; Striatolamia Macrota", "locations": "Seymour Island", "north": -64.209061, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Integrated System Science; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE \u003e EOCENE", "persons": "Kim, Sora; Scher, Howard; Huber, Matthew; Jahn, Alexandra", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Dryad", "repositories": "Dryad", "science_programs": null, "south": -64.261795, "title": "Collaborative Research: Integrating Eocene Shark Paleoecology and Climate Modeling to reveal Southern Ocean Circulation and Antarctic Glaciation", "uid": "p0010146", "west": -56.693516}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": "POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))", "dataset_titles": "2017 GPR Observations of the Whillans and Mercer Ice Streams; Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "datasets": [{"dataset_uid": "601404", "doi": "10.15784/601404", "keywords": "Antarctica; Glaciology; Ice Sheet Flow Model; Ice Shelf Dynamics; Mercer Ice Stream; Model Data; Snow/ice; Snow/Ice; Whillans Ice Stream", "people": "Kaluzienski, Lynn", "repository": "USAP-DC", "science_program": null, "title": "Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "url": "https://www.usap-dc.org/view/dataset/601404"}, {"dataset_uid": "601403", "doi": "10.15784/601403", "keywords": "Antarctica; Crevasses; Glaciology; GPR; GPS; Ice Sheet Flow Model; Ice Shelf Dynamics; Snow/ice; Snow/Ice; Whillans Ice Stream", "people": "Kaluzienski, Lynn", "repository": "USAP-DC", "science_program": null, "title": "2017 GPR Observations of the Whillans and Mercer Ice Streams", "url": "https://www.usap-dc.org/view/dataset/601403"}], "date_created": "Mon, 14 Dec 2020 00:00:00 GMT", "description": "The Siple Coast in West Antarctica has undergone significant glacier changes over the last millenium. Several ice streams--rapidly moving streams of ice bordered by slow-moving ice--exist in this region that feeds into the Ross Ice Shelf. A long-term slowdown of Whillans Ice Stream appears to be occurring, and this is affecting the zone between the Whillans and Mercer Ice Streams. However, the consistency of this slowdown and resulting changes to the shear margin between the two ice streams are unknown. Shear zone stability represents a potentially critical control on mass balance of ice sheets, especially in regions of fast ice flow where basal shear stress is minimal. This project is therefore focused on understanding the spatial and temporal change of ice flow kinematics, shear margin structure, and shear margin location between Whillans and Mercer Ice Streams. A collateral benefit of and driver for this as a RAPID project is to test a method for assessing where crevassing will develop in this zone of steep velocity gradients. Such a method may benefit not only near-term field-project planning in the 2018-19 field season, but also planning for future fieldwork and traverses.\u003cbr/\u003e\u003cbr/\u003eThe team will use velocity estimates derived from available remote sensing datasets to determine transient velocity patterns and shifts in the shear-zone location over the last 20 years. This velocity time series will be incorporated into a large-scale ice-sheet model to estimate ice-sheet susceptibility to changing boundary conditions over the next century based on likely regional ice-flux scenarios. This approach is an extension of recent work conducted by the team that shows promise for predicting areas of changing high strain rates indicative of an active glacier shear margin. The ultimate objectives are to characterize the flow field of merging ice streams over time and investigate lateral boundary migration. This will provide a better understanding of shear-margin control on ice-shelf and up-glacier stability.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -111.0, "geometry": "POINT(-139.5 -84.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Whillans Ice Stream; USAP-DC; Amd/Us; USA/NSF; GLACIER MOTION/ICE SHEET MOTION; MODELS; AMD", "locations": "Whillans Ice Stream", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology; Polar Special Initiatives", "paleo_time": null, "persons": "Campbell, Seth; Koons, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "uid": "p0010145", "west": -168.0}, {"awards": "1908399 Bizimis, Michael; 1908548 Feakins, Sarah", "bounds_geometry": "POLYGON((74.787 -67.27617,74.816483 -67.27617,74.845966 -67.27617,74.875449 -67.27617,74.904932 -67.27617,74.934415 -67.27617,74.963898 -67.27617,74.993381 -67.27617,75.022864 -67.27617,75.052347 -67.27617,75.08183 -67.27617,75.08183 -67.31817,75.08183 -67.36017,75.08183 -67.40217,75.08183 -67.44417,75.08183 -67.48617,75.08183 -67.52817,75.08183 -67.57017,75.08183 -67.61217,75.08183 -67.65417,75.08183 -67.69617,75.052347 -67.69617,75.022864 -67.69617,74.993381 -67.69617,74.963898 -67.69617,74.934415 -67.69617,74.904932 -67.69617,74.875449 -67.69617,74.845966 -67.69617,74.816483 -67.69617,74.787 -67.69617,74.787 -67.65417,74.787 -67.61217,74.787 -67.57017,74.787 -67.52817,74.787 -67.48617,74.787 -67.44417,74.787 -67.40217,74.787 -67.36017,74.787 -67.31817,74.787 -67.27617))", "dataset_titles": "Ejtibbett/EOTproxymodel: Proxy Model Comparison for the Eocene-Oligocene Transition [Computational Notebook]; Paleoceanography and biomarker data from the Antarctic Peninsula over the past 37-3 million years; Prydz Bay East Antarctica, biomarkers and pollen, 36-33 million years; Sabrina Coast East Antarctica, Pollen and Biomarker Data from 59-38 million years ago; Southern High Latitude Temperature Proxies from the Late Eocene and Early Oligocene [Dataset]", "datasets": [{"dataset_uid": "200317", "doi": "10.25921/n9kg-yw91", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Paleoceanography and biomarker data from the Antarctic Peninsula over the past 37-3 million years", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/35613"}, {"dataset_uid": "200335", "doi": "10.5281/zenodo.7254536", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Southern High Latitude Temperature Proxies from the Late Eocene and Early Oligocene [Dataset]", "url": "https://zenodo.org/record/7254536#.Y2BLgOTMI2w"}, {"dataset_uid": "200206", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Prydz Bay East Antarctica, biomarkers and pollen, 36-33 million years", "url": "https://www.ncdc.noaa.gov/paleo-search/study/32052"}, {"dataset_uid": "200259", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Sabrina Coast East Antarctica, Pollen and Biomarker Data from 59-38 million years ago", "url": "https://www.ncdc.noaa.gov/paleo/study/34772"}, {"dataset_uid": "200334", "doi": "10.5281/zenodo.7254786", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Ejtibbett/EOTproxymodel: Proxy Model Comparison for the Eocene-Oligocene Transition [Computational Notebook]", "url": "https://zenodo.org/record/7254786#.Y2BLAeTMI2w"}], "date_created": "Sat, 05 Dec 2020 00:00:00 GMT", "description": "The East Antarctic Ice Sheet holds the largest volume of freshwater on the planet, in total enough to raise sea level by almost two hundred feet. Even minor adjustments in the volume of ice stored have major implications for coastlines and climates around the world. The question motivating this project is how did the ice grow to cover the continent over thirty million years ago when Antarctica changed from a warmer environment to an ice-covered southern continent? The seafloor of Prydz Bay, a major drainage basin of the East Antarctic Ice Sheet (EAIS), has been drilled previously to recover sediments dating from millions of years prior to and across the time when inception of continental ice sheets occurred in Antarctica. The last remnants of plant material found as \u0027biomarkers\u0027 in the ocean sediments record the chemical signatures of rain and snowfall that fed the plants and later the expanding glaciers. Sediment carried by glaciers was also deposited on the seafloor and can be analyzed to discover how glaciers flowed across the landscape. Here, the researchers will identify precipitation changes that result from, and drive, ice sheet growth. This study will gather data and further analyze samples from the seafloor sediment archives of the International Ocean Discovery Program\u0027s (IODP) core repositories. Ultimately these findings can help inform temperature-precipitation-ice linkages within climate and ice sheet models. The project will support the training of three female, early career scientists (PhD \u0026 MS students, and research technician) and both PIs and the PhD student will continue their engagement with broadening participation efforts (e.g., Women in Science and Engineering Program; local chapters of Society for the advancement of Native Americans and Chicanos in Science and other access programs) to recruit undergraduate student participants from underrepresented minorities at both campuses and from local community colleges. Antarctic earth science education materials will be assisted by professional illustrations to be open access and used in public education and communication efforts to engage local communities in Los Angeles CA and Columbia SC. \u003cbr/\u003e\u003cbr/\u003eThe researchers at the University of Southern California and the University of South Carolina will together study the penultimate moment of the early Cenozoic greenhouse climate state: the ~4 million years of global cooling that culminated in the Eocene/Oligocene transition (~34 Ma). Significant gaps remain in the understanding of the conditions that preceded ice expansion on Antarctica. In particular, the supply of raw material for ice sheets (i.e., moisture) and the timing, frequency, and duration of precursor glaciations is poorly constrained. This collaborative proposal combines organic and inorganic proxies to examine how Antarctic hydroclimate changed during the greenhouse to icehouse transition. The central hypothesis is that the hydrological cycle weakened as cooling proceeded. Plant-wax hydrogen and carbon isotopes (hydroclimate proxies) and Hf-Nd isotopes of lithogenous and hydrogenous sediments (mechanical weathering proxies) respond strongly and rapidly to precipitation and glacial advance. This detailed and sensitive combined approach will test whether there were hidden glaciations (and/or warm events) that punctuated the pre-icehouse interval. Studies will be conducted on Prydz Bay marine sediment cores in a depositional area for products of weathering and erosion that were (and are) transported through Lambert Graben from the center of Antarctica. The project will yield proxy information about the presence of plants and the hydroclimate of Antarctica and the timing of glacial advance, and is expected to show drying associated with cooling and ice-sheet growth. The dual approach will untangle climate signals from changes in fluvial versus glacial erosion of plant biomarkers. This proposal is potentially transformative because the combination of organic and inorganic proxies can reveal rapid transitions in aridity and glacial expansion, that may have been missed in slower-response proxies and more distal archives. The research is significant as hydroclimate seems to be a key player in the temperature-cryosphere hysteresis.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 75.08183, "geometry": "POINT(74.934415 -67.48617)", "instruments": null, "is_usap_dc": true, "keywords": "MICROFOSSILS; Prydz Bay; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; DROUGHT/PRECIPITATION RECONSTRUCTION; ISOTOPES; AIR TEMPERATURE RECONSTRUCTION", "locations": "Prydz Bay; Sabrina Coast", "north": -67.27617, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Feakins, Sarah; Scher, Howard", "platforms": null, "repo": "NCEI", "repositories": "NCEI; Zenodo", "science_programs": null, "south": -67.69617, "title": "Collaborative Research: Organic and Inorganic Geochemical Investigation of Hydrologic Change in East Antarctica in the 4 Million Years Before Full Glaciation", "uid": "p0010143", "west": 74.787}, {"awards": "1341736 Adams, Byron", "bounds_geometry": null, "dataset_titles": "Dataset DS-TAMS: Genetic diversity of Collembola from the Transantarctic Mountains; GenBank accession numbers MN619477 to MN619610; Meteoric 10Be data of soils from the Shackleton Glacier region; Shackleton Glacier region soil water-soluble geochemical data; Shackleton Glacier region water-soluble salt isotopes; Soil invertebrate surveys from the Shackleton Glacier region of Antarctica during the 2017-2018 austral summer", "datasets": [{"dataset_uid": "601421", "doi": "10.15784/601421", "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic Radionuclides; Geochemistry; Geomorphology; Shackleton Glacier; Surface Exposure Dates", "people": "Diaz, Melisa A.", "repository": "USAP-DC", "science_program": null, "title": "Meteoric 10Be data of soils from the Shackleton Glacier region", "url": "https://www.usap-dc.org/view/dataset/601421"}, {"dataset_uid": "200258", "doi": "doi:10.6073/pasta/7959821e5f6f8d56d94bb6a26873b3ae", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Soil invertebrate surveys from the Shackleton Glacier region of Antarctica during the 2017-2018 austral summer", "url": "https://doi.org/10.6073/pasta/7959821e5f6f8d56d94bb6a26873b3ae"}, {"dataset_uid": "200174", "doi": "10.5883/DS-TAMS", "keywords": null, "people": null, "repository": "Barcode of Life Datasystems (BOLD)", "science_program": null, "title": "Dataset DS-TAMS: Genetic diversity of Collembola from the Transantarctic Mountains", "url": "http://dx.doi.org/10.5883/DS-TAMS"}, {"dataset_uid": "200175", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "GenBank accession numbers MN619477 to MN619610", "url": "https://www.ncbi.nlm.nih.gov/nuccore/MN619477"}, {"dataset_uid": "601418", "doi": "10.15784/601418", "keywords": "Antarctica; Geochemistry; Shackleton Glacier", "people": "Lyons, W. Berry; Diaz, Melisa A.; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Shackleton Glacier region soil water-soluble geochemical data", "url": "https://www.usap-dc.org/view/dataset/601418"}, {"dataset_uid": "601419", "doi": "10.15784/601419", "keywords": "Antarctica; Geochemistry; Nitrate; Shackleton Glacier; Stable Isotopes; Sulfate; Transantarctic Mountains", "people": "Lyons, W. Berry; Diaz, Melisa A.; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Shackleton Glacier region water-soluble salt isotopes", "url": "https://www.usap-dc.org/view/dataset/601419"}], "date_created": "Mon, 02 Nov 2020 00:00:00 GMT", "description": "The project will characterize the functional, taxonomic, biotic and abiotic drivers of soil ecosystems in the Trans Antarctic Mountains (one of the most remote and harsh terrestrial landscapes on the planet). The work will utilize new high-throughput DNA and RNA sequencing technologies to identify members of the microbial communities and determine if the microbial community structures are independent of local environmental heterogeneities. In addition the project will determine if microbial diversity and function are correlated with time since the last glacial maximum (LGM). The expected results will greatly contribute to our knowledge regarding rates of microbial succession and help define the some of the limits to life and life-maintaining processes on Earth.\u003cbr/\u003e\u003cbr/\u003eThe project will analyze genomes and RNA derived from these genomes to describe the relationships between biodiversity and ecosystem functioning from soils above and below LGM elevations and to correlate these with the environmental drivers associated with their development during the last ~18,000 years. The team will identify the taxonomic diversity and the functional genetic composition within a broad suite of soil biota and examine their patterns of assembly and distribution within the framework of their geological legacies. The project will mentor participants from undergraduate students to postdoctoral researchers and prepare them to effectively engage in research to meet their career aspirations. The project will contribute to ongoing public education efforts through relationships with K-12 teachers and administrators- to include University-Public School partnerships. Less formal activities include public lecture series and weblogs aimed at providing information on Antarctic polar desert ecosystems to the general public. Targeted classrooms near each PI\u0027s institution will participate in online, real-time discussions about current topics in Antarctic ecosystems research.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; LABORATORY; AMD; Amd/Us; USA/NSF; TERRESTRIAL ECOSYSTEMS; Transantarctic Mountains; USAP-DC", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Adams, Byron; Fierer, Noah; Wall, Diana; Diaz, Melisa A.; Gardner, Christopher B.; Lyons, W. Berry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "Barcode of Life Datasystems (BOLD); EDI; NCBI GenBank; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains", "uid": "p0010140", "west": null}, {"awards": "1643873 Hansen, Samantha; 1643798 Emry, Erica", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "GEOSCOPE Network; IU: Global Seismograph Network; Shear Wave Velocity of the Antarctic Upper Mantle from Full Waveform Inversion and Long Period Ambient Seismic Noise; XP (2000-2004): A Broadband Seismic Investigation of Deep Continental Structure Across the East-West Antarctic Boundary ; YT (2007-2023): IPY POLENET-Antarctica: Investigating links between geodynamics and ice sheets; ZJ (2012-2015): Transantarctic Mountains Northern Network ; ZM (2007-2013): A Broadband Seismic Experiment to Image the Lithosphere beneath the Gamburtsev Mountains, East Antarctica", "datasets": [{"dataset_uid": "200171", "doi": "10.7914/SN/YT_2007", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "YT (2007-2023): IPY POLENET-Antarctica: Investigating links between geodynamics and ice sheets", "url": "http://www.fdsn.org/networks/detail/YT_2007/"}, {"dataset_uid": "200168", "doi": "10.18715/GEOSCOPE.G", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "GEOSCOPE Network", "url": "http://geoscope.ipgp.fr/networks/detail/G/"}, {"dataset_uid": "200172", "doi": "10.7914/SN/ZM_2007", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": " ZM (2007-2013): A Broadband Seismic Experiment to Image the Lithosphere beneath the Gamburtsev Mountains, East Antarctica", "url": "http://www.fdsn.org/networks/detail/ZM_2007/"}, {"dataset_uid": "601744", "doi": "10.15784/601744", "keywords": "Ambient Seismic Noise; Antarctica; Full-Waveform Inversion; Seismic Tomography; Shear Wave Velocity; Solid Earth", "people": "Emry, Erica", "repository": "USAP-DC", "science_program": null, "title": "Shear Wave Velocity of the Antarctic Upper Mantle from Full Waveform Inversion and Long Period Ambient Seismic Noise", "url": "https://www.usap-dc.org/view/dataset/601744"}, {"dataset_uid": "200173", "doi": "10.7914/SN/ZJ_2012", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "ZJ (2012-2015): Transantarctic Mountains Northern Network ", "url": "http://www.fdsn.org/networks/detail/ZJ_2012/"}, {"dataset_uid": "200169", "doi": "10.7914/SN/IU", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IU: Global Seismograph Network", "url": "http://www.fdsn.org/networks/detail/IU/"}, {"dataset_uid": "200170", "doi": "10.7914/SN/XP_2000", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "XP (2000-2004): A Broadband Seismic Investigation of Deep Continental Structure Across the East-West Antarctic Boundary ", "url": "http://www.fdsn.org/networks/detail/XP_2000/"}], "date_created": "Thu, 15 Oct 2020 00:00:00 GMT", "description": "Our project is focused on better resolving the three-dimensional Antarctic mantle structure to further understanding of continental tectonics. To accomplish this, we are utilizing a full-waveform tomographic inversion technique that incorporates long-period ambient noise data and which has been shown to more accurately resolve structure than traditional tomographic approaches. The new models have been developed using the Alabama supercomputer facilities in conjunction with software developed at The University of Rhode Island. Our new tomographic results highlight the lithospheric structure beneath the Wilkes and Aurora Subglacial Basins in East Antarctica, where previous rifting episodes and mid-lithospheric discontinuities are being explored. In West Antarctica, the work is elucidating the easternmost extent of the West Antarctic Rift System as well as rifted structure and possible compositional variations within the Weddell Sea. We are also highlighting regions of Antarctica where tomographic resolution is still lacking and where future deployments are needed to improve resolution.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "SEISMIC SURFACE WAVES; USA/NSF; USAP-DC; SEISMOLOGICAL STATIONS; Amd/Us; AMD; POLNET; TECTONICS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Emry, Erica; Hansen, Samantha", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repo": "IRIS", "repositories": "IRIS; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Imaging Seismic Heterogeneity within the Antarctic Mantle with Full Waveform Ambient Noise Tomography", "uid": "p0010139", "west": -180.0}, {"awards": "1643551 Hansen, Samantha", "bounds_geometry": null, "dataset_titles": "Investigating Ultra-low Velocity Zones (ULVZs) using an Antarctic Dataset", "datasets": [{"dataset_uid": "601265", "doi": "10.15784/601265", "keywords": "Antarctica; Core-Mantle Boundary; ScP; Southern Hemisphere; Ultra-Low Velocity Zones", "people": "Hansen, Samantha; Carson, Sarah; Garnero, Edward; Yu, Shule; Rost, Sebastian", "repository": "USAP-DC", "science_program": null, "title": "Investigating Ultra-low Velocity Zones (ULVZs) using an Antarctic Dataset", "url": "https://www.usap-dc.org/view/dataset/601265"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "Non-Technical Project Description\u003cbr/\u003e\u003cbr/\u003eThis research will study Ultralow Velocity Zones (ULVZs), located in Earth\u0027s interior on top of the boundary between the Earth\u0027s solid mantle and its fluid outer core. The ULVZs are so named because seismic waves passing through the Earth slow down dramatically when they encounter these zones. While ULVZs are thought to be related to melting processes, there is growing controversy regarding their origin and the role they play in the thermal and chemical evolution of our planet. The ULVZs may include the largest magma chambers in Earth\u0027s interior. Currently, researchers have only searched 40% of Earth\u0027s core-mantle boundary for the ULVZs and this project would use existing seismic data to map an unexplored area under Antarctica and interpret the nature of the ULVZs. This project will support two graduate students and create opportunities for undergraduate involvement. Project results will be published in scientific journals, presented at science fairs, and communicated through the researchers\u0027 websites. The research team will also take part in the NSF-sponsored PolarTREC (Teachers and Researchers Exploring and Collaborating) program to communicate the science to students and the broader community. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eTechnical Project Description\u003cbr/\u003e\u003cbr/\u003eThe National Research Council has highlighted high-resolution imaging of core-mantle boundary (CMB) structure as a high-priority, emerging research opportunity in the Earth Sciences since anomalies along the CMB likely play a critical role in the thermal and chemical evolution of our planet. Of particular interest are ultralow velocity zones (ULVZs), thin laterally-varying boundary layers associated with dramatic seismic velocity decreases and increases in density that are seen just above the CMB. Many questions exist regarding the origin of ULVZs, but incomplete seismic sampling of the lowermost mantle has limited our ability to map global ULVZ structure in detail. Using recently collected data from the Transantarctic Mountains Northern Network (TAMNNET) in Antarctica, this project will use core-reflected seismic phases (ScP, PcP, and ScS) to investigate ULVZ presence/absence along previously unexplored sections of the CMB. The data sampling includes the southern boundary of the Pacific Large Low Shear Velocity Province (LLSVP), a dominant feature in global shear wave tomography models, and will allow the researchers to examine a possible connection between ULVZs and LLSVPs. The main objectives of the project are to: 1) use TAMNNET data to document ULVZ presence/absence in previously unexplored regions of the lowermost mantle with array-based approaches; 2) model the data with 1- and 2.5-D wave propagation tools to obtain ULVZ properties and to assess trade-offs among the models; 3) use high quality events to augment the densely-spaced TAMNNET data with that from the more geographically-distributed, open-access Antarctic stations to increase CMB coverage with single-station analyses; and 4) explore the implications of ULVZ solution models for origin, present-day dynamics, and evolution, including their connection to other deep mantle structures, like LLSVPs.\u003cbr/\u003e\u003cbr/\u003eThe project aims to provide new constraints on ULVZs, including their potential connection to LLSVPs, and thus relates to other seismic and geodynamic investigations focused on processes within the Earth?s interior. This project will promote a new research collaboration between The University of Alabama (UA) and Arizona State University (ASU), each of which brings specific strengths to the initiative.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; SEISMIC PROFILE; NOT APPLICABLE", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hansen, Samantha", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Antarctic Seismic Investigations of ULVZ Structure", "uid": "p0010136", "west": null}, {"awards": "1141411 Baker, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Laboratory Experiments with H2SO4-Doped Ice; The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "datasets": [{"dataset_uid": "600380", "doi": "10.15784/600380", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Physical Properties; Snow", "people": "Baker, Ian", "repository": "USAP-DC", "science_program": null, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "url": "https://www.usap-dc.org/view/dataset/600380"}, {"dataset_uid": "601081", "doi": "10.15784/601081", "keywords": null, "people": "Hammonds, Kevin", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Experiments with H2SO4-Doped Ice", "url": "https://www.usap-dc.org/view/dataset/601081"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; USAP-DC; SNOW/ICE; Amd/Us; LABORATORY; Antarctica; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "uid": "p0010133", "west": -180.0}, {"awards": "1542885 Dunham, Eric", "bounds_geometry": null, "dataset_titles": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "datasets": [{"dataset_uid": "601320", "doi": "10.15784/601320", "keywords": "Antarctica; Computer Model; Glaciology; Model Data; Shear Stress; Solid Earth; Whillans Ice Stream", "people": "Abrahams, Lauren", "repository": "USAP-DC", "science_program": null, "title": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "url": "https://www.usap-dc.org/view/dataset/601320"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth\u0027s ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students.\u003cbr/\u003e\u003cbr/\u003eSimulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "SEISMIC PROFILE; AMD; Antarctica; GROUND-BASED OBSERVATIONS; USA/NSF; USAP-DC; Amd/Us", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dunham, Eric", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characterizing Brittle Failure and Fracture Propagation in Fast Ice Sliding with Dynamic Rupture Models based on Whillans Ice Stream Seismic/Geodetic Data", "uid": "p0010138", "west": null}, {"awards": "1443213 Kaplan, Michael; 1443433 Licht, Kathy", "bounds_geometry": "POLYGON((159 -83.8,159.5 -83.8,160 -83.8,160.5 -83.8,161 -83.8,161.5 -83.8,162 -83.8,162.5 -83.8,163 -83.8,163.5 -83.8,164 -83.8,164 -83.87,164 -83.94,164 -84.01,164 -84.08,164 -84.15,164 -84.22,164 -84.29,164 -84.36,164 -84.43,164 -84.5,163.5 -84.5,163 -84.5,162.5 -84.5,162 -84.5,161.5 -84.5,161 -84.5,160.5 -84.5,160 -84.5,159.5 -84.5,159 -84.5,159 -84.43,159 -84.36,159 -84.29,159 -84.22,159 -84.15,159 -84.08,159 -84.01,159 -83.94,159 -83.87,159 -83.8))", "dataset_titles": "10Be and 26Al cosmogenic nuclide surface exposure data; 3He input data", "datasets": [{"dataset_uid": "601375", "doi": "10.15784/601375", "keywords": "Antarctica; Cosmogenic Dating; Transantarctic Mountains", "people": "Schaefer, Joerg; Kaplan, Michael; Winckler, Gisela", "repository": "USAP-DC", "science_program": null, "title": "10Be and 26Al cosmogenic nuclide surface exposure data", "url": "https://www.usap-dc.org/view/dataset/601375"}, {"dataset_uid": "601376", "doi": "10.15784/601376", "keywords": "Antarctica; Transantarctic Mountains", "people": "Winckler, Gisela; Schaefer, Joerg; Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "3He input data", "url": "https://www.usap-dc.org/view/dataset/601376"}], "date_created": "Tue, 29 Sep 2020 00:00:00 GMT", "description": "Sediments deposited by the Antarctic ice sheet are an archive of its history with time and help geologists to determine how the remote interior of the ice sheet has changed over the past several hundred thousand years. This project will focus on the formation and dynamics of moraines (accumulations of dirt and rocks that are incorporated in the glacier surface or have been pushed along by the glacier as it moves) near the blue ice area of Mt. Achernar in the central Transantarctic Mountains in Antarctica.. The study will improve basic understanding of the formation of these moraines. Fieldwork at the site will focus on imaging the internal structure of the moraine to determine the processes by which it, and others like it, form over time. Additional analyses will include measurements of ice flow and collection of rock samples to determine the timing of debris deposition and the changes in the sources of sediments from deep within the Antarctic continent. The project will provide both graduate and undergraduate students training in paleoclimate studies, geology, and numerical modeling approaches. The broader impacts of the proposed work include hands on training in the Earth Sciences for graduate and undergraduate students, collaboration with colleagues in New Zealand and Sweden to provide an international research experience for students from the US, and three educational modules to be delivered by student researchers regarding Antarctica\u0027s role in global environments. The research is societally relevant and multidisciplinary and the topics are ideal for sharing with the public. All research findings will be made publicly available to others via timely publication in high-impact, peer-reviewed journals and all data will be submitted to the National Snow and Ice Data Center, and excess samples will be provided to the U.S. Polar Rock Repository.\u003cbr/\u003e\u003cbr/\u003eDirect observations of ice sheet history from the margins of Antarctica\u0027s polar plateau are essential for testing numerical ice sheet models, and the laterally extensive, blue-ice moraines of the Mt. Achernar Moraine complex in the central Transantarctic Mountains contain a unique and nearly untapped direct, quasi-continuous record of ice sheet change over multiple glacial cycles. The project objectives include improved understanding of processes and rates of blue ice moraine formation, as well as identifying the topographic, glaciological, and climatic controls on their evolution. Data to be collected with fieldwork in Antarctica include: imaging of internal ice structure with ground-penetrating radar, measurement of ice flow velocity and direction with a global positioning system (GPS) array, analysis of debris concentration and composition in glacier ice, state-of-the-art cosmogenic multi-nuclide analyses to determine exposure ages of moraine debris, mapping of trimlines and provenance analysis. Numerical model simulations, constrained by field data, will be used to evaluate the factors influencing changes in glacier flow that potentially impact the accumulation of the moraine debris. All together, the new data and modeling efforts will improve conceptual models of blue ice moraine formation, and thereby make them a more valuable proxy for developing a better understanding of the history of the ice sheet.", "east": 164.0, "geometry": "POINT(161.5 -84.15)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; GLACIAL PROCESSES; Mt. Achernar; ABLATION ZONES/ACCUMULATION ZONES; GLACIER ELEVATION/ICE SHEET ELEVATION; Antarctica; Antarctic Ice Sheet; Transantarctic Mountains; GLACIATION; USAP-DC; ICE MOTION; AMD; LABORATORY; Amd/Us", "locations": "Transantarctic Mountains; Antarctic Ice Sheet; Mt. Achernar; Antarctica", "north": -83.8, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Kaplan, Michael; Schaefer, Joerg; Winckler, Gisela; Licht, Kathy", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Collaborative Research: Multidisciplinary Analysis of Antarctic Blue Ice Moraine Formation and their Potential as Climate Archives over Multiple Glacial Cycles", "uid": "p0010131", "west": 159.0}, {"awards": "1542962 Anderson, Robert", "bounds_geometry": "POLYGON((-171 -57,-170.8 -57,-170.6 -57,-170.4 -57,-170.2 -57,-170 -57,-169.8 -57,-169.6 -57,-169.4 -57,-169.2 -57,-169 -57,-169 -57.72,-169 -58.44,-169 -59.16,-169 -59.88,-169 -60.6,-169 -61.32,-169 -62.04,-169 -62.76,-169 -63.48,-169 -64.2,-169.2 -64.2,-169.4 -64.2,-169.6 -64.2,-169.8 -64.2,-170 -64.2,-170.2 -64.2,-170.4 -64.2,-170.6 -64.2,-170.8 -64.2,-171 -64.2,-171 -63.48,-171 -62.76,-171 -62.04,-171 -61.32,-171 -60.6,-171 -59.88,-171 -59.16,-171 -58.44,-171 -57.72,-171 -57))", "dataset_titles": "Expedition Data of NBP1702; Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean ; Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean (SNOWBIRDS)", "datasets": [{"dataset_uid": "200126", "doi": "10.7284/907211", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1702", "url": "https://www.rvdata.us/search/cruise/NBP1702"}, {"dataset_uid": "200166", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean ", "url": "https://www.ncdc.noaa.gov/paleo/study/31312"}, {"dataset_uid": "200165", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean (SNOWBIRDS)", "url": "https://www.bco-dmo.org/dataset/813379/data"}], "date_created": "Fri, 25 Sep 2020 00:00:00 GMT", "description": "General:\r\nScientists established more than 30 years ago that the climate-related variability of carbon dioxide levels in the atmosphere over Earth\u2019s ice-age cycles was regulated by the ocean. Hypotheses to explain how the ocean that regulates atmospheric carbon dioxide have long been debated, but they have proven to be difficult to test. This project was designed test one leading hypothesis, specifically that the ocean experienced greater density stratification during the ice ages. That is, with greater stratification during the ice ages and the slower replacement of deep water by cold dense water formed near the poles, the deep ocean would have held more carbon dioxide, which is produced by biological respiration of the organic carbon that constantly rains to the abyss in the form of dead organisms and organic debris that sink from the sunlit surface ocean. To test this hypothesis, the degree of ocean stratification during the last ice age and the rate of deep-water replacement was to be constrained by comparing the radiocarbon ages of organisms that grew in the surface ocean and at the sea floor within a critical region around Antarctica, where most of the replacement of deep waters occurs. Completing this work was expected to contribute toward improved models of future climate change. Climate scientists rely on models to estimate the amount of fossil fuel carbon dioxide that will be absorbed by the ocean in the future. Currently the ocean absorbs about 25% of the carbon dioxide produced by burning fossil fuels. Most of this carbon is absorbed in the Southern Ocean (the region around Antarctica). How this will change in the future is poorly known. Models have difficulty representing physical conditions in the Southern Ocean accurately, thereby adding substantial uncertainty to projections of future ocean uptake of carbon dioxide. Results of the proposed study will provide a benchmark to test the ability of models to simulate ocean processes under climate conditions distinctly different from those that occur today, ultimately leading to improvement of the models and to more reliable projections of future absorption of carbon dioxide by the ocean. \r\n\r\nTechnical:\r\nThe project added a research component to an existing scientific expedition to the Southern Ocean, in the region between the Ross Sea and New Zealand, that collected sediment cores at locations down the northern flank of the Pacific-Antarctic Ridge at approximately 170\u00b0W. The goal was to collect sediments at each location deposited since early in the peak of the last ice age. This region is unusual in the Southern Ocean in that sediments deposited during the last ice age contain foraminifera, tiny organisms with calcium carbonate shells, in much greater abundance than in other regions of the Southern Ocean. Foraminifera are widely used as an archive of several geochemical tracers of past ocean conditions. We proposed to compare the radiocarbon age of foraminifera that inhabited the surface ocean with the age of contemporary specimens that grew on the seabed. The difference in age between surface and deep-swelling organisms would have been used to discriminate between two proposed mechanisms of deep water renewal during the ice age: formation in coastal polynyas around the edge of Antarctica, much as occurs today, versus formation by open-ocean convection in deep-water regions far from the continent. If the latter mechanism prevails, then it was expected that surface and deep-dwelling foraminifera would exhibit similar radiocarbon ages. In the case of dominance of deep-water formation in coastal polynyas, one expects to find very different radiocarbon ages in the two populations of foraminifera. In the extreme case of greater ocean stratification during the last ice age, one even expects the surface dwellers to appear to be older than contemporary bottom dwellers because the targeted core sites lie directly under the region where the oldest deep waters outcrop at the surface following their long circuitous transit through the deep ocean. The primary objective of the proposed work was to reconstruct the water mass age structure of the Southern Ocean during the last ice age, which, in turn, is a primary factor that controls the amount of carbon dioxide stored in the deep sea. In addition, the presence of foraminifera in the cores to be recovered provides a valuable resource for many other paleoceanographic applications, such as: 1) the application of nitrogen isotopes to constrain the level of nutrient utilization in the Southern Ocean and, thus, the efficiency of the ocean\u2019s biological pump, 2) the application of neodymium isotopes to constrain the transport history of deep water masses, 3) the application of boron isotopes and boron/calcium ratios to constrain the pH and inorganic carbon system parameters of ice-age seawater, and 4) the exploitation of metal/calcium ratios in foraminifera to reconstruct the temperature (Mg/Ca) and nutrient content (Cd/Ca) of deep waters during the last ice age at a location near their source near Antarctica. \r\n\r\nUnfortunately, the cores were shipped to the core repository in a horizontal orientation and there was sufficient distortion of the sediment that the radiocarbon ages of benthic foraminifera were uninterpretable. Therefore, we report only the radiocarbon dates for planktonic foraminifera as well as the total counts of elemental relative abundance from X-ray Fluorescence analysis of the cores. In addition, we used the expedition as an opportunity to collect water samples from which dissolved concentrations of long-lived isotope of thorium and protactinium were determined. Results from those analyses showed that lateral transport by isopycnal mixing dominates the supply of Pa to the Southern Ocean. We have also developed a new algorithm to correct for supply of Th by isopycnal mixing and thereby derive estimates of dust flux to the Southern Ocean. \r\n", "east": -169.0, "geometry": "POINT(-170 -60.6)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; SEDIMENT CHEMISTRY; South Pacific Ocean; SHIPS", "locations": "South Pacific Ocean", "north": -57.