[{"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 Ocean and Atmospheric Sciences; Antarctic Glaciology", "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": "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": "Last Interglacial Southern Ocean paleothermometry from diatom morphometrics: Analysis and application of the F. kerguelensis Valve Rectangularity Sea Surface Temperature proxy.; Pliocene diatom abundance, IODP 397-U1532", "datasets": [{"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Scherer, Reed Paul", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 397-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}, {"dataset_uid": "601767", "doi": null, "keywords": "Amundsen Sea; Antarctica; Sabrina Coast; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Last Interglacial Southern Ocean paleothermometry from diatom morphometrics: Analysis and application of the F. kerguelensis Valve Rectangularity Sea Surface Temperature proxy.", "url": "https://www.usap-dc.org/view/dataset/601767"}], "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", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul", "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": "2232891 Postlethwait, John", "bounds_geometry": "POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2023 00:00:00 GMT", "description": "Antarctic animals face tremendous threats as Antarctic ice sheets melt and temperatures rise. About 34 million years ago, when Antarctica began to cool, most species of fish became locally extinct. A group called the notothenioids, however, survived due to the evolution of antifreeze. The group eventually split into over 120 species. Why did this group of Antarctic fishes evolve into so many species? One possible reason why a single population splits into two species relates to sex genes and sex chromosomes. Diverging species often have either different sex determining genes (genes that specify whether an individual\u2019s gonads become ovaries or testes) or have different sex chromosomes (chromosomes that differ between males and females within a species, like the human X and Y chromosomes). We know the sex chromosomes of only a few notothenioid species and know the genetic basis for sex determination in none of them. \r\nThe aims of this research are to: 1) identify sex chromosomes in species representing every major group of Antarctic notothenioid fish; 2) discover possible sex determining genes in every major group of Antarctic notothenioid fish; and 3) find sex chromosomes and possible sex determining genes in two groups of temperate, warmer water, notothenioid fish. These warmer water fish include groups that never experienced the frigid Southern Ocean and groups that had ancestors inhabiting Antarctic oceans that later adjusted to warmer waters. This project will help explain the mechanisms that led to the division of a group of species threatened by climate change. This information is critical to conserve declining populations of Antarctic notothenioids, which are major food sources for other Antarctic species such as bird and seals. \r\nThe project will offer a diverse group of undergraduates the opportunity to develop a permanent exhibit at the Eugene Science Center Museum. The exhibit will describe the Antarctic environment and explain its rapid climate change. It will also introduce the continent\u2019s bizarre fishes that live below the freezing point of water. The project will collaborate with the university\u2019s Science and Comics Initiative and students in the English Department\u2019s Comics Studies Minor to prepare short graphic novels explaining Antarctic biogeography, icefish specialties, and the science of this project as it develops.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Speciation; Southern Ocean; Dragonfish; Antarctica; Plunderfish; Fish; Notothenioid; FISH; Eleginopsioidea; Icefish; MARINE ECOSYSTEMS; Cryonotothenioid; Sub-Antarctic", "locations": "Antarctica; Southern Ocean; Sub-Antarctic", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Postlethwait, John; Desvignes, Thomas", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA: The Role of Sex Determination in the Radiation of Antarctic Notothenioid Fish", "uid": "p0010431", "west": -180.0}, {"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": "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; Hock, Regine; Fahnestock, Mark", "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": "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": "1917176 Siddoway, Christine; 1916982 Teyssier, Christian; 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": "1645087 Catchen, Julian", "bounds_geometry": null, "dataset_titles": "Chromosome-Level Genome Assembly and Circadian Gene Repertoire of the Patagonia Blennie Eleginops maclovinus\u2014The Closest Ancestral Proxy of Antarctic Cryonotothenioids; Evaluating Illumina-, Nanopore-, and PacBio-based genome assembly strategies with the bald notothen, Trematomus borchgrevinki; Genomics of Secondarily Temperate Adaptation in the Only Non-Antarctic Icefish", "datasets": [{"dataset_uid": "200380", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Genomics of Secondarily Temperate Adaptation in the Only Non-Antarctic Icefish", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA857989"}, {"dataset_uid": "200330", "doi": "", "keywords": null, "people": null, "repository": "NCBI ", "science_program": null, "title": "Evaluating Illumina-, Nanopore-, and PacBio-based genome assembly strategies with the bald notothen, Trematomus borchgrevinki", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA861284"}, {"dataset_uid": "200381", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Chromosome-Level Genome Assembly and Circadian Gene Repertoire of the Patagonia Blennie Eleginops maclovinus\u2014The Closest Ancestral Proxy of Antarctic Cryonotothenioids", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA917608"}, {"dataset_uid": "200331", "doi": "10.5061/dryad.ghx3ffbs3", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Evaluating Illumina-, Nanopore-, and PacBio-based genome assembly strategies with the bald notothen, Trematomus borchgrevinki", "url": "https://datadryad.org/stash/dataset/doi:10.5061/dryad.ghx3ffbs3"}], "date_created": "Mon, 10 Oct 2022 00:00:00 GMT", "description": "As plate tectonics pushed Antarctica into a polar position, by ~34 million years ago, the continent and its surrounding Southern Ocean (SO) became geographically and thermally isolated by the Antarctic Circumpolar Current. Terrestrial and marine glaciation followed, resulting in extinctions as well as the survival and radiation of unique flora and fauna. The notothenioid fish survived and arose from a common ancestral stock into tax with 120 species that dominates today\u0027s SO fish fauna. The Notothenioids evolved adaptive traits including novel antifreeze proteins for survival in extreme cold, but also suffered seemingly adverse trait loss including red blood cells in the icefish family, and the ability to mount cellular responses to mitigate heat stress ? otherwise ubiquitous across all life. This project aims to understand how the notothenoid genomes have changed and contributed to their evolution in the cold. The project will sequence, analyze and compare the genomes of two strategic pairs of notothenioid fishes representing both red-blooded and white-blooded species. Each pair will consist of one Antarctic species and one that has readapted to the temperate waters of S. America or New Zealand. The project will also compare the Antarctic species genomes to a genome of the closet non-Antarctic relative representing the temperate notothenioid ancestor. The work aims to uncover the mechanisms that enabled the adaptive evolution of this ecologically vital group of fish in the freezing Southern Ocean, and shed light on their adaptability to a warming world. The finished genomes will be made available to promote and advance Antarctic research and the project will host a symposium of Polar researchers to discuss the cutting edge developments regarding of genomic adaptations in the polar region.\u003cbr/\u003eDespite subzero, icy conditions that are perilous to teleost fish, the fish fauna of the isolated Southern Ocean (SO) surrounding Antarctica is remarkably bountiful. A single teleost group - the notothenioid fishes - dominate the fauna, comprising over 120 species that arose from a common ancestor. When Antarctica became isolated and SO temperatures began to plunge in early Oligocene, the prior temperate fishes became extinct. The ancestor of Antarctic notothenioids overcame forbidding polar conditions and, absent niche competition, it diversified and filled the SO. How did notothenioids adapt to freezing environmental selection pressures and achieve such extraordinary success? And having specialized to life in chronic cold for 30 myr, can they evolve in pace with today\u0027s warming climate to stay viable? Past studies of Antarctic notothenioid evolutionary adaptation have discovered various remarkable traits including the key, life-saving antifreeze proteins. But life specialized to cold also led to paradoxical trait changes such as the loss of the otherwise universal heat shock response, and of the O2-transporting hemoglobin and red blood cells in the icefish family. A few species interestingly regained abilities to live in temperate waters following the escape of their ancestor out of the freezing SO. \u003cbr/\u003eThis proposed project is the first major effort to advance the field from single trait studies to understanding the full spectrum of genomic and genetic responses to climatic and environmental change during notothenioid evolution, and to evaluate their adaptability to continuing climate change. To this end, the project will sequence the genomes of four key species that embody genomic responses to different thermal selection regimes during notothenioids\u0027 evolutionary history, and by comparative analyses of genomic structure, architecture and content, deduce the responding changes. Specifically, the project will (i) obtain whole genome assemblies of the red-blooded T. borchgrevinki and the S. American icefish C. esox; (ii) using the finished genomes from (i) as template, obtain assemblies of the New Zealand notothenioid N. angustata, and the white-blooded icefish C. gunnari, representing a long (11 myr) and recent (1 myr) secondarily temperate evolutionary history respectively. Genes that are under selection in the temperate environment but not in the Antarctic environment can be inferred to be directly necessary for that environment and the reverse is also true for genes under selection in the Antarctic but not in the temperate environment. Further, genes important for survival in temperate waters will show parallel selection between N. angustata and C. esox despite the fact that the two fish left the Antarctic at far separated time points. Finally, gene families that expanded due to strong selection within the cold Antarctic should show a degradation of duplicates in the temperate environment. The project will test these hypotheses using a number of techniques to compare the content and form of genes, the structure of the chromosomes containing those genes, and through the identification of key characters, such as selfish genetic elements, introns, and structural variants.