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, Robert; Fleisher, Martin; Pavia, Frank", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "R2R", "repositories": "BCO-DMO; NCEI; R2R", "science_programs": null, "south": -64.2, "title": "Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean", "uid": "p0010130", "west": -171.0}, {"awards": "1724670 Williams, Trevor", "bounds_geometry": "POLYGON((-70 -60,-65 -60,-60 -60,-55 -60,-50 -60,-45 -60,-40 -60,-35 -60,-30 -60,-25 -60,-20 -60,-20 -62.5,-20 -65,-20 -67.5,-20 -70,-20 -72.5,-20 -75,-20 -77.5,-20 -80,-20 -82.5,-20 -85,-25 -85,-30 -85,-35 -85,-40 -85,-45 -85,-50 -85,-55 -85,-60 -85,-65 -85,-70 -85,-70 -82.5,-70 -80,-70 -77.5,-70 -75,-70 -72.5,-70 -70,-70 -67.5,-70 -65,-70 -62.5,-70 -60))", "dataset_titles": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "datasets": [{"dataset_uid": "601377", "doi": "10.15784/601377", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601377"}, {"dataset_uid": "601378", "doi": "10.15784/601378", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601378"}, {"dataset_uid": "601379", "doi": "10.15784/601379", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601379"}], "date_created": "Thu, 10 Sep 2020 00:00:00 GMT", "description": "Abstract for the general public:\u003cbr/\u003e\u003cbr/\u003eThe margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this \u0027iceberg-rafted debris\u0027 falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. \u003cbr/\u003e\u003cbr/\u003eThe study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: \u003cbr/\u003e\u003cbr/\u003e1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. \u003cbr/\u003e\u003cbr/\u003e2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. \u003cbr/\u003e\u003cbr/\u003eTechnical abstract:\u003cbr/\u003e\u003cbr/\u003e The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. \u003cbr/\u003e\u003cbr/\u003eGeochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: \u003cbr/\u003e\u003cbr/\u003e1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. \u003cbr/\u003e\u003cbr/\u003e2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages.", "east": -20.0, "geometry": "POINT(-45 -72.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "TERRIGENOUS SEDIMENTS; Subglacial Till; USAP-DC; ICEBERGS; AMD; USA/NSF; ISOTOPES; AGE DETERMINATIONS; Argon; Provenance; Till; Amd/Us; R/V POLARSTERN; FIELD INVESTIGATION; SEDIMENT CHEMISTRY; Weddell Sea; Antarctica; LABORATORY", "locations": "Weddell Sea; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V POLARSTERN", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "uid": "p0010128", "west": -70.0}, {"awards": "1620976 Johnson, Sarah", "bounds_geometry": "POLYGON((160 -77,160.3 -77,160.6 -77,160.9 -77,161.2 -77,161.5 -77,161.8 -77,162.1 -77,162.4 -77,162.7 -77,163 -77,163 -77.1,163 -77.2,163 -77.3,163 -77.4,163 -77.5,163 -77.6,163 -77.7,163 -77.8,163 -77.9,163 -78,162.7 -78,162.4 -78,162.1 -78,161.8 -78,161.5 -78,161.2 -78,160.9 -78,160.6 -78,160.3 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))", "dataset_titles": "GenBank Sequence Read Archive with accession numbers SRR8217969 - SRR8217976 and project accession PRJNA506221", "datasets": [{"dataset_uid": "200164", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "GenBank Sequence Read Archive with accession numbers SRR8217969 - SRR8217976 and project accession PRJNA506221", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA506221/"}], "date_created": "Tue, 01 Sep 2020 00:00:00 GMT", "description": "Despite recent advances, we still know little about how life and its traces persist in extremely harsh conditions. What survival strategies do cells employ when pushed to their limit? Using a new technique, this project will investigate whether Antarctic paleolakes harbor \"microbial seed banks,\" or caches of viable microbes adapted to past paleoenvironments that could help transform our understanding of how cells survive over ancient timescales. Findings from this investigation could also illuminate novel DNA repair pathways with possible biomedical and biotechnology applications and help to refine life detection strategies for Mars. The project will bring Antarctic research to Georgetown University\u0027\u0027s campus for the first time, providing training opportunities in cutting edge analytical techniques for multiple students and a postdoctoral fellow. The field site will be the McMurdo Dry Valleys, which provide an unrivaled opportunity to investigate fundamental questions about the persistence of microbial life. Multiple lines of evidence, from interbedded and overlying ashfall deposits to parameterized models, suggest that the large-scale landforms there have remained essentially fixed as far back as the middle of the Miocene Epoch (i.e., ~8 million years ago). This geologic stability, coupled with geographic isolation and a steady polar climate, mean that biological activity has probably undergone few qualitative changes over the last one to two million years. The team will sample paleolake facies using sterile techniques from multiple Dry Valleys sites and extract DNA from entombed organic material. Genetic material will then be sequenced using Pacific Biosciences\u0027\u0027 Single Molecule, Real-Time DNA sequencing technology, which sequences native DNA as opposed to amplified DNA, thereby eliminating PCR primer bias, and enables read lengths that have never before been possible. The data will be analyzed with a range of bioinformatic techniques, with results that stand to impact our understanding of cell biology, Antarctic paleobiology, microbiology and biogeography, biotechnology, and planetary science.", "east": 163.0, "geometry": "POINT(161.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; COMMUNITY DYNAMICS; BACTERIA/ARCHAEA; CYANOBACTERIA (BLUE-GREEN ALGAE); LABORATORY; Dry Valleys", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Johnson, Sarah", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -78.0, "title": "EAGER: Single-Molecule DNA Sequencing of Antarctic Paleolakes", "uid": "p0010125", "west": 160.0}, {"awards": "1753101 Bernard, Kim", "bounds_geometry": "POLYGON((-65 -64,-64.7 -64,-64.4 -64,-64.1 -64,-63.8 -64,-63.5 -64,-63.2 -64,-62.9 -64,-62.6 -64,-62.3 -64,-62 -64,-62 -64.1,-62 -64.2,-62 -64.3,-62 -64.4,-62 -64.5,-62 -64.6,-62 -64.7,-62 -64.8,-62 -64.9,-62 -65,-62.3 -65,-62.6 -65,-62.9 -65,-63.2 -65,-63.5 -65,-63.8 -65,-64.1 -65,-64.4 -65,-64.7 -65,-65 -65,-65 -64.9,-65 -64.8,-65 -64.7,-65 -64.6,-65 -64.5,-65 -64.4,-65 -64.3,-65 -64.2,-65 -64.1,-65 -64))", "dataset_titles": "2019 Krill Carbon Content; 2019 Krill Morphometrics; CAREER: \"The Omnivores Dilemma\": The Effect of Autumn Diet on Winter Physiology and Condition of Juvenile Antarctic Krill; Expedition of NBP2205; Feeding Experiment - Krill Lipid Classes; Gerlache Strait Krill Demographics", "datasets": [{"dataset_uid": "200368", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "CAREER: \"The Omnivores Dilemma\": The Effect of Autumn Diet on Winter Physiology and Condition of Juvenile Antarctic Krill", "url": "https://www.bco-dmo.org/project/824760"}, {"dataset_uid": "200369", "doi": "10.7284/909918", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition of NBP2205", "url": "https://www.rvdata.us/search/cruise/NBP2205"}, {"dataset_uid": "601706", "doi": "10.15784/601706", "keywords": "Abundance; Antarctica; Antarctic Krill", "people": "Bernard, Kim", "repository": "USAP-DC", "science_program": null, "title": "Gerlache Strait Krill Demographics", "url": "https://www.usap-dc.org/view/dataset/601706"}, {"dataset_uid": "601707", "doi": "10.15784/601707", "keywords": "Antarctica; Antarctic Krill; Palmer Station; Winter", "people": "Bernard, Kim", "repository": "USAP-DC", "science_program": null, "title": "Feeding Experiment - Krill Lipid Classes", "url": "https://www.usap-dc.org/view/dataset/601707"}, {"dataset_uid": "601708", "doi": "10.15784/601708", "keywords": "Antarctica; Antarctic Krill; Palmer Station; Winter", "people": "Bernard, Kim", "repository": "USAP-DC", "science_program": null, "title": "2019 Krill Morphometrics", "url": "https://www.usap-dc.org/view/dataset/601708"}, {"dataset_uid": "601709", "doi": "10.15784/601709", "keywords": "Antarctica; Antarctic Krill; Palmer Station; Winter", "people": "Bernard, Kim", "repository": "USAP-DC", "science_program": null, "title": "2019 Krill Carbon Content", "url": "https://www.usap-dc.org/view/dataset/601709"}], "date_created": "Mon, 31 Aug 2020 00:00:00 GMT", "description": "Antarctic krill are essential in the Southern Ocean as they support vast numbers of marine mammals, seabirds and fishes, some of which feed almost exclusively on krill. Antarctic krill also constitute a target species for industrial fisheries in the Southern Ocean. The success of Antarctic krill populations is largely determined by the ability of their young to survive the long, dark winter, where food is extremely scarce. To survive the long-dark winter, young Antarctic krill must have a high-quality diet in autumn. However, warming in certain parts of Antarctica is changing the dynamics and quality of the polar food web, resulting in a shift in the type of food available to young krill in autumn. It is not yet clear how these dynamic changes are affecting the ability of krill to survive the winter. This project aims to fill an important gap in current knowledge on an understudied stage of the Antarctic krill life cycle, the 1-year old juveniles. The results derived from this work will contribute to the development of improved bioenergetic, population and ecosystem models, and will advance current scientific understanding of this critical Antarctic species. This CAREER projects core education and outreach objectives seek to enhance education and increase diversity within STEM fields. An undergraduate course will be developed that will integrate undergraduate research and writing in way that promotes authentic scientific inquiry and analysis of original research data by the students, and that enhances their communication skills. A graduate course will be developed that will promote students skills in communicating their own research to a non-scientific audience. Graduate students will be supported through the proposed study and will gain valuable research experience. Traditionally underserved undergraduate students will be recruited to conduct independent research under the umbrella of the larger project. Throughout each field season, the research team will maintain a weekly blog that will include short videos, photographs and text highlighting the research, as well as their experiences living and working in Antarctica. The aim of the blog will be to engage the public and increase awareness and understanding of Antarctic ecosystems and the impact of warming, and of the scientific process of research and discovery.\u003cbr/\u003e\u003cbr/\u003eIn this 5-year CAREER project, the investigator will use a combination of empirical and theoretical techniques to assess the effects of diet on 1-year old krill in autumn-winter. The research is centered on four hypotheses: (H1) autumn diet affects 1-year old krill physiology and condition at the onset of winter; (H2) autumn diet has an effect on winter physiology and condition of 1-year old krill under variable winter food conditions; (H3) the rate of change in physiology and condition of 1-year old krill from autumn to winter is dependent on autumn diet; and (H4) the winter energy budget of 1-year old krill will vary between years and will be dependent on autumn diet. Long-term feeding experiments and in situ sampling will be used to measure changes in the physiology and condition of krill in relation to their diet and feeding environment. Empirically-derived data will be used to develop theoretical models of growth rates and energy budgets to determine how diet will influence the overwinter survival of 1-year old krill. The research will be integrated with an education and outreach plan to (1) develop engaging undergraduate and graduate courses, (2) train and develop young scientists for careers in polar research, and (3) engage the public and increase their awareness and understanding.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSFs statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-63.5 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; AMD; FIELD INVESTIGATION; ANIMALS/INVERTEBRATES; PELAGIC; Anvers Island; Amd/Us; USAP-DC; NSF/USA", "locations": "Antarctic Peninsula; Anvers Island", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bernard, Kim", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "BCO-DMO", "repositories": "BCO-DMO; R2R; USAP-DC", "science_programs": null, "south": -65.0, "title": "CAREER: \"The Omnivore\u0027s Dilemma\": The Effect of Autumn Diet on Winter Physiology and Condition of Juvenile Antarctic Krill", "uid": "p0010124", "west": -65.0}, {"awards": "1935755 Lamp, Jennifer; 1935907 Balco, Gregory; 1935945 Tremblay, Marissa", "bounds_geometry": "POLYGON((160 -77.25,160.4 -77.25,160.8 -77.25,161.2 -77.25,161.6 -77.25,162 -77.25,162.4 -77.25,162.8 -77.25,163.2 -77.25,163.6 -77.25,164 -77.25,164 -77.325,164 -77.4,164 -77.475,164 -77.55,164 -77.625,164 -77.7,164 -77.775,164 -77.85,164 -77.925,164 -78,163.6 -78,163.2 -78,162.8 -78,162.4 -78,162 -78,161.6 -78,161.2 -78,160.8 -78,160.4 -78,160 -78,160 -77.925,160 -77.85,160 -77.775,160 -77.7,160 -77.625,160 -77.55,160 -77.475,160 -77.4,160 -77.325,160 -77.25))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 25 Aug 2020 00:00:00 GMT", "description": "Part I: Nontechnical\r\nScientists study the Earth\u0027s past climate in order to understand how the climate will respond to ongoing global change in the future. One of the best analogs for future climate might the period that occurred approximately 3 million years ago, during an interval known as the mid-Pliocene Warm Period. During this period, the concentration of carbon dioxide in the atmosphere was similar to today\u0027s and sea level was 15 or more meters higher, due primarily to warming and consequent ice sheet melting in polar regions. However, the temperatures in polar regions during the mid-Pliocene Warm Period are not well determined, in part because we do not have records like ice cores that extend this far back in time. This project will provide constraints on surface temperatures in Antarctica during the mid-Pliocene Warm Period using a new type of climate proxy, known as cosmogenic noble gas paleothermometry. This project focuses on an area of Antarctica called the McMurdo Dry Valleys. In this area, climate models suggest that temperatures were more than 10 \u00baC warmer during the mid-Pliocene than they are today, but indirect geologic observations suggest that temperatures may have been similar to today. The McMurdo Dry Valleys are also a place where rocks have been exposed to Earth surface conditions for several million years, and where this new climate proxy can be readily applied. The team will reconstruct temperatures in the McMurdo Dry Valleys during the mid-Pliocene Warm Period in order to resolve the discrepancy between models and indirect geologic observations and provide much-needed constraints on the sensitivity of Antarctic ice sheets to warming temperatures. The temperature reconstructions generated in this project will have scientific impact in multiple disciplines, including climate science, glaciology, geomorphology, and planetary science. In addition, the project will (1) broaden the participation of underrepresented groups by supporting two early-career female principal investigators, (2) build STEM talent through the education and training of a graduate student, (3) enhance infrastructure for research via publication of a publicly-accessible, open-source code library, and (4) be broadly disseminated via social media, blog posts, publications, and conference presentations. \r\n\r\nPart II: Technical Description\r\nThe mid-Pliocene Warm Period (3\u20133.3 million years ago) is the most recent interval of the geologic past when atmospheric CO2 concentrations exceeded 400 ppm, and is widely considered an analog for how Earths climate system will respond to current global change. Climate models predict polar amplification the occurrence of larger changes in temperatures at high latitudes than the global average due to a radiative forcing both during the mid-Pliocene Warm Period and due to current climate warming. However, the predicted magnitude of polar amplification is highly uncertain in both cases. The magnitude of polar amplification has important implications for the sensitivity of ice sheets to warming and the contribution of ice sheet melting to sea level change. Proxy-based constraints on polar surface air temperatures during the mid-Pliocene Warm Period are sparse to non-existent. In Antarctica, there is only indirect evidence for the magnitude of warming during this time. This project will provide constraints on surface temperatures in the McMurdo Dry Valleys of Antarctica during the mid-Pliocene Warm Period using a newly developed technique called cosmogenic noble gas (CNG) paleothermometry. CNG paleothermometry utilizes the diffusive behavior of cosmogenic 3He in quartz to quantify the temperatures rocks experience while exposed to cosmic-ray particles within a few meters of the Earths surface. The very low erosion rates and subzero temperatures characterizing the McMurdo Dry Valleys make this region uniquely suited for the application of CNG paleothermometry for addressing the question: what temperatures characterized the McMurdo Dry Valleys during the mid-Pliocene Warm Period? To address this question, the team will collect bedrock samples at several locations in the McMurdo Dry Valleys where erosion rates are known to be low enough that cosmic ray exposure extends into the mid-Pliocene or earlier. They will pair cosmogenic 3He measurements, which will record the thermal histories of our samples, with measurements of cosmogenic 10Be, 26Al, and 21Ne, which record samples exposure and erosion histories. We will also make in situ measurements of rock and air temperatures at sample sites in order to quantify the effect of radiative heating and develop a statistical relationship between rock and air temperatures, as well as conduct diffusion experiments to quantify the kinetics of 3He diffusion specific to each sample. This suite of observations will be used to model permissible thermal histories and place constraints on temperatures during the mid-Pliocene Warm Period interval of cosmic-ray exposure.", "east": 164.0, "geometry": "POINT(162 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; AMD; LABORATORY; USA/NSF; Amd/Us; ISOTOPES; Dry Valleys; AIR TEMPERATURE RECONSTRUCTION; GEOCHEMISTRY; USAP-DC", "locations": "Dry Valleys", "north": -77.25, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative \r\nResearch: Reconstructing Temperatures during the Mid-Pliocene Warm \r\nPeriod in the McMurdo Dry Valleys with Cosmogenic Noble Gases", "uid": "p0010123", "west": 160.0}, {"awards": "1541285 Tauxe, Lisa", "bounds_geometry": "POLYGON((162.144 -77.2233,162.8676 -77.2233,163.5912 -77.2233,164.3148 -77.2233,165.0384 -77.2233,165.762 -77.2233,166.4856 -77.2233,167.2092 -77.2233,167.9328 -77.2233,168.6564 -77.2233,169.38 -77.2233,169.38 -77.34097,169.38 -77.45864,169.38 -77.57631,169.38 -77.69398,169.38 -77.81165,169.38 -77.92932,169.38 -78.04699,169.38 -78.16466,169.38 -78.28233,169.38 -78.4,168.6564 -78.4,167.9328 -78.4,167.2092 -78.4,166.4856 -78.4,165.762 -78.4,165.0384 -78.4,164.3148 -78.4,163.5912 -78.4,162.8676 -78.4,162.144 -78.4,162.144 -78.28233,162.144 -78.16466,162.144 -78.04699,162.144 -77.92932,162.144 -77.81165,162.144 -77.69398,162.144 -77.57631,162.144 -77.45864,162.144 -77.34097,162.144 -77.2233))", "dataset_titles": "Four-Dimensional paleomagnetic dataset: Late Neogene paleodirection and paleointensity results from the Erebus Volcanic Province, Antarctica", "datasets": [{"dataset_uid": "200162", "doi": "", "keywords": null, "people": null, "repository": "Magnetics Infomation Consortiums MagIC", "science_program": null, "title": "Four-Dimensional paleomagnetic dataset: Late Neogene paleodirection and paleointensity results from the Erebus Volcanic Province, Antarctica", "url": "https://www2.earthref.org/MagIC/16912/14b%20cd18-4c33-858e-de5eab74c528"}], "date_created": "Mon, 24 Aug 2020 00:00:00 GMT", "description": "A fundamental assumption in paleomagnetism is that a geocentric axial dipole (GAD) geomagnetic field structure extends to the ancient field. Global paleodirectional compilations that span 0 - 10 Myr support a GAD dominated field structure with minor non-GAD contributions, however, the paleointensity data over the same period do not.\r\n\r\nIn a GAD field, higher latitudes should preserve higher intensity, but the current database suggests that intensities are independent of latitude. To determine whether the seemingly \"low\" intensities from Antarctica reflect the ancient field, rather than low quality data or inadequate temporal sampling, we have conducted a new study of the paleomagnetic field in Antarctica. Our investigation focuses on the paleomagnetic field structure over the Late Neogene. We combined and re- analyzed new and published paleodirectional and paleointensity results from the Erebus volcanic province to recover directions from 111 sites that were both thermally and AF demagnetized and then subjected to a set of strict selection criteria and 28 paleointensity estimates from specimens that underwent the IZZI modified Thellier-Thellier experiment and were also subjected to a strict set of selection criteria. The paleopole (232.0oE, 86.91oN and \u03b195 of 5.37o) recovered from our paleodirectional study supports the GAD hypothesis and the scatter of the virtual geomagnetic poles is within the uncertainty of that predicted by TK03 paleosecular variation model. Our time averaged field strength estimate, 33.01 \u03bcT \u00b1 2.59 \u03bcT, is significantly lower than that expected for a GAD field estimated from the present field, but consistent with the long term average field.\r\n", "east": 169.38, "geometry": "POINT(165.762 -77.81165)", "instruments": null, "is_usap_dc": true, "keywords": "McMurdo; PALEOMAGNETISM; LABORATORY", "locations": "McMurdo", "north": -77.2233, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Tauxe, Lisa; Staudigel, Hubertus", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Magnetics Infomation Consortiums MagIC", "repositories": "Magnetics Infomation Consortiums MagIC", "science_programs": null, "south": -78.4, "title": "Finding the Missing Geomagnetic Dipole Signal in Global Pleointensity Data: Revisiting the High Southerly Latitudes", "uid": "p0010122", "west": 162.144}, {"awards": "1543441 Fricker, Helen; 1543396 Christner, Brent; 1543405 Leventer, Amy; 1543347 Rosenheim, Brad; 1543453 Lyons, W. Berry; 1543537 Priscu, John", "bounds_geometry": "POLYGON((-163.611 -84.33543,-162.200034 -84.33543,-160.789068 -84.33543,-159.378102 -84.33543,-157.967136 -84.33543,-156.55617 -84.33543,-155.145204 -84.33543,-153.734238 -84.33543,-152.323272 -84.33543,-150.912306 -84.33543,-149.50134 -84.33543,-149.50134 -84.3659157,-149.50134 -84.3964014,-149.50134 -84.4268871,-149.50134 -84.4573728,-149.50134 -84.4878585,-149.50134 -84.5183442,-149.50134 -84.5488299,-149.50134 -84.5793156,-149.50134 -84.6098013,-149.50134 -84.640287,-150.912306 -84.640287,-152.323272 -84.640287,-153.734238 -84.640287,-155.145204 -84.640287,-156.55617 -84.640287,-157.967136 -84.640287,-159.378102 -84.640287,-160.789068 -84.640287,-162.200034 -84.640287,-163.611 -84.640287,-163.611 -84.6098013,-163.611 -84.5793156,-163.611 -84.5488299,-163.611 -84.5183442,-163.611 -84.4878585,-163.611 -84.4573728,-163.611 -84.4268871,-163.611 -84.3964014,-163.611 -84.3659157,-163.611 -84.33543))", "dataset_titles": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset; Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland; CTD data from Mercer Subglacial Lake and access borehole; Discrete bulk sediment properties data from Mercer Subglacial Lake; Isotopic data from Whillans Ice Stream grounding zone, West Antarctica; Mercer Subglacial Lake radiocarbon and stable isotope data ; Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995); Mercer Subglacial Lake (SLM) noble gas and isotopic data; Mercer Subglacial Lake water column viral metagenomic sequencing; Salsa sediment cores; Sediment porewater properties data from Mercer Subglacial Lake; Water column biogeochemical data from Mercer Subglacial Lake", "datasets": [{"dataset_uid": "200212", "doi": "10.7283/PT0Q-JB95", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/PT0Q-JB95"}, {"dataset_uid": "200342", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Mercer Subglacial Lake water column viral metagenomic sequencing", "url": "https://www.ncbi.nlm.nih.gov/biosample/32811410"}, {"dataset_uid": "200213", "doi": "10.7283/F7BB-JH05", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F7BB-JH05"}, {"dataset_uid": "200214", "doi": "10.7283/YW8Z-TK03", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/YW8Z-TK03"}, {"dataset_uid": "200215", "doi": "10.7283/C503-KS23", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/C503-KS23"}, {"dataset_uid": "200216", "doi": "10.7283/F8NH-CV04", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F8NH-CV04"}, {"dataset_uid": "200282", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA790995"}, {"dataset_uid": "601657", "doi": "10.15784/601657", "keywords": "Antarctica; Conductivity; CTD; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hot Water Drill; Mercer Subglacial Lake; Physical Properties; SALSA; Subglacial Lake; Temperature", "people": "Rosenheim, Brad; Leventer, Amy; Priscu, John; Dore, John", "repository": "USAP-DC", "science_program": null, "title": "CTD data from Mercer Subglacial Lake and access borehole", "url": "https://www.usap-dc.org/view/dataset/601657"}, {"dataset_uid": "601498", "doi": "10.15784/601498", "keywords": "Antarctica; Mercer Subglacial Lake; Noble Gas", "people": "Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake (SLM) noble gas and isotopic data", "url": "https://www.usap-dc.org/view/dataset/601498"}, {"dataset_uid": "601661", "doi": "10.15784/601661", "keywords": "Antarctica; Carbon; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iron; Mercer Subglacial Lake; Mineralogy; Particle Size; Physical Properties; SALSA; Sediment Core; Sulfur; West Antarctic Ice Sheet", "people": "Tranter, Martyn; Hawkings, Jon; Campbell, Timothy; Skidmore, Mark; Dore, John; Michaud, Alexander; Venturelli, Ryan A; Science Team, SALSA", "repository": "USAP-DC", "science_program": null, "title": "Discrete bulk sediment properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601661"}, {"dataset_uid": "601663", "doi": "10.15784/601663", "keywords": "Antarctica; Carbon; Cell Counts; Geochemistry; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mercer Subglacial Lake; Microbes; Nutrients; SALSA; Stable Isotopes; Trace Elements; West Antarctic Ice Sheet", "people": "Hawkings, Jon; Dore, John; Skidmore, Mark; Steigmeyer, August; Li, Wei; Barker, Joel; Tranter, Martyn; Priscu, John; Science Team, SALSA", "repository": "USAP-DC", "science_program": null, "title": "Water column biogeochemical data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601663"}, {"dataset_uid": "601664", "doi": "10.15784/601664", "keywords": "Antarctica; Gas; Geochemistry; Glacier; Glaciology; Mercer Subglacial Lake; Methane; SALSA; Sediment Core; West Antarctic Ice Sheet", "people": "Skidmore, Mark; Dore, John; Michaud, Alexander; Science Team, SALSA; Tranter, Martyn; Steigmeyer, August", "repository": "USAP-DC", "science_program": null, "title": "Sediment porewater properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601664"}, {"dataset_uid": "200217", "doi": "10.7283/3JMY-Y504", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/3JMY-Y504"}, {"dataset_uid": "200246", "doi": "", "keywords": null, "people": null, "repository": "OSU-MGR", "science_program": null, "title": "Salsa sediment cores", "url": "https://osu-mgr.org"}, {"dataset_uid": "601672", "doi": "10.15784/601672", "keywords": "Antarctica; Isotope; Mercer Subglacial Lake; Radiocarbon; Subglacial Lake", "people": "Venturelli, Ryan; Rosenheim, Brad", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake radiocarbon and stable isotope data ", "url": "https://www.usap-dc.org/view/dataset/601672"}, {"dataset_uid": "601360", "doi": "10.15784/601360", "keywords": "Antarctica; Radiocarbon; Sediment; Whillans Ice Stream", "people": "Venturelli, Ryan A", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Isotopic data from Whillans Ice Stream grounding zone, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601360"}, {"dataset_uid": "601472", "doi": "10.15784/601472", "keywords": "Antarctica; Bistatic Radar; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS Data; Greenland; Lake Whillans; Radar; Store Glacier; Whillans Ice Stream; WISSARD", "people": "Siegfried, Matthew; Bienert, Nicole; Schroeder, Dustin; Peters, Sean; MacKie, Emma; Dawson, Eliza; Christoffersen, Poul", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland", "url": "https://www.usap-dc.org/view/dataset/601472"}], "date_created": "Thu, 16 Jul 2020 00:00:00 GMT", "description": "The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website.\u003cbr/\u003e\u003cbr/\u003eSubglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \\\"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\\\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.", "east": -149.50134, "geometry": "POINT(-156.55617 -84.4878585)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; Antarctica; ISOTOPES; Subglacial Lake; USAP-DC; VIRUSES; PALEOCLIMATE RECONSTRUCTIONS; BACTERIA/ARCHAEA; LABORATORY; Radiocarbon; Whillans Ice Stream; AMD; SALSA; ECOSYSTEM FUNCTIONS; RADIOCARBON; FIELD INVESTIGATION; ICE MOTION; Mercer Ice Stream; Amd/Us; USA/NSF; GLACIERS/ICE SHEETS", "locations": "Antarctica; Mercer Ice Stream; Whillans Ice Stream", "north": -84.33543, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Instrumentation and Support; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Rosenheim, Brad; Fricker, Helen; Priscu, John; Leventer, Amy; Dore, John; Lyons, W. Berry; Christner, Brent", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "UNAVCO", "repositories": "GenBank; NCBI GenBank; OSU-MGR; UNAVCO; USAP-DC", "science_programs": null, "south": -84.640287, "title": "Collaborative Research: Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated Study of Carbon Cycling in Hydrologically-active Subglacial Environments", "uid": "p0010119", "west": -163.611}, {"awards": "1443482 Mak, John", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Carbon monoxide mixing ratios and stable isotopic values, SPICE", "datasets": [{"dataset_uid": "601356", "doi": "10.15784/601356", "keywords": "Antarctica; CO; Delta 13C; Delta 18O; South Pole; SPICEcore", "people": "Mak, John", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Carbon monoxide mixing ratios and stable isotopic values, SPICE", "url": "https://www.usap-dc.org/view/dataset/601356"}], "date_created": "Thu, 09 Jul 2020 00:00:00 GMT", "description": "The investigators plan to reconstruct historical variations in the sources of atmospheric carbon monoxide (CO) from measurements of the concentration and stable isotopic abundance of carbon monoxide ([CO], 13CO and C18O) in the South Pole Ice Core, which is being drilled in 2014-2016. The goal is to strategically sample and reconstruct the relative variations in CO source strengths over the past 20,000 years. These will be the first measurements to extend the CO record beyond 650 years before present, back to the last glacial maximum. Both atmospheric chemical processes and variations in CO sources can impact the CO budget, and variations in the CO budget are useful in identifying and quantifying chemistry-climate interactions.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "LABORATORY; TRACE GASES/TRACE SPECIES; FIELD INVESTIGATION; South Pole", "locations": "South Pole", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Mak, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Using Stable Isotopes to Constrain the Atmospheric Carbon Monoxide Budget over the Last 20,000 Years", "uid": "p0010117", "west": -180.0}, {"awards": "0125602 Padman, Laurence; 0125252 Padman, Laurence", "bounds_geometry": "POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.1617,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.1386,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))", "dataset_titles": "Antarctic Tide Gauge Database, version 1; AntTG_Database_Tools; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; pyTMD; TMD_Matlab_Toolbox_v2.5", "datasets": [{"dataset_uid": "601358", "doi": "10.15784/601358", "keywords": "Antarctica; Oceans; Sea Surface Height; Tide Gauges; Tides", "people": "Howard, Susan L.; King, Matt; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Tide Gauge Database, version 1", "url": "https://www.usap-dc.org/view/dataset/601358"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Howard, Susan L.; Erofeeva, Svetlana; Sutterley, Tyler; Greene, Chad A.; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}, {"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Erofeeva, Svetlana; Howard, Susan L.; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "200158", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "pyTMD", "url": "https://github.com/tsutterley/pyTMD"}, {"dataset_uid": "200157", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "TMD_Matlab_Toolbox_v2.5", "url": "https://github.com/EarthAndSpaceResearch/TMD_Matlab_Toolbox_v2.5"}, {"dataset_uid": "200156", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "AntTG_Database_Tools", "url": "https://github.com/EarthAndSpaceResearch/AntTG_Database_Tools"}], "date_created": "Tue, 07 Jul 2020 00:00:00 GMT", "description": "The ocean tide is a large component of total variability of ocean surface height and currents in the seas surrounding Antarctica, including under the floating ice shelves. Maximum tidal height range exceeds 7 m (near the grounding line of Rutford Ice Stream) and maximum tidal currents exceed 1 m/s (near the shelf break in the northwest Ross Sea). Tides contribute to several important climate and ecosystems processes including: ocean mixing, production of dense bottom water, flow of warm Circumpolar Deep Water onto the continental shelves, melting at the bases of ice shelves, fracturing of the ice sheet near a glacier or ice stream\u2019s grounding line, production and decay of sea ice, and sediment resuspension. Tide heights and, in particular, currents can change as the ocean background state changes, and as the geometry of the coastal margins of the Antarctic Ice Sheet varies through ice shelf thickness changes and ice-front and grounding-line advances or retreats. For satellite-based studies of ocean surface height and ice shelf thickness changes, tide heights are a source of substantial noise that must be removed. Similarly, tidal currents can also be a substantial noise signal when trying to estimate mean ocean currents from short-term measurements such as from acoustic Doppler current profilers mounted on ships and CTD rosettes. Therefore, tide models play critical roles in understanding current and future ocean and ice states, and as a method for removing tides in various measurements. A paper in Reviews of Geophysics (Padman, Siegfried and Fricker, 2018, see list of project-related publications below) provides a detailed review of tides and tidal processes around Antarctica.\r\n\nThis project provides a gateway to tide models and a database of tide height coefficients at the Antarctic Data Center, and links to toolboxes to work with these models and data.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e TIDE GAUGES", "is_usap_dc": true, "keywords": "Tide Gauges; OCEAN CURRENTS; Sea Surface Height; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; Tides; Antarctica; MODELS; FIELD INVESTIGATION", "locations": "Antarctica", "north": -40.231, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Arctic System Science", "paleo_time": null, "persons": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana; King, Matt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "GitHub; USAP-DC", "science_programs": null, "south": -90.0, "title": "Ocean Tides around Antarctica and in the Southern Ocean", "uid": "p0010116", "west": -180.0}, {"awards": "1235094 Thurnherr, Andreas", "bounds_geometry": "POLYGON((-19 -19,-18.2 -19,-17.4 -19,-16.6 -19,-15.8 -19,-15 -19,-14.2 -19,-13.4 -19,-12.6 -19,-11.8 -19,-11 -19,-11 -19.4,-11 -19.8,-11 -20.2,-11 -20.6,-11 -21,-11 -21.4,-11 -21.8,-11 -22.2,-11 -22.6,-11 -23,-11.8 -23,-12.6 -23,-13.4 -23,-14.2 -23,-15 -23,-15.8 -23,-16.6 -23,-17.4 -23,-18.2 -23,-19 -23,-19 -22.6,-19 -22.2,-19 -21.8,-19 -21.4,-19 -21,-19 -20.6,-19 -20.2,-19 -19.8,-19 -19.4,-19 -19))", "dataset_titles": "Expedition Data; NBP1406 Expedition data; NBP1508 Expedition data; Processed Current Measurement Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508; Processed Current Measurement, Pressure and Temperature Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508 (2015); Processed Current Measurement, Pressure, Salinity and Temperature Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508", "datasets": [{"dataset_uid": "001408", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1406"}, {"dataset_uid": "601353", "doi": null, "keywords": "CTD; CTD Data; Current Measurements; Current Meter; Mid-Ocean Ridge; Mooring; NBP1508; Oceans; Physical Oceanography; Pressure; R/v Nathaniel B. Palmer; Salinity; South Atlantic Ocean; Temperature", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Processed Current Measurement, Pressure and Temperature Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508 (2015)", "url": "https://www.usap-dc.org/view/dataset/601353"}, {"dataset_uid": "601354", "doi": "10.15784/601354", "keywords": "Current Measurements; LADCP; Mid-Ocean Ridge; NBP1508; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; South Atlantic Ocean", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Processed Current Measurement Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508", "url": "https://www.usap-dc.org/view/dataset/601354"}, {"dataset_uid": "200153", "doi": "10.7284/903009", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1406 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1406"}, {"dataset_uid": "200154", "doi": "10.7284/906708", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1508 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1508"}, {"dataset_uid": "601352", "doi": null, "keywords": "CTD; Mid-Ocean Ridge; Mooring; NBP1508; Oceans; Physical Oceanography; Pressure; R/v Nathaniel B. Palmer; Salinity; South Atlantic Ocean; Temperature", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Processed Current Measurement, Pressure, Salinity and Temperature Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508", "url": "https://www.usap-dc.org/view/dataset/601352"}], "date_created": "Thu, 02 Jul 2020 00:00:00 GMT", "description": "Overview: In order to close the global overturning circulation, high-density deep- and bottom waters produced at high latitudes must be made less dense and upwell to shallower depths. Available observations from the subtropical South Atlantic indicate that the bulk of the mixing in the deep ocean there takes place over the topographically rough Mid-Atlantic Ridge, in particular in the quasi-regularly spaced \"fracture zone canyons\" corrugating the ridge flanks. There, dense water is advected toward the ridge crest (i.e. upwelled) by persistent along-valley currents that flow down the unidirectional density gradients, which are maintained by strong turbulence (diapycnal mixing). Most of the data on which these inferences are based were collected during the Brazil Basin Tracer Release Experiment (BBTRE) along a single ridge-flank canyon in the western South Atlantic near 22S where previous analyses have shown that both tidal mixing and overflow processes are important. Therefore, it is likely that both processes must be considered in order to understand and parameterize the effects of turbulence and mixing in the canyons corrugating the flanks of all slow-spreading ridges, which make up large fractions of the sea floor, in particular in the Atlantic, Indian and Southern Oceans. The primary aim of this follow-on project is to improve our understanding of the dynamics over the corrugated flanks of slow-spreading mid-ocean ridges. Due to the coarse sampling resolution and choice of station locations it is not possible to answer important questions, such as the relative importance of tidal and sill mixing, from the BBTRE data. Therefore, high-resolution surveys of hydrography, three-dimensional flow, turbulence and mixing will be carried out in two neighboring canyons and over the intervening topographic spur in the BBTRE region to determine the relative contributions of tidal and sill-related mixing. Furthermore, profiling moorings deployed on two nearby sill regions will be used to derive time series of spatially integrated mixing related buoyancy fluxes and to investigate the strong but unexplained sub-inertial variability of the along-canyon flow recorded previously. Additionally, three small moorings will be deployed in saddles between the two canyons to investigate inter-canyon exchange. The data analysis will include available data from previous experiments, including a set of tracer profiles that has not been analyzed before. Intellectual Merit: The corrugated flanks of slow-spreading ridges cover large areas of the sea floor of several major ocean basins. Therefore, understanding the dynamics in the ~100 km of ridge-flank canyons and its effects on the buoyancy and upwelling budget of the abyssal ocean is of global significance. In addition to determining the relative importance of tidal mixing and cross-sill flows in two canyons, the temporal variability of turbulence and mixing from tidal to yearly time scales will be investigated to gain insights into the forcing of the along-canyon flows, the exchange between neighboring canyons, and the eventual fate of the canyon waters. Broader Impacts: It is anticipated that insights gained during this project will improve our understanding of abyssal mixing in many different regions with similar bottom topography and provide the basis for better parameterizations of the effects of turbulence and mixing in large-scale circulation and climate models that cannot resolve these small-scale processes. As part of the project, a graduate student and a post-doctoral researcher will be trained in all aspects of observational physical oceanography, from data acquisition to interpretation. ", "east": -11.0, "geometry": "POINT(-15 -21)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "OCEAN CURRENTS; South Atlantic Ocean; R/V NBP; WATER MASSES", "locations": "South Atlantic Ocean", "north": -19.0, "nsf_funding_programs": null, "paleo_time": null, "persons": "Thurnherr, Andreas", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -23.0, "title": "Collaborative Research: Flow, Turbulence and Mixing in Mid-Ocean Ridge Fracture Zone Canyons", "uid": "p0010114", "west": -19.0}, {"awards": "1341658 Mukhopadhyay, Sujoy", "bounds_geometry": "POLYGON((-116.45 -84.786,-116.443 -84.786,-116.436 -84.786,-116.429 -84.786,-116.422 -84.786,-116.415 -84.786,-116.408 -84.786,-116.401 -84.786,-116.394 -84.786,-116.387 -84.786,-116.38 -84.786,-116.38 -84.7864,-116.38 -84.7868,-116.38 -84.7872,-116.38 -84.7876,-116.38 -84.788,-116.38 -84.7884,-116.38 -84.7888,-116.38 -84.7892,-116.38 -84.7896,-116.38 -84.79,-116.387 -84.79,-116.394 -84.79,-116.401 -84.79,-116.408 -84.79,-116.415 -84.79,-116.422 -84.79,-116.429 -84.79,-116.436 -84.79,-116.443 -84.79,-116.45 -84.79,-116.45 -84.7896,-116.45 -84.7892,-116.45 -84.7888,-116.45 -84.7884,-116.45 -84.788,-116.45 -84.7876,-116.45 -84.7872,-116.45 -84.7868,-116.45 -84.7864,-116.45 -84.786))", "dataset_titles": "Ohio Range Subglacial rock core cosmogenic nuclide data", "datasets": [{"dataset_uid": "601351", "doi": "10.15784/601351", "keywords": "Aluminum-26; Antarctica; Beryllium-10; Cosmogenic Dating; Cosmogenic Radionuclides; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Fluctuations; Ohio Range; Rocks", "people": "Mukhopadhyay, Sujoy", "repository": "USAP-DC", "science_program": null, "title": "Ohio Range Subglacial rock core cosmogenic nuclide data", "url": "https://www.usap-dc.org/view/dataset/601351"}], "date_created": "Sun, 28 Jun 2020 00:00:00 GMT", "description": "Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare.\r\nTo test model predictions,sub-glacial rock cores were obtained from the Ohio Range along the Transantarctic Mountains near the present-day WAIS divide using a Winkie drill. Rock cores were recovered from 10 to ~30 m under the present-day ice levels. At the Ohio Range, the glacial to interglacial variations in ice sheet levels is ~120 meters. So 30 meters represent a significant fraction of the variation over the course of an ice age.\r\nHigh concentrations of the cosmic ray produced isotopes were detected in the rock cores, indicating extensive periods of ice-free exposure to cosmic irradiation during the last 2 million years. Modeling of the data suggest that bedrock surfaces at the Ohio Range that are currently covered by 30 meters of ice experienced more exposure than ice cover, especially in the Pleistocene. An ice sheet model prediction for the Ohio Range subglacial sample sites however, significantly underestimates exposure in the last 2 million years, and over-predicts ice cover in the Pleistocene. To adjust for the higher amounts of exposure we observe in our samples, the ice sheet model simulations require more frequent and/or longer-lasting WAIS ice drawdowns. This has important implications for future sea-level change as the model maybe under-predicting the magnitude of sea-level contributions from WAIS during the ice-age cycles. Improving the accuracy of the ice sheet models through model-data comparison should remain a prime objective in the face of a warming planet as understanding WAIS behavior is going to be key for predicting and planning for the effects of sea-level change. The project helped support and train a graduate student in climate research related to Antarctica, cosmogenic nuclide analyses and led to a Master\u2019s Thesis. The project also provide partial support to a postdoctoral scholar obtaining cosmogenic neon measurements and for training and mentoring the graduate student\u0027s cosmogenic neon measurements and interpretation. The project results were communicated to the scientific community at conferences and through seminars. The broader community was engaged through the University of California Davis\u0027s Picnic Day celebration, an annual open house that attracts over 70,000 people to the campus, and through classroom visit at a local elementary school.", "east": -116.38, "geometry": "POINT(-116.415 -84.788)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Sheet Fluctuations; ALUMINUM-26 ANALYSIS; BERYLLIUM-10 ANALYSIS; Cosmogenic Radionuclides; USAP-DC; FIELD INVESTIGATION; AMD; Ohio Range; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; LABORATORY", "locations": "Ohio Range", "north": -84.786, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukhopadhyay, Sujoy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.79, "title": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier", "uid": "p0010113", "west": -116.45}, {"awards": "1246465 Brook, Edward J.", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "WAIS Divide Ice Core Marine Isotope Stage 3 CO2 record", "datasets": [{"dataset_uid": "601337", "doi": "10.15784/601337", "keywords": "Antarctica; Carbon Cycle; CO2; Gas Chromatograph; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; WAIS Divide", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Marine Isotope Stage 3 CO2 record", "url": "https://www.usap-dc.org/view/dataset/601337"}], "date_created": "Mon, 22 Jun 2020 00:00:00 GMT", "description": "This award supports a project to measure the carbon dioxide (CO2) concentration in the WAIS Divide ice core covering the time period 25,000 to 60,000 years before present, and to analyze the isotopic composition of CO2 in selected time intervals. The research will improve understanding of how and why atmospheric CO2 varied during the last ice age, focusing particularly on abrupt transitions in the concentration record that are associated with abrupt climate change. These events represents large perturbations to the global climate system and better information about the CO2 response should inform our understanding of carbon cycle-climate feedbacks and radiative forcing of climate. The research will also improve analytical methods in support of these goals, including completing development of sublimation methods to replace laborious mechanical crushing of ice to release air for analysis. The intellectual merit of the proposed work is that it will increase knowledge about the magnitude and timing of atmospheric CO2 variations during the last ice age, and their relationship to regional climate in Antarctica, global climate history, and the history of abrupt climate change in the Northern Hemisphere. The temporal resolution of the proposed record will in most intervals be ~ 4 x higher than previous data sets for this time period, and for selected intervals up to 8-10 times higher. Broader impacts of the proposed work include a significant addition to the amount of data documenting the history of the most important long-lived greenhouse gas in the atmosphere and more information about carbon cycle-climate feedbacks - important parameters for predicting future climate change. The project will contribute to training a postdoctoral researcher, research experience for an undergraduate and a high school student, and outreach to local middle school and other students. It will also improve the analytical infrastructure at OSU, which will be available for future projects.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Carbon Cycle; Ice Core Records; USAP-DC; CO2; FIELD INVESTIGATION; CARBON DIOXIDE; LABORATORY; WAIS Divide", "locations": "WAIS Divide", "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Completing the WAIS Divide Ice Core CO2 record", "uid": "p0010110", "west": -112.1115}, {"awards": "1745341 Sumner, Dawn", "bounds_geometry": "POLYGON((161.595 -77.527,161.5953 -77.527,161.5956 -77.527,161.5959 -77.527,161.5962 -77.527,161.5965 -77.527,161.5968 -77.527,161.5971 -77.527,161.5974 -77.527,161.5977 -77.527,161.598 -77.527,161.598 -77.5271,161.598 -77.5272,161.598 -77.5273,161.598 -77.5274,161.598 -77.5275,161.598 -77.5276,161.598 -77.5277,161.598 -77.5278,161.598 -77.5279,161.598 -77.528,161.5977 -77.528,161.5974 -77.528,161.5971 -77.528,161.5968 -77.528,161.5965 -77.528,161.5962 -77.528,161.5959 -77.528,161.5956 -77.528,161.5953 -77.528,161.595 -77.528,161.595 -77.5279,161.595 -77.5278,161.595 -77.5277,161.595 -77.5276,161.595 -77.5275,161.595 -77.5274,161.595 -77.5273,161.595 -77.5272,161.595 -77.5271,161.595 -77.527))", "dataset_titles": "GP0191362, Gp0191371; JAAXLU000000000, JAAXLT000000000", "datasets": [{"dataset_uid": "200151", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "JAAXLU000000000, JAAXLT000000000", "url": "https://www.ncbi.nlm.nih.gov/nuccore/JAAXLU000000000"}, {"dataset_uid": "200152", "doi": "", "keywords": null, "people": null, "repository": "IMG Gold", "science_program": null, "title": "GP0191362, Gp0191371", "url": "https://gold.jgi.doe.gov/study?id=Gs0127369"}], "date_created": "Mon, 22 Jun 2020 00:00:00 GMT", "description": "Atmospheric oxygen rose suddenly approximately 2.4 billion years ago after Cyanobacteria evolved the ability to produce oxygen through photosynthesis (oxygenic photosynthesis). This change permanently altered the future of life on Earth, yet little is known about the evolutionary processes leading to it. The Melainabacteria were first discovered in 2013 and are closely related non-photosynthetic relatives of the first group of organisms capable of oxygenic photosynthesis. This project will utilize existing data on metagenomes from microbial mats in Lake Vanda, an ice-covered lake in Antarctica where many sequences of Melainabacteria have been previously identified. \r\n\r\nFrom this genetic information, we identified a new cyanobacterium, named Aurora vandensis, that is sister to all other Cyanobacteria, providing evolutionary insights. In addition, we assessed the metabolic capabilities of the Melainabacteria with good genomic coverage to identify their potential ecological roles. None contain photosynthetic genes, and we are evaluating the evolutionary relationships among the Cyanobacteria and Melainabacteria, particularly with respect to metabolic genes that will allow an advancement in understanding of the evolutionary path that lead to oxygenic photosynthesis on Earth.\r\n\r\nThe project will focus on extracting evolutionary information from the genomic data of Melainabacteria and Sericytochromatia, recently-described groups closely related to but basal to the Cyanobacteria. The characterization of novel members of these groups in samples from Lake Vanda, Antarctica, provide insights into the path and processes involved in the evolution of oxygenic photosynthesis. The research identified a novel cyanobacterial genus that is sister to all other Cyanobacteria, is most closely related to Gloeobacter, and shares evolutionary differences with that genus. Results also show that characterized Melainabacteria lack photosynthesis genes, but their respiration genes provide insight into evolutionary relationships among Melainabacteria and Cyanobacteria. Results provide unexpected constraints. The project focuses on 12 metagenomes, from which Melainabacteria and novel Cyanobacteria bins are annotated and preliminary metabolic pathways will be constructed. The project utilizes full-length sequences of marker genes from across the bacterial domain with a particular focus on taxa that are oxygenic or anoxygenic phototrophs and use the marker genes, to build a rooted \"backbone\" tree. Incomplete or short sequences from the metagenomes are added to the tree using the Evolutionary Placement Algorithm. The researchers built a corresponding phylogenetic tree using a Bayesian framework and compare their topologies. By doing so, the project aims to improve the understanding of the evolution of oxygenic photosynthesis, which caused the most significant change in Earth\u0027s surface chemistry. Specifically, we document a novel and basal cyanobacterium, significantly broader metabolic diversity within the Melainabacteria than has been previously identified, gain significant insights into their metabolic evolution, their evolutionary relationships with the Cyanobacteria, and the evolutionary steps leading to the origin of oxygenic photosynthesis. This research is constraining key evolutionary processes in the origin of oxygenic photosynthesis. It provides the foundation for future studies by indicating where a genomic record of the evolution of oxygenic photosynthesis may be preserved. Results will are being shared with middle school children through the development of scientific lesson plans in collaboration with teachers.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 161.598, "geometry": "POINT(161.5965 -77.5275)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; FIELD INVESTIGATION; CYANOBACTERIA (BLUE-GREEN ALGAE); Lake Vanda; LABORATORY; LAKE/POND; Genetic Analysis", "locations": "Lake Vanda", "north": -77.527, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sumner, Dawn; Eisen, Jonathan; Tazi, Loubna", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NCBI GenBank", "repositories": "IMG Gold; NCBI GenBank", "science_programs": null, "south": -77.528, "title": "Evolution of Oxygenic Photosynthesis as Preserved in Melainabacterial Genomes from Lake Vanda, Antarctica", "uid": "p0010112", "west": 161.595}, {"awards": "1907974 Saltzman, Eric", "bounds_geometry": "POLYGON((129.26 -89.86,130.261 -89.86,131.262 -89.86,132.263 -89.86,133.264 -89.86,134.265 -89.86,135.266 -89.86,136.267 -89.86,137.268 -89.86,138.269 -89.86,139.27 -89.86,139.27 -89.861,139.27 -89.862,139.27 -89.863,139.27 -89.864,139.27 -89.865,139.27 -89.866,139.27 -89.867,139.27 -89.868,139.27 -89.869,139.27 -89.87,138.269 -89.87,137.268 -89.87,136.267 -89.87,135.266 -89.87,134.265 -89.87,133.264 -89.87,132.263 -89.87,131.262 -89.87,130.261 -89.87,129.26 -89.87,129.26 -89.869,129.26 -89.868,129.26 -89.867,129.26 -89.866,129.26 -89.865,129.26 -89.864,129.26 -89.863,129.26 -89.862,129.26 -89.861,129.26 -89.86))", "dataset_titles": "H2 in South Pole firn air", "datasets": [{"dataset_uid": "601332", "doi": "10.15784/601332", "keywords": "Antarctica; Firn; Glaciology; Hydrogen; Ice Core Records; Snow/ice; Snow/Ice; South Pole", "people": "Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "H2 in South Pole firn air", "url": "https://www.usap-dc.org/view/dataset/601332"}], "date_created": "Tue, 09 Jun 2020 00:00:00 GMT", "description": "Hydrogen (H2) is one of the most abundant trace gases in the atmosphere, with a mean level of 500 ppb and an atmospheric lifetime of about two years. Hydrogen has an impact on both air quality and climate, due to its role as a precursor for tropospheric ozone and stratospheric water vapor. Projections indicate that a future \"hydrogen economy\" would increase hydrogen emissions. Understanding of the atmospheric hydrogen budget is largely based on a 30-year record of surface air measurements, but there are no long-term records with which to assess either: 1) the influence of climate change on atmospheric hydrogen, or 2) the extent to which humans have impacted the hydrogen budget. Polar ice core records of hydrogen will advance our understanding of the atmospheric hydrogen cycle and provide a stronger basis for projecting future changes to atmospheric levels of hydrogen and their impacts. \u003cbr/\u003e\u003cbr/\u003eThe research will involve laboratory work to enable the collection and analysis of hydrogen in polar ice cores. Hydrogen is a highly diffusive molecule and, unlike most other atmospheric gases, diffusion of hydrogen in ice is so rapid that ice samples must be stored in impermeable containers immediately upon drilling and recovery. This project will: 1) construct a laboratory system for extracting and analyzing hydrogen in polar ice, 2) develop and test materials and construction designs for vessels to store ice core samples in the field, and 3) test the method on samples of opportunity previously stored in the field. The goal of this project is a proven, cost-effective design for storage flasks to be fabricated for use on future polar ice coring projects. This project will support the dissertation research of a graduate student in the UC Irvine Department of Earth System Science.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 139.27, "geometry": "POINT(134.265 -89.865)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Firn; TRACE GASES/TRACE SPECIES; South Pole; FIELD INVESTIGATION; USAP-DC", "locations": "South Pole", "north": -89.86, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Glaciology; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Saltzman, Eric", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -89.87, "title": "EAGER: Feasibility of Reconstructing the Atmospheric History of Molecular Hydrogen from Antarctic Ice", "uid": "p0010106", "west": 129.26}, {"awards": "1443576 Panter, Kurt", "bounds_geometry": "POLYGON((-154.1 -86.9,-154.03 -86.9,-153.96 -86.9,-153.89 -86.9,-153.82 -86.9,-153.75 -86.9,-153.68 -86.9,-153.61 -86.9,-153.54 -86.9,-153.47 -86.9,-153.4 -86.9,-153.4 -86.92,-153.4 -86.94,-153.4 -86.96,-153.4 -86.98,-153.4 -87,-153.4 -87.02,-153.4 -87.04,-153.4 -87.06,-153.4 -87.08,-153.4 -87.1,-153.47 -87.1,-153.54 -87.1,-153.61 -87.1,-153.68 -87.1,-153.75 -87.1,-153.82 -87.1,-153.89 -87.1,-153.96 -87.1,-154.03 -87.1,-154.1 -87.1,-154.1 -87.08,-154.1 -87.06,-154.1 -87.04,-154.1 -87.02,-154.1 -87,-154.1 -86.98,-154.1 -86.96,-154.1 -86.94,-154.1 -86.92,-154.1 -86.9))", "dataset_titles": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "datasets": [{"dataset_uid": "601331", "doi": "10.15784/601331", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochronology; Glacial Volcanism; Magma Differentiation; Major Elements; Mantle Melting; Solid Earth; Trace Elements; Transantarctic Mountains", "people": "Panter, Kurt", "repository": "USAP-DC", "science_program": null, "title": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601331"}], "date_created": "Fri, 05 Jun 2020 00:00:00 GMT", "description": "Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world\u0027s largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student\u0027s research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise \u0027snapshots\u0027 of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.", "east": -153.4, "geometry": "POINT(-153.75 -87)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Mantle Melting; Magma Differentiation; Geochronology; Glacial Volcanism; GEOCHEMISTRY; Major Elements; ISOTOPES; Trace Elements; Transantarctic Mountains; LABORATORY; LAVA COMPOSITION/TEXTURE; USAP-DC; LAND RECORDS", "locations": "Transantarctic Mountains", "north": -86.9, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Panter, Kurt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.1, "title": "Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province", "uid": "p0010105", "west": -154.1}, {"awards": "1744883 Wiens, Douglas", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "ANT-20: A 3D seismic model of the upper mantle and transition zone structure beneath Antarctica and the surrounding southern oceans; CWANT-PSP: A 3-D shear velocity model from a joint inversion of receiver functions and surface wave dispersion derived from ambient noise and teleseismic earthquakes.", "datasets": [{"dataset_uid": "200178", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "CWANT-PSP: A 3-D shear velocity model from a joint inversion of receiver functions and surface wave dispersion derived from ambient noise and teleseismic earthquakes.", "url": "http://ds.iris.edu/ds/products/emc-cwant-psp/"}, {"dataset_uid": "200179", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "ANT-20: A 3D seismic model of the upper mantle and transition zone structure beneath Antarctica and the surrounding southern oceans", "url": "http://ds.iris.edu/ds/products/emc-ant-20/"}], "date_created": "Tue, 02 Jun 2020 00:00:00 GMT", "description": "The geological structure and history of Antarctica remains poorly understood because much of the continental crust is covered by ice. Here, the PIs will analyze over 15 years of seismic data recorded by numerous projects in Antarctica to develop seismic structural models of the continent. The seismic velocity models will reveal features including crustal thinning due to rifting in West Antarctica, the structures associated with mountain building, and the boundaries between different tectonic blocks. The models will be compared to continents that are better understood geologically to constrain the tectonic evolution of Antarctica. In addition, the work will provide better insight into how the solid earth interacts with and influences the development of the ice sheet. Surface heat flow will be mapped and used to identify regions in Antarctica with potential melting at the base of the ice sheet. This melt can lead to reduced friction and lower resistance to ice sheet movement. The models will help to determine whether the earth response to ice mass changes occurs over decades, hundreds, or thousands of years. Estimates of mantle viscosity calculated from the seismic data will be used to better understand the pattern and timescales of the response of the solid earth to changes in ice mass in various parts of Antarctica.\u003cbr/\u003e\u003cbr/\u003eThe study will advance our knowledge of the structure of Antarctica by constructing two new seismic models and a thermal model using different but complementary methodologies. Because of the limitations of different seismic analysis methods, efforts will be divided between a model seeking the highest possible resolution within the upper 200 km depth in the well instrumented region (Bayesian Monte-Carlo joint inversion), and another model determining the structure of the entire continent and surrounding oceans extending through the mantle transition zone (adjoint full waveform inversion). The Monte-Carlo inversion will jointly invert Rayleigh wave group and phase velocities from earthquakes and ambient noise correlation along with P-wave receiver functions and Rayleigh H/V ratios. The inversion will be done in a Bayesian framework that provides uncertainty estimates for the structural model. Azimuthal anisotropy will be determined from Rayleigh wave velocities, providing constraints on mantle fabric and flow patterns. The seismic data will also be inverted for temperature structure, providing estimates of lithospheric thickness and surface heat flow. The larger-scale model will cover the entire continent as well as the surrounding oceans, and will be constructed using an adjoint inversion of phase differences between three component seismograms and synthetic seismograms calculated in a 3D earth model using the spectral element method. This model will fit the entire waveforms, including body waves and both fundamental and higher mode surface waves. Higher resolution results will be obtained by using double-difference methods and by incorporating Green\u0027s functions from ambient noise cross-correlation, and solving for both radial and azimuthal anisotropy.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USA/NSF; Carbon Cycle; SEISMIC PROFILE; Seismology; Southern Ocean; Amd/Us; Antarctica; West Antarctica; MODELS; SEISMIC SURFACE WAVES; AMD; TECTONICS; USAP-DC", "locations": "Antarctica; West Antarctica; Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas; Shen, Weisen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "Comprehensive Seismic and Thermal Models for Antarctica and the Southern Oceans: A Synthesis of 15-years of Seismic Exploration", "uid": "p0010103", "west": -180.0}, {"awards": "1643722 Brook, Edward J.", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole Ice Core Methane Data and Gas Age Time Scale; South Pole ice core (SPC14) total air content (TAC)", "datasets": [{"dataset_uid": "601546", "doi": "10.15784/601546", "keywords": "Antarctica; South Pole", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) total air content (TAC)", "url": "https://www.usap-dc.org/view/dataset/601546"}, {"dataset_uid": "601329", "doi": "10.15784/601329", "keywords": "Antarctica; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; South Pole", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Methane Data and Gas Age Time Scale", "url": "https://www.usap-dc.org/view/dataset/601329"}], "date_created": "Tue, 02 Jun 2020 00:00:00 GMT", "description": "This award supports a project to measure the concentration of the gas methane in air trapped in an ice core collected from the South Pole. The data will provide an age scale (age as a function of depth) by matching the South Pole methane changes with similar data from other ice cores for which the age vs. depth relationship is well known. The ages provided will allow all other gas measurements made on the South Pole core (by the PI and other NSF supported investigators) to be interpreted accurately as a function of time. This is critical because a major goal of the South Pole coring project is to understand the history of rare gases in the atmosphere like carbon monoxide, carbon dioxide, ethane, propane, methyl chloride, and methyl bromide. Relatively little is known about what controls these gases in the atmosphere despite their importance to atmospheric chemistry and climate. Undergraduate assistants will work on the project and be introduced to independent research through their work. The PI will continue visits to local middle schools to introduce students to polar science, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) as part of the project. \u003cbr/\u003e\u003cbr/\u003eMethane concentrations from a major portion (2 depth intervals, excluding the brittle ice-zone which is being measured at Penn State University) of the new South Pole ice core will be used to create a gas chronology by matching the new South Pole ice core record with that from the well-dated WAIS Divide ice core record. In combination with measurements made at Penn State, this will provide gas dating for the entire 50,000-year record. Correlation will be made using a simple but powerful mid-point method that has been previously demonstrated, and other methods of matching records will be explored. The intellectual merit of this work is that the gas chronology will be a fundamental component of this ice core project, and will be used by the PI and other investigators for dating records of atmospheric composition, and determining the gas age-ice age difference independently of glaciological models, which will constrain processes that affected firn densification in the past. The methane data will also provide direct stratigraphic markers of important perturbations to global biogeochemical cycles (e.g., rapid methane variations synchronous with abrupt warming and cooling in the Northern Hemisphere) that will tie other ice core gas records directly to those perturbations. A record of the total air content will also be produced as a by-product of the methane measurements and will contribute to understanding of this parameter. The broader impacts include that the work will provide a fundamental data set for the South Pole ice core project and the age scale (or variants of it) will be used by all other investigators working on gas records from the core. The project will employ an undergraduate assistant(s) in both years who will conduct an undergraduate research project which will be part of the student\u0027s senior thesis or other research paper. The project will also offer at least one research position for the Oregon State University Summer REU site program. Visits to local middle schools, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) will also be part of the project.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "AMD; LABORATORY; METHANE; ICE CORE RECORDS; Gas Chromatography; South Pole; USAP-DC", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "A High Resolution Atmospheric Methane Record from the South Pole Ice Core", "uid": "p0010102", "west": 0.0}, {"awards": "1807522 Jones, Tyler", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "datasets": [{"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Vaughn, Bruce; Bradley, Elizabeth; Price, Michael; Garland, Joshua; Jones, Tyler R.; White, James; Morris, Valerie", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}, {"dataset_uid": "601326", "doi": "10.15784/601326", "keywords": "Antarctica; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Snow/ice; Snow/Ice; WAIS Divide Ice Core; Water Isotopes; West Antarctic Ice Sheet", "people": "Vaughn, Bruce; Jones, Tyler R.; White, James; Morris, Valerie", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601326"}, {"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Ice cores contain detailed accounts of Earth\u0027s climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process.This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "AMD; West Antarctic Ice Sheet; ISOTOPES; Amd/Us; USAP-DC; USA/NSF; Water Isotopes; WAIS Divide Ice Core; Deuterium; LABORATORY", "locations": "West Antarctic Ice Sheet", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Garland, Joshua; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Targeted resampling of deep polar ice cores using information theory", "uid": "p0010100", "west": -112.085}, {"awards": "1743643 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": "Major and trace element analyses of Eocene-Oligocene marine sediments from ODP Site 696, South Orkney Microcontinent; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "datasets": [{"dataset_uid": "601581", "doi": "10.15784/601581", "keywords": "Antarctica; Glaciation; IODP 696; Marine Geoscience; Marine Sediments; Paleoceanography; Sediment Core Data; Weddell Sea", "people": "Passchier, Sandra; Horowitz Castaldo, Josie; Lepp, Allison; Light, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "url": "https://www.usap-dc.org/view/dataset/601581"}, {"dataset_uid": "601582", "doi": "10.15784/601582", "keywords": "Antarctica; Glaciation; IODP 650; IODP 696; Paleoceanography; Provenance; Sediment Core Data; Weathering; Weddell Sea", "people": "States, Abbey; Hojnacki, Victoria; Li, Xiaona; Lepp, Allison; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Major and trace element analyses of Eocene-Oligocene marine sediments from ODP Site 696, South Orkney Microcontinent", "url": "https://www.usap-dc.org/view/dataset/601582"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Abstract (non-technical)\u003cbr/\u003eSea level rise is a problem of global importance and it is increasingly affecting the tens of millions of Americans living along coastlines. The melting of glaciers in mountain areas worldwide in response to global warming is a major cause of sea level rise and increases in nuisance coastal flooding. However, the world\u0027s largest land-based ice sheets are situated in the Polar Regions and their response under continued warming is very difficult to predict. One reason for this uncertainty is a lack of observations of ice behavior and melt under conditions of warming, as it is a relatively new global climate state lasting only a few generations so far. Researchers will investigate ice growth on Antarctica under past warm conditions using geological archives embedded in the layers of sand and mud under the sea floor near Antarctica. By peeling back at the layers beneath the seafloor investigators can read the history book of past events affecting the ice sheet. The Antarctic continent on the South Pole, carries the largest ice mass in the world. The investigator\u0027s findings will substantially improve scientists understanding of the response of ice sheets to global warming and its effect on sea level rise.