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Mcmurdo Sound; Genome Assembly; FISH; Icefish; SHIPS; Notothenioid; Puerto Natales, Chile", "locations": "Mcmurdo Sound; Puerto Natales, Chile", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Catchen, Julian; Cheng, Chi-Hing", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "NCBI", "repositories": "Dryad; NCBI; NCBI ", "science_programs": null, "south": null, "title": "Evolutionary Genomic Responses in Antarctic Notothenioid Fishes", "uid": "p0010384", "west": null}, {"awards": "1654922 de la Pena, Santiago", "bounds_geometry": "POINT(0 -90)", "dataset_titles": " South Pole Weather and Accumulation Measurements 2017-2020", "datasets": [{"dataset_uid": "601591", "doi": "10.15784/601591", "keywords": "Accumulation; Antarctica; Snow; South Pole; Surface Mass Balance", "people": "de la Pe\u00f1a, Santiago", "repository": "USAP-DC", "science_program": null, "title": " South Pole Weather and Accumulation Measurements 2017-2020", "url": "https://www.usap-dc.org/view/dataset/601591"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "To obtain observations of temporal variability of firn processes in Antarctica, we designed a cost-efficient, reliable, and easily deployable firn monitoring system capable of operating with little or no maintenance over a period of several seasons. The prototype station was installed in December 2017 in the vicinity of the geographical South Pole and at a short distance from the Amundsen-Scott South Pole Research Station in Antarctica. The data presented was acquired between December of 2017 and January of 2020. During the first year, of the months without sunlight the longest period without SMB measurements was 22 days, yielding enough measurements to obtain monthly estimates of every variable. During the polar night of 2019, a technical issue related to extreme cold prevented the data logger attached to the CRNCs to record correctly so the sensor was placed under a stand-by mode until the 2nd of December 2019 when temperatures raised. Firn compaction, temperature and wind were recorded continuously during the 2-year period with the exception of a couple of weeks during the Austral winter. The project finalized in January 2020 and the system was taken down on January 15th. ", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "South Pole; SNOW", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Support; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "de la Pe\u00f1a, Santiago", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "EAGER: An Operational System to Measure Surface Mass Balance Deep in the Interior of the Antarctic Ice Sheet", "uid": "p0010360", "west": 0.0}, {"awards": "1744649 Christianson, Knut", "bounds_geometry": "POLYGON((-120 -85.5,-117.5 -85.5,-115 -85.5,-112.5 -85.5,-110 -85.5,-107.5 -85.5,-105 -85.5,-102.5 -85.5,-100 -85.5,-97.5 -85.5,-95 -85.5,-95 -85.62,-95 -85.74,-95 -85.86,-95 -85.98,-95 -86.1,-95 -86.22,-95 -86.34,-95 -86.46000000000001,-95 -86.58,-95 -86.7,-97.5 -86.7,-100 -86.7,-102.5 -86.7,-105 -86.7,-107.5 -86.7,-110 -86.7,-112.5 -86.7,-115 -86.7,-117.5 -86.7,-120 -86.7,-120 -86.58,-120 -86.46000000000001,-120 -86.34,-120 -86.22,-120 -86.1,-120 -85.98,-120 -85.86,-120 -85.74,-120 -85.62,-120 -85.5))", "dataset_titles": "Hercules Dome ApRES Data; Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data; Hercules Dome Ice-Penetrating Radar Swath Topographies; Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets; ITASE Impulse Radar Hercules Dome to South Pole", "datasets": [{"dataset_uid": "601710", "doi": "10.15784/601710", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Horlings, Annika; Christian, John; O\u0027Connor, Gemma; Christianson, Knut; Hoffman, Andrew; Hills, Benjamin", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data", "url": "https://www.usap-dc.org/view/dataset/601710"}, {"dataset_uid": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}, {"dataset_uid": "601739", "doi": "10.15784/601739", "keywords": "Antarctica; Apres; Crystal Orientation Fabric; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hercules Dome; Ice Dynamic; Ice Penetrating Radar; Radar Interferometry; Radar Polarimetry", "people": "Horlings, Annika; Erwin, Emma; Steig, Eric J.; Christianson, Knut; Fudge, Tyler J; Hoffman, Andrew; Holschuh, Nicholas; Hills, Benjamin", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome ApRES Data", "url": "https://www.usap-dc.org/view/dataset/601739"}, {"dataset_uid": "601712", "doi": "10.15784/601712", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Welch, Brian; Christianson, Knut; Hoffman, Andrew; Jacobel, Robert", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "ITASE Impulse Radar Hercules Dome to South Pole", "url": "https://www.usap-dc.org/view/dataset/601712"}, {"dataset_uid": "601711", "doi": "10.15784/601711", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Christianson, Knut; Paden, John; Hoffman, Andrew", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome Ice-Penetrating Radar Swath Topographies", "url": "https://www.usap-dc.org/view/dataset/601711"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington\u0027s annual Polar Science Weekend in Seattle, and art-science collaboration.\u003cbr/\u003e\u003cbr/\u003eThis project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a \"Raymond Bump\") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.\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 -86.1)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; ICE DEPTH/THICKNESS; East Antarctica", "locations": "West Antarctica; East Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.7, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "uid": "p0010359", "west": -120.0}, {"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": "1443637 Zakon, Harold", "bounds_geometry": null, "dataset_titles": "Evolutionary analysis of transient receptor potential (TRP) channels in notothenioid fishes; Functional characterization of temperature activated ion channels from Antarctic fishes; TagSeq tissue specific expression data for Antarctic Harpagifer antarcticus and tropical African cichlid Astatotilapia (Haplochromis) burtoni", "datasets": [{"dataset_uid": "200292", "doi": "10.18738/T8/NXGNEI", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Evolutionary analysis of transient receptor potential (TRP) channels in notothenioid fishes", "url": "https://doi.org/10.18738/T8/NXGNEI"}, {"dataset_uid": "601695", "doi": "10.15784/601695", "keywords": "Antarctica; Notothenioid; Southern Ocean", "people": "York, Julia", "repository": "USAP-DC", "science_program": null, "title": "Functional characterization of temperature activated ion channels from Antarctic fishes", "url": "https://www.usap-dc.org/view/dataset/601695"}, {"dataset_uid": "200293", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "TagSeq tissue specific expression data for Antarctic Harpagifer antarcticus and tropical African cichlid Astatotilapia (Haplochromis) burtoni", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA758918"}], "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "We studied the molecular evolution and physiology of two types of ion channels: voltage gated potassium channels and transient receptor potential (TRP) channels. We also studied the molecular evolution and expression of water-passing channels, the aquaporins, to determine if these show signs of evolutionary change in notothenioids. \r\n\r\nWe noted apparent amino acid substitutions at a number of sites in a muscle-expressing\r\npotassium channel (Kv1.3). We were surprised to find that although the AAs at these sites\r\nappeared highly conserved in teleosts and even in tetrapods, reverting them singly, in pairs,\r\nor all together back to the ancestral condition had no effect on the biophysical properties of\r\nthe channels that we measured (voltage-sensitivity; rate of activation) at room temperature\r\nas well as over a range of temperatures down to 4oC.\r\n\r\nThe results for the TRP channels and aquaporins can be accessed in their publications. York and Zakon (2022) in Genome Biology and Evolution, and two forthcoming papers.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USAP-DC; USA/NSF; FIELD INVESTIGATION; AMD; FISHERIES", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Zakon, Harold", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "Texas Data Repository", "repositories": "GenBank; Texas Data Repository; USAP-DC", "science_programs": null, "south": null, "title": "Analysis of Voltage-gated Ion Channels in Antarctic Fish", "uid": "p0010331", "west": null}, {"awards": "1744759 Dunham, Eric; 1744856 Bromirski, Peter; 1744958 Wei, Yong", "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": "Almquist, Martin; Dunham, Eric; Tazhimbetov, Nurbek", "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 Glaciology; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Dunham, Eric", "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": "2046260 Salvatore, Mark; 2045880 Sokol, Eric", "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": "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": "2039419 Swanger, Kate", "bounds_geometry": "POLYGON((161 -77.3,161.2 -77.3,161.4 -77.3,161.6 -77.3,161.8 -77.3,162 -77.3,162.2 -77.3,162.4 -77.3,162.6 -77.3,162.8 -77.3,163 -77.3,163 -77.35,163 -77.4,163 -77.45,163 -77.5,163 -77.55,163 -77.6,163 -77.65,163 -77.7,163 -77.75,163 -77.8,162.8 -77.8,162.6 -77.8,162.4 -77.8,162.2 -77.8,162 -77.8,161.8 -77.8,161.6 -77.8,161.4 -77.8,161.2 -77.8,161 -77.8,161 -77.75,161 -77.7,161 -77.65,161 -77.6,161 -77.55,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 Dec 2021 00:00:00 GMT", "description": "The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina.\r\n\r\nThe PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master\u2019s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics.", "east": 163.0, "geometry": "POINT(162 -77.55)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; SEDIMENTS; USA/NSF; AMD; Dry Valleys; USAP-DC", "locations": "Dry Valleys", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -77.8, "title": "Collaborative Research: Holocene and Late Pleistocene Stream Deposition in the McMurdo Dry Valleys, Antarctica as a Proxy for Glacial Meltwater and Paleoclimate", "uid": "p0010285", "west": 161.0}, {"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": "2046800 Thurber, Andrew", "bounds_geometry": "POLYGON((162 -77,162.6 -77,163.2 -77,163.8 -77,164.4 -77,165 -77,165.6 -77,166.2 -77,166.8 -77,167.4 -77,168 -77,168 -77.1,168 -77.2,168 -77.3,168 -77.4,168 -77.5,168 -77.6,168 -77.7,168 -77.8,168 -77.9,168 -78,167.4 -78,166.8 -78,166.2 -78,165.6 -78,165 -78,164.4 -78,163.8 -78,163.2 -78,162.6 -78,162 -78,162 -77.9,162 -77.8,162 -77.7,162 -77.6,162 -77.5,162 -77.4,162 -77.3,162 -77.2,162 -77.1,162 -77))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 21 Aug 2021 00:00:00 GMT", "description": "Due to persistent cold temperatures, geographical isolation, and resulting evolutionary distinctness of Southern Ocean fauna, the study of Antarctic reducing habitats has the potential to fundamentally alter our understanding of the biologic processes that inhibit greenhouse gas emissions from our oceans. Marine methane, a greenhouse gas 25x as potent as carbon dioxide for warming our atmosphere, is currently a minor component of atmospheric forcing due to the microbial oxidation of methane within the oceans. Based on studies of persistent deep-sea seeps at mid- and northern latitudes we have learned that bacteria and archaea create a \u2018sediment filter\u2019 that oxidizes methane prior to its release. As increasing global temperatures have and will continue to alter the rate and variance of methane release, the ability of the microbial filter to respond to fluctuations in methane cycles is a critical yet unexplored avenue of research. Antarctica contains vast reservoirs of methane, equivalent to all of the permafrost in the Arctic, and yet we know almost nothing about the fauna that may mitigate its release, as until recently, we had not discovered an active methane seep.\r\n\r\nIn 2012, a methane seep was discovered in the Ross Sea, Antarctica that formed in 2011 providing the first opportunity to study an active Antarctic methane-fueled habitat and simultaneously the impact of microbial succession on the oxidation of methane, a critical ecosystem service. Previous work has shown that after 5 years of seepage, the community was at an early stage of succession and unable to mitigate the release of methane from the seafloor. In addition, additional areas of seepage had begun nearby. This research aims to quantify the community trajectory of these seeps in relation to their role in the Antarctic Ecosystem, from greenhouse gas mitigation through supporting the food web. Through the application of genomic and transcriptomic approaches, taxa involved in methane cycling and genes activated by the addition of methane will be identified and contrasted with those from other geographical locations. These comparisons will elucidate how taxa have evolved and adapted to the polar environment.\r\n\r\nThis research uses a \u2018genome to ecosystem\u2019 approach to advance our understanding of organismal and systems ecology in Antarctica. By quantifying the trajectory of community succession following the onset of methane emission, the research will decipher temporal shifts in biodiversity/ecosystem function relationships. Phylogenomic approaches focusing on taxa involved in methane cycling will advance the burgeoning field of microbial biogeography on a continent where earth\u2019s history may have had a profound yet unquantified impact on microbial evolution. Further, the research will empirically quantify the role of chemosynthesis as a form of export production from seeps and in non-seep habitats in the nearshore Ross Sea benthos, informing our understanding of Antarctic carbon cycling.\r\n", "east": 168.0, "geometry": "POINT(165 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Mcmurdo Sound; USA/NSF; USAP-DC; BACTERIA/ARCHAEA; BENTHIC; FIELD SURVEYS; Amd/Us; ECOSYSTEM FUNCTIONS", "locations": "Mcmurdo Sound", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -78.0, "title": "CAREER: Ecosystem Impacts of Microbial Succession and Production at Antarctic Methane Seeps", "uid": "p0010250", "west": 162.0}, {"awards": "1954241 O\u0027\u0027Brien, Kristin", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 17 Aug 2021 00:00:00 GMT", "description": "The frequency and severity of hypoxic events are increasing in marine and freshwater environments worldwide with climate warming, threatening the health of aquatic ecosystems and the viability of fish populations. The Southern Ocean surrounding Antarctica has historically been a stable, icy-cold, and oxygen-rich environment, but is now warming at an unprecedented rate and faster than all other regions in the Southern hemisphere. Evolution at sub-zero temperatures has equipped Antarctic fishes with traits allowing them to thrive in frigid waters, but has diminished their resilience to warming. Presently little is known about the ability of Antarctic fishes to withstand hypoxic conditions that often accompany warming. This research will investigate the hypoxia tolerance of four species of Antarctic fishes, including two species of icefishes that lack the oxygen-carrying protein, hemoglobin, which may compromise their ability to oxygenate tissues under hypoxic conditions. The hypoxia tolerance of Antarctic fish species will be compared to that of a related fish species inhabiting coastal regions of South America. Physiological and biochemical responses to hypoxia will be evaluated and compared amongst the five species to bolster our predictions of the capacity of Antarctic fishes to cope with a changing environment. This research will provide training opportunities for undergraduate and graduate students, and a postdoctoral research fellow. A year-long seminar series hosted by the Aquarium of the Pacific will feature female scientists who work in Antarctica to inspire youth in the greater Los Angeles area to pursue careers in science.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; FIELD SURVEYS; USAP-DC; AMD; USA/NSF; Amd/Us; FISH", "locations": "Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "O\u0027Brien, Kristin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "ANT LIA: Hypoxia Tolerance in Notothenioid Fishes", "uid": "p0010246", "west": null}, {"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", "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"}], "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", "science_programs": null, "south": -77.75, "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion", "uid": "p0010243", "west": 162.0}, {"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": "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": "Mah, Merlin; Kurbatov, Andrei V.; Talghader, Joseph", "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": "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": "Aksoy, Mustafa; Kar, Rahul; Kaurejo, Dua", "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": "Kaurejo, Dua; Kar, Rahul; 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": "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": "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": "1848887 McClintock, James", "bounds_geometry": "POINT(-64.0527 -64.77423)", "dataset_titles": "2020 daily seawater carbonate chemistry; 2023 daily seawater carbonate chemistry; Amphipod counts from 2020 ocean acidification experiment", "datasets": [{"dataset_uid": "601700", "doi": "10.15784/601700", "keywords": "Antarctica; Palmer Station", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "2020 daily seawater carbonate chemistry", "url": "https://www.usap-dc.org/view/dataset/601700"}, {"dataset_uid": "601702", "doi": "10.15784/601702", "keywords": "Antarctica; Palmer Station", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Amphipod counts from 2020 ocean acidification experiment", "url": "https://www.usap-dc.org/view/dataset/601702"}, {"dataset_uid": "601701", "doi": "10.15784/601701", "keywords": "Antarctica; Palmer Station", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "2023 daily seawater carbonate chemistry", "url": "https://www.usap-dc.org/view/dataset/601701"}], "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "Undersea forests of seaweeds dominate the shallow waters of the central and northern coast of the western Antarctic Peninsula and provide critical structural habitat and carbon resources (food) for a host of marine organisms. Most of the seaweeds are chemically defended against herbivores yet support very high densities of herbivorous shrimp-like grazers (crustaceans, primarily amphipods) which greatly benefit their hosts by consuming filamentous and microscopic algae that otherwise overgrow the seaweeds. The amphipods benefit from the association with the chemically defended seaweeds by gaining an associational refuge from fish predation. The project builds on recent work that has demonstrated that several species of amphipods that are key members of crustacean assemblages associated with the seaweeds suffer significant mortality when chronically exposed to increased seawater acidity (reduced pH) and elevated temperatures representative of near-future oceans. By simulating these environmental conditions in the laboratory at Palmer Station, Antarctica, the investigators will test the overall hypothesis that ocean acidification will play a significant role in structuring crustacean assemblages associated with seaweeds. Broader impacts include expanding fundamental knowledge of the impacts of global climate change by focusing on a geographic region of the earth uniquely susceptible to climate change. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This includes training graduate students and early career scientists with an emphasis on diversity, presentations to K-12 groups and the general public, and a variety of social media-based outreach programs.\r\n\r\nThe project will compare population and assemblage-wide impacts of natural (ambient) and carbon dioxide enriched seawater on assemblages of seaweed-associated crustacean grazers. Based on prior results, it is likely that some species will be relative \"winners\" and some will be relative \"losers\" under the changed conditions. The project will then aim to carry out measurements of growth, calcification, mineralogy, the incidence of molts, and biochemical and energetic body composition for two key amphipod \"winners\" and two key amphipod \"losers\". These measurements will allow an assessment of what factors drive species-specific enhanced or diminished performance under conditions of ocean acidification and sea surface warming. The project will expand on what little is known about prospective impacts of changing conditions on benthic marine Crustacea, in Antarctica, a taxonomic group that faces the additional physiological stressor of molting. The project is likely to provide additional insight on the indirect regulation of the seaweeds that comprise Antarctic undersea forests that provide key architectural components of the coastal marine ecosystem.", "east": -64.0527, "geometry": "POINT(-64.0527 -64.77423)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; Amd/Us; AMD; COASTAL; BENTHIC; USAP-DC; Palmer Station; ANIMALS/INVERTEBRATES; FIELD INVESTIGATION; MACROALGAE (SEAWEEDS)", "locations": "Palmer Station", "north": -64.77423, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Amsler, Charles; McClintock, James", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.77423, "title": "Assemblage-wide effects of ocean acidification and ocean warming on ecologically important macroalgal-associated crustaceans in Antarctica", "uid": "p0010193", "west": -64.0527}, {"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": "Arctic Natural Sciences; Antarctic Glaciology", "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": "1443329 Balco, Gregory; 1443321 Bromley, Gordon", "bounds_geometry": "POLYGON((-180 -85.40705,-179.659078 -85.40705,-179.318156 -85.40705,-178.977234 -85.40705,-178.636312 -85.40705,-178.29539 -85.40705,-177.954468 -85.40705,-177.613546 -85.40705,-177.272624 -85.40705,-176.931702 -85.40705,-176.59078 -85.40705,-176.59078 -85.422615,-176.59078 -85.43818,-176.59078 -85.453745,-176.59078 -85.46931,-176.59078 -85.484875,-176.59078 -85.50044,-176.59078 -85.516005,-176.59078 -85.53157,-176.59078 -85.547135,-176.59078 -85.5627,-176.931702 -85.5627,-177.272624 -85.5627,-177.613546 -85.5627,-177.954468 -85.5627,-178.29539 -85.5627,-178.636312 -85.5627,-178.977234 -85.5627,-179.318156 -85.5627,-179.659078 -85.5627,180 -85.5627,179.277561 -85.5627,178.555122 -85.5627,177.832683 -85.5627,177.110244 -85.5627,176.387805 -85.5627,175.665366 -85.5627,174.942927 -85.5627,174.220488 -85.5627,173.498049 -85.5627,172.77561 -85.5627,172.77561 -85.547135,172.77561 -85.53157,172.77561 -85.516005,172.77561 -85.50044,172.77561 -85.484875,172.77561 -85.46931,172.77561 -85.453745,172.77561 -85.43818,172.77561 -85.422615,172.77561 -85.40705,173.498049 -85.40705,174.220488 -85.40705,174.942927 -85.40705,175.665366 -85.40705,176.387805 -85.40705,177.110244 -85.40705,177.832683 -85.40705,178.555122 -85.40705,179.277561 -85.40705,-180 -85.40705))", "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": "Sun, 20 Dec 2020 00:00:00 GMT", "description": "This investigation will reconstruct past behavior of the East Antarctic Ice Sheet during periods of warmer-than-present climate, such as the Pliocene, in order to better project the likely response of Earth\u0027s largest ice sheet to anthropogenic warming. Containing the equivalent of ~55 m sea-level rise, the future evolution of the East Antarctic Ice Sheet has clear societal ramifications on a global scale as temperatures continue to rise. Therefore, determining ice-sheet sensitivity to climate on the scale predicted for the next two centuries is a matter of increasing urgency, particularly in light of evidence suggesting the East Antarctic Ice Sheet is more dynamic than previously thought. This research will provide a terrestrial geologic record of long-term ice-sheet behavior from sites immediately adjacent the East Antarctic Ice Sheet in the Transantarctic Mountains, with which the project will help ascertain how the ice sheet responded to past warm periods. The project will focus primarily on the Pliocene warm period, 5 to 3 million years ago, as this represents the closest analogue to 21st Century climate conditions.