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eAbstract (technical)\u003cbr/\u003eThe melt of land based ice is raising global sea levels with at present only minor contributions from polar ice sheets. However, the future role of polar ice sheets in climate change is one of the most critical uncertainties in predictions of sea level rise around the globe. The respective roles of oceanic and atmospheric greenhouse forcing on ice sheets are poorly addressed with recent measurements of polar climatology, because of the extreme rise in greenhouse forcing the earth is experiencing at this time. Data on the evolution of the West Antarctic ice sheet is particularly sparse. To address the data gap, researchers will reconstruct the timing and spatial distribution of Antarctic ice growth through the last greenhouse to icehouse climate transition around 37 to 33 Ma. They will collect sedimentological and geochemical data on core samples from a high-latitude paleoarchive to trace the shutdown of the chemical weathering system, the onset of glacial erosion, ice rafting, and sea ice development, as East and West Antarctic ice sheets coalesced in the Weddell Sea sector. Their findings will lead to profound increases in the understanding of the role of greenhouse forcing in ice sheet development and its effect on the global climate system.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; SEDIMENTS; LABORATORY; USA/NSF; USAP-DC; Weddell Sea", "locations": "Weddell Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition", "uid": "p0010101", "west": null}, {"awards": "9978236 Bell, Robin", "bounds_geometry": "POLYGON((101 -75.5,101.9 -75.5,102.8 -75.5,103.7 -75.5,104.6 -75.5,105.5 -75.5,106.4 -75.5,107.3 -75.5,108.2 -75.5,109.1 -75.5,110 -75.5,110 -75.85,110 -76.2,110 -76.55,110 -76.9,110 -77.25,110 -77.6,110 -77.95,110 -78.3,110 -78.65,110 -79,109.1 -79,108.2 -79,107.3 -79,106.4 -79,105.5 -79,104.6 -79,103.7 -79,102.8 -79,101.9 -79,101 -79,101 -78.65,101 -78.3,101 -77.95,101 -77.6,101 -77.25,101 -76.9,101 -76.55,101 -76.2,101 -75.85,101 -75.5))", "dataset_titles": "SOAR-Lake Vostok Survey airborne radar data; SOAR-Lake Vostok Survey bed elevation data; SOAR-Lake Vostok Survey Gravity data; SOAR-Lake Vostok Survey ice thickness data; SOAR-Lake Vostok survey magnetic anomaly data; SOAR-Lake Vostok Survey surface elevation data", "datasets": [{"dataset_uid": "601295", "doi": "10.1594/IEDA/306563", "keywords": "Airborne Gravity; Airplane; Antarctica; East Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Lake Vostok; Potential Field; Solid Earth", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey Gravity data", "url": "https://www.usap-dc.org/view/dataset/601295"}, {"dataset_uid": "601300", "doi": "10.1594/IEDA/306568", "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Navigation; Radar; SOAR; Subglacial Lakes", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601300"}, {"dataset_uid": "601296", "doi": " 10.1594/IEDA/306564", "keywords": "Airborne Magnetic; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lake Vostok; Magnetic; Magnetic Anomaly; Magnetometer; Potential Field; SOAR; Solid Earth", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok survey magnetic anomaly data", "url": "https://www.usap-dc.org/view/dataset/601296"}, {"dataset_uid": "601297", "doi": "10.1594/IEDA/306567", "keywords": "Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Sheet; Ice Stratigraphy; Ice Thickness; Ice Thickness Distribution; Lake Vostok; Radar; Radar Altimetry; Radar Echo Sounder; SOAR; Subglacial Lake", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey ice thickness data", "url": "https://www.usap-dc.org/view/dataset/601297"}, {"dataset_uid": "601298", "doi": "10.1594/IEDA/306566", "keywords": "Airborne Altimetry; Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Elevation; Ice Surface; Lake Vostok; Radar Echo Sounder; SOAR; Surface Elevation", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey surface elevation data", "url": "https://www.usap-dc.org/view/dataset/601298"}, {"dataset_uid": "601299", "doi": "10.1594/IEDA/306565", "keywords": "Airborne Laser Altimeters; Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bed Elevation; Bedrock Elevation; Digital Elevation Model; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Lake Vostok; Radar; Radar Echo Sounder; SOAR", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey bed elevation data", "url": "https://www.usap-dc.org/view/dataset/601299"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "This award, provided by the Office of Polar Programs under the Life in Extreme Environments (LExEn) Program, supports a geophysical study of Lake Vostok, a large lake beneath the East Antarctic Ice Sheet. \u003cbr/\u003e\u003cbr/\u003eSubglacial ecosystems, in particular subglacial lake ecosystems are extreme oligotrophic environments. These environments, and the ecosystems which may exist within them, should provide key insights into a range of fundamental questions about the development of Earth and other bodies in the Solar System including: 1) the processes associated with rapid evolutionary radiation after the extensive Neoproterozoic glaciations; 2) the overall carbon cycle through glacial and interglacial periods; and 3) the possible adaptations organisms may require to thrive in environments such as on Europa, the ice covered moon of Jupiter. Over 70 subglacial lakes have been identified beneath the 3-4 kilometer thick ice of Antarctica. One lake, Lake Vostok, is sufficiently large to be clearly identified from space with satellite altimetry. Lake Vostok is similar to Lake Ontario in area but with a much larger volume including measured water depths of 600 meters. The overlying ice sheet is acting as a conveyer belt continually delivering new water, nutrients, gas hydrates, sediments and microbes as the ice sheet flows across the lake. \u003cbr/\u003e\u003cbr/\u003eThe goal of this program is to determine the fundamental boundary conditions for this subglacial lake as an essential first step toward understanding the physical processes within the lake. An aerogeophysical survey over the lake and into the surrounding regions will be acquired to meet this goal. This data set includes gravity, magnetic, laser altimetry and ice penetrating radar data and will be used to compile a basic set of ice surface elevation, subglacial topography, gravity and magnetic anomaly maps. \u003cbr/\u003e\u003cbr/\u003ePotential field methods widely used in the oil industry will be modified to estimate the subglacial topography from gravity data where the ice penetrating radar will be unable to recover the depth of the lake. A similar method can be modified to estimate the thickness of the sediments beneath the lake from magnetic data. These methods will be tested and applied to subglacial lakes near South Pole prior to the Lake Vostok field campaign and will provide valuable comparisons to the planned survey. Once the methods have been adjusted for the Lake Vostok application, maps of the water cavity and sediment thickness beneath the lake will be produced.\u003cbr/\u003e\u003cbr/\u003eThese maps will become tools to explore the geologic origin of the lake. The two endmember models are, first, that the lake is an active tectonic rift such as Lake Baikal and, second, the lake is the result of glacial scouring. The distinct characteristics of an extensional rift can be easily identified with our aerogeophysical survey. The geological interpretation of the airborne geophysical survey will provide the first geological constraints of the interior of the East Antarctic continent based on modern data. In addition, the underlying geology will influence the ecosystem within the lake. \u003cbr/\u003e\u003cbr/\u003eOne of the critical issues for the ecosystem within the lake will be the flux of nutrients. A preliminary estimation of the regions of freezing and melting based on the distance between distinctive internal layers observed on the radar data will be made. These basic boundary conditions will provide guidance for a potential international effort aimed at in situ exploration of the lake and improve the understanding of East Antarctic geologic structures.", "east": 110.0, "geometry": "POINT(105.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e MAGNETOMETERS \u003e MGF; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e AIRGRAV", "is_usap_dc": true, "keywords": "Gravity; GLACIERS/ICE SHEETS; East Antarctica; USAP-DC; Lake Vostok; Airborne Radar; Subglacial Lake; MAGNETIC FIELD; GRAVITY", "locations": "East Antarctica; Lake Vostok", "north": -75.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work\r\n", "uid": "p0010097", "west": 101.0}, {"awards": "9615832 Blankenship, Donald; 9615704 Bell, Robin", "bounds_geometry": "POLYGON((-180 -74,-176 -74,-172 -74,-168 -74,-164 -74,-160 -74,-156 -74,-152 -74,-148 -74,-144 -74,-140 -74,-140 -75.6,-140 -77.2,-140 -78.8,-140 -80.4,-140 -82,-140 -83.6,-140 -85.2,-140 -86.8,-140 -88.4,-140 -90,-144 -90,-148 -90,-152 -90,-156 -90,-160 -90,-164 -90,-168 -90,-172 -90,-176 -90,180 -90,174 -90,168 -90,162 -90,156 -90,150 -90,144 -90,138 -90,132 -90,126 -90,120 -90,120 -88.4,120 -86.8,120 -85.2,120 -83.6,120 -82,120 -80.4,120 -78.8,120 -77.2,120 -75.6,120 -74,126 -74,132 -74,138 -74,144 -74,150 -74,156 -74,162 -74,168 -74,174 -74,-180 -74))", "dataset_titles": "SOAR-PPT Airborne gravity data; SOAR-WLK Airborne gravity data", "datasets": [{"dataset_uid": "601293", "doi": "10.15784/601293", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WLK Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601293"}, {"dataset_uid": "601292", "doi": "10.15784/601292", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-PPT Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601292"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.", "east": -140.0, "geometry": "POINT(170 -82)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; Transantarctic Mountains; GRAVITY FIELD; TECTONICS", "locations": "Transantarctic Mountains", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Buck, W. Roger; Blankenship, Donald D.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Contrasting Architecture and Dynamics of the Transantarctic Mountains", "uid": "p0010095", "west": 120.0}, {"awards": "1840058 Jenouvrier, Stephanie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Causes and consequences of pair-bond disruption in a sex-skewed population of a long-lived monogamous seabird: the wandering Albatross; Demographic outputs and their variances for three life history complexes for the Southern Fulmar across contrasted sea ice conditions.; Impact of Climate Change on Pair-Bond Dynamics of Snow Petrels (Pagodroma nivea); Supplementary material from \"Boldness predicts divorce rates in wandering albatrosses", "datasets": [{"dataset_uid": "601585", "doi": "10.15784/601585", "keywords": "Antarctica; Biota; Birds; East Antarctica; Southern Fulmar", "people": "Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "Demographic outputs and their variances for three life history complexes for the Southern Fulmar across contrasted sea ice conditions.", "url": "https://www.usap-dc.org/view/dataset/601585"}, {"dataset_uid": "601832", "doi": null, "keywords": "Antarctica; Climate Change; Cryosphere; Ile des Petrels, Pointe Geologie Archipelago (66\u25e640\u2032 S, 140\u25e601\u2032 106 E), Terre Adelie, Antarctica.", "people": "jenouvrier, stephanie", "repository": "USAP-DC", "science_program": null, "title": "Impact of Climate Change on Pair-Bond Dynamics of Snow Petrels (Pagodroma nivea)", "url": "https://www.usap-dc.org/view/dataset/601832"}, {"dataset_uid": "200372", "doi": "https://rs.figshare.com/collections/Supplementary_material_from_Boldness_predicts_divorce_rates_in_wandering_albatrosses_i_Diomedea_exulans_i_/6181063", "keywords": null, "people": null, "repository": "https://rs.figshare.com/", "science_program": null, "title": "Supplementary material from \"Boldness predicts divorce rates in wandering albatrosses", "url": "https://rs.figshare.com/collections/Supplementary_material_from_Boldness_predicts_divorce_rates_in_wandering_albatrosses_i_Diomedea_exulans_i_/6181063"}, {"dataset_uid": "601518", "doi": "10.15784/601518", "keywords": "Antarctica; Biota; Wandering Albatross", "people": "Jenouvrier, Stephanie; Sun, Ruijiao; Barbraud, Christophe; Delord, Karine", "repository": "USAP-DC", "science_program": null, "title": "Causes and consequences of pair-bond disruption in a sex-skewed population of a long-lived monogamous seabird: the wandering Albatross", "url": "https://www.usap-dc.org/view/dataset/601518"}], "date_created": "Wed, 01 Apr 2020 00:00:00 GMT", "description": "The goal of this project is to understand the drivers of pair disruption and quantify its resulting effects on individual fitness components and population growth rate and structure for two procellariiformes breeding in the Southern Ocean: the wandering albatross and the snow petrel, which both form long-lasting pair bonds. The mechanisms of pair disruption may be contrasted between these species, as pair disruption in wandering albatross may occur with the death of a partner by incidental by-catch in fisheries, while in snow petrels it may occur through divorce and climate-related conditions. Unique long-term individual mark-recapture data sets exist for these iconic polar species, allowing for a comprehensive study of the rates, causes and consequences of pair disruption and how they differ among species.\r\n\r\nThis study will result in the most detailed analysis to date of the impact of social monogamy and long-term pair bonds on individual fitness components (vital rates: survival, recruitment and fecundity; life-history outcomes: life expectancy, age at 1st breeding and lifetime reproductive success; and occupancy times: duration of pair bond or widowhood) and population growth and structure (e.g, sex ratio of individuals available for mating). Specifically, the investigators will assess:\r\n1. Variations in pair disruption rates, and if they are related to global change (by-catch in the case of albatross widowing, and climate in the case of petrel divorce) by developing a state-of-the-art statistical multievent mark-recapture model. \r\n2. Impacts of pair disruption on vital rates, specifically whether i) greater familiarity and better coordination within pairs improves breeding performance and survival, ii) mating costs reduce the probability of breeding and iii) divorce is more likely to occur after a breeding failure. \r\n3. Impacts of pair disruption on life-history outcomes and occupancy times using Markov chain stochastic life cycle models. \r\n4. Impacts of pair disruption on population dynamics by developing a novel non-linear two-sex matrix population model. \r\nThe investigators will develop novel sensitivity and Life Table Response Experiment analyses to examine the respective effects of fisheries, climate, vital rates, and pair-disruption rates on life-history outcomes, occupancy times, and population growth and structure, and their variations among year and species. \r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": true, "keywords": "ECOLOGICAL DYNAMICS; FIELD INVESTIGATION; East Antarctica; USAP-DC", "locations": "East Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jenouvrier, Stephanie", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "https://rs.figshare.com/; USAP-DC", "science_programs": null, "south": -90.0, "title": "Polar Seabirds with Long-term Pair Bonds: Effects of Mating on Individual Fitness and Population Dynamics", "uid": "p0010090", "west": -180.0}, {"awards": "1643733 Trusel, Luke; 1643715 Moussavi, Mahsa Sadat", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Supraglacial Lakes in Antarctica", "datasets": [{"dataset_uid": "601401", "doi": "10.15784/601401", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Landsat-8; Satellite Imagery; Supraglacial Lake", "people": "Halberstadt, Anna Ruth; Abdalati, Waleed; Trusel, Luke; Moussavi, Mahsa; Pope, Allen", "repository": "USAP-DC", "science_program": null, "title": "Supraglacial Lakes in Antarctica", "url": "https://www.usap-dc.org/view/dataset/601401"}], "date_created": "Mon, 16 Mar 2020 00:00:00 GMT", "description": "Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. This project will use a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate and ice-shelf models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project directly supports the scientific training of a postdoctoral associate and several undergraduate researchers. In addition, it will promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers.\u003cbr/\u003e\u003cbr/\u003eAccurate prediction of sea-level contributions from Antarctica critically requires understanding current melting and supraglacial lake conditions. This project will quantify Antarctic surface melt and supraglacial lakes, and the linkages between the two phenomena. Scatterometer data will enable generation of a 19-year multi-sensor melt time series. Synthetic aperture radar data will document melt conditions across all Antarctic ice shelves at the highest spatial resolution to date (40 m). Multispectral satellite imagery will be used to delineate and measure the depth of supraglacial lakes--for the first time studying the spatial and temporal variations of Antarctic supraglacial lakes. Melt and lake observations will be compared to identify agreement and disagreement. Melt observations will be used to evaluate biases in a widely used, reanalysis-driven, regional climate model. This model will then be used to examine climatic and glaciological variables associated with supraglacial lakes. Finally, in situ observations and climate model output will drive a numerical model that simulates the entire lifecycle of surface melt and possible subsequent lake formation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Supraglacial Lake; ICE SHEETS; Satellite Imagery; LANDSAT; Antarctica; USAP-DC; AMD; USA/NSF; SENTINEL-2A", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Moussavi, Mahsa; Pope, Allen; Trusel, Luke", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SENTINEL-2 \u003e SENTINEL-2A", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Water on the Antarctic Ice Sheet: Quantifying Surface Melt and Mapping Supraglacial Lakes", "uid": "p0010088", "west": -180.0}, {"awards": "1341663 O\u0027Brien, Kristin; 1341602 Crockett, Elizabeth", "bounds_geometry": null, "dataset_titles": "Acclimation of cardiovascular function in Notothenia coriiceps; Adrenergic and adenosinergic regulation of the cardiovascular system in the Antarctic icefish Chaenocephalus aceratus; Cardiac metabolism in Antarctic fishes in response to an acute increase in temperature; Chaenocephalus aceratus HIF-1A mRNA, complete cds; Chionodraco rastrospinosus HIF-1A mRNA, partial cds; Effects of acute warming on cardiovascular performance of Antarctic fishes; Eleginops maclovinus HIF-1A mRNA, partial cds; Gymnodraco acuticeps HIF-1A mRNA, partial cds; Hypoxia response of hearts of Antarctic fishes; Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature\u2019s natural knockouts; Measurements of splenic contraction in Antarctic fishes; Mitochondrial membranes in cardiac muscle from Antarctic notothenioid fishes vary in phospholipid composition and membrane fluidity; Notothenia coriiceps HIF-1A mRNA, complete cds; Parachaenichthys charcoti HIF-1A mRNA, partial cds; Physical, chemical, and functional properties of neuronal membranes vary between species of Antarctic notothenioids differing in thermal tolerance; Thermal sensitivity of membrane fluidity and integrity in hearts of Antarctic fishes that vary in expression of hemoglobin and myoglobin", "datasets": [{"dataset_uid": "200186", "doi": "10.5061/dryad.qm0b25h", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Physical, chemical, and functional properties of neuronal membranes vary between species of Antarctic notothenioids differing in thermal tolerance", "url": "https://doi.org/10.5061/dryad.qm0b25h"}, {"dataset_uid": "601405", "doi": "10.15784/601405", "keywords": "Antarctica; Antarctic Peninsula", "people": "O\u0027Brien, Kristin", "repository": "USAP-DC", "science_program": null, "title": "Cardiac metabolism in Antarctic fishes in response to an acute increase in temperature", "url": "https://www.usap-dc.org/view/dataset/601405"}, {"dataset_uid": "601406", "doi": "10.15784/601406", "keywords": "Antarctica; Antarctic Peninsula", "people": "O\u0027Brien, Kristin", "repository": "USAP-DC", "science_program": null, "title": "Hypoxia response of hearts of Antarctic fishes", "url": "https://www.usap-dc.org/view/dataset/601406"}, {"dataset_uid": "601407", "doi": "10.15784/601407", "keywords": "Antarctica; Antarctic Peninsula", "people": "Axelsson, Michael; Joyce, William; O\u0027Brien, Kristin", "repository": "USAP-DC", "science_program": null, "title": "Measurements of splenic contraction in Antarctic fishes", "url": "https://www.usap-dc.org/view/dataset/601407"}, {"dataset_uid": "601408", "doi": "10.15784/601408", "keywords": "Antarctica; Antarctic Peninsula", "people": "Axelsson, Michael; Farrell, Anthony; Egginton, Stuart; Joyce, William; O\u0027Brien, Kristin; Crockett, Elizabeth", "repository": "USAP-DC", "science_program": null, "title": "Acclimation of cardiovascular function in Notothenia coriiceps", "url": "https://www.usap-dc.org/view/dataset/601408"}, {"dataset_uid": "601409", "doi": "10.15784/601409", "keywords": "Antarctica; Antarctic Peninsula", "people": "Axelsson, Michael; Farrell, Anthony; Egginton, Stuart; O\u0027Brien, Kristin; Joyce, Michael", "repository": "USAP-DC", "science_program": null, "title": "Adrenergic and adenosinergic regulation of the cardiovascular system in the Antarctic icefish Chaenocephalus aceratus", "url": "https://www.usap-dc.org/view/dataset/601409"}, {"dataset_uid": "601410", "doi": "10.15784/601410", "keywords": "Antarctica; Antarctic Peninsula; Biota; Fish", "people": "Egginton, Stuart; O\u0027Brien, Kristin; Joyce, William; Crockett, Elizabeth; Axelsson, Michael; Farrell, Anthony", "repository": "USAP-DC", "science_program": null, "title": "Effects of acute warming on cardiovascular performance of Antarctic fishes", "url": "https://www.usap-dc.org/view/dataset/601410"}, {"dataset_uid": "200192", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Chionodraco rastrospinosus HIF-1A mRNA, partial cds", "url": "https://www.ncbi.nlm.nih.gov/nuccore/kx950831"}, {"dataset_uid": "601414", "doi": "10.15784/601414", "keywords": "Antarctica; Antarctic Peninsula", "people": "Crockett, Elizabeth; O\u0027Brien, Kristin; Evans, Elizabeth; Farnoud, Amir", "repository": "USAP-DC", "science_program": null, "title": "Thermal sensitivity of membrane fluidity and integrity in hearts of Antarctic fishes that vary in expression of hemoglobin and myoglobin", "url": "https://www.usap-dc.org/view/dataset/601414"}, {"dataset_uid": "200191", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Gymnodraco acuticeps HIF-1A mRNA, partial cds", "url": "https://www.ncbi.nlm.nih.gov/nuccore/kx950832"}, {"dataset_uid": "200190", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Parachaenichthys charcoti HIF-1A mRNA, partial cds", "url": "https://www.ncbi.nlm.nih.gov/nuccore/KX950833"}, {"dataset_uid": "200189", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Eleginops maclovinus HIF-1A mRNA, partial cds", "url": "https://www.ncbi.nlm.nih.gov/nuccore/KX950830"}, {"dataset_uid": "200188", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Notothenia coriiceps HIF-1A mRNA, complete cds", "url": "https://www.ncbi.nlm.nih.gov/nuccore/KX950829"}, {"dataset_uid": "200184", "doi": "10.5061/dryad.83vc5", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature\u2019s natural knockouts", "url": "https://doi.org/10.5061/dryad.83vc5"}, {"dataset_uid": "200185", "doi": "10.5061/dryad.k90h35k", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Mitochondrial membranes in cardiac muscle from Antarctic notothenioid fishes vary in phospholipid composition and membrane fluidity", "url": "https://doi.org/10.5061/dryad.k90h35k"}, {"dataset_uid": "200187", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Chaenocephalus aceratus HIF-1A mRNA, complete cds", "url": "https://www.ncbi.nlm.nih.gov/nuccore/KX950828"}], "date_created": "Wed, 26 Feb 2020 00:00:00 GMT", "description": "The ocean surrounding Antarctica is home to an extraordinary assemblage of fishes, dominated by a single group that are extremely well-suited to life in icy waters and which are of significant ecological importance there. Of great concern is the capacity of these fishes to withstand increases in temperature as the region of the Western Antarctic Peninsula warms at a rate faster than any other area in the Southern hemisphere. One particular group of Antarctic fishes, known as the icefishes, are particularly vulnerable to increases in temperature because unlike all other vertebrates on earth, icefishes are white-blooded due to their lack of the oxygen-binding protein hemoglobin. This greatly reduces their capacity to transport and deliver oxygen to tissues compared to red-blooded Antarctic fishes. Previous studies have shown that icefishes are indeed less tolerant to elevations in temperature but the underlying factors are completely unknown. Additionally, it is not understood if red- or white-blooded Antarctic fishes can adjust, or acclimate, to modest increases in temperature, similar to those changes in temperature the animals might experience as the earth warms. The investigators will determine if heart function and/or nervous system function limits thermal tolerance of Antarctic fishes, and will determine their capacity to acclimate to warmer temperatures. The project will further the NSF goal of training new generations of scientists by training graduate and undergraduate students. In addition, the project will collaborate with a high school biology teacher from a school which serves a largely minority student body. The students will learn about the marine environment, and will construct a camera to be used in the field to learn more about Antarctic fishes. Two students and the teacher will also attend a summer marine biology internship program.\u003cbr/\u003e\u003cbr/\u003eAntarctic fishes within the suborder Notothenioidei (called \"notothenioids\") are among the organisms on earth least able to deal with changes in temperature. The hemoglobinless icefish are even less able to withstand temperature changes than are red-blooded notothenioids. While this is well documented, the underlying physiological and biochemical mechanisms responsible are unknown. The investigators will test the hypotheses that cardiac work is significantly greater in icefishes compared to red-blooded species, and that as temperature increases, the greater cardiac work of icefishes, coupled with reduced blood oxygen-carrying capacity, results in cardiac failure at a lower temperature compared to red-blooded species. They also hypothesize that neuronal function limits thermal tolerance of red-blooded notothenioids. These hypotheses will be tested using a wide variety of experiments. For example, the investigators will measure heart rate concurrently with critical thermal maximum. They will also characterize metabolic and gene-expression responses to elevated temperature and determine if mitochondrial function contributes to thermal tolerance using a variety of techniques. To determine if neuronal function limits thermal tolerance they will quantify behavioral responses to warming of whole animals and to warming of only the brain area. They will also determine if acclimation to warmer temperatures impacts heart function and they will measure activities of a variety of enzymes from central metabolic pathways.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Amd/Us; FISH; USA/NSF; FIELD INVESTIGATION; AMD; Antarctic Peninsula; LABORATORY; USAP-DC", "locations": "Antarctica; Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Crockett, Elizabeth; O\u0027Brien, Kristin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Dryad", "repositories": "Dryad; GenBank; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "uid": "p0010084", "west": null}, {"awards": "1644013 Gaetani, Glenn; 1644020 Sims, Kenneth W.; 1644027 Wallace, Paul", "bounds_geometry": "POLYGON((164.1 -77.1,164.65 -77.1,165.2 -77.1,165.75 -77.1,166.3 -77.1,166.85 -77.1,167.4 -77.1,167.95 -77.1,168.5 -77.1,169.05 -77.1,169.6 -77.1,169.6 -77.235,169.6 -77.37,169.6 -77.505,169.6 -77.64,169.6 -77.775,169.6 -77.91,169.6 -78.045,169.6 -78.18,169.6 -78.315,169.6 -78.45,169.05 -78.45,168.5 -78.45,167.95 -78.45,167.4 -78.45,166.85 -78.45,166.3 -78.45,165.75 -78.45,165.2 -78.45,164.65 -78.45,164.1 -78.45,164.1 -78.315,164.1 -78.18,164.1 -78.045,164.1 -77.91,164.1 -77.775,164.1 -77.64,164.1 -77.505,164.1 -77.37,164.1 -77.235,164.1 -77.1))", "dataset_titles": "G170 Electron Microprobe Analyses of Melt Inclusions and Host Olivines; G170 Raman Spectroscopy \u0026 Tomography Volumes of Melt Inclusions and Vapor Bubbles; G170 Sample Locations Ross Island \u0026 Discovery Province; G170 Secondary Ion Mass Spectrometry Analses of Melt Inclusion Volatiles; G170 Secondary Ion Mass Spectrometry Analyses of Melt Inclusion Hydrogen Isotopes; Location and Description of Tephra Samples from the Erebus and Discovery Sub-provinces", "datasets": [{"dataset_uid": "601504", "doi": "10.15784/601504", "keywords": "Antarctica; Ross Island; Sample/collection Description; Sample/Collection Description; Sample Location", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Sample Locations Ross Island \u0026 Discovery Province", "url": "https://www.usap-dc.org/view/dataset/601504"}, {"dataset_uid": "601250", "doi": "10.15784/601250", "keywords": "Antarctica; Hut Point Peninsula; Mt. Bird; Mt. Morning; Mt. Terror; Ross Island; Turks Head; Turtle Rock", "people": "Pamukcu, Ayla; Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "Location and Description of Tephra Samples from the Erebus and Discovery Sub-provinces", "url": "https://www.usap-dc.org/view/dataset/601250"}, {"dataset_uid": "601507", "doi": "10.15784/601507", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Hydrogen; Ion Mass Spectrometry; Ross Island", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Secondary Ion Mass Spectrometry Analyses of Melt Inclusion Hydrogen Isotopes", "url": "https://www.usap-dc.org/view/dataset/601507"}, {"dataset_uid": "601506", "doi": "10.15784/601506", "keywords": "Antarctica; Ion Mass Spectrometry; Ross Island; Volatiles", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Secondary Ion Mass Spectrometry Analses of Melt Inclusion Volatiles", "url": "https://www.usap-dc.org/view/dataset/601506"}, {"dataset_uid": "601505", "doi": "10.15784/601505", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Electron Microprobe Analyses; Olivine; Petrography; Ross Island", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Electron Microprobe Analyses of Melt Inclusions and Host Olivines", "url": "https://www.usap-dc.org/view/dataset/601505"}, {"dataset_uid": "601508", "doi": "10.15784/601508", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Melt Inclusions; Raman Spectroscopy; Ross Island; Vapor Bubbles; Volcanic", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Raman Spectroscopy \u0026 Tomography Volumes of Melt Inclusions and Vapor Bubbles", "url": "https://www.usap-dc.org/view/dataset/601508"}], "date_created": "Sat, 08 Feb 2020 00:00:00 GMT", "description": "The depths at which magmas are stored, their pre-eruptive volatile contents, and the rates at which they ascend to the Earth\u0027s surface are important controls on the dynamics of volcanic eruptions. Basaltic magmas are likely to be vapor undersaturated as they begin their ascent from the mantle through the crust, but volatile solubility drops with decreasing pressure. Once vapor saturation is achieved and the magma begins to degas, its pre-eruptive volatile content is determined largely by the depth at which it resides within the crust. Magma stored in deeper reservoirs tend to experience less pre-eruptive degassing and to be richer in volatiles than magma shallower reservoirs. Eruptive style is influenced by the rate at which a magma ascends from the reservoir to the surface through its effect on the efficiency of vapor bubble nucleation, growth, and coalescence. The proposed work will advance our understanding of pre-eruptive storage conditions and syn-eruptive ascent rates through a combined field and analytical research program. Volatile measurements from olivine-hosted melt inclusions will be used to systematically investigate magma storage depths and ascent rates associated with alkaline volcanism in the Erebus volcanic province. A central goal of the project is to provide a spatial and temporal framework for interpreting results from studies of present-day volcanic processes at Mt Erebus volcano. The Erebus volcanic province of Antarctica is especially well suited to this type of investigation because: (1) there are many exposed mafic scoria cones, fissure vents, and hyaloclastites (exposed in sea cliffs) that produced rapidly quenched, olivine-rich tephra; (2) existing volatile data for Ross Island MIs show that magma storage was relatively deep compared to many mafic volcanic systems; (3) some of the eruptive centers ejected mantle xenoliths, allowing for comparison of ascent rates for xenolith-bearing and xenolith-free eruptions, and comparison of ascent rates for those bearing xenoliths with times estimated from settling velocities; and (4) the cold, dry conditions in Antarctica result in excellent tephra preservation compared to tropical and even many temperate localities. The project provides new tools for assessing volcanic hazards, facilitates collaboration involving researchers from three different institutions (WHOI, U Wyoming, and U Oregon), supports the researchers\u0027 involvement in teaching, advising, and outreach, and provides an educational opportunity for a promising young postdoctoral researcher. Understanding the interrelationships among magma volatile contents, reservoir depths, and ascent rates is vital for assessing volcanic hazards associated with alkaline volcanism across the globe.\r\n\r\n", "east": 169.6, "geometry": "POINT(166.85 -77.775)", "instruments": null, "is_usap_dc": true, "keywords": "Tephra; Turtle Rock; USA/NSF; Amd/Us; LABORATORY; AMD; Ross Island; Turks Head; Hut Point Peninsula; LAVA SPEED/FLOW; USAP-DC; Mt. Morning; Mt. Terror; ROCKS/MINERALS/CRYSTALS; Mt. Bird; FIELD INVESTIGATION", "locations": "Ross Island; Mt. Morning; Mt. Bird; Mt. Terror; Hut Point Peninsula; Turtle Rock; Turks Head", "north": -77.1, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Gaetani, Glenn; Le Roux, Veronique; Sims, Kenneth; Wallace, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.45, "title": "Collaborative Research: Determining Magma Storage Depths and Ascent Rates for the Erebus Volcanic Province, Antarctica Using Diffusive Water Loss from Olivine-hosted Melt Inclusion", "uid": "p0010081", "west": 164.1}, {"awards": "1842064 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-115 -74,-113.9 -74,-112.8 -74,-111.7 -74,-110.6 -74,-109.5 -74,-108.4 -74,-107.3 -74,-106.2 -74,-105.1 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105.1 -76,-106.2 -76,-107.3 -76,-108.4 -76,-109.5 -76,-110.6 -76,-111.7 -76,-112.8 -76,-113.9 -76,-115 -76,-115 -75.8,-115 -75.6,-115 -75.4,-115 -75.2,-115 -75,-115 -74.8,-115 -74.6,-115 -74.4,-115 -74.2,-115 -74))", "dataset_titles": "Gravity-derived bathymetry for the Thwaites, Crosson and Dotson ice shelves (2009-2019); Processed line aerogravity data over the Thwaites Glacier region (2018/19 season)", "datasets": [{"dataset_uid": "200160", "doi": "10.5285/7803de8b-8a74-466b-888e-e8c737bf21ce", "keywords": null, "people": null, "repository": "UK PDC", "science_program": null, "title": "Gravity-derived bathymetry for the Thwaites, Crosson and Dotson ice shelves (2009-2019)", "url": "https://data.bas.ac.uk/metadata.php?id=GB/NERC/BAS/PDC/01332"}, {"dataset_uid": "200159", "doi": "10.5285/b9b28a35-8620-4182-bf9c-638800b6679b", "keywords": null, "people": null, "repository": "UK PDC", "science_program": null, "title": "Processed line aerogravity data over the Thwaites Glacier region (2018/19 season)", "url": "https://data.bas.ac.uk/metadata.php?id=GB/NERC/BAS/PDC/01241"}], "date_created": "Wed, 08 Jan 2020 00:00:00 GMT", "description": "Considerable uncertainty remains in projections of future ice loss from West Antarctica. A recent decadal style U.S. National Academy of Sciences, Engineering, and Medicine report entitled: A Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research (2015) identifies changing ice in Antarctica as one of the highest priority science problems facing communities around the globe. The report identifies Thwaites Glacier as a target for collaborative intense research efforts in the coming years. This project contributes to that effort by deploying an instrument on board airborne surveys that will help to constrain the unknown terrains beneath the Thwaites Ice Shelf and in the region of the grounding line where the inland ice goes afloat. By improving the accuracy and resolution of these data, which are fed into predictive numerical models, the team will help to constrain the magnitude and rate of increase in the contribution of ice from Thwaites Glacier to the global ocean.\u003cbr/\u003e\u003cbr/\u003eThe team will enhance the capabilities of the already planned British Antarctic Survey aerogeophysics survey of Thwaites Glacier during the 2018/19 field season. Their Inertial Measurement Unit will be paired with a state-of-the-art commercial gravity meter to acquire high-quality and significantly enhanced resolution data both over the ice shelf and at the grounding line. Data will be processed immediately following collection and raw and observed data will be released six months after collection.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -104.0, "geometry": "POINT(-109.5 -75)", "instruments": null, "is_usap_dc": true, "keywords": "GRAVITY; Antarctica", "locations": "Antarctica", "north": -74.0, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Tinto, Kirsty", "platforms": null, "repo": "UK PDC", "repositories": "UK PDC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "RAPID: High-Resolution Gravity for Thwaites Glacier", "uid": "p0010077", "west": -115.0}, {"awards": "1341496 Girton, James", "bounds_geometry": "POLYGON((-142 -66,-135.3 -66,-128.6 -66,-121.9 -66,-115.2 -66,-108.5 -66,-101.8 -66,-95.1 -66,-88.4 -66,-81.7 -66,-75 -66,-75 -66.8,-75 -67.6,-75 -68.4,-75 -69.2,-75 -70,-75 -70.8,-75 -71.6,-75 -72.4,-75 -73.2,-75 -74,-81.7 -74,-88.4 -74,-95.1 -74,-101.8 -74,-108.5 -74,-115.2 -74,-121.9 -74,-128.6 -74,-135.3 -74,-142 -74,-142 -73.2,-142 -72.4,-142 -71.6,-142 -70.8,-142 -70,-142 -69.2,-142 -68.4,-142 -67.6,-142 -66.8,-142 -66))", "dataset_titles": "Bottom Photographs from the Antarctic Peninsula acquired during R/V Laurence M. Gould expedition LMG1703; Expedition Data; Expedition data of NBP1701", "datasets": [{"dataset_uid": "601302", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Benthic Images; Benthos; Biota; LMG1708; Oceans; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould; Ship; Yoyo Camera", "people": "Girton, James", "repository": "USAP-DC", "science_program": null, "title": "Bottom Photographs from the Antarctic Peninsula acquired during R/V Laurence M. Gould expedition LMG1703", "url": "https://www.usap-dc.org/view/dataset/601302"}, {"dataset_uid": "002661", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1701", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}], "date_created": "Tue, 10 Dec 2019 00:00:00 GMT", "description": "Current oceanographic interest in the interaction of relatively warm water of the Southern Ocean Circumpolar Deep Water (CDW) as it moves southward to the frigid waters of the Antarctic continental shelves is based on the potential importance of heat transport from the global ocean to the base of continental ice shelves. This is needed to understand the longer term mass balance of the continent, the stability of the vast Antarctic ice sheets and the rate at which sea-level will rise in a warming world. Improved observational knowledge of the mechanisms of how warming CDW moves across the Antarctic Circumpolar Current (ACC) is needed. Understanding this dynamical transport, believed to take place through the eddy flux of time-varying mesoscale circulation features, will improve coupled ocean-atmospheric climate models. The development of the next generation of coupled ocean-ice-climate models help us understand future changes in atmospheric heat fluxes, glacial and sea-ice balance, and changes in the Antarctic ecosystems. A recurring obstacle to our understanding is the lack of data in this distant region. In this project, a total of 10 subsurface profiling EM-APEX floats adapted to operate under sea ice were launched in 12 missions (and 2 recoveries) from 4 cruises of opportunity to the Amundsen Sea sector of the Antarctic continental margin during Austral summer. The floats were launched south of the Polar Front and measured shear, turbulence, temperature, and salinity to 2000m depth for 1-2 year missions while drifting with the CDW layer between profiles.", "east": -75.0, "geometry": "POINT(-108.5 -70)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA", "is_usap_dc": true, "keywords": "OCEAN TEMPERATURE; R/V NBP; USAP-DC; ICE DEPTH/THICKNESS; HEAT FLUX; OCEAN CURRENTS; SALINITY/DENSITY; LMG1703; Bellingshausen Sea; Yoyo Camera; WATER MASSES; R/V LMG; NBP1701", "locations": "Bellingshausen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Girton, James; Rynearson, Tatiana", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -74.0, "title": "Collaborative Research: Pathways of Circumpolar Deep Water to West Antarctica from Profiling Float and Satellite Measurements", "uid": "p0010074", "west": -142.0}, {"awards": "1444167 Detrich, H. William", "bounds_geometry": "POLYGON((-70 -58,-68.5 -58,-67 -58,-65.5 -58,-64 -58,-62.5 -58,-61 -58,-59.5 -58,-58 -58,-56.5 -58,-55 -58,-55 -59.8,-55 -61.6,-55 -63.4,-55 -65.2,-55 -67,-55 -68.8,-55 -70.6,-55 -72.4,-55 -74.2,-55 -76,-56.5 -76,-58 -76,-59.5 -76,-61 -76,-62.5 -76,-64 -76,-65.5 -76,-67 -76,-68.5 -76,-70 -76,-70 -74.2,-70 -72.4,-70 -70.6,-70 -68.8,-70 -67,-70 -65.2,-70 -63.4,-70 -61.6,-70 -59.8,-70 -58))", "dataset_titles": "Assembled Contig Dat for Daane et al. (2019); E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish); Expedition Data of LMG1603; Expedition Data of LMG1604; Expedition Data of LMG1605; Expedition Data of LMG1803; Expedition Data of LMG1804; Expedition Data of LMG1805; Full raw data set, computer code, and evolutionary trajectories for all species in Damsgaard et al. (2019); Histology-, CT-, ultrasound-, and MRI-scans (~2 TB) for Damsgaard et al. (2019); PRJNA420419: Genome and Transcriptome Data for Kim et al. (2019) Blackfin Icefish Genome; PRJNA531677: Sequencing Data for Daane et al. (2019); S-BSST132: Assembled Transcriptomes for Berthelot et al. (2018); SRP047484 RAD-tag Sequences of Genetically Mapped Notothenia coriiceps embryos; SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos; Transposable element sequences and genome sizes, refs 142597 to MF142757", "datasets": [{"dataset_uid": "200102", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Transposable element sequences and genome sizes, refs 142597 to MF142757", "url": "https://www.ncbi.nlm.nih.gov/nuccore?LinkName=pubmed_nuccore\u0026from_uid=29739320"}, {"dataset_uid": "200099", "doi": "10.5281/zenodo.2628936", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Assembled Contig Dat for Daane et al. (2019)", "url": "https://zenodo.org/record/2628936#.Xegqj3dFw2w"}, {"dataset_uid": "200098", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA531677: Sequencing Data for Daane et al. (2019)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA531677"}, {"dataset_uid": "200096", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "SRP047484 RAD-tag Sequences of Genetically Mapped Notothenia coriiceps embryos", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRP047484"}, {"dataset_uid": "200095", "doi": "", "keywords": null, "people": null, "repository": "BioStudies", "science_program": null, "title": "S-BSST132: Assembled Transcriptomes for Berthelot et al. (2018)", "url": "https://www.ebi.ac.uk/biostudies/studies/S-BSST132"}, {"dataset_uid": "200094", "doi": "", "keywords": null, "people": null, "repository": "Array Express", "science_program": null, "title": "E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish)", "url": "https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-6759/"}, {"dataset_uid": "200093", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos", "url": "https://www.ncbi.nlm.nih.gov/sra/SRP118539 "}, {"dataset_uid": "200092", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA420419: Genome and Transcriptome Data for Kim et al. (2019) Blackfin Icefish Genome", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=prjna420419"}, {"dataset_uid": "200249", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1803", "url": "https://www.rvdata.us/search/cruise/LMG1803"}, {"dataset_uid": "200250", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1603", "url": "https://www.rvdata.us/search/cruise/LMG1603"}, {"dataset_uid": "200251", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1804", "url": "https://www.rvdata.us/search/cruise/LMG1804"}, {"dataset_uid": "200252", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1604", "url": "https://www.rvdata.us/search/cruise/LMG1604"}, {"dataset_uid": "200253", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1605", "url": "https://www.rvdata.us/search/cruise/LMG1605"}, {"dataset_uid": "200254", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1805", "url": "https://www.rvdata.us/search/cruise/LMG1805"}, {"dataset_uid": "200104", "doi": "", "keywords": null, "people": null, "repository": "eLife", "science_program": null, "title": "Histology-, CT-, ultrasound-, and MRI-scans (~2 TB) for Damsgaard et al. (2019)", "url": "https://retinaevolution.bios.au.dk/eLife%20documentation/README.txt"}, {"dataset_uid": "200103", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Full raw data set, computer code, and evolutionary trajectories for all species in Damsgaard et al. (2019)", "url": "https://github.com/elifesciences-publications/Retinaevolution"}], "date_created": "Wed, 04 Dec 2019 00:00:00 GMT", "description": "Antarctic fish and their early developmental stages are an important component of the food web that sustains life in the cold Southern Ocean (SO) that surrounds Antarctica. They feed on smaller organisms and in turn are eaten by larger animals, including seals and killer whales. Little is known about how rising ocean temperatures will impact the development of Antarctic fish embryos and their growth after hatching. This project will address this gap by assessing the effects of elevated temperatures on embryo viability, on the rate of embryo development, and on the gene \"toolkits\" that respond to temperature stress. One of the two species to be studied does not produce red blood cells, a defect that may make its embryos particularly vulnerable to heat. The outcomes of this research will provide the public and policymakers with \"real world\" data that are necessary to inform decisions and design strategies to cope with changes in the Earth\u0027s climate, particularly with respect to protecting life in the SO. The project will also further the NSF goals of training new generations of scientists, including providing scientific training for undergraduate and graduate students, and of making scientific discoveries available to the general public. This includes the unique educational opportunity for undergraduates to participate in research in Antarctica and engaging the public in several ways, including the development of professionally-produced educational videos with bi-lingual \r\nclosed captioning. \r\nSince the onset of cooling of the SO about 40 million years ago, evolution of Antarctic marine organisms has been driven by the development of cold temperatures. Because body temperatures of Antarctic fishes fall in a narrow range determined by their habitat (-1.9 to +2.0 C), they are particularly attractive models for understanding how organismal physiology and biochemistry have been shaped to maintain life in a cooling environment. Yet these fishes are now threatened by rapid warming of the SO. The long-term objective of this project is to understand the capacities of Antarctic fishes to acclimatize and/or adapt to oceanic warming through analysis of their underlying genetic \"toolkits.\" This objective will be accomplished through three Specific Aims: 1) assessing the effects of elevated temperatures on gene expression during development of embryos; 2) examining the effects of elevated temperatures on embryonic morphology and on the temporal and spatial patterns of gene expression; and 3) evaluating the evolutionary mechanisms that have led to the loss of the red blood cell genetic program by the white-blooded fishes. Aims 1 and 2 will be investigated by acclimating experimental embryos of both red-blooded and white-blooded fish to elevated temperatures. Differential gene expression will be examined through the use of high throughput RNA sequencing. The temporal and spatial patterns of gene expression in the context of embryonic morphology (Aim 2) will be determined by microscopic analysis of embryos \"stained\" with (hybridized to) differentially expressed gene probes revealed by Aim 1; other key developmental marker genes will also be used. The genetic lesions resulting from loss of red blood cells by the white-blooded fishes (Aim 3) will be examined by comparing genes and genomes in the two fish groups.", "east": -55.0, "geometry": "POINT(-62.5 -67)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Polar; South Shetland Islands; USAP-DC; COASTAL", "locations": "Polar; South Shetland Islands", "north": -58.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "Array Express; BioStudies; eLife; GitHub; NCBI BioProject; NCBI GenBank; NCBI SRA; R2R; Zenodo", "science_programs": null, "south": -76.0, "title": "Antarctic Notothenioid Fishes: Sentinel Taxa for Southern Ocean Warming", "uid": "p0010073", "west": -70.0}, {"awards": "1341680 Sletten, Ronald", "bounds_geometry": "POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))", "dataset_titles": "Chemical and physical characterization of Beacon Valley and Victoria Valley permafrost cores", "datasets": [{"dataset_uid": "601247", "doi": "10.15784/601247", "keywords": "Aluminum-26; Antarctica; Be-10; Cosmogenic; Dry Valleys; Geochemistry; Permafrost", "people": "Sletten, Ronald S.", "repository": "USAP-DC", "science_program": null, "title": "Chemical and physical characterization of Beacon Valley and Victoria Valley permafrost cores", "url": "https://www.usap-dc.org/view/dataset/601247"}], "date_created": "Thu, 21 Nov 2019 00:00:00 GMT", "description": "Intellectual Merit: This project will yield new information on the long term Antarctic climate and landscape evolution from measurements of cosmogenic nuclides in quartz sand from two unique permafrost cores collected in Beacon Valley, Antarctica. The two cores have already been drilled in ice-cemented, sand-rich permafrost at 5.5 and 30.6 meters depth, and are currently in cold storage at the University of Washington. The cores are believed to record the monotonic accumulation of sand that has been blown into lower Beacon Valley and inflated the surface over time. The rate of accumulation and any hiatus in the accumulation are believed to reflect in part the advance and retreat of the Taylor Glacier. Preliminary measurements of cosmogenically-produced beryllium (10Be) and aluminum (26Al) in quartz sand in the 5.5-meter depth core reveal that it has been accreting at a rate of 2.5 meters/Myr for the past million years. Furthermore, prior to that time, lower Beacon Valley was most likely covered (shielded from the atmosphere thereby having no or very low production of cosmogenic nuclides in quartz) by Taylor Glacier from 1 to 3.5 Myr BP. These preliminary measurements also suggest that the 30.6 meter core may provide a record of over 10 million years. The emphasis is the full characterization of the core and analysis of cosmogenic nuclides (including cosmogenic neon) in the 30.6 meter permafrost core to develop a burial history of the sands and potentially a record the waxing and waning of the Taylor Glacier. This will allow new tests of our current understanding of surface dynamics and climate history in the McMurdo Dry Valleys (MDV) based on the dated stratigraphy of eolian sand that has been accumulating and inflating the surface for millions of years. This is a new process of surface inflation whose extent has not been well documented, and holds the potential to develop a continuous history of surface burial and glacial expansion. This project will provide a new proxy for understanding the climatic history of the Dry Valleys and will test models for the evolution of permafrost in Beacon Valley.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003e\u003cbr/\u003eThe landscape history of the McMurdo Dry Valleys is important because geological deposits there comprise the richest terrestrial record available from Antarctica. By testing the current age model for these deposits, we will improve understanding of Antarctica?s role in global climate change. This project will train one graduate and one undergraduate student in geochemistry, geochronology, and glacial and periglacial geology. They will participate substantively in the research and are expected to develop their own original ideas. Results from this work will be incorporated into undergraduate and graduate teaching curricula, will be published in the peer reviewed literature, and the data will be made public.", "east": 162.0, "geometry": "POINT(161 -77.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE; BOREHOLES; Antarctica", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Sletten, Ronald S.; Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Ancient landscape-active Surfaces: Periglacial Hyperinflation in soils of Beacon Valley, Antarctica", "uid": "p0010068", "west": 160.0}, {"awards": "1443105 Steig, Eric", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core; South Pole high resolution ice core water stable isotope record for dD, d18O; South Pole Ice Core Holocene Major Ion Dataset; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Schauer, Andrew; Stevens, Max; Conway, Howard; Epifanio, Jenna; White, James; Waddington, Edwin D.; Kahle, Emma; Steig, Eric J.; Jones, Tyler R.; Fudge, T. J.; Koutnik, Michelle; Morris, Valerie; Vaughn, Bruce; Buizert, Christo", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}, {"dataset_uid": "601239", "doi": "10.15784/601239", "keywords": "Antarctica; Cavity Ring Down Spectrometers; Delta 18O; Delta Deuterium; Deuterium Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Oxygen Isotope; Snow/ice; Snow/Ice; Stable Isotopes", "people": "Jones, Tyler R.; Schauer, Andrew; Kahle, Emma; Vaughn, Bruce; Morris, Valerie; White, James; Steig, Eric J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole high resolution ice core water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601239"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601429", "doi": "10.15784/601429", "keywords": "Antarctica; Climate; Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrogen; Ice; Ice Core; Ice Core Chemistry; Oxygen; Paleoclimate; Snow/ice; Snow/Ice; South Pole; Stable Isotopes", "people": "Steig, Eric J.; Vaughn, Bruce; Jones, Tyler R.; Kahle, Emma; White, James; Schauer, Andrew; Morris, Valerie", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core", "url": "https://www.usap-dc.org/view/dataset/601429"}, {"dataset_uid": "601399", "doi": "10.15784/601399", "keywords": "Antarctica; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601399"}], "date_created": "Sun, 17 Nov 2019 00:00:00 GMT", "description": "This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible.\u003cbr/\u003e\u003cbr/\u003eThis project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "SPICEcore; D18O; LABORATORY; OXYGEN ISOTOPE ANALYSIS; Oxygen Isotope; South Pole; USAP-DC; GLACIERS/ICE SHEETS; Antarctica; AMD; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Steig, Eric J.; White, James", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole", "uid": "p0010065", "west": 0.0}, {"awards": "1738942 Wellner, Julia", "bounds_geometry": "POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.5,-100 -72,-100 -72.5,-100 -73,-100 -73.5,-100 -74,-100 -74.5,-100 -75,-100 -75.5,-100 -76,-102 -76,-104 -76,-106 -76,-108 -76,-110 -76,-112 -76,-114 -76,-116 -76,-118 -76,-120 -76,-120 -75.5,-120 -75,-120 -74.5,-120 -74,-120 -73.5,-120 -73,-120 -72.5,-120 -72,-120 -71.5,-120 -71))", "dataset_titles": "A multibeam-bathymetric compilation for the southern Amundsen Sea shelf, 1999-2019; Expedition Data of NBP2002; NBP1902 Expedition data; Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "datasets": [{"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}, {"dataset_uid": "200248", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2002", "url": "https://www.rvdata.us/search/cruise/NBP2002"}, {"dataset_uid": "601514", "doi": "10.15784/601514", "keywords": "Antarctica; Chemistry:sediment; Chemistry:Sediment; Glaciomarine Sediment; Grain Size; Magnetic Susceptibility; Marine Geoscience; Marine Sediments; NBP1902; NBP2002; Physical Properties; R/v Nathaniel B. Palmer; Sediment Core Data; Thwaites Glacier; Trace Elements; XRF", "people": "Lepp, Allison", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "url": "https://www.usap-dc.org/view/dataset/601514"}, {"dataset_uid": "200161", "doi": "10.5285/F2DFEDA9-BF44-4EF5-89A3-EE5E434A385C", "keywords": null, "people": null, "repository": "UK PDC", "science_program": null, "title": "A multibeam-bathymetric compilation for the southern Amundsen Sea shelf, 1999-2019", "url": "https://doi.org/10.5285/F2DFEDA9-BF44-4EF5-89A3-EE5E434A385C"}], "date_created": "Fri, 01 Nov 2019 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Satellite observations extending over the last 25 years show that Thwaites Glacier is rapidly thinning and accelerating. Over this same period, the Thwaites grounding line, the point at which the glacier transitions from sitting on the seabed to floating, has retreated. Oceanographic studies demonstrate that the main driver of these changes is incursion of warm water from the deep ocean that flows beneath the floating ice shelf and causes basal melting. The period of satellite observation is not long enough to determine how a large glacier, such as Thwaites, responds to long-term and near-term changes in the ocean or the atmosphere. As a result, records of glacier change from the pre-satellite era are required to build a holistic understanding of glacier behavior. Ocean-floor sediments deposited at the retreating grounding line and further offshore contain these longer-term records of changes in the glacier and the adjacent ocean. An additional large unknown is the topography of the seafloor and how it influences interactions of landward-flowing warm water with Thwaites Glacier and affects its stability. Consequently, this project focuses on the seafloor offshore from Thwaites Glacier and the records of past glacial and ocean change contained in the sediments deposited by the glacier and surrounding ocean.\u003cbr/\u003e\u003cbr/\u003eUncertainty in model projections of the future of Thwaites Glacier will be significantly reduced by cross-disciplinary investigations seaward of the current grounding line, including extracting the record of decadal to millennial variations in warm water incursion, determining the pre-satellite era history of grounding-line migration, and constraining the bathymetric pathways that control flow of warm water to the grounding line. Sedimentary records and glacial landforms preserved on the seafloor will allow reconstruction of changes in drivers and the glacial response to them over a range of timescales, thus providing reference data that can be used to initiate and evaluate the reliability of models. Such data will further provide insights on the influence of poorly understood processes on marine ice sheet dynamics. This project will include an integrated suite of marine and sub-ice shelf research activities aimed at establishing boundary conditions seaward of the Thwaites Glacier grounding line, obtaining records of the external drivers of change, improving knowledge of processes leading to collapse of Thwaites Glacier, and determining the history of past change in grounding line migration and conditions at the glacier base. These objectives will be achieved through high-resolution geophysical surveys of the seafloor and analysis of sediments collected in cores from the inner shelf seaward of the Thwaites Glacier grounding line using ship-based equipment, and from beneath the ice shelf using a corer deployed through the ice shelf via hot water drill holes.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-110 -73.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS", "is_usap_dc": true, "keywords": "BATHYMETRY; Antarctica; MARINE SEDIMENTS; AMD; MARINE GEOPHYSICS; Amd/Us; USAP-DC; Thwaites Glacier; LABORATORY; Southern Ocean; ICE SHEETS; USA/NSF; GLACIERS/ICE SHEETS; R/V NBP", "locations": "Antarctica; Southern Ocean; Thwaites Glacier", "north": -71.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Wellner, Julia; Larter, Robert; Minzoni, Rebecca; Hogan, Kelly; Anderson, John; Graham, Alastair; Hillenbrand, Claus-Dieter; Nitsche, Frank O.; Simkins, Lauren; Smith, James A.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; UK PDC; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: THwaites Offshore Research (THOR)", "uid": "p0010062", "west": -120.0}, {"awards": "1142646 Twickler, Mark; 1142517 Aydin, Murat; 1141839 Steig, Eric", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "South Pole Ice Core Holocene Major Ion Dataset; South Pole ice core (SPC14) discrete methane data; South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601221", "doi": "10.15784/601221", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "people": "Fegyveresi, John; Hargreaves, Geoff; Kahle, Emma; Nicewonger, Melinda R.; Souney, Joseph Jr.; Twickler, Mark; Casey, Kimberly A.; Aydin, Murat; Steig, Eric J.; Nunn, Richard; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601221"}, {"dataset_uid": "601399", "doi": "10.15784/601399", "keywords": "Antarctica; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601399"}, {"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Schauer, Andrew; Stevens, Max; Conway, Howard; Epifanio, Jenna; White, James; Waddington, Edwin D.; Kahle, Emma; Steig, Eric J.; Jones, Tyler R.; Fudge, T. J.; Koutnik, Michelle; Morris, Valerie; Vaughn, Bruce; Buizert, Christo", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Winski, Dominic A.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; Amd/Us; Antarctica; ANALYTICAL LAB; USA/NSF; AMD; South Pole; ICE CORE RECORDS; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A 1500m Ice Core from South Pole", "uid": "p0010060", "west": 90.0}, {"awards": "1443190 Parizek, Byron", "bounds_geometry": "POLYGON((-130 -73,-125.5 -73,-121 -73,-116.5 -73,-112 -73,-107.5 -73,-103 -73,-98.5 -73,-94 -73,-89.5 -73,-85 -73,-85 -73.9,-85 -74.8,-85 -75.7,-85 -76.6,-85 -77.5,-85 -78.4,-85 -79.3,-85 -80.2,-85 -81.1,-85 -82,-89.5 -82,-94 -82,-98.5 -82,-103 -82,-107.5 -82,-112 -82,-116.5 -82,-121 -82,-125.5 -82,-130 -82,-130 -81.1,-130 -80.2,-130 -79.3,-130 -78.4,-130 -77.5,-130 -76.6,-130 -75.7,-130 -74.8,-130 -73.9,-130 -73))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 16 Sep 2019 00:00:00 GMT", "description": "Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region as well as processes governing changes in outlet glacier flow. To this end, we will test an ice-sheet model against existing observations and improve treatment of key processes within ice sheet models.\r\n\r\nThis is a four-year (one year of no-cost extension) modeling study using the open-source Ice Sheet System Model in coordination with other models to help improve projections of future sea-level change. Overall project goals, which are distributed across the collaborating institutions, are to:\r\n1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance;\r\n2. utilize observations from glacial settings and efficient process-oriented models to develop a better understanding of key processes associated with outlet glacier dynamics and to create numerically efficient parameterizations for these often sub-grid-scale processes;\r\n3. project a range of evolutions of the Amundsen Sea Embayment sector in the next several centuries given various forcings and inclusion or omission of physical processes in the model.\r\n", "east": -85.0, "geometry": "POINT(-107.5 -77.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; GLACIER MOTION/ICE SHEET MOTION; NOT APPLICABLE", "locations": "Antarctica", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pollard, David; Parizek, Byron R.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -82.0, "title": "Collaborative Research: Evaluating Retreat in the Amundsen Sea Embayment: Assessing Controlling Processes, Uncertainties, and Projections", "uid": "p0010054", "west": -130.0}, {"awards": "1443336 Osterberg, Erich; 1443397 Kreutz, Karl; 1443663 Cole-Dai, Jihong", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements; SPICEcore 400-480 m Major Ions SDSU; The South Pole Ice Core (SPICEcore) chronology and supporting data", "datasets": [{"dataset_uid": "601399", "doi": "10.15784/601399", "keywords": "Antarctica; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601399"}, {"dataset_uid": "601553", "doi": "10.15784/601553", "keywords": "Antarctica; Dust; Ice Core; South Pole", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements", "url": "https://www.usap-dc.org/view/dataset/601553"}, {"dataset_uid": "601206", "doi": "10.15784/601206", "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Cole-Dai, Jihong; Winski, Dominic A.; Fudge, T. J.; Dunbar, Nelia; Buizert, Christo; Bay, Ryan; Souney, Joseph Jr.; Sigl, Michael; McConnell, Joseph; Fegyveresi, John; Thundercloud, Zayta; Cox, Thomas S.; Kreutz, Karl; Epifanio, Jenna; Ortman, Nikolas; Brook, Edward J.; Beaudette, Ross; Sowers, Todd A.; Steig, Eric J.; Morris, Valerie; Kahle, Emma; Ferris, David G.; Aydin, Murat; Nicewonger, Melinda R.; Casey, Kimberly A.; Alley, Richard; Waddington, Edwin D.; Osterberg, Erich; Iverson, Nels; Severinghaus, Jeffrey P.; Jones, Tyler R.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "url": "https://www.usap-dc.org/view/dataset/601206"}, {"dataset_uid": "601675", "doi": "10.15784/601675", "keywords": "Antarctica; South Pole; SPICEcore", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.", "url": "https://www.usap-dc.org/view/dataset/601675"}, {"dataset_uid": "601754", "doi": "10.15784/601754", "keywords": "Antarctica; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601754"}, {"dataset_uid": "601430", "doi": "10.15784/601430", "keywords": "Antarctica; Ions; South Pole; SPICEcore", "people": "Larrick, Carleigh; Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore 400-480 m Major Ions SDSU", "url": "https://www.usap-dc.org/view/dataset/601430"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Winski, Dominic A.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. \u003cbr/\u003e\u003cbr/\u003eThe investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators\u0027 efforts to disseminate outcomes of climate change science to the broader community.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; USAP-DC; Amd/Us; USA/NSF; LABORATORY; AMD", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Osterberg, Erich", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "uid": "p0010051", "west": -180.0}, {"awards": "1401489 Sigman, Daniel", "bounds_geometry": "POLYGON((-180 -45,-144 -45,-108 -45,-72 -45,-36 -45,0 -45,36 -45,72 -45,108 -45,144 -45,180 -45,180 -47.5,180 -50,180 -52.5,180 -55,180 -57.5,180 -60,180 -62.5,180 -65,180 -67.5,180 -70,144 -70,108 -70,72 -70,36 -70,0 -70,-36 -70,-72 -70,-108 -70,-144 -70,-180 -70,-180 -67.5,-180 -65,-180 -62.5,-180 -60,-180 -57.5,-180 -55,-180 -52.5,-180 -50,-180 -47.5,-180 -45))", "dataset_titles": "Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age; Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4.; Diatom-bound nitrogen isotope and opal flux records over the Holocene period in Southern Ocean sediment cores MD12-3396, MD11-3353 and PS75/072-4.; GOSHIP section IO8S and P18S", "datasets": [{"dataset_uid": "200048", "doi": "doi.pangaea.de/10.1594/PANGAEA.891436.", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Diatom-bound nitrogen isotope and opal flux records over the Holocene period in Southern Ocean sediment cores MD12-3396, MD11-3353 and PS75/072-4.", "url": "https://doi.pangaea.de/10.1594/PANGAEA.891436"}, {"dataset_uid": "200049", "doi": "doi.org/10.1594/PANGAEA.848271", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4.", "url": "https://doi.org/10.1594/PANGAEA.848271"}, {"dataset_uid": "200050", "doi": "", "keywords": null, "people": null, "repository": "CLIVAR", "science_program": null, "title": "GOSHIP section IO8S and P18S", "url": "https://cchdo.ucsd.edu/"}, {"dataset_uid": "200051", "doi": "", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age", "url": "https://www.pnas.org/content/suppl/2017/03/14/1615718114.DCSupplemental"}], "date_created": "Thu, 08 Aug 2019 00:00:00 GMT", "description": "ABSTRACT\u003cbr/\u003eIntellectual Merit:\u003cbr/\u003eThe high concentration of the major nutrients nitrate and phosphate is a fundamental characteristic of the Antarctic Zone in the Southern Ocean and is central to its role in global ocean fertility and the global carbon cycle. The isotopic composition of diatom-bound organic nitrogen is one of the best hopes for reconstructing the nutrient status of polar surface waters over glacial cycles, which in turn may hold the explanation for the decline in atmospheric carbon dioxide during ice ages. The PIs propose to generate detailed diatom-bound nitrogen isotope (\u0026#948;15Ndb) records from high sedimentation rate cores from the Kerguelen Plateau. Because the cores were collected at relatively shallow seafloor depths, they have adequate planktonic and benthic foraminifera to develop accurate age models. The resulting data could be compared with climate records from Antarctic ice cores and other archives to investigate climate-related changes, including the major steps into and out of ice ages and the millennial-scale events that occur during ice ages and at their ends. The records generated in this project will provide a critical test of hypotheses for the cause of lower ice age CO2.\u003cbr/\u003e\u003cbr/\u003eBroader impacts:\u003cbr/\u003eThis study will contribute to the goal of understanding ice ages and past CO2 changes, which both have broad implications for future climate. Undergraduates will undertake summer internships, with the possibility of extending their work into junior year projects and senior theses. In addition, the PI will lead modules for two Princeton programs for middle school teachers and will host a teacher for a six-week summer research project.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; South Pacific Ocean; USAP-DC; NOT APPLICABLE", "locations": "South Pacific Ocean", "north": -45.