\u003cbr/\u003e\u003cbr/\u003eThe proposed research will investigate glacial deposits corresponding to the East Antarctic Ice Sheet in the central Transantarctic Mountains in order to expand the geologic record of past ice-sheet behavior. The overarching research objectives are to improve understanding of the East Antarctic Ice Sheet\u0027s configuration during periods of warmer-than-present climate, such as the Pliocene warm period, and to determine whether the ice sheet underwent significant volume changes or remained relatively stable in response to warming. To address these goals, the investigation will map and date glacial deposits preserved at mountain sites immediately adjacent the ice sheet. Specifically, we will: (i) employ multiple cosmogenic nuclides (10Be, 26Al, 21Ne) to establish more fully ice-thickness histories for the upper Shackleton and Beardmore Glaciers, where they exit the ice sheet; (ii) use this record to identify periods during which the East Antarctic Ice Sheet was at least as extensive as today; and (iii) use these data to assess long-term ice-sheet variability in East Antarctica, with particular emphasis on Pliocene warm episodes. This research will require Antarctic fieldwork, glacial-geologic mapping, and cosmogenic surface-exposure dating.", "east": -176.59078, "geometry": "POINT(178.092415 -85.484875)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Transantarctic Mountains; GLACIERS/ICE SHEETS; AMD; GLACIER THICKNESS/ICE SHEET THICKNESS; GLACIER ELEVATION/ICE SHEET ELEVATION; NOT APPLICABLE; Antarctica", "locations": "Antarctica; Transantarctic Mountains", "north": -85.40705, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Balco, Gregory; Bromley, Gorden; BROMLEY, GORDON", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -85.5627, "title": "Collaborative Research: Potential Direct Geologic Constraint of Ice Sheet Thickness in the Central Transantarctic Mountains during the Pliocene Warm Period", "uid": "p0010153", "west": 172.77561}, {"awards": "1842059 Huber, Matthew; 1842176 Bizimis, Michael; 1842115 Jahn, Alexandra; 1842049 Kim, Sora", "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 Earth Sciences; Antarctic Integrated System Science", "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": "1543539 Liwanag, Heather", "bounds_geometry": null, "dataset_titles": "metabolic measurements; Sedation dose and response; TDR and weather data", "datasets": [{"dataset_uid": "601524", "doi": "10.15784/601524", "keywords": "Antarctica; Mcmurdo Sound; Metabolic Rate; Thermoregulation; Weddell Seal", "people": "Pearson, Linnea", "repository": "USAP-DC", "science_program": null, "title": "metabolic measurements", "url": "https://www.usap-dc.org/view/dataset/601524"}, {"dataset_uid": "601435", "doi": "10.15784/601435", "keywords": "Antarctica; Mcmurdo Sound; Weddell Seal", "people": "Weitzner, Emma; Liwanag, Heather; Pearson, Linnea", "repository": "USAP-DC", "science_program": null, "title": "TDR and weather data", "url": "https://www.usap-dc.org/view/dataset/601435"}, {"dataset_uid": "601631", "doi": "10.15784/601631", "keywords": "Antarctica; Mcmurdo Sound; Weddell Seal", "people": "Pearson, Linnea", "repository": "USAP-DC", "science_program": null, "title": "Sedation dose and response", "url": "https://www.usap-dc.org/view/dataset/601631"}], "date_created": "Sat, 12 Dec 2020 00:00:00 GMT", "description": "The transition of young from parental care to independence is a critical stage in the life of many animals. Surviving this stage can be especially challenging for polar mammals where the extreme cold requires extra energy to keep warm, rather than using the majority of energy for growth, development and physical activities. Young Weddell seals (Leptonychotes weddellii) have only weeks to develop the capabilities to survive both on top of the sea ice and within the -1.9\u00b0C seawater where they can forage for food. The project seeks to better understand how Weddell seal pups rapidly develop (within weeks) the capacity to transition between these two extreme environments (that differ greatly in their abilities to conduct heat) and how they budget their energy during the transition. Though the biology and physiology of adult Weddell seals is well studied, the energetic and physiological strategies of pups during development is still unclear. Understanding factors that may affect survival at critical life history events is essential for better understanding factors that might affect marine mammal populations. Weddell seals are the southernmost breeding mammal and are easily recognizable as quintessential Antarctic seals. Determining potential vulnerabilities at critical life stages to change in the Antarctic environment will facilitate the researchers\u0027 ability to not only gain public interest but also communicate how research is revealing ways in which changes are occurring at the poles and how these changes may affect polar ecosystems. By collaborating with the Marine Mammal Center, the project will directly reach the public, through curricular educational materials and public outreach that will impact over 100,000 visitors annually.\u003cbr/\u003e\u003cbr/\u003eTo elucidate the physiological strategies that facilitate the survival of Weddell seal pups from birth to independence, the proposed study examines the development of their thermoregulation and diving capability. To achieve this, the project will determine the mechanisms that Weddell seal pups use to maintain a stable, warm body temperature in air and in water and then examine the development of diving capability as the animals prepare for independent foraging. The researchers will take a fully integrative approach- making assessments from proteins to tissues to the whole-animal level- when investigating both these objectives. To assess the development of thermoregulatory capability, researchers will quantify body insulation, resting metabolic rates in air and in water, muscle thermogenesis (shivering), and body surface temperatures in the field. The project will also assess the development of dive capability by quantifying oxygen storage capacities and measuring early dive behavior. To identify possible cellular mechanisms for how Weddell seals navigate this trade-off during development, the program will quantify several key developmental regulators of increased hypoxic capacity (HIF, VEGF and EPO) using qPCR, as well as follow the proteomic changes of adipose and muscle tissue, which will include abundance changes of metabolic, antioxidant, cytoskeletal, and Ca2+-regulating proteins. The study of the physiological development leading up to the transition to independence in pinnipeds will help researchers better predict the effects of climate change on the distribution and abundance of this species and how this will affect other trophic levels. Environmental changes that alter habitat suitability have been shown to decrease population health, specifically because of declines in juvenile survival.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MAMMALS; FIELD INVESTIGATION; Mcmurdo Sound", "locations": "Mcmurdo Sound", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Liwanag, Heather; Pearson, Linnea; Tomanek, Lars", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "RUI: Growing Up on Ice: Physiological Adaptations and Developmental Plasticity in Weddell Seal Pups Across Two Extreme Physical Environments", "uid": "p0010144", "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": "1644187 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((161 -76.9,161.75 -76.9,162.5 -76.9,163.25 -76.9,164 -76.9,164.75 -76.9,165.5 -76.9,166.25 -76.9,167 -76.9,167.75 -76.9,168.5 -76.9,168.5 -77.04,168.5 -77.18,168.5 -77.32,168.5 -77.46,168.5 -77.6,168.5 -77.74,168.5 -77.88,168.5 -78.02,168.5 -78.16,168.5 -78.3,167.75 -78.3,167 -78.3,166.25 -78.3,165.5 -78.3,164.75 -78.3,164 -78.3,163.25 -78.3,162.5 -78.3,161.75 -78.3,161 -78.3,161 -78.16,161 -78.02,161 -77.88,161 -77.74,161 -77.6,161 -77.46,161 -77.32,161 -77.18,161 -77.04,161 -76.9))", "dataset_titles": "ANTAEM project airborne EM resistivity data from McMurdo Region", "datasets": [{"dataset_uid": "601373", "doi": "10.15784/601373", "keywords": "Antarctica; Dry Valleys; Hydrology; Ice Shelf; Mcmurdo; Permafrost", "people": "Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "ANTAEM project airborne EM resistivity data from McMurdo Region", "url": "https://www.usap-dc.org/view/dataset/601373"}], "date_created": "Sun, 13 Sep 2020 00:00:00 GMT", "description": "In Antarctica, millions of years of freezing have led to the development of hundreds of meters of thick permafrost (i.e., frozen ground). Recent research demonstrated that this slow freezing has trapped and concentrated water into local and regional briny aquifers, many times more salty than seawater. Because salt depresses the freezing point of water, these saline brines are able to persist as liquid water at temperatures well below the normal freezing point of freshwater. Such unusual groundwater systems may support microbial life, supply nutrients to coastal ocean and ice-covered lakes, and influence motion of glaciers. These briny aquifers also represent potential terrestrial analogs for deep life habitats on other planets, such as Mars, and provide a testing ground for the search for extraterrestrial water. Whereas much effort has been invested in understanding the physics, chemistry, and biology of surface and near-surface waters in cold polar regions, it has been comparably difficult to investigate deep subsurface aquifers in such settings. Airborne ElectroMagnetics (AEM) subsurface imaging provides an efficient way for mapping salty groundwater. An international collaboration with the University of Aarhus in Denmark will enable knowledge and skill transfer in AEM techniques that will enhance US polar research capabilities and provide US undergraduates and graduate students with unique training experiences. This project will survey over 1000 km2 of ocean and land near McMurdo Station in Antarctica, and will reveal if cold polar deserts hide a subsurface pool of liquid water. This will have significant implications for understanding cold polar glaciers, ice-covered lakes, frozen ground, and polar microbiology as well as for predictions of their response to future change. Improvements in permafrost mapping techniques and understanding of permafrost and of underlying groundwaters will benefit human use of high polar regions in the Antarctic and the Arctic.\u003cbr/\u003e\u003cbr/\u003eThe project will provide the first integrative system-scale overview of subsurface water distribution and hydrological connectivity in a partly ice-free coastal region of Antarctica, the McMurdo Dry Valleys. Liquid water is relatively scarce in this environment but plays an outsized role by influencing, and integrating, biological, biogeochemical, glaciological, and geological processes. Whereas surface hydrology and its role in ecosystem processes has been thoroughly studied over the last several decades, it has been difficult to map out and characterize subsurface water reservoirs and to understand their interactions with regional lakes, glaciers, and coastal waters. The proposed project builds on the \"proof-of-concept\" use of AEM technology in 2011. Improvements in sensor and data processing capabilities will result in about double the depth of penetration of the subsurface during the new data collection when compared to the 2011 proof-of-concept survey, which reached depths of 300-400m. The first field season will focus on collecting deep soundings with a ground-based system in key locations where: (i) independent constraints on subsurface structure exist from past drilling projects, and (ii) the 2011 resistivity dataset indicates the need for deeper penetration and high signal-to-noise ratios achievable only with a ground-based system. The regional airborne survey will take place during the second field season and will yield subsurface electrical resistivity data from across several valleys of different sizes and different ice cover fractions.", "east": 168.5, "geometry": "POINT(164.75 -77.6)", "instruments": null, "is_usap_dc": true, "keywords": "FROZEN GROUND; GLACIERS/ICE SHEETS; HELICOPTER; GROUND WATER; RIVERS/STREAMS; Dry Valleys", "locations": "Dry Valleys", "north": -76.9, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Mikucki, Jill", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "Collaborative Research: Antarctic Airborne ElectroMagnetics (ANTAEM) - Revealing Subsurface Water in Coastal Antarctica", "uid": "p0010129", "west": 161.0}, {"awards": "1935945 Tremblay, Marissa; 1935907 Balco, Gregory; 1935755 Lamp, Jennifer", "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": "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": "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": "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"}, {"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": "White, James; Morris, Valerie; Jones, Tyler R.; Vaughn, Bruce", "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": "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": "Price, Michael; Garland, Joshua; Bradley, Elizabeth; Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "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"}], "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": null, "bounds_geometry": null, "dataset_titles": "J-9 Drill Hole Temperatures", "datasets": [{"dataset_uid": "601316", "doi": "10.15784/601316", "repository": "USAP-DC", "science_program": null, "title": "J-9 Drill Hole Temperatures", "url": "http://www.usap-dc.org/view/dataset/601316"}], "date_created": "Tue, 05 May 2020 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Ross Ice Shelf", "locations": "Ross Ice