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sigman, Daniel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PANGAEA", "repositories": "CLIVAR; PANGAEA; Publication", "science_programs": null, "south": -70.0, "title": "High-resolution, Assemblage-specific Records of Diatom-bound N Isotopes from the Indian Sector of the Antarctic Ocean", "uid": "p0010046", "west": -180.0}, {"awards": "1643684 Saito, Mak; 1644073 DiTullio, Giacomo", "bounds_geometry": "POLYGON((-180 -72,-173.6 -72,-167.2 -72,-160.8 -72,-154.4 -72,-148 -72,-141.6 -72,-135.2 -72,-128.8 -72,-122.4 -72,-116 -72,-116 -72.7,-116 -73.4,-116 -74.1,-116 -74.8,-116 -75.5,-116 -76.2,-116 -76.9,-116 -77.6,-116 -78.3,-116 -79,-122.4 -79,-128.8 -79,-135.2 -79,-141.6 -79,-148 -79,-154.4 -79,-160.8 -79,-167.2 -79,-173.6 -79,180 -79,178 -79,176 -79,174 -79,172 -79,170 -79,168 -79,166 -79,164 -79,162 -79,160 -79,160 -78.3,160 -77.6,160 -76.9,160 -76.2,160 -75.5,160 -74.8,160 -74.1,160 -73.4,160 -72.7,160 -72,162 -72,164 -72,166 -72,168 -72,170 -72,172 -72,174 -72,176 -72,178 -72,-180 -72))", "dataset_titles": "Algal pigment concentrations from the Ross Sea; Biogenic silica concentrations from the Ross Sea; NBP1801 Expedition data; Nutrients from NBP18-01 CICLOPS", "datasets": [{"dataset_uid": "200056", "doi": "10.7284/907753", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1801 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1801"}, {"dataset_uid": "601205", "doi": "10.15784/601205", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Chlorophyll; Chromatography; Liquid Chromatograph; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Water; Seawater Measurements; Southern Ocean; Water Measurements; Water Samples", "people": "Ditullio, Giacomo", "repository": "USAP-DC", "science_program": null, "title": "Algal pigment concentrations from the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601205"}, {"dataset_uid": "601428", "doi": "10.15784/601428", "keywords": "Amundsen Sea; Antarctica; NBP1801; Nitrate; Nitrite; Nutrients; Phosphate; Ross Sea; R/v Nathaniel B. Palmer; Silicic Acid; Terra Nova Bay", "people": "Saito, Mak", "repository": "USAP-DC", "science_program": null, "title": "Nutrients from NBP18-01 CICLOPS", "url": "https://www.usap-dc.org/view/dataset/601428"}, {"dataset_uid": "601225", "doi": "10.15784/601225", "keywords": "Antarctica; Biogenic Silica; Biogenic Silica Concentrations; Chemistry:Water; Geochemistry; NBP1801; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Water; Southern Ocean; Spectroscopy; Water Measurements; Water Samples", "people": "Ditullio, Giacomo; Schanke, Nicole", "repository": "USAP-DC", "science_program": null, "title": "Biogenic silica concentrations from the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601225"}], "date_created": "Thu, 08 Aug 2019 00:00:00 GMT", "description": "Phytoplankton blooms in the coastal waters of the Ross Sea, Antarctica are typically dominated by either diatoms or Phaeocystis Antarctica (a flagellated algae that often can form large colonies in a gelatinous matrix). The project seeks to determine if an association of bacterial populations with Phaeocystis antarctica colonies can directly supply Phaeocystis with Vitamin B12, which can be an important co-limiting micronutrient in the Ross Sea. The supply of an essential vitamin coupled with the ability to grow at lower iron concentrations may put Phaeocystis at a competitive advantage over diatoms. Because Phaeocystis cells can fix more carbon than diatoms and Phaeocystis are not grazed as efficiently as diatoms, the project will help in refining understanding of carbon dynamics in the region as well as the basis of the food web webs. Such understanding also has the potential to help refine predictive ecological models for the region. The project will conduct public outreach activities and will contribute to undergraduate and graduate research. Engagement of underrepresented students will occur during summer student internships. A collaboration with Italian Antarctic researchers, who have been studying the Terra Nova Bay ecosystem since the 1980s, aims to enhance the project and promote international scientific collaborations. \u003cbr/\u003e\u003cbr/\u003eThe study will test whether a mutualistic symbioses between attached bacteria and Phaeocystis provides colonial cells a mechanism for alleviating chronic Vitamin B12 co-limitation effects thereby conferring them with a competitive advantage over diatom communities. The use of drifters in a time series study will provide the opportunity to track in both space and time a developing algal bloom in Terra Nova Bay and to determine community structure and the physiological nutrient status of microbial populations. A combination of flow cytometry, proteomics, metatranscriptomics, radioisotopic and stable isotopic labeling experiments will determine carbon and nutrient uptake rates and the role of bacteria in mitigating potential vitamin B12 and iron limitation. Membrane inlet and proton transfer reaction mass spectrometry will also be used to estimate net community production and release of volatile organic carbon compounds that are climatically active. Understanding how environmental parameters can influence microbial community dynamics in Antarctic coastal waters will advance an understanding of how changes in ocean stratification and chemistry could impact the biogeochemistry and food web dynamics of Southern Ocean ecosystems.", "east": 160.0, "geometry": "POINT(-158 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; NBP1801; Amd/Us; USA/NSF; USAP-DC; NUTRIENTS; PIGMENTS; CHLOROPHYLL; R/V NBP; Ross Sea; AMD", "locations": "Ross Sea", "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "DiTullio, Giacomo; Lee, Peter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Cobalamin and Iron Co-Limitation Of Phytoplankton Species in Terra Nova Bay", "uid": "p0010045", "west": -116.0}, {"awards": "1443420 Dodd, Justin", "bounds_geometry": "POLYGON((167.07 -77.87,167.073 -77.87,167.076 -77.87,167.079 -77.87,167.082 -77.87,167.085 -77.87,167.088 -77.87,167.091 -77.87,167.094 -77.87,167.097 -77.87,167.1 -77.87,167.1 -77.873,167.1 -77.876,167.1 -77.879,167.1 -77.882,167.1 -77.885,167.1 -77.888,167.1 -77.891,167.1 -77.894,167.1 -77.897,167.1 -77.9,167.097 -77.9,167.094 -77.9,167.091 -77.9,167.088 -77.9,167.085 -77.9,167.082 -77.9,167.079 -77.9,167.076 -77.9,167.073 -77.9,167.07 -77.9,167.07 -77.897,167.07 -77.894,167.07 -77.891,167.07 -77.888,167.07 -77.885,167.07 -77.882,167.07 -77.879,167.07 -77.876,167.07 -77.873,167.07 -77.87))", "dataset_titles": "Diatom Oxygen Isotope Evidence of Pliocene (~4.68 to 3.44 Ma) Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "datasets": [{"dataset_uid": "601220", "doi": "10.15784/601220", "keywords": "And-1B; Andrill; Antarctica; Chemistry:sediment; Chemistry:Sediment; Delta 18O; Diatom; Mass Spectrometer; Oxygen Isotope; Paleoclimate; Pliocene; Sediment; Wais Project; West Antarctic Ice Sheet", "people": "Dodd, Justin; Abbott, Tirzah", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Diatom Oxygen Isotope Evidence of Pliocene (~4.68 to 3.44 Ma) Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "url": "https://www.usap-dc.org/view/dataset/601220"}], "date_created": "Tue, 06 Aug 2019 00:00:00 GMT", "description": "Abstract\u003cbr/\u003eDuring the Early Pliocene, 4.8 to 3.4 million years ago, warmer-than-present global temperatures resulted in a retreat of the Ross Ice Shelf and West Antarctic Ice Sheet. Understanding changes in ocean dynamics during times of reduced ice volume and increased temperatures in the geologic past will improve the predictive models for these conditions. The primary goal of the proposed research is to develop a new oxygen isotope record of Pliocene oceanographic conditions near the Antarctic continent. Oxygen isotope values from the carbonate tests of benthic foraminifera have become the global standard for paleo-oceanographic studies, but foraminifera are sparse in high-latitude sediment cores. This research will instead make use of oxygen isotope measurements from diatom silica preserved in a marine sediment core from the Ross Sea. The project is the first attempt at using this method and will advance understanding of global ocean dynamics and ice sheet-ocean interactions during the Pliocene. The project will foster the professional development of two early-career scientists and serve as training for graduate and undergraduate student researchers. The PIs will use this project to introduce High School students to polar/oceanographic research, as well as stable isotope geochemistry. Collaboration with teachers via NSTA and Polar Educators International will ensure the implementation of excellent STEM learning activities and curricula for younger students. \u003cbr/\u003e\u003cbr/\u003eTechnical Description\u003cbr/\u003eThis project will produce a high-resolution oxygen isotope record from well-dated diatom rich sediments that have been cross-correlated with global benthic foraminifera oxygen isotope records. Diatom silica frustules deposited during the Early Pliocene and recovered by the ANDRILL Project (AND-1B) provide ideal material for this objective. Diatomite unites in the AND-1B core are nearly pure, with little evidence of opal formation. A diatom oxygen isotope record from this core offers the potential to constrain lingering uncertainties about Ross Sea and Southern Ocean paleoceanography and Antarctic Ice Sheet history during a time of high atmospheric carbon dioxide concentrations. Specifically, oxygen isotope variations will be used to constrain changes in the water temperature and/or freshwater flux in the Pliocene Ross Sea. Diatom species data from the AND-1B core have been used to infer variations in the extent and duration of seasonal sea ice coverage, sea surface temperatures, and mid-water advection onto the continental shelf. However, the diatom oxygen isotope record will provide the first direct measure of water/oxygen isotope values at the Antarctic continental margin during the Pliocene.", "east": 167.1, "geometry": "POINT(167.085 -77.885)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "OXYGEN ISOTOPES; USAP-DC; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -77.87, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Dodd, Justin; Scherer, Reed Paul; Warnock, Jonathan", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.9, "title": "Diatom and Oxygen Isotope Evidence of Pliocene Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "uid": "p0010042", "west": 167.07}, {"awards": "1443550 Brook, Edward J.", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Polar Ice Cores 3,000 Year Nitrous Oxide d15N and d18O Data; SPICEcore Holocene CO2 and N2O data", "datasets": [{"dataset_uid": "601197", "doi": "10.15784/601197", "keywords": "Antarctica; Carbon Dioxide; Ice Core Gas Records; Nitrous Oxide; South Pole; SPICEcore", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore Holocene CO2 and N2O data", "url": "https://www.usap-dc.org/view/dataset/601197"}, {"dataset_uid": "200055", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Polar Ice Cores 3,000 Year Nitrous Oxide d15N and d18O Data", "url": "https://www.ncdc.noaa.gov/paleo-search/study/25530"}], "date_created": "Tue, 06 Aug 2019 00:00:00 GMT", "description": "The temperature of the earth is controlled, in part, by heat trapping gases that include carbon dioxide, methane, and nitrous oxide. Despite their importance to climate, direct measurements of these gases in the atmosphere are limited to the last 50 years at best. Air trapped in ice cores extends those data back hundreds of millennia, and measurements of greenhouse gases in ice cores underpin much of our understanding of global chemical cycles relevant to modern climate change. Existing records vary in quality and detail. The proposed work fills gaps in our knowledge of nitrous oxide and carbon dioxide over the last 10,000 years. New measurements from an ice core from the South Pole will be used to determine what role changes in ocean and land based processes played in controlling these gases, which decreased during the first 2,000 years of this time period, then gradually increased toward the present. The work will address a major controversy over whether early human activities could have impacted the atmosphere, and provide data to improve mathematical models of the land-ocean-atmosphere system that predict how future climate change will impact the composition of the atmosphere and climate. \u003cbr/\u003e\u003cbr/\u003eFor nitrous oxide the work will improve on existing concentration records It will also develop measurement of the isotopomers of nitrous oxide and explore their utility for understanding aspects of the Holocene nitrous oxide budget. The primary goal is to determine if marine and/or terrestrial emissions of nitrous oxide change in response to changes in Holocene climate. A new Holocene isotopic record for carbon dioxide (stable carbon and oxygen isotopes), will improve the precision of existing records by a factor 5 and increase the temporal resolution. These data will be used to evaluate controversial hypotheses about why carbon dioxide concentrations changed in the Holocene and provide insight into millennial scale processes in the carbon cycle, which are not resolved by current isotopic data. A graduate student and post doc will receive advanced training during and the student and principle investigator will conduct outreach efforts targeted at local middle school students. The proposed work will also contribute to teaching efforts by the PI and to public lectures on climate and climate change. The results will be disseminated through publications, data archive, and the OSU Ice Core Lab web site. New analytical methods of wide utility will also be developed and documented.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; CARBON DIOXIDE; NOT APPLICABLE; USAP-DC; TRACE GASES/TRACE SPECIES; NITROUS OXIDE", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Controls on Variations in Atmospheric Carbon Dioxide and Nitrous Oxide During the Last 10,000 years", "uid": "p0010043", "west": -180.0}, {"awards": "1543311 LaRue, Michelle; 1543230 Ainley, David; 1543003 Stammerjohn, Sharon; 1542791 Salas, Leonardo", "bounds_geometry": "POLYGON((-180 -64,-144 -64,-108 -64,-72 -64,-36 -64,0 -64,36 -64,72 -64,108 -64,144 -64,180 -64,180 -65.4,180 -66.8,180 -68.2,180 -69.6,180 -71,180 -72.4,180 -73.8,180 -75.2,180 -76.6,180 -78,144 -78,108 -78,72 -78,36 -78,0 -78,-36 -78,-72 -78,-108 -78,-144 -78,-180 -78,-180 -76.6,-180 -75.2,-180 -73.8,-180 -72.4,-180 -71,-180 -69.6,-180 -68.2,-180 -66.8,-180 -65.4,-180 -64))", "dataset_titles": "ContinentalWESEestimates; Counting seals from space tutorial; Fast Ice Tool; Weddell seals habitat suitability model for the Ross Sea", "datasets": [{"dataset_uid": "200046", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Weddell seals habitat suitability model for the Ross Sea", "url": "https://github.com/leosalas/WeddellSeal_SOS"}, {"dataset_uid": "200045", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Fast Ice Tool", "url": "https://github.com/leosalas/FastIceCovars"}, {"dataset_uid": "200234", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "ContinentalWESEestimates", "url": "https://github.com/leosalas/ContinentalWESEestimates"}, {"dataset_uid": "200047", "doi": "", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Counting seals from space tutorial", "url": "https://www.int-res.com/articles/suppl/m612p193_supp.pdf"}], "date_created": "Fri, 02 Aug 2019 00:00:00 GMT", "description": "The Weddell seal is the southern-most mammal in the world, having a circumpolar distribution around Antarctica; the McMurdo Sound population in Antarctica is one of the best-studied mammal populations on earth. However, despite this, an understanding of how populations around the continent will fare under climate change is poorly understood. A complicating matter is the potential effects of a commercial enterprise in the Antarctic: a fishery targeting toothfish, which are important prey for Weddell seals. Although the species is easily detected and counted during the breeding season, no reliable estimates of continent-wide Weddell seal numbers exist, due to the logistic difficulties of surveying vast regions of Antarctica. Large-scale estimates are needed to understand how seal populations are responding to the fishery and climate change, because these drivers of change operate at scales larger than any single population, and may affect seals differently in different regions of the continent. We will take advantage of the ease of detectability of darkly colored seals when they the on ice to develop estimates of abundance from satellite images. This project will generate baseline data on the global distribution and abundance of Weddell seals around the Antarctic and will link environmental variables to population changes to better understand how the species will fare as their sea ice habitat continues to change. These results will help disentangle the effects of climate change and fishery operations, results that are necessary for appropriate international policy regarding fishery catch limits, impacts on the environment, and the value of marine protected areas. The project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. It will engage \"arm-chair\" scientists of all ages through connections with several non-governmental organizations and the general public. Anyone with access to the internet, including people who are physically unable to participate in field research directly, can participate in this project while simultaneously learning about multiple aspects of polar ecology through the project\u0027s interactive website. \u003cbr/\u003e\u003cbr/\u003eSpecifically, this research project will: 1) Quantify the distribution of Weddell seals around Antarctica and 2) Determine the impact of environmental variables (such as fast ice extent, ocean productivity, bathymetry) on habitat suitability and occupancy. To do this, the project will crowd-source counting of seals on high-resolution satellite images via a commercial citizen science platform. Variation in seal around the continent will then be related to habitat variables through generalized linear models. Specific variables, such as fast ice extent will be tested to determine their influence on population variability through both space and time. The project includes a rigorous plan for ensuring quality control in the dataset including ground truth data from other, localized projects concurrently funded by the National Science Foundation\u0027s Antarctic Science Program.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "COASTAL; Southern Ocean; COMMUNITY DYNAMICS; MAMMALS; SEA ICE; NOT APPLICABLE; Antarctica; PENGUINS; USAP-DC", "locations": "Antarctica; Southern Ocean", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "LaRue, Michelle; Stamatiou, Kostas", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub; Publication", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Determining Factors Affecting Distribution and Population Variability of the Ice-obligate Weddell Seal", "uid": "p0010041", "west": -180.0}, {"awards": "1543267 Brook, Edward J.; 1543229 Severinghaus, Jeffrey", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Multi-site ice core Krypton stable isotope ratios; Noble Gas Data from recent ice in Antarctica for 86Kr problem", "datasets": [{"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Bertler, Nancy; Shackleton, Sarah; Pyne, Rebecca L.; Mosley-Thompson, Ellen; Mulvaney, Robert; Buizert, Christo; Severinghaus, Jeffrey P.; Bereiter, Bernhard; Brook, Edward J.; Etheridge, David; Baggenstos, Daniel", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601195", "doi": "10.15784/601195", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Krypton; Noble Gas; Xenon", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Noble Gas Data from recent ice in Antarctica for 86Kr problem", "url": "https://www.usap-dc.org/view/dataset/601195"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Baggenstos, Daniel; Mosley-Thompson, Ellen; Bertler, Nancy; Bereiter, Bernhard; Severinghaus, Jeffrey P.; Etheridge, David; Shackleton, Sarah; Mulvaney, Robert; Brook, Edward J.; Buizert, Christo; Pyne, Rebecca L.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Baggenstos, Daniel; Shackleton, Sarah; Severinghaus, Jeffrey P.; Brook, Edward J.; Buizert, Christo; Bereiter, Bernhard; Etheridge, David; Bertler, Nancy; Pyne, Rebecca L.; Mulvaney, Robert; Mosley-Thompson, Ellen", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}], "date_created": "Wed, 10 Jul 2019 00:00:00 GMT", "description": "Overview: The funded work investigated whether ice core 86Kr acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere (SH) westerly winds. Pressure variations drive macroscopic air movement in the firn column, which reduces the gravitational isotopic enrichment of slow-diffusing gases (such as Kr). The 86Kr deviation from gravitational equilibrium (denoted D86Kr) thus reflects the magnitude of pressure variations (among other things). Atmospheric reanalysis data suggest that pressure variability over Antarctica is linked to the Southern Annular Mode (SAM) index and the position of the SH westerly winds. Preliminary data from the WAIS Divide ice core show a large excursion in D86Kr during the last deglaciation (20-9 ka before present). In this project the investigators (1) performed high-precision 86Kr analysis on ice core and firn air samples to establish whether D86Kr is linked to pressure variability; (2) Refined the deglacial WAIS Divide record of Kr isotopes; (3) Investigated the role of pressure variability in firn air transport using firn air models with firn microtomography data and Lattice- Boltzmann modeling; and (4) Investigated how barometric pressure variability in Antarctica is linked to the SAM index and the position/strength of the SH westerlies in past and present climates using GCM and reanalysis data. A key finding was that D86Kr in recent ice samples (e.g. last 50 years) from a broad spatial array of sites in Antarctica and Greenland showed a significant correlation with directly measured barometric pressure variability at the ice core site. This strongly supports the hypothesis that 86Kr can be used as a paleo-proxy for storminess.\r\nIntellectual Merit: The SH westerlies are a key component of the global climate system; they are an important control on the global oceanic overturning circulation and possibly on atmospheric CO2 concentrations. Poleward movement of the SH westerlies during the last deglaciation has been hypothesized, yet evidence from proxy and modeling studies remains inconclusive. The funded work could provide valuable new constraints on deglacial movement of the SH westerlies. This record can be compared to high-resolution CO2 data from the same core, allowing us to test hypotheses that link CO2 to the SH westerlies. Climate proxies are at the heart of paleoclimate research. The funded work has apparently led to the discovery of a completely new proxy, opening up exciting new research possibilities and increasing the scientific value of existing ice cores. Once validated, the 86Kr proxy could be applied to other time periods as well, providing a long-term perspective on the movement of the SH westerlies. The funded work has furthermore provided valuable new insights into firn air transport. \r\n\r\nBroader impact: The Southern Ocean is presently an important sink of atmospheric CO2, thereby reducing the warming associated with anthropogenic CO2 emissions. Stratospheric ozone depletion and greenhouse warming have displaced the SH westerlies poleward, with potential consequences for the future magnitude of this oceanic carbon uptake. The funded work may provide a paleo-perspective on past movement of the SH westerlies and its link to atmospheric CO2, which could guide projections of future oceanic CO2 uptake, with strong societal benefits. The awarded funds supported and trained an early-career postdoctoral scholar at OSU, and fostered (international) collaboration. Data from the study will be available to the scientific community and the broad public through recognized data centers. During this project the PI and senior personnel have continued their commitment to public outreach through media interviews and speaking to schools and the public about their work. The PI provides services to the community by chairing the IPICS (International Partnership in Ice Core Sciences) working group and organizing annual PIRE (Partnerships in International Research and Education) workshops.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USA/NSF; FIRN; ICE CORE RECORDS; USAP-DC; Greenland; Xenon; Noble Gas; Ice Core; Amd/Us; Antarctica; AMD; LABORATORY; Krypton; ATMOSPHERIC PRESSURE", "locations": "Greenland; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last\r\ndeglaciation", "uid": "p0010037", "west": -180.0}, {"awards": "1443498 Fricker, Helen; 1443677 Padman, Laurence; 1443534 Bell, Robin; 1443497 Siddoway, Christine", "bounds_geometry": "POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,178.1 -86,176.2 -86,174.3 -86,172.4 -86,170.5 -86,168.6 -86,166.7 -86,164.8 -86,162.9 -86,161 -86,161 -85.1,161 -84.2,161 -83.3,161 -82.4,161 -81.5,161 -80.6,161 -79.7,161 -78.8,161 -77.9,161 -77,162.9 -77,164.8 -77,166.7 -77,168.6 -77,170.5 -77,172.4 -77,174.3 -77,176.2 -77,178.1 -77,-180 -77))", "dataset_titles": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice); LiDAR Nadir and Swath Data from Ross Ice Shelf, Antarctica (ROSETTA-Ice); ROSETTA-Ice data page; Ross Sea ocean model simulation used to support ROSETTA-Ice ; Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "datasets": [{"dataset_uid": "601789", "doi": null, "keywords": "Airborne Radar; Antarctica; Cryosphere; Ice Thickness; Remote Sensing; Ross Ice Shelf", "people": "Frearson, Nicholas; Bell, Robin; Chu, Winnie; Spergel, Julian; Das, Indrani; Dong, LingLing; Bertinato, Christopher; Dhakal, Tejendra; Cordero, Isabel; Wilner, Joel; Millstein, Joanna", "repository": "USAP-DC", "science_program": null, "title": "Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601789"}, {"dataset_uid": "601794", "doi": null, "keywords": "Antarctica; Cryosphere; Remote Sensing; Ross Ice Shelf", "people": "Bertinato, Christopher; Cordero, Isabel; Frearson, Nicholas; Dhakal, Tejendra; Chu, Winnie; Keeshin, Skye; Wearing, Martin; Spergel, Julian; Packard, Sarah; Dong, LingLing; Das, Indrani; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601794"}, {"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Erofeeva, Svetlana; Howard, Susan L.; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "200100", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "ROSETTA-Ice data page", "url": "http://wonder.ldeo.columbia.edu/data/ROSETTA-Ice/"}, {"dataset_uid": "601788", "doi": null, "keywords": "Antarctica; Cryosphere; Ross Ice Shelf", "people": "Locke, Caitlin; Dhakal, Tejendra; Boghosian, Alexandra; Starke, Sarah; Becker, Maya K; Bertinato, Christopher", "repository": "USAP-DC", "science_program": null, "title": "LiDAR Nadir and Swath Data from Ross Ice Shelf, Antarctica (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601788"}, {"dataset_uid": "601242", "doi": "10.15784/601242", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice-Shelf Basal Melting; Radar Echo Sounder; Radar Echo Sounding; Snow/ice; Snow/Ice", "people": "Dhakal, Tejendra; Das, Indrani; Mosbeux, Cyrille; Cordero, Isabel; Siegfried, Matt; Tinto, Kirsty; Bell, Robin; Padman, Laurence; Fricker, Helen; Hulbe, Christina; Siddoway, Christine; Frearson, Nicholas", "repository": "USAP-DC", "science_program": null, "title": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601242"}, {"dataset_uid": "601255", "doi": "10.15784/601255", "keywords": "Antarctica; Basal Melt; Ice Shelf; Model Output; Ocean Circulation Model; Ross Ice Shelf; Ross Sea", "people": "Howard, Susan L.; Springer, Scott; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea ocean model simulation used to support ROSETTA-Ice ", "url": "https://www.usap-dc.org/view/dataset/601255"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Howard, Susan L.; Erofeeva, Svetlana; Sutterley, Tyler; Greene, Chad A.; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}], "date_created": "Wed, 03 Jul 2019 00:00:00 GMT", "description": "The Ross Ice Shelf is the largest existing ice shelf in Antarctica, and is currently stabilizing significant portions of the land ice atop the Antarctic continent. An ice shelf begins where the land ice goes afloat on the ocean, and as such, the Ross Ice Shelf interacts with the ocean and seafloor below, and the land ice behind. Currently, the Ross Ice Shelf slows down, or buttresses, the fast flowing ice streams of the West Antarctic Ice Sheet (WAIS), a marine-based ice sheet, which if melted, would raise global sea level by 3-4 meters. The Ross Ice Shelf average ice thickness is approximately 350 meters, and it covers approximately 487,000 square kilometers, an area slightly larger than the state of California. The Ross Ice Shelf has disappeared during prior interglacial periods, suggesting in the future it may disappear again. Understanding the dynamics, stability and future of the West Antarctic Ice Sheet therefore requires in-depth knowledge of the Ross Ice Shelf. The ROSETTA-ICE project brings together scientists from 4 US institutions and from the Institute of Geological and Nuclear Sciences Limited, known as GNS Science, New Zealand. The ROSETTA-ICE data on the ice shelf, the water beneath the ice shelf, and the underlying rocks, will allow better predictions of how the Ross Ice Shelf will respond to changing climate, and therefore how the WAIS will behave in the future. The interdisciplinary ROSETTA-ICE team will train undergraduate and high school students in cutting edge research techniques, and will also work to educate the public via a series of vignettes integrating ROSETTA-ICE science with the scientific and human history of Antarctic research.\u003cbr/\u003e\u003cbr/\u003eThe ROSETTA-ICE survey will acquire gravity and magnetics data to determine the water depth beneath the ice shelf. Radar, LIDAR and imagery systems will be used to map the Ross Ice Shelf thickness and fine structure, crevasses, channels, debris, surface accumulation and distribution of marine ice. The high resolution aerogeophysical data over the Ross Ice Shelf region in Antarctica will be acquired using the IcePod sensor suite mounted externally on an LC-130 aircraft operating from McMurdo Station, Antarctica. Field activities will include ~36 flights on LC-130 aircraft over two field seasons in Antarctica. The IcePod instrument suite leverages the unique experience of the New York Air National Guard operating in Antarctica for NSF scientific research as well as infrastructure and logistics. The project will answer questions about the stability of the Ross Ice Shelf in future climate, and the geotectonic evolution of the Ross Ice Shelf Region, a key component of the West Antarctic Rift system. The comprehensive benchmark data sets acquired will enable broad, interdisciplinary analyses and modeling, which will also be performed as part of the project. ROSETTA-ICE will illuminate Ross ice sheet-ice shelf-ocean dynamics as the system nears a critical juncture but still is intact. Through interacting with an online data visualization tool, and comparing the ROSETTA-ICE data and results from earlier studies, we will engage students and young investigators, equipping them with new capabilities for the study of critical earth systems that influence global climate.", "east": 161.0, "geometry": "POINT(-174.5 -81.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e PROTON MAGNETOMETER", "is_usap_dc": true, "keywords": "Airborne Radar; LIDAR; Ross Ice Shelf; SALINITY; SALINITY/DENSITY; CONDUCTIVITY; ICE DEPTH/THICKNESS; Tidal Models; GRAVITY ANOMALIES; Ross Sea; Antarctica; BATHYMETRY; C-130; MAGNETIC ANOMALIES; USAP-DC; Airborne Gravity", "locations": "Ross Sea; Antarctica; Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Bell, Robin; Frearson, Nicholas; Das, Indrani; Fricker, Helen; Padman, Laurence; Springer, Scott; Siddoway, Christine; Tinto, Kirsty", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e C-130", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)", "uid": "p0010035", "west": -150.0}, {"awards": "1745036 Marchetti, Adrian; 1744760 Hopkinson, Brian", "bounds_geometry": "POLYGON((-77 -61,-75.2 -61,-73.4 -61,-71.6 -61,-69.8 -61,-68 -61,-66.2 -61,-64.4 -61,-62.6 -61,-60.8 -61,-59 -61,-59 -62.1,-59 -63.2,-59 -64.3,-59 -65.4,-59 -66.5,-59 -67.6,-59 -68.7,-59 -69.8,-59 -70.9,-59 -72,-60.8 -72,-62.6 -72,-64.4 -72,-66.2 -72,-68 -72,-69.8 -72,-71.6 -72,-73.4 -72,-75.2 -72,-77 -72,-77 -70.9,-77 -69.8,-77 -68.7,-77 -67.6,-77 -66.5,-77 -65.4,-77 -64.3,-77 -63.2,-77 -62.1,-77 -61))", "dataset_titles": "Photosynthetic physiological data of Proteorhodopsin containing diatoms under differing iron availabilities", "datasets": [{"dataset_uid": "601530", "doi": "10.15784/601530", "keywords": "Antarctica; Diatom", "people": "Hopkinson, Brian; Andrew, Sarah; Plumb, Kaylie; Marchetti, Adrian", "repository": "USAP-DC", "science_program": null, "title": "Photosynthetic physiological data of Proteorhodopsin containing diatoms under differing iron availabilities", "url": "https://www.usap-dc.org/view/dataset/601530"}], "date_created": "Sun, 16 Jun 2019 00:00:00 GMT", "description": "Proteorhodopsins (PR) are retinal-binding membrane proteins that can act as light-driven proton pumps to generate energy that can be used for metabolism and growth. The discovery of PRs in many diverse marine prokaryotic microbes has initiated extensive investigations into their distributions and functional roles. Recently, a rhodopsin-like gene of the proton-pumping variety was identified in diatoms thus revealing their presence within obligate marine eukaryotic photoautotrophs. Since this time, PRs have been identified in a number of diatom isolates although there appears to be a much higher frequency of\r\nPR in diatoms residing in cold, iron-limited regions of the ocean, particularly in the Southern Ocean (SO). PR is especially suited for use in SO phytoplankton since unlike conventional photosynthesis, it uses no iron and its reaction rate is insensitive to temperature. The overall objective of our proposed project is to characterize Antarctic diatom-PR and determine its role in the adaptation of SO diatoms to the prevailing conditions of low iron concentrations and extremely low temperatures. Our research objectives will be achieved through a combination of molecular, biochemical and physiological measurements in diatom isolates recently obtained from the Western Antarctic Peninsula region. We will determine the proton-pumping characteristics and pumping rates of PR as a function of light intensity and wavelength, the resultant PR-linked intracellular ATP production rates, and the cellular localization of the protein. We will examine under which environmental conditions Antarctic diatom-PR is most highly expressed and construct a cellular energy budget that includes diatom-PR when grown under these different growth conditions. Estimates of the energy flux generated by PR in PR-containing diatoms will be compared to total energy generation by the photosynthetic light reactions and metabolically coupled respiration rates. Finally, we will compare the characteristics and gene expression of diatom-PR in Antarctic diatoms to PR-containing diatoms isolated from temperate regions in order to investigate if there is a preferential dependence on energy production through diatom-PR in diatoms residing in cold, iron-limited regions of the ocean.", "east": -59.0, "geometry": "POINT(-68 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; NSF/USA; Southern Ocean; AMD; Amd/Us; LABORATORY; USAP-DC; BIOGEOCHEMICAL CYCLES", "locations": "Southern Ocean", "north": -61.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marchetti, Adrian; Septer, Alecia; Hopkinson, Brian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.0, "title": "Collaborative research: Antarctic diatom proteorhodopsins: Characterization and a potential role in the iron-limitation response", "uid": "p0010033", "west": -77.0}, {"awards": "1443552 Paul Winberry, J.; 1443356 Conway, Howard", "bounds_geometry": "POLYGON((-175 -82.7,-173.9 -82.7,-172.8 -82.7,-171.7 -82.7,-170.6 -82.7,-169.5 -82.7,-168.4 -82.7,-167.3 -82.7,-166.2 -82.7,-165.1 -82.7,-164 -82.7,-164 -82.77,-164 -82.84,-164 -82.91,-164 -82.98,-164 -83.05,-164 -83.12,-164 -83.19,-164 -83.26,-164 -83.33,-164 -83.4,-165.1 -83.4,-166.2 -83.4,-167.3 -83.4,-168.4 -83.4,-169.5 -83.4,-170.6 -83.4,-171.7 -83.4,-172.8 -83.4,-173.9 -83.4,-175 -83.4,-175 -83.33,-175 -83.26,-175 -83.19,-175 -83.12,-175 -83.05,-175 -82.98,-175 -82.91,-175 -82.84,-175 -82.77,-175 -82.7))", "dataset_titles": "2015_Antarctica_Ground; Geophysical data from Crary Ice Rise, Ross Sea Embayment", "datasets": [{"dataset_uid": "200177", "doi": "", "keywords": null, "people": null, "repository": "CReSIS/ku.edu", "science_program": null, "title": "2015_Antarctica_Ground", "url": "https://data.cresis.ku.edu/data/accum/2015_Antarctica_Ground/"}, {"dataset_uid": "601181", "doi": "10.15784/601181", "keywords": "Antarctica; Bed Elevation; Crary Ice Rise; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Ice Sheet Elevation; Ice Shelf; Ice Thickness; Internal Stratigraphy; Radar; Ross Ice Shelf; Snow/ice; Snow/Ice; Surface Elevation", "people": "Koutnik, Michelle; Paden, John; Conway, Howard; Winberry, Paul", "repository": "USAP-DC", "science_program": null, "title": "Geophysical data from Crary Ice Rise, Ross Sea Embayment", "url": "https://www.usap-dc.org/view/dataset/601181"}], "date_created": "Mon, 06 May 2019 00:00:00 GMT", "description": "Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities.\u003cbr/\u003e\u003cbr/\u003eNew tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change?", "east": -164.0, "geometry": "POINT(-169.5 -83.05)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Amd/Us; FIELD SURVEYS; Antarctica; USA/NSF; AMD; USAP-DC; Radar; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -82.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Koutnik, Michelle; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "CReSIS/ku.edu", "repositories": "CReSIS/ku.edu; USAP-DC", "science_programs": null, "south": -83.4, "title": "Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited", "uid": "p0010026", "west": -175.0}, {"awards": "1543031 Ivany, Linda", "bounds_geometry": null, "dataset_titles": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ; Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ; Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "datasets": [{"dataset_uid": "601174", "doi": "10.15784/601174", "keywords": "Antarctica; Biota; Bivalves; Cucullaea; Eocene; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Oxygen Isotope; Paleotemperature; Retrotapes; Seasonality; Seymour Island", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601174"}, {"dataset_uid": "601173", "doi": "10.15784/601173 ", "keywords": "Antarctica; Carbon Isotopes; Driftwood; Eocene; Geochemistry; Geochronology; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Organic Carbon Isotopes; Seasonality; Seymour Island; Wood", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ", "url": "https://www.usap-dc.org/view/dataset/601173"}, {"dataset_uid": "601175", "doi": "10.15784/601175 ", "keywords": "Antarctica; Atmosphere; Climate Model; Computer Model; Eocene; Genesis; Global Circulation Model; Modeling; Model Output; Seasonality; Temperature", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ", "url": "https://www.usap-dc.org/view/dataset/601175"}], "date_created": "Tue, 23 Apr 2019 00:00:00 GMT", "description": "In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth\u0027s past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth\u0027s ancient climate and what we can learn from it.\u003cbr/\u003e\u003cbr/\u003eAntarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.", "east": -56.0, "geometry": "POINT(-56.5 -64.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "PALEOCLIMATE RECONSTRUCTIONS; USAP-DC; ISOTOPES; NOT APPLICABLE; MACROFOSSILS; Antarctica", "locations": "Antarctica", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ivany, Linda; Lu, Zunli; Junium, Christopher; Samson, Scott", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.5, "title": "Seasonality, Summer Cooling, and Calibrating the Approach of the Icehouse in Late Eocene Antarctica", "uid": "p0010025", "west": -57.0}, {"awards": "1249631 Wilson, Terry; 1246666 Huerta, Audrey; 1246776 Nyblade, Andrew; 1246712 Wiens, Douglas; 1419268 Aster, Richard; 1247518 Smalley, Robert; 1249513 Dalziel, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Network/Campaign: Antarctica POLENET - ANET; POLENET - Network YT", "datasets": [{"dataset_uid": "200012", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "POLENET - Network YT", "url": "http://ds.iris.edu/mda/YT/?timewindow=2007-2018"}, {"dataset_uid": "200011", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Network/Campaign: Antarctica POLENET - ANET", "url": "https://www.unavco.org/data/gps-gnss/data-access-methods/dai2/app/dai2.html#grouping=Antarctica%20POLENET%20-%20ANET;scope=Station;sampleRate=normal;groupingMod=contains"}], "date_created": "Sun, 17 Feb 2019 00:00:00 GMT", "description": "Intellectual Merit: The PIs continued and expanded GPS and seismic measurements for ANET-POLENET to advance understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. ANET-POLENET science themes include: 1) determining ice mass change since the last glacial maximum, including modern ice mass balance; 2) solid earth influence on ice sheet dynamics; and 3) tectonic evolution of West Antarctica and feedbacks with ice sheet evolution. Nine new remote continuous GPS stations augmented ANET-POLENET instrumentation deployed during Phase 1. Siting was designed to better constrain uplift centers predicted by GIA models and indicated by Phase 1 results. A mini-array of temporary seismic sites was deployed to improve resolution of earth structure below West Antarctica. ANET-POLENET Phase 2 achievements included 1) seismic images of crust and mantle structure that resolve the highly heterogeneous thermal and viscosity structure of the Antarctic lithosphere and underlying mantle; 2) improved estimates of intraplate vertical and horizontal bedrock crustal motions; and 3) elucidation of controls on glacial isostatic adjustment-induced crustal motions due to laterally varying earth structure. \r\n\r\nBroader impacts: Monitoring and understanding mass change and dynamic behavior of the Antarctic ice sheet using in situ GPS and seismological studies has improved understanding of how Antarctic ice sheets respond to a warming world and how this response impacts sea-level and other global changes. Seismic and geodetic data collected by the ANET-POLENET network are openly available to the scientific community. ANET-POLENET has been integral in the development and realization of technological and logistical innovations for year-round operation of instrumentation at remote polar sites, helping to advance scientifically and geographically broad studies of the polar regions. The ANET-POLENET carried out a training initiative to mentor young polar scientists in complex, multidisciplinary and internationally collaborative research, including 2 week-long training schools on \"Glacial Isostatic Adjustment\" and \"Glacial Seismology\". ANET-POLENET continued broad public outreach about polar science through the polenet.org website, university lectures, and K-12 school visits. This research involved multiple international partners.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Geodesy; USAP-DC; SEISMIC SURFACE WAVES; CRUSTAL MOTION; TECTONICS; Broadband Seismic; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry; Dalziel, Ian W.; Bevis, Michael; Aster, Richard; Huerta, Audrey D.; Winberry, Paul; Anandakrishnan, Sridhar; Nyblade, Andrew; Wiens, Douglas; Smalley, Robert", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": "POLENET", "south": -90.0, "title": "Collaborative Research: POLENET-Antarctica: Investigating Links Between Geodynamics and Ice Sheets - Phase 2", "uid": "p0010013", "west": -180.0}, {"awards": "1443347 Condron, Alan; 1443394 Pollard, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios; Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming; Simulated changes in Southern Ocean salinity", "datasets": [{"dataset_uid": "601442", "doi": "10.15784/601442", "keywords": "Antarctica; Computer Model; Freshwater; Glaciers/ice Sheet; Glaciers/Ice Sheet; Model Data; Ocean Model; Oceans; Salinity", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Simulated changes in Southern Ocean salinity", "url": "https://www.usap-dc.org/view/dataset/601442"}, {"dataset_uid": "601154", "doi": "10.15784/601154 ", "keywords": "Antarctic; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Model; Meltwater; Model Data; Modeling; Model Output", "people": "Pollard, David", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios", "url": "https://www.usap-dc.org/view/dataset/601154"}, {"dataset_uid": "601449", "doi": "10.15784/601449", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meltwater", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming", "url": "https://www.usap-dc.org/view/dataset/601449"}], "date_created": "Mon, 04 Feb 2019 00:00:00 GMT", "description": "A great deal of uncertainty remains over how changes in high-latitude freshwater forcing will impact the stability of global ocean circulation, and in particular the strength of the Atlantic Meridional Overturning Circulation (AMOC) in the next 100-300 years, especially in realistic models. Indeed, it is still not understood whether increased Southern Ocean freshwater forcing will act to intensify the AMOC and warm the Northern Hemisphere or weaken it and trigger a cooling. The requirement to accurately assess climate sensitivity to freshwater forcing is heightened by increasing evidence that the marine-based West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse on multidecadal-to-centennial timescales. Observations collected over the last 30 years indicate that WAIS is losing ice at an accelerated rate and may signal that the ice sheet has already begun a rapid and irreversible collapse. In addition, future simulations of the Antarctic ice sheet by members of our Project Team show the potential for far more rapid Antarctic ice sheet retreat in the future than previously simulated, suggesting that the discharge of enormous fluxes of icebergs and freshwater to the Southern Ocean should be considered a possibility in the near-future. Here, we performed a suite of coupled numerical climate model simulations to more accurately determine the sensitivity of global ocean circulation to freshwater and iceberg discharge from the Antarctic Ice Sheet (AIS) in the future under IPCC RCP scenarios 4.5 and 8.5. In our model, the input of freshwater and ice was provided by a dynamic ice sheet-shelf model that predicts a full collapse of the WAIS in the next ~100 years. Significantly, we find that accounting for Antarctic discharge raises subsurface ocean temperatures by \u003e1\u00b0C at the ice sheet grounding line, relative to model simulations that are unable to capture this discharge. In contrast, we find that the increased meltwater causes a dramatic expansion of sea ice and a 2\u00b0 - 10\u00b0C cooling of the surface air and surface ocean temperatures over the Southern Ocean that would have the potential to stabilize/reduce projected future ice sheet melt rates. Our work thus highlights that the future stability of the Antarctic ice sheet will likely be governed by whether any surface cooling can counteract any increased rates of subsurface melt.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; AMD; MODELS; Amd/Us; Antarctica; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Pollard, David; Condron, Alan; DeConto, Robert", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet", "uid": "p0010007", "west": -180.0}, {"awards": "1443464 Sowers, Todd; 1443472 Brook, Edward J.; 1443710 Severinghaus, Jeffrey", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole CH4 data for termination; South Pole Ice Core Isotopes of N2 and Ar; South Pole ice core (SPC14) discrete methane data; South Pole ice core total air content; South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2; SP19 Gas Chronology", "datasets": [{"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Winski, Dominic A.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601230", "doi": "10.15784/601230", "keywords": "Antarctica; Atmospheric CH4; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Data; Methane; Methane Concentration; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole CH4 data for termination", "url": "https://www.usap-dc.org/view/dataset/601230"}, {"dataset_uid": "601231", "doi": "10.15784/601231", "keywords": "Air Content; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core total air content", "url": "https://www.usap-dc.org/view/dataset/601231"}, {"dataset_uid": "601517", "doi": "10.15784/601517", "keywords": "Antarctica; Argon; Argon Isotopes; Firn; Firn Temperature Gradient; Firn Thickness; Gas Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Nitrogen; Nitrogen Isotopes; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.; Morgan, Jacob", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Isotopes of N2 and Ar", "url": "https://www.usap-dc.org/view/dataset/601517"}, {"dataset_uid": "601152", "doi": "10.15784/601152", "keywords": "Antarctica; Antarctic Ice Sheet; Chemistry:gas; Chemistry:Gas; Chemistry:ice; Chemistry:Ice; Delta 18O; Dole Effect; Firn Thickness; Gas Isotopes; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Gravitational Settling; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Inert Gases; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2", "url": "https://www.usap-dc.org/view/dataset/601152"}], "date_created": "Sat, 02 Feb 2019 00:00:00 GMT", "description": "Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today\u0027s concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. \u003cbr/\u003e \u003cbr/\u003eThis award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole.\u003cbr/\u003e\u003cbr/\u003eThe project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. \u003cbr/\u003e\u003cbr/\u003eThe increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; AMD; LABORATORY; Antarctica; NITROGEN ISOTOPES; USA/NSF; METHANE; Amd/Us; FIELD INVESTIGATION", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Sowers, Todd A.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core", "uid": "p0010005", "west": 0.0}, {"awards": "1246407 Jenouvrier, Stephanie", "bounds_geometry": "POINT(70.2433 -49.6875)", "dataset_titles": "Demographic outputs and their variances for three life history complexes for the Southern Fulmar across contrasted sea ice conditions.; Desprez, M., Jenouvrier, S., Barbraud, C., Delord, K. and Weimerskirch, H., 2018. Linking oceanographic conditions, migratory schedules and foraging behaviour during the non\u2010breeding season to reproductive performance in a long\u2010lived seabird. Functional ecology, 32(8), pp.2040-2053.; Jenouvrier, S., Desprez, M., Fay, R., Barbraud, C., Weimerskirch, H., Delord, K. and Caswell, H., 2018. Climate change and functional traits affect population dynamics of a long\u2010lived seabird. Journal of Animal Ecology, 87(4), pp.906-920.; Linking oceanographic conditions, migratory schedules and foraging behaviour during the non-breeding season to reproductive performance in a long-lived seabird", "datasets": [{"dataset_uid": "601585", "doi": "10.15784/601585", "keywords": "Antarctica; Biota; Birds; East Antarctica; Southern Fulmar", "people": "Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "Demographic outputs and their variances for three life history complexes for the Southern Fulmar across contrasted sea ice conditions.", "url": "https://www.usap-dc.org/view/dataset/601585"}, {"dataset_uid": "601140", "doi": "10.15784/601140", "keywords": "Albatross; Animal Behavior Observation; Antarctica; Biota; Birds; Black-Browed Albatross (thalassarche Melanophris); Field Investigations; Foraging; Kerguelen Island; Ocean Island/plateau; Ocean Island/Plateau; Southern Ocean", "people": "Jenouvrier, Stephanie", "repository": "USAP-DC", "science_program": null, "title": "Linking oceanographic conditions, migratory schedules and foraging behaviour during the non-breeding season to reproductive performance in a long-lived seabird", "url": "https://www.usap-dc.org/view/dataset/601140"}, {"dataset_uid": "200008", "doi": "10.1111/1365-2435.13117", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Desprez, M., Jenouvrier, S., Barbraud, C., Delord, K. and Weimerskirch, H., 2018. Linking oceanographic conditions, migratory schedules and foraging behaviour during the non\u2010breeding season to reproductive performance in a long\u2010lived seabird. Functional ecology, 32(8), pp.2040-2053.", "url": "https://datadryad.org/resource/doi:10.5061/dryad.pb209db"}, {"dataset_uid": "200007", "doi": "10.1111/1365-2656.12827.", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Jenouvrier, S., Desprez, M., Fay, R., Barbraud, C., Weimerskirch, H., Delord, K. and Caswell, H., 2018. Climate change and functional traits affect population dynamics of a long\u2010lived seabird. Journal of Animal Ecology, 87(4), pp.906-920.", "url": "https://doi.org/10.5061/dryad.h5vk5"}], "date_created": "Thu, 31 Jan 2019 00:00:00 GMT", "description": "Understanding the ecological consequences - present and future-of climate change is a central question in conservation biology. The goal of this project is to identify the effects of climate change on the Black-Browed Albatross, a seabird breeding in the Southern Ocean. The Black-Browed Albatross exhibits remarkable flight adaptations, using winds as an energy source to glide for long distances. This is the basis of their foraging strategy, by which they obtain food for themselves and their offspring. Climate change, however, is expected to modify wind patterns over the Southern Ocean. This project will analyze the effect of winds on life history traits (foraging behaviors, body conditions and demographic traits), and the effects of these traits on populations. New demographic models will provide the link between foraging behavior and the physical environment, and evaluate the persistence of this population in the face of climate change.\u003cbr/\u003e\u003cbr/\u003eUnderstanding and predicting population responses to climate change is important because the world?s climate will continue to change throughout the 21st century and beyond. To help guide conservation strategies and policy decisions in the face of climate change, reliable assessments of population extinction risks are urgently needed. The Black-Browed Albatross is considered endangered by the International Union for Conservation of Nature due to recent drastic reductions in its population size. This project will improve our understanding of the mechanisms by which climate affects the life history and populations of Black-Browed Albatross to improve prediction of extinction risks under future climate change.", "east": 70.2433, "geometry": "POINT(70.2433 -49.6875)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Southern Ocean; NOT APPLICABLE; USAP-DC; BIRDS", "locations": "Southern Ocean", "north": -49.6875, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jenouvrier, Stephanie", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "Dryad; USAP-DC", "science_programs": null, "south": -49.6875, "title": "Linking Foraging Behaviors to Demography to understand Albatrosses Population Responses to Climate Change", "uid": "p0010002", "west": 70.2433}, {"awards": "1543313 VanTongeren, Jill", "bounds_geometry": null, "dataset_titles": "U-Pb ages and mineral compositions from Dufek Intrusion", "datasets": [{"dataset_uid": "601132", "doi": "10.15784/601132", "keywords": "Antarctica; Chemical Composition; Chemistry:rock; Chemistry:Rock; Crystallization; Dufek Complex; Geochemistry; Magma Chamber Procesess; Mass Spectrometry; Rocks; Snow/ice; Snow/Ice; Solid Earth; TIMS; Volcanic Deposits", "people": "VanTongeren, Jill", "repository": "USAP-DC", "science_program": null, "title": "U-Pb ages and mineral compositions from Dufek Intrusion", "url": "https://www.usap-dc.org/view/dataset/601132"}], "date_created": "Mon, 29 Oct 2018 00:00:00 GMT", "description": "The solidified remnants of large magma bodies within the continental crust hold the key to understanding the chemical and physical evolution of volcanic provinces through time. These deposits also commonly contain some of the world\u0027s most important ore deposits. Exposed deposits in South Africa, Greenland, USA, Canada, and Antarctica have led researchers to propose that the bigger the magma body, the faster it will crystallize. While this might seem counter-intuitive (typically it is thought that more magma = hotter = harder to cool), the comparison of these exposures show that bigger magma chambers maintain a molten top that is always in contact with the colder crust; whereas smaller magma chambers insulate themselves by crystallizing at the margins. The process is similar to the difference between a large cup of coffee with no lid, and a smaller cup of coffee held in a thermos. The large unprotected cup of coffee will cool down much faster than that held in the thermos. This research project of VanTongeren and Schoene will use previously collected rocks from the large (~8-9 km thick) Dufek Intrusion in Antarctica to precisely quantify how fast the magma chamber crystallized, and compare that rate to the much smaller magma chamber exposed in the Skaergaard Intrusion of E. Greenland. The work is an important step towards improving our understanding of time-scales associated with the thermal and chemical evolution of nearly all magma chambers on Earth, which will ultimately lead to better predictions of volcanic hazards globally. The work will also yield important insights into the timescales and conditions necessary for developing vast magmatic ore deposits, which is essential to the platinum and steel industries in the USA and abroad.\u003cbr/\u003e\u003cbr/\u003eBased on observations of solidification fronts in six of the world\u0027s most completely exposed layered mafic intrusions, it was recently proposed that bigger magma chambers must crystallize faster than small magma chambers. While this is initially counter-intuitive, the hypothesis falls out of simple heat balance equations and the observation that the thickness of cumulates at the roofs of such intrusions is negatively proportional to the size of the intrusion. In this study, VanTongeren and Schoene will directly test the hypothesis that bigger magma chambers crystallize faster by applying high precision U-Pb zircon geochronology on 5-10 samples throughout the large Dufek Intrusion of Antarctica. Due to uncertainties in even the highest-precision ID-TIMS analyses, the Dufek Intrusion of Antarctica is the only large layered mafic intrusion on Earth where this research can be accomplished. VanTongeren and Schoene will place the geochronological measurements of the Dufek Intrusion into a comprehensive petrologic framework by linking zircon crystallization to other liquidus phases using mineral geochemistry, zircon saturation models, and petrologic models for intrusion crystallization. The research has the potential to radically change the way that we understand the formation and differentiation of large magma bodies within the shallow crust. Layered intrusions are typically thought to cool and crystallize over very long timescales allowing for significant differentiation of the magmas and reorganization of the cumulate rocks. If the \u0027bigger magma chambers crystallize faster hypothesis\u0027 holds this could reduce the calculated solidification time scales of the early earth and lunar magma oceans and have important implications for magma chamber dynamics of active intraplate volcanism and long-lived continental arcs. Furthermore, while the Dufek Intrusion is one of only two large layered intrusions exposed on Earth, very little is known about its petrologic evolution. The detailed geochemical and petrologic work of VanTongeren and Schoene based on analyses of previously collected samples will provide important observations with which to compare the Dufek and other large magma chambers.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "VanTongeren, Jill", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Testing the Hypothesis that Bigger Magma Chambers Crystallize Faster", "uid": "p0000135", "west": null}, {"awards": "1141916 Aster, Richard", "bounds_geometry": null, "dataset_titles": "Dynamic Response of the Ross Ice Shelf to Ocean Waves and Structure and Dynamics of the Ross Sea", "datasets": [{"dataset_uid": "002573", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Ocean Waves and Structure and Dynamics of the Ross Sea", "url": "http://www.iris.washington.edu/mda/XH?timewindow=2014-2017"}], "date_created": "Mon, 22 Oct 2018 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003e\u003cbr/\u003eThe PIs propose to establish an ice shelf network of 18 broadband seismographs deployed for two years to obtain high-resolution, mantle-scale images of Earth structure underlying the Ross Sea Embayment. Prior marine geophysical work provides good crustal velocity models for the region seaward of the ice shelf but mantle structure is constrained by only low-resolution images due to the lack of prior seismic deployments. The proposed stations would be established between Ross Island and Marie Byrd Land. These stations would fill a major geological gap within this extensional continental province and would link data sets collected in the Transantarctic Mountain transition/Plateau region (TAMSEIS) and in West Antarctica (POLENET) to improve resolution of mantle features beneath Antarctica. The proposed deployment would allow the PIs to collect seismic data without the expense, logistical complexity, and iceberg hazards associated with ocean bottom seismograph deployments. Tomographic models developed from the proposed data will be used to choose between competing models for the dynamics of the Ross Sea. In particular, the PIs will investigate whether a broad region of hot mantle, including the Eastern Ross Sea, indicates distributed recent tectonic activity, which would call into question models proposing that Eastern Ross extension ceased during the Mesozoic. These data will also allow the PIs to investigate the deeper earth structure to evaluate the possible role of mantle plumes and/or small-scale convection in driving regional volcanism and tectonism across the region.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003e\u003cbr/\u003eData from this deployment will be of broad interdisciplinary use. This project will support three graduate and two undergraduate students. At least one student will be an underrepresented minority student. The PIs will interact with the media and include K-12 educators in their fieldwork.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Earth Sciences", "paleo_time": null, "persons": "Aster, Richard", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": null, "title": "Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf", "uid": "p0000761", "west": null}, {"awards": "1443263 Higgins, John; 1443306 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores; Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores; Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores; Greenhouse gas composition in the Allan Hills S27 ice core; Methane concentration in Allan Hills ice cores; Stable isotope composition of the trapped air in the Allan Hills S27 ice core; Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "datasets": [{"dataset_uid": "601201", "doi": "10.15784/601201", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Argon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Gas Records; Krypton; Mass Spectrometer; Noble Gas; Snow/ice; Snow/Ice; Xenon", "people": "Ng, Jessica; Bender, Michael; Yan, Yuzhen; Severinghaus, Jeffrey P.; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601201"}, {"dataset_uid": "601129", "doi": "10.15784/601129", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Isotope Data; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601129"}, {"dataset_uid": "601425", "doi": "10.15784/601425", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Ice Core; Methane", "people": "Brook, Edward J.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Greenhouse gas composition in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601425"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable isotope composition of the trapped air in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601512"}, {"dataset_uid": "601202", "doi": "10.15784/601202", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Carbon Dioxide; Carbon Isotopes; Chemistry:ice; Chemistry:Ice; CO2; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Gas Records; Ice Core Records; Mass Spectrometer; Mass Spectrometry; Methane; Snow/ice; Snow/Ice", "people": "Bender, Michael; Higgins, John; Yan, Yuzhen; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601202"}, {"dataset_uid": "601128", "doi": "10.15784/601128", "keywords": "Allan Hills; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Mass Spectrometry; Stable Water Isotopes", "people": "Introne, Douglas; Yan, Yuzhen; Kurbatov, Andrei V.; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601128"}, {"dataset_uid": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Higgins, John; Yan, Yuzhen; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601483"}, {"dataset_uid": "601203", "doi": "10.15784/601203", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Chemistry:ice; Chemistry:Ice; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenhouse Gas; Ice; Ice Core Data; Ice Core Gas Records; Methane; Snow/ice; Snow/Ice", "people": "Brook, Edward J.; Yan, Yuzhen; Bender, Michael; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Methane concentration in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601203"}, {"dataset_uid": "601130", "doi": "10.15784/601130", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Gas Records; Ice Core Records; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Kurbatov, Andrei V.; Introne, Douglas; Yan, Yuzhen; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601130"}], "date_created": "Thu, 18 Oct 2018 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores permit the direct reconstruction of atmospheric composition and allow us to link greenhouse gases and global climate over the last 800,000 years. Previous field expeditions to the Allan Hills blue ice area, Antarctica, have recovered ice cores that date to one million years, the oldest ice cores yet recovered from Antarctica. These records have revealed that interglacial CO2 concentrations decreased by 800,000 years ago and that, in the warmer world 1 million years ago, CO2 and Antarctic temperature were linked as during the last 800,000 years. This project will return to the Allan Hills blue ice area to recover additional ice cores that date to 1 million years or older. The climate records developed from the drilled ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Our results will help answer questions about issues associated with anthropogenic change. These include the relationship between temperature change and the mass balance of Antarctic ice; precipitation and aridity variations associated with radiatively forced climate change; and the climate significance of sea ice extent. The project will entrain two graduate students and a postdoctoral scholar, and will conduct outreach including workshops to engage teachers in carbon science and ice cores.\u003cbr/\u003e\u003cbr/\u003eBetween about 2.8-0.9 million years ago, Earth\u0027s climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth\u0027s spin axis. Much is known about the \"40,000-year\" world from studies of deep-sea sediments, but our understanding of climate change during this period is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of ancient ice from the Main Ice Field, Allan Hills, Antarctica. During previous field seasons we recovered ice extending, discontinuously, from 0.1-1.0 million years old. Ice was dated by measuring the 40Ar/38Ar (Argon) ratio of the trapped gases. Our discovery of million year-old ice demonstrates that there is gas-record-quality ice from the 40,000-year world in the Allan Hills Main Ice Field. We have identified two different sites, each overlying bedrock at ~ 200 m depth, that are attractive targets for coring ice dating to 1 million years and older. This project aims to core the ice at these two sites, re-occupy a previous site with million year-old ice and drill it down to the bedrock, and generate 10-20 short (~10-meter) cores in areas where our previous work and terrestrial meteorite ages suggest ancient surface ice. We plan to date the ice using the 40Ar/38Ar ages of trapped Argon. We also plan to characterize the continuity of our cores by measuring the deuterium and oxygen isotope ratios in the ice, methane, ratios of Oxygen and Argon to Nitrogen in trapped gas, the Nitrogen-15 isotope (d15N) of Nitrogen, and the Oxygen-18 isotope (d18O) of Oxygen. As the ice may be stratigraphically disturbed, these measurements will provide diagnostic properties for assessing the continuity of the ice-core records. Successful retrieval of ice older than one million years will provide the opportunity for follow-up work to measure the CO2 concentration and other properties within the ice to inform on the temperature history of the Allan Hills region, dust sources and source-area aridity, moisture sources, densification conditions, global average ocean temperature, and greenhouse gas concentrations. We will analyze the data in the context of leading hypotheses of the 40,000-year world and the Mid-Pleistocene Transition to the 100,000-year world. We expect to advance understanding of climate dynamics during these periods.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Allan Hills; USA/NSF; FIELD INVESTIGATION; USAP-DC; Ice Core; LABORATORY", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": null, "title": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area", "uid": "p0000760", "west": null}, {"awards": "1245915 Ray, Laura", "bounds_geometry": null, "dataset_titles": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "datasets": [{"dataset_uid": "601102", "doi": "10.15784/601102", "keywords": "Antarctica; Firn; Folds; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Snow/ice; Snow/Ice", "people": "Walker, Ben; Kaluzienski, Lynn; Koons, Peter; Lever, Jim; Ray, Laura; Arcone, Steven", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "url": "https://www.usap-dc.org/view/dataset/601102"}], "date_created": "Thu, 27 Sep 2018 00:00:00 GMT", "description": "This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth\u0027s current NSF GK-12 program, build on faculty-educator relationships established during University of Maine\u0027s recent GK-12 program, and incorporate project results into University of Maine\u0027s IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Ray, Laura", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Flow and Fracture Dynamics in an Ice Shelf Lateral Margin: Observations and Modeling of the McMurdo Shear Zone", "uid": "p0000701", "west": null}, {"awards": "0839107 Powell, Ross; 0839059 Powell, Ross; 0838947 Tulaczyk, Slawek; 0838764 Anandakrishnan, Sridhar; 0838763 Anandakrishnan, Sridhar; 0838855 Jacobel, Robert; 0839142 Tulaczyk, Slawek", "bounds_geometry": null, "dataset_titles": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line; Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD); Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES); IRIS ID#s 201035, 201162, 201205; IRIS offers free and open access to a comprehensive data store of raw geophysical time-series data collected from a large variety of sensors, courtesy of a vast array of US and International scientific networks, including seismometers (permanent and temporary), tilt and strain meters, infrasound, temperature, atmospheric pressure and gravimeters, to support basic research aimed at imaging the Earth\u0027s interior.; Paleogene marine and terrestrial development of the West Antarctic Rift System: Biomarker Data Set; Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set; Radar Studies of Subglacial Lake Whillans and the Whillans Ice Stream Grounding Zone; The IRIS DMC archives and distributes data to support the seismological research community.; UNAVCO ID#s WHL1, WHL2, LA02, LA09 (full data link not provided)", "datasets": [{"dataset_uid": "000148", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS ID#s 201035, 201162, 201205", "url": "http://ds.iris.edu/"}, {"dataset_uid": "601122", "doi": "10.15784/601122", "keywords": "Antarctica; Flexure Zone; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Ice-Shelf Basal Melting; Ice-Shelf Strain Rate", "people": "Begeman, Carolyn", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line", "url": "https://www.usap-dc.org/view/dataset/601122"}, {"dataset_uid": "001406", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "The IRIS DMC archives and distributes data to support the seismological research community.", "url": "http://ds.iris.edu/ds/nodes/dmc/"}, {"dataset_uid": "001405", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS offers free and open access to a comprehensive data store of raw geophysical time-series data collected from a large variety of sensors, courtesy of a vast array of US and International scientific networks, including seismometers (permanent and temporary), tilt and strain meters, infrasound, temperature, atmospheric pressure and gravimeters, to support basic research aimed at imaging the Earth\u0027s interior.", "url": "http://www.iris.edu/hq/data_and_software"}, {"dataset_uid": "601234", "doi": "10.15784/601234", "keywords": "ACL; Antarctica; Biomarker; BIT Index; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Stream; Whillans Ice Stream; WISSARD", "people": "Askin, Rosemary; Scherer, Reed Paul; Baudoin, Patrick; Casta\u00f1eda, Isla; Warny, Sophie; Coenen, Jason", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Biomarker Data Set", "url": "https://www.usap-dc.org/view/dataset/601234"}, {"dataset_uid": "601245", "doi": "10.15784/601245", "keywords": "Antarctica; Pollen; West Antarctica; WISSARD", "people": "Scherer, Reed Paul; Casta\u00f1eda, Isla; Askin, Rosemary; Coenen, Jason; Baudoin, Patrick; Warny, Sophie", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set", "url": "https://www.usap-dc.org/view/dataset/601245"}, {"dataset_uid": "600155", "doi": "10.15784/600155", "keywords": "Antarctica; Glaciology; Oceans; Southern Ocean; WISSARD", "people": "Powell, Ross", "repository": "USAP-DC", "science_program": null, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)", "url": "https://www.usap-dc.org/view/dataset/600155"}, {"dataset_uid": "000150", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "UNAVCO ID#s WHL1, WHL2, LA02, LA09 (full data link not provided)", "url": "http://www.unavco.org/"}, {"dataset_uid": "609594", "doi": "10.7265/N54J0C2W", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS; Radar; Whillans Ice Stream", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": null, "title": "Radar Studies of Subglacial Lake Whillans and the Whillans Ice Stream Grounding Zone", "url": "https://www.usap-dc.org/view/dataset/609594"}, {"dataset_uid": "600154", "doi": "10.15784/600154", "keywords": "Antarctica; Biota; Diatom; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Whillans; Paleoclimate; Ross Sea; Southern Ocean; Subglacial Lake; WISSARD", "people": "Powell, Ross", "repository": "USAP-DC", "science_program": null, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD)", "url": "https://www.usap-dc.org/view/dataset/600154"}], "date_created": "Mon, 10 Sep 2018 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF\u0027s Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. \u003cbr/\u003e\u003cbr/\u003eINTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. \u003cbr/\u003e\u003cbr/\u003eBROADER IMPACTS: Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS", "is_usap_dc": true, "keywords": "USAP-DC; Ice Penetrating Radar; Antarctic; Subglacial Lake; Subglacial Hydrology; Grounding Line; Sea Level Rise; Bed Reflectivity; Ice Sheet Stability; Stability; Radar; Sub-Ice-Shelf; Geophysics; Biogeochemical; LABORATORY; Sediment; Sea Floor Sediment; Ice Thickness; Model; Ice Stream Stability; Basal Ice; SATELLITES; Ice Sheet Thickness; Subglacial; Antarctica; NOT APPLICABLE; Antarctic Ice Sheet; Ice Sheet; FIELD SURVEYS; Surface Elevation; Geochemistry; FIELD INVESTIGATION; Not provided", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Fisher, Andrew; Powell, Ross; Anandakrishnan, Sridhar; Jacobel, Robert; Scherer, Reed Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "IRIS", "repositories": "IRIS; UNAVCO; USAP-DC", "science_programs": "WISSARD", "south": null, "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "uid": "p0000105", "west": null}, {"awards": "1141866 Conway, Howard; 1141889 Winberry, J. Paul", "bounds_geometry": null, "dataset_titles": "Beardmore Glacier High-Frequency Impulse Radar Data; Geophysical measurements Beardmore Glacier, Antarctica; Project code ZF for passive seismic and 17-030 for active source", "datasets": [{"dataset_uid": "601121", "doi": "10.15784/601121", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Radar", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Geophysical measurements Beardmore Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601121"}, {"dataset_uid": "000210", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Project code ZF for passive seismic and 17-030 for active source", "url": "https://ds.iris.edu/mda/17-030"}, {"dataset_uid": "601713", "doi": "10.15784/601713", "keywords": "Antarctica; Beardmore Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut; Hoffman, Andrew; Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Beardmore Glacier High-Frequency Impulse Radar Data", "url": "https://www.usap-dc.org/view/dataset/601713"}], "date_created": "Sun, 09 Sep 2018 00:00:00 GMT", "description": "Conway/1141866\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to conduct a suite of experiments to study spatial and temporal variations of basal conditions beneath Beardmore Glacier, an East Antarctic outlet glacier that discharges into the Ross Sea Embayment. The intellectual merit of the project is that it should help verify whether or not global warming will play a much larger role in the future mass balance of ice sheets than previously considered. Recent observations of rapid changes in discharge of fast-flowing outlet glaciers and ice streams suggest that dynamical responses to warming could affect that ice sheets of Greenland and Antarctica. Assessment of possible consequences of these responses is hampered by the lack of information about the basal boundary conditions. The leading hypothesis is that variations in basal conditions exert strong control on the discharge of outlet glaciers. Airborne and surface-based radar measurements of Beardmore Glacier will be made to map the ice thickness and geometry of the sub-glacial trough and active and passive seismic experiments, together with ground-based radar and GPS measurements will be made to map spatial and temporal variations of conditions at the ice-bed interface. The observational data will be used to constrain dynamic models of glacier flow. The models will be used to address the primary controls on the dynamics of Antarctic outlet glaciers, the conditions at the bed, their spatial and temporal variation, and how such variability might affect the sliding and flow of these glaciers. The work will also explore whether or not these outlet glaciers could draw down the interior of East Antarctica, and if so, how fast. The study will take three years including two field seasons to complete and results from the work will be disseminated through public and professional meetings and journal publications. All data and metadata will be made available through the NSIDC web portal. The broader impacts of the work are that it will help elucidate the fundamental physics of outlet glacier dynamics which is needed to improve predictions of the response of ice sheets to changing environmental conditions. The project will also provide support for early career investigators and will provide training and support for one graduate and two undergraduate students. All collaborators are currently involved in scientific outreach and graduate student education and they are committed to fostering diversity.