Shelf; Antarctica", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Clough, John", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "0231006 DeVries, Arthur; 1142158 Cheng, Chi-Hing", "bounds_geometry": "POLYGON((163 -76.5,163.5 -76.5,164 -76.5,164.5 -76.5,165 -76.5,165.5 -76.5,166 -76.5,166.5 -76.5,167 -76.5,167.5 -76.5,168 -76.5,168 -76.63,168 -76.76,168 -76.89,168 -77.02,168 -77.15,168 -77.28,168 -77.41,168 -77.54,168 -77.67,168 -77.8,167.5 -77.8,167 -77.8,166.5 -77.8,166 -77.8,165.5 -77.8,165 -77.8,164.5 -77.8,164 -77.8,163.5 -77.8,163 -77.8,163 -77.67,163 -77.54,163 -77.41,163 -77.28,163 -77.15,163 -77.02,163 -76.89,163 -76.76,163 -76.63,163 -76.5))", "dataset_titles": "High-resolution benthic seawater temperature record 1999-2012 (25-40m depth) from near intake jetty at McMurdo Station, Antarctica", "datasets": [{"dataset_uid": "601275", "doi": null, "keywords": "Antarctica; Benthic; Mcmurdo Sound; Mcmurdo Station; Oceans; Physical Oceanography; Temperature Probe; Water Temperature", "people": "Cziko, Paul; Cheng, Chi-Hing; Devries, Arthur", "repository": "USAP-DC", "science_program": null, "title": "High-resolution benthic seawater temperature record 1999-2012 (25-40m depth) from near intake jetty at McMurdo Station, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601275"}], "date_created": "Wed, 08 Apr 2020 00:00:00 GMT", "description": "Antarctic notothenioid fishes exhibit two adaptive traits to survive in frigid temperatures. The first of these is the production of anti-freeze proteins in their blood and tissues. The second is a system-wide ability to perform cellular and physiological functions at extremely cold temperatures.The proposal goals are to show how Antarctic fishes use these characteristics to avoid freezing, and which additional genes are turned on, or suppressed in order for these fishes to maintain normal physiological function in extreme cold temperatures. Progressively colder habitats are encountered in the high latitude McMurdo Sound and Ross Shelf region, along with somewhat milder near?shore water environments in the Western Antarctic Peninsula (WAP). By quantifying the extent of ice crystals invading and lodging in the spleen, the percentage of McMurdo Sound fish during austral summer (Oct-Feb) will be compared to the WAP intertidal fish during austral winter (Jul-Sep) to demonstrate their capability and extent of freeze avoidance. Resistance to ice entry in surface epithelia (e.g. skin, gill and intestinal lining) is another expression of the adaptation of these fish to otherwise lethally freezing conditions.\u003cbr/\u003e\u003cbr/\u003eThe adaptive nature of a uniquely characteristic polar genome will be explored by the study of the transcriptome (the set of expressed RNA transcripts that constitutes the precursor to set of proteins expressed by an entire genome). Three notothenioid species (E.maclovinus, D. Mawsoni and C. aceratus) will be analysed to document evolutionary genetic changes (both gain and loss) shaped by life under extreme chronic cold. A differential gene expression (DGE) study will be carried out on these different species to evaluate evolutionary modification of tissue-wide response to heat challenges. The transcriptomes and other sequencing libraries will contribute to de novo ice-fish genome sequencing efforts.", "east": 168.0, "geometry": "POINT(165.5 -77.15)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD", "is_usap_dc": true, "keywords": "MARINE ECOSYSTEMS; Water Temperature; Mcmurdo Sound; AQUATIC SCIENCES; OCEAN TEMPERATURE; FIELD INVESTIGATION; USAP-DC", "locations": "Mcmurdo Sound", "north": -76.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cheng, Chi-Hing; Devries, Arthur", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "Antarctic Notothenioid Fish Freeze Avoidance and Genome-wide Evolution for Life in the Cold", "uid": "p0010091", "west": 163.0}, {"awards": "1443470 Aydin, Murat", "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": "South Pole ice core (SPC14) discrete methane data; SP19 Gas Chronology; SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "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": "Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Aydin, Murat", "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": "601270", "doi": "10.15784/601270", "keywords": "Antarctica", "people": "Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601270"}], "date_created": "Thu, 26 Mar 2020 00:00:00 GMT", "description": "In the past, Earth\u0027s climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth\u0027s atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth\u0027s climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record.\u003cbr/\u003e\u003cbr/\u003eThe primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; CARBONYL SULFIDE; HALOCARBONS AND HALOGENS; TRACE GASES/TRACE SPECIES; Antarctic; USAP-DC", "locations": "Antarctic", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core", "uid": "p0010089", "west": -180.0}, {"awards": "1341661 Near, Thomas", "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": "Phylogenomics of Antarctic notothenioid fishes", "datasets": [{"dataset_uid": "601264", "doi": null, "keywords": "Adaptive Radiation; Antarctica; Fish; Notothenioidei; Phylogeny; Southern Ocean; Speciation", "people": "Near, Thomas; Dornburg, Alex", "repository": "USAP-DC", "science_program": null, "title": "Phylogenomics of Antarctic notothenioid fishes", "url": "https://www.usap-dc.org/view/dataset/601264"}, {"dataset_uid": "601262", "doi": "10.15784/601262", "keywords": "Adaptive Radiation; Antarctica; Fish; Notothenioidei; Phylogeny; Southern Ocean; Speciation", "people": "Dornburg, Alex; Near, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Phylogenomics of Antarctic notothenioid fishes", "url": "https://www.usap-dc.org/view/dataset/601262"}], "date_created": "Sat, 29 Feb 2020 00:00:00 GMT", "description": "Understanding how groups of organisms respond to climate change is fundamentally important to assessing the impacts of human activities as well as understanding how past climatic shifts have shaped biological diversity over deep stretches of time. The fishes occupying the near-shore marine habitats around Antarctica are dominated by one group of closely related species called notothenioids. It appears dramatic changes in Antarctic climate were important in the origin and evolutionary diversification of this economically important lineage of fishes. Deposits of fossil fishes in Antarctica that were formed when the continent was experiencing milder temperatures show that the area was home to a much more diverse array of fish lineages. Today the waters of the Southern Ocean are very cold, and often below freezing, but notothenioids fishes exhibit a number of adaptions to live in this harsh set of marine habitats, including the presence of anti-freeze proteins. This research project will collect DNA sequences from hundreds of genes to infer the genealogical relationships of nearly all 124 notothenioid species, and use mathematical techniques to estimate the ages of species and lineages. Knowledge on the timing of evolutionary divergence in notothenioids will allow investigators to assess if timing of previous major climatic shifts in Antarctica are correlated with key events in the formation of the modern Southern Ocean fish fauna. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The project will support educational outreach activities to teenager groups and to the general public through a natural history museum exhibit and other public lectures. It will provide professional training opportunities for graduate students and a postdoctoral research scholar. \u003cbr/\u003e\u003cbr/\u003eAdaptive radiation, where lineages experience high rates of evolutionary diversification coincident with ecological divergence, is mostly studied in island ecosystems. Notothenioids dominate the fish fauna of the Southern Ocean and exhibit antifreeze glycoproteins that allow occupation of the subzero waters. Notothenioids are noted as one of the only examples of adaptive radiation among marine fishes, but the evolutionary history of diversification and radiation into different ecological habitats is poorly understood. This research will generate a species phylogeny (evolutionary history) for nearly all of the 124 recognized notothenioid species to investigate the mechanisms of adaptive radiation in this lineage. The phylogeny is inferred from approximately 350 genes sampled using next generation DNA sequencing and related techniques. Morphometric data are taken for museum specimens to investigate the tempo of morphological diversification and to determine if there are correlations between rates of lineage diversification and the origin of morphological disparity. The patterns of lineage, morphological, and ecological diversification in the notothenioid radiation will be compared to the paleoclimatic record to determine if past instances of global climate change have shaped the evolutionary diversification of this lineage of polar-adapted fishes.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "FISH; Fish; AMD; USA/NSF; Southern Ocean; Amd/Us; NOT APPLICABLE; USAP-DC; MARINE ECOSYSTEMS; Notothenioidei; Phylogeny", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Near, Thomas", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Phylogenomic Study of Adaptive Radiation in Antarctic Fishes", "uid": "p0010087", "west": -180.0}, {"awards": "1341602 Crockett, Elizabeth; 1341663 O\u0027Brien, Kristin", "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": "601407", "doi": "10.15784/601407", "keywords": "Antarctica; Antarctic Peninsula", "people": "Axelsson, Michael; O\u0027Brien, Kristin; Joyce, William", "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": "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": "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": "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"}, {"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": "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": "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": "601408", "doi": "10.15784/601408", "keywords": "Antarctica; Antarctic Peninsula", "people": "O\u0027Brien, Kristin; Axelsson, Michael; Crockett, Elizabeth; Joyce, William; Farrell, Anthony; Egginton, Stuart", "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; O\u0027Brien, Kristin; Egginton, Stuart; Joyce, Michael; Farrell, Anthony", "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": "Crockett, Elizabeth; Egginton, Stuart; Axelsson, Michael; Farrell, Anthony; Joyce, William; O\u0027Brien, Kristin", "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": "601414", "doi": "10.15784/601414", "keywords": "Antarctica; Antarctic Peninsula", "people": "Farnoud, Amir; Evans, Elizabeth; Crockett, Elizabeth; O\u0027Brien, Kristin", "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": "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": "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": "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"}], "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": "USAP-DC", "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": "1246111 Dalziel, Ian", "bounds_geometry": "POLYGON((-44 -53,-42.9 -53,-41.8 -53,-40.7 -53,-39.6 -53,-38.5 -53,-37.4 -53,-36.3 -53,-35.2 -53,-34.1 -53,-33 -53,-33 -53.4,-33 -53.8,-33 -54.2,-33 -54.6,-33 -55,-33 -55.4,-33 -55.8,-33 -56.2,-33 -56.6,-33 -57,-34.1 -57,-35.2 -57,-36.3 -57,-37.4 -57,-38.5 -57,-39.6 -57,-40.7 -57,-41.8 -57,-42.9 -57,-44 -57,-44 -56.6,-44 -56.2,-44 -55.8,-44 -55.4,-44 -55,-44 -54.6,-44 -54.2,-44 -53.8,-44 -53.4,-44 -53))", "dataset_titles": "BAS Geological Collection: Central Scotia Sea (full data link not provided); Nathaniel B Palmer NBP 1408; South Georgia: SOG1, SOG2, SOG3", "datasets": [{"dataset_uid": "200105", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "South Georgia: SOG1, SOG2, SOG3", "url": "https://www.unavco.org/data/gps-gnss/gps-gnss.html"}, {"dataset_uid": "200107", "doi": "", "keywords": null, "people": null, "repository": "British Antarctic Survey", "science_program": null, "title": "BAS Geological Collection: Central Scotia Sea (full data link not provided)", "url": "https://www.bas.ac.uk/data/our-data/collections/geological-collections/"}, {"dataset_uid": "200106", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Nathaniel B Palmer NBP 1408", "url": "http://www.marine-geo.org/tools/search/entry.php?id=NBP1408"}], "date_created": "Tue, 28 Jan 2020 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eOpening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eA graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.A network of four continuous Global Navigational Satellite Systems (GNSS) receivers was installed on the bedrock of South Georgia in the Southern Ocean in 2013 and 2014. An additional receiver on a concrete foundation provides a tie to a tide gauge, part of the United Kingdom South Atlantic Tide Gauge Network. The GNSS receivers have already provided data suggesting that the South Georgia microcontinent (SGM) is moving independent of both the South American plate to the north and the Scotia plate to the south. The data also demonstrate that the SGM is being uplifted. ", "east": -33.0, "geometry": "POINT(-38.5 -55)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Scotia Sea; PLATE BOUNDARIES; TECTONIC PROCESSES; NOT APPLICABLE; COASTAL ELEVATION; Southern Ocean; USAP-DC", "locations": "Scotia Sea; Southern Ocean", "north": -53.