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC; Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Winberry, Paul", "platforms": "Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "IRIS; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: East Antarctic Outlet Glacier Dynamics", "uid": "p0000437", "west": null}, {"awards": "1443126 MacAyeal, Douglas", "bounds_geometry": "POLYGON((166.1631 -77.9007,166.19736 -77.9007,166.23162 -77.9007,166.26588 -77.9007,166.30014 -77.9007,166.3344 -77.9007,166.36866 -77.9007,166.40292 -77.9007,166.43718 -77.9007,166.47144 -77.9007,166.5057 -77.9007,166.5057 -77.90423,166.5057 -77.90776,166.5057 -77.91129,166.5057 -77.91482,166.5057 -77.91835,166.5057 -77.92188,166.5057 -77.92541,166.5057 -77.92894,166.5057 -77.93247,166.5057 -77.936,166.47144 -77.936,166.43718 -77.936,166.40292 -77.936,166.36866 -77.936,166.3344 -77.936,166.30014 -77.936,166.26588 -77.936,166.23162 -77.936,166.19736 -77.936,166.1631 -77.936,166.1631 -77.93247,166.1631 -77.92894,166.1631 -77.92541,166.1631 -77.92188,166.1631 -77.91835,166.1631 -77.91482,166.1631 -77.91129,166.1631 -77.90776,166.1631 -77.90423,166.1631 -77.9007))", "dataset_titles": "McMurdo Ice Shelf AWS data; McMurdo Ice Shelf GPS survey of vertical motion; Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica; Time-lapse video of McMurdo Ice Shelf surface melting and hydrology", "datasets": [{"dataset_uid": "601107", "doi": "10.15784/601107", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ice Shelf; Ice-Shelf Flexure; Snow/ice; Snow/Ice; Surface Melt", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf GPS survey of vertical motion", "url": "https://www.usap-dc.org/view/dataset/601107"}, {"dataset_uid": "601116", "doi": "10.15784/601116", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Snow/ice; Snow/Ice; Subglacial And Supraglacial Water Depth; Supraglacial Lake; Supraglacial Meltwater; Water Depth", "people": "Banwell, Alison; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601116"}, {"dataset_uid": "601106", "doi": "10.15784/601106", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrology; Ice Shelf; Snow/ice; Snow/Ice; Surface Hydrology; Surface Mass Balance; Weather Station Data", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf AWS data", "url": "https://www.usap-dc.org/view/dataset/601106"}, {"dataset_uid": "601113", "doi": "10.15784/601113", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Photo/video; Photo/Video; Supraglacial Meltwater", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "Time-lapse video of McMurdo Ice Shelf surface melting and hydrology", "url": "https://www.usap-dc.org/view/dataset/601113"}], "date_created": "Tue, 24 Jul 2018 00:00:00 GMT", "description": "Meltwater lakes that sit on top of Antarctica\u0027s floating ice shelves have likely contributed to the dramatic changes seen in Antarctica\u0027s glacial ice cover over the past two decades. In 2002, the 1,600-square-kilometer Larsen B Ice Shelf located on the Eastern side of the Antarctic Peninsula, for example, broke into thousands of small icebergs, which subsequently floated away as a result of the formation of more than 2,000 meltwater lakes on its surface over the prior decade. Our research project addresses the reasons why surface lakes form on Antarctic ice shelves and how these surface lakes subsequently contribute to the forces that may contribute to ice-shelf breakup like that of the Larsen B. Our project focuses primarily on making precise global positioning system (GPS) measurements of ice-shelf bending in response to the filling and draining of a surface lake on the McMurdo Ice Shelf. The observed vertical displacements (on the order of tens of centimeters) in response to lake filling will be used to calibrate and test computer simulation models that predict the response of ice shelves to surface lakes more generally and in a variety of future climate conditions. Our project will make hourly measurements of both vertical ice-shelf movements (using GPS surveying instruments) and of temperature and sunlight conditions (that drive melting) around a surface lake located close to the McMurdo Station airfield. Following this initial data-gathering effort, computer simulations and other more theoretical analysis will be undertaken to determine the suitability of the chosen McMurdo Ice Shelf surface lake as a field-laboratory for continued study. Ultimately, the research will contribute to understanding of the glaciological processes that link climate change to rising sea level. A successful outcome of the research will allow glaciologists to better assess the processes that promote or erode the influence Antarctic ice shelves have in controlling the transfer of ice from the interior of Antarctica into the ocean. The project will undertake two outreach activities: (1) web-posting of a field-activity journal and (2) establishing an open-access glaciological teaching and outreach web-sharing site for the International Glaciological Society.\u003cbr/\u003e\u003cbr/\u003eThe proposed project seeks to experimentally verify a theory of ice-shelf instability proposed to explain the explosive break-up of Larsen B Ice Shelf in 2002. This theory holds that the filling and draining of supraglacial lakes on floating ice shelves induces sufficient flexure stress within the ice to (a) induce upward/downward propagating fractures originating at the base/surface of the ice shelf that (b) dissect the ice shelf into fragments that tend to have widths less than about half the ice thickness. The significance of narrow widths is that they promote capsize of the ice-shelf fragments during the break-up process. This capsize releases large amounts of gravitational potential energy (comparable to thousands of kilotons of TNT for the Larsen B Ice Shelf) thereby promoting explosiveness of the Larsen B event. The observational motivation for experimentally verifying the surface-lake mechanism for ice-shelf breakup is based on the fact that \u003e2,000 surface lakes developed on the Larsen B Ice Shelf in the decade prior to its break up, and that these lakes were observed (via satellite imagery) to drain in a coordinated fashion during the day prior to the initiation of the break up.\u003cbr/\u003e\u003cbr/\u003eThe field-observation component of the project will focus on a supraglacial lake on the McMurdo Ice Shelf where there is persistent summer season surface melting. The lake will be studied during a single provisional field season to determine whether grooming of surrounding surface streams and shorelines with heavy construction equipment will allow surface water to be manually encouraged to fill the lake. If successfully encouraged to develop, the McMurdo Ice Shelf surface lake will allow measurements of key ice-shelf flexure and stress variables needed to develop the theory of ice-shelf surface lakes without having to access the much more logistically demanding surface lakes of ice-shelves located elsewhere in Antarctica. Data to be gathered during the 6-week provisional field season include: energy- and water-balance parameters determining how the surface lake grows and fills, and various global positioning system measurements of the vertical bending of the ice sheet in response to the changing meltwater load contained within the surface lake. These data will be used to (1) constrain a computer model of viscoelastic flexure and possible fracture of the ice shelf in response to the increasing load of meltwater in the lake, and (2) determine whether continued study of the incipient surface-meltwater lake features on the McMurdo Ice Shelf provides a promising avenue for constraining the more-general behavior of surface meltwater lakes on other ice shelves located in warmer parts of Antarctica. Computer models constrained by the observational data obtained from the field project will inform energy- and water-balance models of ice shelves in general, and allow more accurate forecasts of changing ice-shelf conditions surrounding the inland ice of Antarctica. The project will create the first-ever ground-based observations useful for spawning the development of models capable of predicting viscoelastic and fracture behavior of ice shelves in response to supraglacial lake evolution, including slow changes due to energy balance effects, as well as fast changes due to filling and draining.", "east": 166.5057, "geometry": "POINT(166.3344 -77.91835)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS", "is_usap_dc": true, "keywords": "USAP-DC; AWOS", "locations": null, "north": -77.9007, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e AWOS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.936, "title": "Impact of Supraglacial Lakes on Ice-Shelf Stability", "uid": "p0000138", "west": 166.1631}, {"awards": "1443341 Hawley, Robert; 1443471 Koutnik, Michelle", "bounds_geometry": "POLYGON((110 -89,117 -89,124 -89,131 -89,138 -89,145 -89,152 -89,159 -89,166 -89,173 -89,180 -89,180 -89.1,180 -89.2,180 -89.3,180 -89.4,180 -89.5,180 -89.6,180 -89.7,180 -89.8,180 -89.9,180 -90,173 -90,166 -90,159 -90,152 -90,145 -90,138 -90,131 -90,124 -90,117 -90,110 -90,110 -89.9,110 -89.8,110 -89.7,110 -89.6,110 -89.5,110 -89.4,110 -89.3,110 -89.2,110 -89.1,110 -89))", "dataset_titles": "7MHz radar in the vicinity of South Pole; Firn density and compaction rates 50km upstream of South Pole; Firn temperatures 50km upstream of South Pole; Shallow radar near South Pole; South Pole area GPS velocities; SPICEcore Advection", "datasets": [{"dataset_uid": "601100", "doi": "10.15784/601100", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Velocity", "people": "Lilien, David; Conway, Howard; Koutnik, Michelle; Fudge, T. J.; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole area GPS velocities", "url": "https://www.usap-dc.org/view/dataset/601100"}, {"dataset_uid": "601525", "doi": "10.15784/601525", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice; South Pole; SPICEcore; Temperature", "people": "Lilien, David; Waddington, Edwin D.; Koutnik, Michelle; Conway, Howard; Stevens, Christopher Max; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Firn temperatures 50km upstream of South Pole", "url": "https://www.usap-dc.org/view/dataset/601525"}, {"dataset_uid": "601680", "doi": "10.15784/601680", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Snow/ice; Snow/Ice; South Pole; Temperature", "people": "Lilien, David; Fudge, T. J.; Conway, Howard; Waddington, Edwin D.; Koutnik, Michelle; Stevens, Christopher Max", "repository": "USAP-DC", "science_program": null, "title": "Firn density and compaction rates 50km upstream of South Pole", "url": "https://www.usap-dc.org/view/dataset/601680"}, {"dataset_uid": "601369", "doi": "10.15784/601369", "keywords": "Antarctica; Ice Sheet", "people": "Waddington, Edwin D.; Conway, Howard; Koutnik, Michelle; Fudge, T. J.; Lilien, David; Stevens, Max", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "7MHz radar in the vicinity of South Pole", "url": "https://www.usap-dc.org/view/dataset/601369"}, {"dataset_uid": "601099", "doi": "10.15784/601099", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; Snow Accumulation; Snow/ice; Snow/Ice", "people": "Koutnik, Michelle; Lilien, David; Fudge, T. J.; Conway, Howard; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Shallow radar near South Pole", "url": "https://www.usap-dc.org/view/dataset/601099"}, {"dataset_uid": "601266", "doi": "10.15784/601266", "keywords": "Antarctica; Ice Core Data; South Pole; SPICEcore", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore Advection", "url": "https://www.usap-dc.org/view/dataset/601266"}], "date_created": "Thu, 14 Jun 2018 00:00:00 GMT", "description": "Ice-core records are critical to understanding past climate variations. An Antarctic ice core currently being drilled at the South Pole will allow detailed investigation of atmospheric gases and fill an important gap in understanding the pattern of climate variability across Antarctica. Critical to the interpretation of any ice core are: 1) accurate chronologies for both the ice and the trapped gas and 2) demonstration that records from the ice core reliably reflect climate. The proposed research will improve the ice and gas chronologies by making measurements of snow compaction in the upstream catchment in order to constrain age models of the ice. These measurements will be a key data set needed for better understanding and predicting time-varying conditions in the upper part of the ice sheet. The research team will measure the modern spatial gradients in accumulation rate, surface temperature, and water stable isotopes from shallow ice cores in the upstream catchment in order to determine the climate history from the ice-core record. The new ice-flow measurements will make it possible to define the path of ice from upstream to the South Pole ice-core drill site to assess spatial gradients in snowfall and to infer histories of snowfall from internal layers within the ice sheet. The project will be led by an early-career scientist, provide broad training to graduate students, and engage in public outreach on polar science.\u003cbr/\u003e\u003cbr/\u003eIce-core records of stable isotopes, aerosol-born particles, and atmospheric gases are critical to understanding past climate variations. The proposed research will improve the ice and gas chronologies in the South Pole ice core by making in situ measurements of firn compaction in the upstream catchment to constrain models of the gas-age ice-age difference. The firn measurements will be a key data set needed to form a constitutive relationship for firn, and will drive better understanding and prediction of transient firn evolution. The research team will measure the modern gradients in accumulation rate, surface temperature, and water stable isotopes in the upstream catchment to separate spatial (advection) variations from temporal (climate) variations in the ice-core records. The ice-flow measurements will define the flowline upstream of the drill site, assess spatial gradients in accumulation, and infer histories of accumulation from radar-observed internal layers. Results will directly enhance interpretation of South Pole ice-core records, and also advance understanding of firn densification and drive next-generation firn models.", "east": 180.0, "geometry": "POINT(145 -89.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIRN; Firn; USAP-DC; South Pole; Radar; FIELD SURVEYS; ICE CORE RECORDS", "locations": "South Pole", "north": -89.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Conway, Howard; Waddington, Edwin D.; Fudge, T. J.; Hawley, Robert L.; Osterberg, Erich", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Characterization of Upstream Ice and Firn Dynamics affecting the South Pole Ice Core", "uid": "p0000200", "west": 110.0}, {"awards": "1341585 Sorlien, Christopher", "bounds_geometry": "POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33))", "dataset_titles": "Ross Sea unconformities digital grids in depth and two-way time", "datasets": [{"dataset_uid": "601098", "doi": "10.15784/601098", "keywords": "Antarctica; Continental Margin; Geology/Geophysics - Other; Marine Geoscience; Miocene; Oligocene; Seismic Reflection", "people": "Wilson, Douglas S.; Sorlien, Christopher", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea unconformities digital grids in depth and two-way time", "url": "https://www.usap-dc.org/view/dataset/601098"}], "date_created": "Fri, 25 May 2018 00:00:00 GMT", "description": "Intellectual Merit:\u003cbr/\u003eThis project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.", "east": -171.0, "geometry": "POINT(177 -76)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.33, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sorlien, Christopher; Luyendyk, Bruce P.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.67, "title": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea", "uid": "p0000271", "west": 165.0}, {"awards": "1443232 Waddington, Edwin", "bounds_geometry": "POLYGON((110 -89,117 -89,124 -89,131 -89,138 -89,145 -89,152 -89,159 -89,166 -89,173 -89,180 -89,180 -89.1,180 -89.2,180 -89.3,180 -89.4,180 -89.5,180 -89.6,180 -89.7,180 -89.8,180 -89.9,180 -90,173 -90,166 -90,159 -90,152 -90,145 -90,138 -90,131 -90,124 -90,117 -90,110 -90,110 -89.9,110 -89.8,110 -89.7,110 -89.6,110 -89.5,110 -89.4,110 -89.3,110 -89.2,110 -89.1,110 -89))", "dataset_titles": "AC-ECM for SPICEcore; ECM (DC and AC) multi-track data and images from 2016 processing season", "datasets": [{"dataset_uid": "601189", "doi": " 10.15784/601189 ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; SPICEcore; Volcanic", "people": "Waddington, Edwin D.; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "AC-ECM for SPICEcore", "url": "https://www.usap-dc.org/view/dataset/601189"}, {"dataset_uid": "601366", "doi": "10.15784/601366", "keywords": "Antarctica", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "ECM (DC and AC) multi-track data and images from 2016 processing season", "url": "https://www.usap-dc.org/view/dataset/601366"}], "date_created": "Tue, 08 May 2018 00:00:00 GMT", "description": "Ice cores record detailed histories of past climate variations. The South Pole ice core will allow investigation of atmospheric trace gases and fill an important gap in understanding the pattern of climate variability across Antarctica. An accurate timescale that assigns an age to the ice at each depth in the core is essential to interpretation of the ice-core records. This work will use electrical methods to identify volcanic eruptions throughout the past ~40,000 years in the core by detecting the enhanced electrical conductance in those layers due to volcanic impurities in the ice. These eruptions will be pattern-matched to other cores across Antarctica, synchronizing the timing of climate variations among cores and allowing the precise timescales developed for other Antarctic ice cores to be transferred to the South Pole ice core. The well-dated records of volcanic forcing will be combined with records of atmospheric gases, stable water-isotopes, and aerosols to better understand the large natural climate variations of the past 40,000 years. \u003cbr/\u003e \u003cbr/\u003eThe electrical conductance method and dielectric profiling measurements will be made along the length of each section of the South Pole ice core at the National Ice Core Lab. These measurements will help to establish a timescale for the core. Electrical measurements will provide a continuous record of volcanic events for the entire core including through the brittle ice (550-1250m representing ~10,000-20,000 year-old ice) where the core quality and thin annual layers may prevent continuous melt analysis and cause discrete measurements to miss volcanic events. The electrical measurements also produce a 2-D image of the electrical layering on a longitudinal cut surface of each core. These data will be used to identify any irregular or absent layering that would indicate a stratigraphic disturbance in the core. A robust chronology is essential to interpretation of the paleoclimate records from the South Pole ice core. The investigators will engage teachers through talks and webinars with the National Science Teachers Association and will share information with the public at events such as Polar Science Weekend at the Pacific Science Center. Results will be disseminated through publications and conference presentations and the data will be archived and publicly available.", "east": 180.0, "geometry": "POINT(145 -89.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Amd/Us; AMD; LABORATORY", "locations": null, "north": -89.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Waddington, Edwin D.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology", "uid": "p0000378", "west": 110.0}, {"awards": "1341729 Kirschvink, Joseph", "bounds_geometry": "POLYGON((-58.9 -63.5,-58.63 -63.5,-58.36 -63.5,-58.09 -63.5,-57.82 -63.5,-57.55 -63.5,-57.28 -63.5,-57.01 -63.5,-56.74 -63.5,-56.47 -63.5,-56.2 -63.5,-56.2 -63.62,-56.2 -63.74,-56.2 -63.86,-56.2 -63.98,-56.2 -64.1,-56.2 -64.22,-56.2 -64.34,-56.2 -64.46,-56.2 -64.58,-56.2 -64.7,-56.47 -64.7,-56.74 -64.7,-57.01 -64.7,-57.28 -64.7,-57.55 -64.7,-57.82 -64.7,-58.09 -64.7,-58.36 -64.7,-58.63 -64.7,-58.9 -64.7,-58.9 -64.58,-58.9 -64.46,-58.9 -64.34,-58.9 -64.22,-58.9 -64.1,-58.9 -63.98,-58.9 -63.86,-58.9 -63.74,-58.9 -63.62,-58.9 -63.5))", "dataset_titles": "2016 Paleomagnetic samples from the James Ross Basin, Antarctica; Expedition data of NBP1601", "datasets": [{"dataset_uid": "002665", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1601", "url": "https://www.rvdata.us/search/cruise/NBP1601"}, {"dataset_uid": "601094", "doi": "10.15784/601094", "keywords": "Antarctica; Geochronology; Geology/Geophysics - Other; Glaciology; James Ross Basin; Marine Geoscience; Marine Sediments", "people": "Kirschvink, Joseph; Skinner, Steven", "repository": "USAP-DC", "science_program": null, "title": "2016 Paleomagnetic samples from the James Ross Basin, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601094"}], "date_created": "Fri, 27 Apr 2018 00:00:00 GMT", "description": "Non-Technical Summary:\u003cbr/\u003e About 80 million years ago, the tip of the Antarctic Peninsula in the vicinity of what is now James Ross Island experienced an episode of rapid subsidence, creating a broad depositional basin that collected sediments eroding from the high mountains to the West. This depression accumulated a thick sequence of fossil-rich, organic-rich sediments of the sort that are known to preserve hydrocarbons, and for which Argentina, Chile, and the United Kingdom have overlapping territorial claims. The rocks preserve one of the highest resolution records of the biological and climatic events that led to the eventual death of the dinosaurs at the Cretaceous-Tertiary boundary (about 66 million years ago). A previous collaboration between scientists from the Instituto Ant\u00c3\u00a1rtico Argentino (IAA) and NSF-supported teams from Caltech and the University of Washington were able to show that this mass extinction event started nearly 50,000 years before the sudden impact of an asteroid. The asteroid obviously hit the biosphere hard, but something else knocked it off balance well before the asteroid hit. \u003cbr/\u003e A critical component of the previous work was the use of reversals in the polarity of the Earth?s magnetic field as a dating tool ? magnetostratigraphy. This allowed the teams to correlate the pattern of magnetic reversals from Antarctica with elsewhere on the planet. This includes data from a major volcanic eruption (a flood basalt province) that covered much of India 65 million years ago. The magnetic patterns indicate that the Antarctic extinction started with the first pulse of this massive eruption, which was also coincident with a rapid spike in polar temperature. The Argentinian and US collaborative teams will extend this magnetic polarity record back another ~ 20 million years in time, and expand it laterally to provide magnetic reversal time lines across the depositional basin. They hope to recover the end of the Cretaceous Long Normal interval, which is one of the most distinctive events in the history of Earth?s magnetic field. The new data should refine depositional models of the basin, allow better estimates of potential hydrocarbon reserves, and allow biotic events in the Southern hemisphere to be compared more precisely with those elsewhere on Earth. Other potential benefits of this work include exposing several US students and postdoctoral fellows to field based research in Antarctica, expanding the international aspects of this collaborative work via joint IAA/US field deployments, and follow-up laboratory investigations and personnel exchange of the Junior scientists.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eTechnical Description of Project \u003cbr/\u003eThe proposed research will extend the stratigraphic record in the late Cretaceous and early Tertiary sediments (~ 83 to 65 Ma before present) of the James Ross Basin, Antarctica, using paleo-magnetic methods. Recent efforts provided new methods to analyze these rocks, yielding their primary magnetization, and producing both magnetic polarity patterns and paleomagnetic pole positions. This provided the first reliable age constraints for the younger sediments on Seymour Island, and quantified the sedimentation rate in this part of the basin. The new data will allow resolution of the stable, remnant magnetization of the sediments from the high deposition rate James Ross basin (Tobin et al., 2012), yielding precise chronology/stratigraphy. This approach will be extended to the re-maining portions of this sedimentary basin, and will allow quantitative estimates for tectonic and sedimentary processes between Cretaceous and Early Tertiary time. The proposed field work will refine the position of several geomagnetic reversals that occurred be-tween the end of the Cretaceous long normal period (Chron 34N, ~ 83 Ma), and the lower portion of Chron 31R (~ 71 Ma). Brandy Bay provides the best locality for calibrating the stratigraphic position of the top of the Cretaceous Long Normal Chron, C34N. Although the top of the Cretaceous long normal Chron is one of the most important correlation horizons in the entire geological timescale, it is not properly correlated to the southern hemisphere biostratigraphy. Locating this event, as well as the other reversals, will be a major addition to understanding of the geological history of the Antarctic Peninsula. These data will also help refine tectonic models for the evolution of the Southern continents, which will be of use across the board for workers in Cretaceous stratigraphy (including those involved in oil exploration).\u003cbr/\u003eThis research is a collaborative effort with Dr. Edward Olivero of the Centro Austral de Investigaciones Cientificas (CADIC/CONICET) and Prof. Augusto Rapalini of the University of Buenos Aires. The collaboration will include collection of samples on their future field excursions to important targets on and around James Ross Island, supported by the Argentinian Antarctic Program (IAA). Argentinian scientists and students will also be involved in the US Antarctic program deployments, proposed here for the R/V Laurence Gould, and will continue the pattern of joint international publication of the results.", "east": -56.2, "geometry": "POINT(-57.55 -64.1)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; R/V NBP; USAP-DC", "locations": null, "north": -63.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kirschvink, Joseph; Christensen, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -64.7, "title": "Paleomagnetism and Magnetostratigraphy of the James Ross Basin, Antarctica", "uid": "p0000276", "west": -58.9}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}, {"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"awards": "1056396 Morgan-Kiss, Rachael", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "datasets": [{"dataset_uid": "000241", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "url": "https://www.ncbi.nlm.nih.gov/genbank/"}], "date_created": "Mon, 26 Feb 2018 00:00:00 GMT", "description": "This CAREER proposal will support an early career female PI to establish an integrated research and education program in the fields of polar biology and environmental microbiology, focusing on single-celled eukaryotes (protists) in high latitude ice-covered Antarctic lakes systems. Protists play important roles in energy flow and material cycling, and act as both primary producers (fixing inorganic carbon by photosynthesis) and consumers (preying on bacteria by phagotrophic digestion). The McMurdo Dry Valleys (MDV) located in Victoria Land, Antarctica, harbor microbial communities which are isolated in the unique aquatic ecosystem of perennially ice-capped lakes. The lakes support exclusively microbial consortia in chemically stratified water columns that are not influenced by seasonal mixing, allochthonous inputs, or direct human impact. This project will exploit permanently stratified biogeochemistry that is unique across the water columns of several MDV lakes to address gaps in our understanding of protist trophic function in aquatic food webs. The proposed research will examine (1) the impact of permanent biogeochemical gradients on protist trophic strategy, (2) the effect of major abiotic drivers (light and nutrients) on the distribution of two key mixotrophic and photoautotrophic protist species, and (3) the effect of episodic nutrient pulses on mixotroph communities in high latitude (ultraoligotrophic) MDV lakes versus low latitude (eutrophic) watersheds. The project will impact the fields of microbial ecology and environmental microbiology by combining results from field, laboratory and in situ incubation studies to synthesize new models for the protist trophic roles in the aquatic food web. The research component of this proposed project will be tightly integrated with the development of two new education activities designed to exploit the inherent excitement associated with polar biological research. The educational objectives are: 1) to establish a teaching module in polar biology in a core undergraduate course for microbiology majors; 2) to develop an instructional module to engage middle school girls in STEM disciplines. Undergraduates and middle school girls will also work with a doctoral student on his experiments in local Ohio watersheds.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Morgan-Kiss, Rachael", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -90.0, "title": "CAREER:Protist Nutritional Strategies in Permanently Stratified Antarctic Lakes", "uid": "p0000310", "west": -180.0}, {"awards": "0944021 Brook, Edward J.; 0943466 Hawley, Robert; 0944307 Conway, Howard", "bounds_geometry": "POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))", "dataset_titles": "Roosevelt Island Borehole Firn temperatures; Roosevelt Island Borehole Optical Televiewer logs; Roosevelt Island Ice Core Time Scale and Associated Data; Roosevelt Island: Radar and GPS", "datasets": [{"dataset_uid": "601085", "doi": "10.15784/601085", "keywords": "Antarctica; Borehole; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Records; Ice Fabric; Optical Images; Roosevelt Island; Snow/ice; Snow/Ice; Temperature", "people": "Hawley, Robert L.; Giese, Alexandra; Clemens-Sewall, David", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Firn temperatures", "url": "https://www.usap-dc.org/view/dataset/601085"}, {"dataset_uid": "601086", "doi": "10.15784/601086", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Roosevelt Island; Snow/ice; Snow/Ice", "people": "Hawley, Robert L.; Clemens-Sewall, David", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Optical Televiewer logs", "url": "https://www.usap-dc.org/view/dataset/601086"}, {"dataset_uid": "601070", "doi": "10.15784/601070", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS Data; Ice Velocity; Navigation; Radar; Roosevelt Island; Ross Sea", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island: Radar and GPS", "url": "https://www.usap-dc.org/view/dataset/601070"}, {"dataset_uid": "601359", "doi": "10.15784/601359", "keywords": "Antarctica; CO2; Ice Core; Roosevelt Island", "people": "Brook, Edward J.; Lee, James", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Ice Core Time Scale and Associated Data", "url": "https://www.usap-dc.org/view/dataset/601359"}], "date_created": "Fri, 16 Feb 2018 00:00:00 GMT", "description": "This award supports a project to use the Roosevelt Island ice core as a glaciological dipstick for the eastern Ross Sea. Recent attention has focused on the eastern Ross Embayment, where there are no geological constraints on ice thickness changes, due to the lack of protruding rock \"dipsticks\" where the ice sheet can leave datable records of high stands. Recent work has shown how dated ice cores can be used as dipsticks to derive ice-thickness histories. Partners from New Zealand and Denmark will extract an ice core from Roosevelt Island during the 2010-2011 and 2011-12 austral summers. Their science objective is to contribute to understanding of climate variability over the past 40kyr. The science goal of this project is not the climate record, but rather the history of deglaciation in the Ross Sea. The new history from the eastern Ross Sea will be combined with the glacial histories from the central Ross Sea (Siple Dome and Byrd) and existing and emerging histories from geologic and marine records along the western Ross Sea margin and will allow investigators to establish an updated, self-consistent model of the configuration and thickness of ice in the Ross Embayment during the LGM, and the timing of deglaciation. Results from this work will provide ground truth for new-generation ice-sheet models that incorporate ice streams and fast-flow dynamics. Realistic ice-sheet models are needed not only for predicting the response to future possible environments, but also for investigating past behaviors of ice sheets. This research contributes to the primary goals of the West Antarctic Ice Sheet Initiative as well as the IPY focus on ice-sheet history and dynamics. It also contributes to understanding spatial and temporal patterns of climate change and climate dynamics over the past 40kyr, one of the primary goals of the International Partnerships in Ice Core Sciences (IPICS). The project will help to develop the next generation of scientists and will contribute to the education and training of two Ph.D. students. All participants will benefit from the international collaboration, which will expose them to different field and laboratory techniques and benefit future collaborative work. All participants are involved in scientific outreach and undergraduate education, and are committed to fostering diversity. Outreach will be accomplished through regularly scheduled community and K-12 outreach events, talks and popular writing by the PIs, as well as through University press offices.", "east": -161.0, "geometry": "POINT(-162 -79.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; Amd/Us; Deglaciation; USAP-DC; USA/NSF; NOT APPLICABLE; Ice Core; Not provided; Ross Sea Embayment", "locations": "Ross Sea Embayment", "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Brook, Edward J.; Hawley, Robert L.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.5, "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "uid": "p0000272", "west": -163.0}, {"awards": "1341669 DeMaster, David", "bounds_geometry": "POLYGON((-70 -62,-68.8 -62,-67.6 -62,-66.4 -62,-65.2 -62,-64 -62,-62.8 -62,-61.6 -62,-60.4 -62,-59.2 -62,-58 -62,-58 -62.6,-58 -63.2,-58 -63.8,-58 -64.4,-58 -65,-58 -65.6,-58 -66.2,-58 -66.8,-58 -67.4,-58 -68,-59.2 -68,-60.4 -68,-61.6 -68,-62.8 -68,-64 -68,-65.2 -68,-66.4 -68,-67.6 -68,-68.8 -68,-70 -68,-70 -67.4,-70 -66.8,-70 -66.2,-70 -65.6,-70 -65,-70 -64.4,-70 -63.8,-70 -63.2,-70 -62.6,-70 -62))", "dataset_titles": "DeMaster Compiled Larsen Ice Shelf and the West Antarctic Peninsula C14 Data; Expedition Data of NBP1203; Labile Organic Carbon distributions on the West Antarctic Peninsula Shelf; Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf; Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "datasets": [{"dataset_uid": "601304", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Box Corer; LARISSA; Larsen Ice Shelf; Macrofauna; Megafauna; NBP1203; Oceans; R/v Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601304"}, {"dataset_uid": "601082", "doi": "10.15784/601082", "keywords": null, "people": "DeMaster, David", "repository": "USAP-DC", "science_program": "LARISSA", "title": "DeMaster Compiled Larsen Ice Shelf and the West Antarctic Peninsula C14 Data", "url": "https://www.usap-dc.org/view/dataset/601082"}, {"dataset_uid": "601319", "doi": "10.15784/601319", "keywords": "Antarctica; Antarctic Peninsula; Biota; Bioturbation Coefficients; Diagenesis; Labile Organic Carbon; LOC Mean Residence Times; Marguerite Bay; Oceans; Organic Carbon Degradation Rates; Sediment Core", "people": "Taylor, Richard; DeMaster,