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Dalziel, Ian W.; Lawver, Lawrence; Krissek, Lawrence", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "UNAVCO", "repositories": "British Antarctic Survey; MGDS; UNAVCO", "science_programs": null, "south": -57.0, "title": "Collaborative Research: Role of the Central Scotia Sea Floor and North Scotia Ridge in the Onset and Development of the Antarctic Circumpolar Current", "uid": "p0010078", "west": -44.0}, {"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": "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": "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": "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": "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": "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": "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": "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": "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": "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": "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"}, {"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": "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": "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": "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"}], "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": "R2R", "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": "1643550 Sletten, Ronald", "bounds_geometry": "POLYGON((160.5 -77.3,160.67 -77.3,160.84 -77.3,161.01 -77.3,161.18 -77.3,161.35 -77.3,161.52 -77.3,161.69 -77.3,161.86 -77.3,162.03 -77.3,162.2 -77.3,162.2 -77.35,162.2 -77.4,162.2 -77.45,162.2 -77.5,162.2 -77.55,162.2 -77.6,162.2 -77.65,162.2 -77.7,162.2 -77.75,162.2 -77.8,162.03 -77.8,161.86 -77.8,161.69 -77.8,161.52 -77.8,161.35 -77.8,161.18 -77.8,161.01 -77.8,160.84 -77.8,160.67 -77.8,160.5 -77.8,160.5 -77.75,160.5 -77.7,160.5 -77.65,160.5 -77.6,160.5 -77.55,160.5 -77.5,160.5 -77.45,160.5 -77.4,160.5 -77.35,160.5 -77.3))", "dataset_titles": "Timelapse photography of Don Juan Pond and surrounding basin", "datasets": [{"dataset_uid": "601487", "doi": "10.15784/601487", "keywords": "Antarctica; Brine; CaCl2; Don Juan Pond; Dry Valleys; Salt", "people": "Toner, Jonathan; Mushkin, Amit; Sletten, Ronald S.", "repository": "USAP-DC", "science_program": null, "title": "Timelapse photography of Don Juan Pond and surrounding basin", "url": "https://www.usap-dc.org/view/dataset/601487"}], "date_created": "Thu, 21 Nov 2019 00:00:00 GMT", "description": "This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment.\u003cbr/\u003e\u003cbr/\u003ePast research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.", "east": 162.2, "geometry": "POINT(161.35 -77.55)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Antarctica; USA/NSF; USAP-DC; SOIL CHEMISTRY; FIELD INVESTIGATION", "locations": "Antarctica", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sletten, Ronald S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "Formation and Characteristics of Brine-rich Water in the Dry Valleys, Antarctica", "uid": "p0010069", "west": 160.5}, {"awards": "1543419 Place, Sean", "bounds_geometry": "POLYGON((163 -76,163.5 -76,164 -76,164.5 -76,165 -76,165.5 -76,166 -76,166.5 -76,167 -76,167.5 -76,168 -76,168 -76.2,168 -76.4,168 -76.6,168 -76.8,168 -77,168 -77.2,168 -77.4,168 -77.6,168 -77.8,168 -78,167.5 -78,167 -78,166.5 -78,166 -78,165.5 -78,165 -78,164.5 -78,164 -78,163.5 -78,163 -78,163 -77.8,163 -77.6,163 -77.4,163 -77.2,163 -77,163 -76.8,163 -76.6,163 -76.4,163 -76.2,163 -76))", "dataset_titles": "Hsc71 MK948005; Hsc71 MN045883; Hsp40 MK948006; Hsp40 MN045884; Hsp90ab MK948004; Hsp90aB MN045885; Hsp90b MN367227; Hspa12a MN367222; Hspa12a MN367224; Hspa13 MN367223; Hspa13 MN367225; Hspa4 MK948003; Hspa4 MN045886; Hspa6 MN367221; HspA6 MN367226; miRNA Characterization in Antarctic fish", "datasets": [{"dataset_uid": "200058", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa4 MK948003", "url": ""}, {"dataset_uid": "200066", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsc71 MN045883", "url": ""}, {"dataset_uid": "200065", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa13 MN367223", "url": ""}, {"dataset_uid": "200064", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa12a MN367222", "url": ""}, {"dataset_uid": "200063", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa6 MN367221", "url": ""}, {"dataset_uid": "200062", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsp40 MK948006", "url": ""}, {"dataset_uid": "200061", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsc71 MK948005", "url": ""}, {"dataset_uid": "200060", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsp90ab MK948004", "url": ""}, {"dataset_uid": "200059", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa4 MK948003", "url": ""}, {"dataset_uid": "200057", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "miRNA Characterization in Antarctic fish", "url": "https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE128132"}, {"dataset_uid": "200073", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsp90b MN367227", "url": ""}, {"dataset_uid": "200072", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "HspA6 MN367226", "url": ""}, {"dataset_uid": "200071", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa13 MN367225", "url": ""}, {"dataset_uid": "200070", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa12a MN367224", "url": ""}, {"dataset_uid": "200069", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hspa4 MN045886", "url": ""}, {"dataset_uid": "200068", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsp90aB MN045885", "url": ""}, {"dataset_uid": "200067", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Hsp40 MN045884", "url": ""}], "date_created": "Thu, 19 Sep 2019 00:00:00 GMT", "description": "The project will integrate analyses of fish physiology, protein production and genetics to determine if regulation of molecular chaperones (a class of proteins that facilitate the proper folding of proteins in a cell) has been permanently lost in a key fish species (Trematomus bernacchii) inhabiting the Southern Ocean. To do so, efforts will be undertaken to analyze chaperones in these fishes and how elevated temperatures impact protein turnover and protein damage. These studies should more definitively determine if the interruption of chaperone function is environmentally controlled (which could suggest these fish could benefit in some form by increasing sea surface temperatures) or if there is complete loss of chaperone function due to a change in its structure through evolutionary processes (which would suggest these fish are less likely to be able to adapt to warming). In addition to filling key gaps in our knowledge about the diversity and evolution of fishes in the southern ocean and the potential impacts changing temperatures might have on fish populations, the project will support the training of undergraduate and graduate students at an RUI institution. Specifically, activities and content directly related to this project\u0027s aims will be incorporated into the undergraduate curriculum at Sonoma State University in an effort to increase undergraduate participation in research, especially with respect to underrepresented groups.\u003cbr/\u003e\u003cbr/\u003eThe project has specific aims to perform a comparative analysis of nucleotide divergence resulting in non-synonymous amino acid changes in the trans-regulatory elements, namely members of the heat shock factor (HSF) family of transcription factors, in T. bernacchii and N. angustata. The project will also utilize metabolic labeling of newly synthesized proteins from isolated hepatocytes to monitor protein turnover rates in fish acclimated to both -1.5 and +4 \u00b0C for an extended period. Changes in chaperoning capacity and levels of damaged proteins will be quantified in multiple tissues to gain a better understanding of the cellular requirements for maintaining protein homeostasis under long-term acclimations to +4 \u00b0C. In combination, the work will help answer questions regarding divergence in these fishes as well a fundamental information regarding protein structure and function that may also have bio-medical implications.", "east": 168.0, "geometry": "POINT(165.5 -77)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; FISH; NOT APPLICABLE; Southern Ocean", "locations": "Southern Ocean", "north": -76.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Place, Sean", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -78.0, "title": "RUI: Characterizing Protein Homeostasis and the Regulatory Mechanisms Controlling Molecular Chaperone Expression in the Highly Stenothermal Notothenioid Fish, Trematomus Bernacchii", "uid": "p0010055", "west": 163.0}, {"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": "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; Marchetti, Adrian; Plumb, Kaylie", "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": "1543483 Sedwick, Peter; 1341717 Ackley, Stephen; 1341606 Stammerjohn, Sharon; 1341725 Guest, Peter; 1341513 Maksym, Edward", "bounds_geometry": "POLYGON((-180 -55,-177 -55,-174 -55,-171 -55,-168 -55,-165 -55,-162 -55,-159 -55,-156 -55,-153 -55,-150 -55,-150 -57.3,-150 -59.6,-150 -61.9,-150 -64.2,-150 -66.5,-150 -68.8,-150 -71.1,-150 -73.4,-150 -75.7,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -75.7,160 -73.4,160 -71.1,160 -68.8,160 -66.5,160 -64.2,160 -61.9,160 -59.6,160 -57.3,160 -55,162 -55,164 -55,166 -55,168 -55,170 -55,172 -55,174 -55,176 -55,178 -55,-180 -55))", "dataset_titles": "ASPeCt Visual Ice Observations on PIPERS Cruise NBP1704 April-June 2017; Expedition data of NBP1704; Impact of Convective Processes and Sea Ice Formation on the Distribution of Iron in the Ross Sea: Closing the Seasonal Cycle; NBP1704 CTD sensor data; NBP1704 Expedition Data; PIPERS airborne lidar; PIPERS lidar data; PIPERS Meteorology Rawinsonde Data; PIPERS Meteorology Time Series; PIPERS Noble Gases; Sea Ice Layer Cakes, PIPERS 2017; SUMO unmanned aerial system (UAS) atmospheric data", "datasets": [{"dataset_uid": "002663", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1704", "url": "https://www.rvdata.us/search/cruise/NBP1704"}, {"dataset_uid": "200150", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Impact of Convective Processes and Sea Ice Formation on the Distribution of Iron in the Ross Sea: Closing the Seasonal Cycle", "url": "https://www.bco-dmo.org/project/815403"}, {"dataset_uid": "601422", "doi": "10.15784/601422", "keywords": "Antarctica; CTD; CTD Data; NBP1704; Ocean Profile Data; Ross Sea; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Stammerjohn, Sharon", "repository": "USAP-DC", "science_program": null, "title": "NBP1704 CTD sensor data", "url": "https://www.usap-dc.org/view/dataset/601422"}, {"dataset_uid": "601183", "doi": "10.15784/601183", "keywords": "Antarctica; Glaciology; Ice Concentration; Ice Thickness; Ice Type; NBP1704; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Ice; Snow Depth; Snow/ice; Snow/Ice; Visual Observations", "people": "Ackley, Stephen", "repository": "USAP-DC", "science_program": null, "title": "ASPeCt Visual Ice Observations on PIPERS Cruise NBP1704 April-June 2017", "url": "https://www.usap-dc.org/view/dataset/601183"}, {"dataset_uid": "601184", "doi": "10.15784/601184 ", "keywords": "Air Temperature; Antarctica; Atmosphere; Meteorology; Near-Surface Air Temperatures; PIPERS; Radiation; Sea Ice Temperatures; Temperature; Weather Station Data; Wind Direction; Wind Speed", "people": "Guest, Peter", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Meteorology Time Series", "url": "https://www.usap-dc.org/view/dataset/601184"}, {"dataset_uid": "601185", "doi": "10.15784/601185 ", "keywords": "Air Temperature; Antarctica; Atmosphere; Atmospheric Surface Winds; Meteorology; NBP1704; PIPERS; Pressure; Radiosonde; Rawinsonde; Relative Humidity; Ross Sea; R/v Nathaniel B. Palmer; Wind Direction; Wind Speed", "people": "Guest, Peter", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Meteorology Rawinsonde Data", "url": "https://www.usap-dc.org/view/dataset/601185"}, {"dataset_uid": "601188", "doi": "", "keywords": "Aerogeophysics; Airborne Laser Altimetry; Antarctica; LIDAR; PIPERS; Ross Sea; Sea Ice", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "PIPERS airborne lidar", "url": "https://www.usap-dc.org/view/dataset/601188"}, {"dataset_uid": "001363", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1704 Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1704"}, {"dataset_uid": "601191", "doi": "10.15784/601191", "keywords": "Air Temperature; Antarctica; Atmosphere; Meteorology; NBP1704; PIPERS; R/v Nathaniel B. Palmer; Southern Ocean; Temperature Profiles; UAV; Unmanned Aircraft", "people": "Cassano, John", "repository": "USAP-DC", "science_program": null, "title": "SUMO unmanned aerial system (UAS) atmospheric data", "url": "https://www.usap-dc.org/view/dataset/601191"}, {"dataset_uid": "601207", "doi": "10.15784/601207", "keywords": "Antarctica; Digital Elevation Model; Glaciology; Ice; Ice Thickness; Ice Thickness Distribution; LIDAR; NBP1704; PIPERS; Ross Sea; R/v Nathaniel B. Palmer; Sea Ice; Snow; Snow Depth; Surface Elevation", "people": "Mei, M. Jeffrey; Jeffrey Mei, M.; Maksym, Edward", "repository": "USAP-DC", "science_program": null, "title": "Sea Ice Layer Cakes, PIPERS 2017", "url": "https://www.usap-dc.org/view/dataset/601207"}, {"dataset_uid": "601609", "doi": "10.15784/601609", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Mass Spectrometer; NBP1704; Noble Gas; Oceans; Ross Sea; R/v Nathaniel B. Palmer", "people": "Loose, Brice", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Noble Gases", "url": "https://www.usap-dc.org/view/dataset/601609"}, {"dataset_uid": "200101", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "PIPERS lidar data", "url": "http://wonder.ldeo.columbia.edu/data/publicationData/PIPERS/"}], "date_created": "Mon, 10 Jun 2019 00:00:00 GMT", "description": "The one place on Earth consistently showing increases in sea ice area, duration, and concentration is the Ross Sea in Antarctica. Satellite imagery shows about half of the Ross Sea increases are associated with changes in the austral fall, when the new sea ice is forming. The most pronounced changes are also located near polynyas, which are areas of open ocean surrounded by sea ice. To understand the processes driving the sea ice increase, and to determine if the increase in sea ice area is also accompanied by a change in ice thickness, this project will conduct an oceanographic cruise to the polynyas of the Ross Sea in April and May, 2017, which is the austral fall. The team will deploy state of the art research tools including unmanned airborne systems (UASs, commonly called drones), autonomous underwater vehicles (AUVs), and remotely operated underwater vehicles (ROVs). Using these tools and others, the team will study atmospheric, oceanic, and sea ice properties and processes concurrently. A change in sea ice production will necessarily change the ocean water below, which may have significant consequences for global ocean circulation patterns, a topic of international importance. All the involved institutions will be training students, and all share the goal of expanding climate literacy in the US, emphasizing the role high latitudes play in the Earth\u0027s dynamic climate.\u003cbr/\u003e\u003cbr/\u003eThe main goal of the project is to improve estimates of sea ice production and water mass transformation in the Ross Sea. The team will fully capture the spatial and temporal changes in air-ice-ocean interactions when they are initiated in the austral fall, and then track the changes into the winter and spring using ice buoys, and airborne mapping with the newly commissioned IcePod instrument system, which is deployed on the US Antarctic Program\u0027s LC-130 fleet. The oceanographic cruise will include stations in and outside of both the Terra Nova Bay and Ross Ice Shelf polynyas. Measurements to be made include air-sea boundary layer fluxes of heat, freshwater, and trace gases, radiation, and meteorology in the air; ice formation processes, ice thickness, snow depth, mass balance, and ice drift within the sea ice zone; and temperature, salinity, and momentum in the ocean below. Following collection of the field data, the team will improve both model parameterizations of air-sea-ice interactions and remote sensing algorithms. Model parameterizations are needed to determine if sea-ice production has increased in crucial areas, and if so, why (e.g., stronger winds or fresher oceans). The remote sensing validation will facilitate change detection over wider areas and verify model predictions over time. Accordingly this project will contribute to the international Southern Ocean Observing System (SOOS) goal of measuring essential climate variables continuously to monitor the state of the ocean and ice cover into the future.", "east": -150.0, "geometry": "POINT(-175 -66.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; 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; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; 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 MIXED LAYER; TRACE ELEMENTS; CARBON DIOXIDE; ATMOSPHERIC RADIATION; ICE GROWTH/MELT; AMD; BOUNDARY LAYER TEMPERATURE; SULFUR COMPOUNDS; NBP1704; HEAT FLUX; ICE DEPTH/THICKNESS; R/V NBP; USA/NSF; BOUNDARY LAYER WINDS; SNOW DEPTH; VERTICAL PROFILES; METHANE; POLYNYAS; CONDUCTIVITY; SEA ICE; Ross Sea; WATER MASSES; TURBULENCE; USAP-DC; Amd/Us", "locations": "Ross Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Ackley, Stephen; Bell, Robin; Weissling, Blake; Nuss, Wendell; Maksym, Edward; Stammerjohn, Sharon; Cassano, John; Guest, Peter; Sedwick, Peter; Xie , Hongjie", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "BCO-DMO; PI website; R2R; USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica", "uid": "p0010032", "west": 160.0}, {"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": "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"}, {"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": "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"}], "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": "1247510 Detrich, H. William", "bounds_geometry": null, "dataset_titles": "E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish); Expedition Data; Expedition data of LMG1003; Expedition data of LMG1004; PRJNA420419: Chaenocephalus aceratus Genome sequencing; PRJNA66471: Notothenia coriiceps Genome Sequencing Notothenia coriiceps isolate:Sejong01 (black rockcod); S-BSST 132: Assembled Transcriptomes for Berthelot et al. (2018); SRA091269: Notothenia coriiceps RNA Raw Sequence Reads; SRP047484: RAD-tag Sequences of Genetically Mapped Notothenia coriiceps Embryos ; SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos", "datasets": [{"dataset_uid": "001509", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0806"}, {"dataset_uid": "002685", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1004", "url": "https://www.rvdata.us/search/cruise/LMG1004"}, {"dataset_uid": "200145", "doi": "", "keywords": null, "people": null, "repository": "BioStudies", "science_program": null, "title": "S-BSST 132: Assembled Transcriptomes for Berthelot et al. (2018)", "url": "https://www.ebi.ac.uk/biostudies/studies/S-BSST132"}, {"dataset_uid": "002684", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1003", "url": "https://www.rvdata.us/search/cruise/LMG1003"}, {"dataset_uid": "001508", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0807"}, {"dataset_uid": "200142", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA66471: Notothenia coriiceps Genome Sequencing Notothenia coriiceps isolate:Sejong01 (black rockcod)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/66471"}, {"dataset_uid": "200026", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "SRA091269: Notothenia coriiceps RNA Raw Sequence Reads", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRA091269"}, {"dataset_uid": "200144", "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": "200143", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA420419: Chaenocephalus aceratus Genome sequencing", "url": "https://www.ncbi.nlm.nih.gov/bioproject/420419"}, {"dataset_uid": "200146", "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": "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 "}], "date_created": "Mon, 08 Apr 2019 00:00:00 GMT", "description": "Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~40-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. As circum-Antarctic coastal temperatures declined during this period from ~20\u00b0C to the modern -1.9 to +2.0\u00b0C (reached ~8-10 million years ago), the psychrophilic (cold-loving) ectotherms of the Southern Ocean evolved compensatory molecular, cellular, and physiological traits that enabled them to maintain normal metabolic function at cold temperatures. Today, these organisms are threatened by rapid warming of the Southern Ocean over periods measured in centuries (as much as 5\u00b0C/100 yr), a timeframe so short that re-adaptation and/or acclimatization to the \"new warm\" may not be possible. Thus, the long-term goals of this research project are: 1) to understand the biochemical and physiological capacities of the embryos of Antarctic notothenioid fish to resist or compensate for rapid oceanic warming; and 2) to assess the genetic toolkit available to support the acclimatization and adaptation of Antarctic notothenioid embryos to their warming habitat. The specific aims of this work are: 1) to determine the capacity of the chaperonin complex of notothenioid fishes to assist protein folding at temperatures between -4 and +20\u00b0C; and 2) to evaluate the genetic responses of notothenioid embryos, measured as global differential gene transcription, to temperature challenge, with -1.9\u00b0C as the \"normal\" control and +4 and +10\u00b0C as high temperature insults.\r\nThe physiology of embryonic development of marine stenotherms under future climate change scenarios is an important but understudied problem. This project will provide valuable insights into the capacity of Antarctic fish embryos to acclimatize and adapt to plausible climate change scenarios by examining multiple levels of biological organization, from the biochemical to the organismal. The results should also be broadly applicable to understanding the impact of global warming on marine biota worldwide. The research will also introduce graduate and undergraduate students to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e TRAWLS/NETS \u003e BOTTOM TRAWL", "is_usap_dc": false, "keywords": "AQUATIC SCIENCES; R/V LMG; USAP-DC; Southern Ocean", "locations": "Southern Ocean", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "Array Express; BioStudies; NCBI BioProject; NCBI SRA; R2R", "science_programs": null, "south": null, "title": "Protein Folding and Embryogenesis in Antarctic Fishes: A Comparative Approach to Environmental Stress", "uid": "p0010024", "west": null}, {"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": "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": "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": "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": "1341476 Moran, Amy", "bounds_geometry": "POINT(166.666 -77.84999)", "dataset_titles": "Cuticle morphology and oxygen gradients of Antarctic sea spiders; Physiological and biochemical measurements on Pycnogonida from McMurdo Sound; Physiological, biomechanical, and locomotory data on Antarctic sea spiders fouled and unfouled with epibionts; Size scaling of oxygen physiology and metabolic rate of Antarctic sea spiders", "datasets": [{"dataset_uid": "601145", "doi": "10.15784/601145", "keywords": "Antarctica; Benthos; Biota; Body Size; Cuticle; Mcmurdo Sound; Microelectrodes; Microscope; Microscopy; Oxygen; Pore; Respiration; Sea Spider; Southern Ocean", "people": "Arthur Woods, H.; Woods, H. Arthur", "repository": "USAP-DC", "science_program": null, "title": "Cuticle morphology and oxygen gradients of Antarctic sea spiders", "url": "https://www.usap-dc.org/view/dataset/601145"}, {"dataset_uid": "601142", "doi": "10.15784/601142", "keywords": "Antarctica; Biomechanics; Biota; Cold Adaptation; Mcmurdo Sound; Metabolism; Oceans; Oxygen; Pycnogonida; Southern Ocean", "people": "Woods, H. Arthur; Tobalske, Bret; Moran, Amy", "repository": "USAP-DC", "science_program": null, "title": "Physiological and biochemical measurements on Pycnogonida from McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601142"}, {"dataset_uid": "601150", "doi": "10.15784/601150", "keywords": "Antarctica; Biota; Body Size; Cuticle; Metabolic Rate; Oxygen; Polar Gigantism; Respiration; Size Limits; Southern Ocean; Temperature", "people": "Lane, Steven J.; Moran, Amy; Shishido, Caitlin; Woods, H. Arthur", "repository": "USAP-DC", "science_program": null, "title": "Size scaling of oxygen physiology and metabolic rate of Antarctic sea spiders", "url": "https://www.usap-dc.org/view/dataset/601150"}, {"dataset_uid": "601149", "doi": "10.15784/601149", "keywords": "Antarctica; Barnacles; Biota; Cuticle; Epibionts; Fouling; Grooming; Locomotion; Oxygen; Respiration", "people": "Moran, Amy; Lane, Steven J.; Woods, H. Arthur; Shishido, Caitlin; Tobalske, Bret", "repository": "USAP-DC", "science_program": null, "title": "Physiological, biomechanical, and locomotory data on Antarctic sea spiders fouled and unfouled with epibionts", "url": "https://www.usap-dc.org/view/dataset/601149"}], "date_created": "Mon, 10 Dec 2018 00:00:00 GMT", "description": "Beginning with the earliest expeditions to the poles, scientists have noted that many polar taxa grow to unusually large body sizes, a phenomenon now known as \u0027polar gigantism.\u0027 Although scientists have been interested in polar giants for many years, many questions still remain about the biology of this significant form of polar diversity. This award from the Antarctic Organisms and Ecosystems program within the Polar Sciences Division at the National Science Foundation will investigate the respiratory and biomechanical mechanisms underlying polar gigantism in Antarctic pycnogonids (commonly known as sea spiders). The project will use a series of manipulative experiments to investigate the effects of temperature and oxygen availability on respiratory capacity and biomechanical strength, and will compare Antarctic sea spiders to related species from temperate and tropical regions. The research will provide insight into the ability of polar giants to withstand the warming polar ocean temperatures associated with climate change.\u003cbr/\u003e\u003cbr/\u003eThe prevailing hypothesis to explain the evolution of gigantism invokes shifts in respiratory relationships in extremely cold ocean waters: in the cold, oxygen is more plentiful while at the same time metabolic rates are very low. Together these effects alleviate constraints on oxygen supply that restrict organisms living in warmer waters. Respiratory capacity must evolve in the context of adaptive tradeoffs, so for organisms including pycnogonids there must be tradeoffs between respiratory capacity and resistance to biomechanical stresses. The investigators will test a novel hypothesis that respiratory challenges are not associated with particular body sizes, and will answer the following questions: What are the dynamics of oxygen transport and consumption in Antarctic pycnogonids; how do structural features related to oxygen diffusion trade off with requirements for body support and locomotion; how does body size influence vulnerability to environmental hypoxia and to temperature-oxygen interactions; and does the cold-driven high oxygen availability in the Antarctic raise the limit on body size by reducing trade-offs between diffusivity and structural integrity? The research will explore the effects of increased ocean temperatures upon organisms that have different body sizes. In addition, it will provide training for graduate and undergraduate students affiliated with universities in EPSCOR states.", "east": 166.666, "geometry": "POINT(166.666 -77.84999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE", "locations": null, "north": -77.84999, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Moran, Amy; Woods, H. Arthur", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.84999, "title": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida", "uid": "p0000007", "west": 166.666}, {"awards": "1341311 Timmermann, Axel", "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": "784 ka transient Antarctic ice-sheet model simulation data", "datasets": [{"dataset_uid": "000247", "doi": "", "keywords": null, "people": null, "repository": "IBS Center for Climate Physics ICCP", "science_program": null, "title": "784 ka transient Antarctic ice-sheet model simulation data", "url": "http://climatedata.ibs.re.kr/grav/data/psu-love/antarctic-ice-sheet"}], "date_created": "Tue, 26 Jun 2018 00:00:00 GMT", "description": "This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth\u0027s orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no 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": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Timmermann, Axel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IBS Center for Climate Physics ICCP", "repositories": "IBS Center for Climate Physics ICCP", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Bipolar Coupling of late Quaternary Ice Sheet Variability", "uid": "p0000379", "west": -180.0}, {"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": "Fudge, T. J.; Koutnik, Michelle; Waddington, Edwin D.; Conway, Howard; Lilien, David", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole area GPS velocities", "url": "https://www.usap-dc.org/view/dataset/601100"}, {"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"}, {"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": "Conway, Howard; Fudge, T. J.; Koutnik, Michelle; Waddington, Edwin D.; Lilien, David; 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": "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": "Stevens, Christopher Max; Fudge, T. J.; Waddington, Edwin D.; Koutnik, Michelle; Conway, Howard; Lilien, David", "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": "601099", "doi": "10.15784/601099", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; Snow Accumulation; Snow/ice; Snow/Ice", "people": "Koutnik, Michelle; Fudge, T. J.; Waddington, Edwin D.; Lilien, David; Conway, Howard", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Shallow radar near South Pole", "url": "https://www.usap-dc.org/view/dataset/601099"}, {"dataset_uid": "601369", "doi": "10.15784/601369", "keywords": "Antarctica; Ice Sheet", "people": "Koutnik, Michelle; Waddington, Edwin D.; Stevens, Max; Lilien, David; Fudge, T. J.; Conway, Howard", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "7MHz radar in the vicinity of South Pole", "url": "https://www.usap-dc.org/view/dataset/601369"}], "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": "0944021 Brook, Edward; 0944307 Conway, Howard; 0943466 Hawley, Robert", "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": "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": "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": "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.; Clemens-Sewall, David; Giese, Alexandra", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Firn temperatures", "url": "https://www.usap-dc.org/view/dataset/601085"}, {"dataset_uid": "601359", "doi": "10.15784/601359", "keywords": "Antarctica; CO2; Ice Core; Roosevelt Island", "people": "Lee, James; Brook, Edward J.", "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 Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "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": "1246342 Fountain, Andrew; 1245749 Levy, Joseph; 1246203 Gooseff, Michael", "bounds_geometry": "POLYGON((160.105465 -77.2119,160.7907435 -77.2119,161.476022 -77.2119,162.1613005 -77.2119,162.846579 -77.2119,163.5318575 -77.2119,164.217136 -77.2119,164.9024145 -77.2119,165.587693 -77.2119,166.2729715 -77.2119,166.95825 -77.2119,166.95825 -77.3189628,166.95825 -77.4260256,166.95825 -77.5330884,166.95825 -77.6401512,166.95825 -77.747214,166.95825 -77.8542768,166.95825 -77.9613396,166.95825 -78.0684024,166.95825 -78.1754652,166.95825 -78.282528,166.2729715 -78.282528,165.587693 -78.282528,164.9024145 -78.282528,164.217136 -78.282528,163.5318575 -78.282528,162.846579 -78.282528,162.1613005 -78.282528,161.476022 -78.282528,160.7907435 -78.282528,160.105465 -78.282528,160.105465 -78.1754652,160.105465 -78.0684024,160.105465 -77.9613396,160.105465 -77.8542768,160.105465 -77.747214,160.105465 -77.6401512,160.105465 -77.5330884,160.105465 -77.4260256,160.105465 -77.3189628,160.105465 -77.2119))", "dataset_titles": "2014-2015 lidar survey of the McMurdo Dry Valleys, Antarctica; Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica", "datasets": [{"dataset_uid": "000209", "doi": "", "keywords": null, "people": null, "repository": "OpenTopo", "science_program": null, "title": "2014-2015 lidar survey of the McMurdo Dry Valleys, Antarctica", "url": "http://opentopo.sdsc.edu/datasetMetadata?otCollectionID=OT.112016.3294.1"}, {"dataset_uid": "601075", "doi": "10.15784/601075", "keywords": "Antarctica; Dry Valleys; Glaciology; Paleoclimate; Permafrost; Soil Temperature; Taylor Valley", "people": "Gooseff, Michael N.", "repository": "USAP-DC", "science_program": null, "title": "Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica", "url": "https://www.usap-dc.org/view/dataset/601075"}], "date_created": "Wed, 20 Dec 2017 00:00:00 GMT", "description": "Collaborative Research: THE MCMURDO DRY VALLEYS: A Landscape on the Threshold of Change is supported by the Antarctic Integrated System Science (AISS) program in the Antarctic Sciences Section of the Division of Polar Programs within the Geosciences Directorate of the National Sciences Foundation (NSF). The funds will support the collection of state-of-the-art high resolution LIDAR (combining the terms light and radar) imagery of the Dry Valleys of Antarctica in the 2014/2015 Antarctic field season, with LIDAR data collection and processing being provided by the NSF-supported NCALM (National Center for Airborne Laser Mapping) facility. LIDAR images collected in 2014/2015 will be compared to images from 2001 in order to detect decadal change. Additional fieldwork will look at the distribution of buried massive ice, and the impacts that major changes like slumping are having on the biota. All field data will be used to improve models on energy balance, and hydrology.\u003cbr/\u003e\u003cbr/\u003eIntellectual Merit: There have been dramatic changes over the past decade in the McMurdo Dry Valleys: rivers are incising by more than three meters, and thermokarst slumps are appearing near several streams and lakes. These observations have all been made by researchers in the field, but none of the changes have been mapped on a valley-wide scale. This award will provide a new baseline map for the entire Dry Valley system, with high-resolution imagery provided for the valley floors, and lower resolution imagery available for the higher elevation areas that are undergoing less change. The project will test the idea that sediment-covered ice is associated with the most dramatic changes, due to differential impacts of the increased solar radiation on sediment-covered compared to clean ice, and despite the current trend of slightly cooling air temperatures within the Dry Valleys. Information collected on the topography, coupled with the GPR determined buried ice distributions, will also be incorporated into improved energy and hydrological models. In addition to providing the new high-resolution digital elevation model (DEM), the project will ultimately result in identification of areas that are susceptible to sediment-enhanced melt-driven change, providing a powerful prediction tool for the impacts of climate change.\u003cbr/\u003e\u003cbr/\u003eBroader Impacts: The new DEM will be immediately useful to a wide range of disciplines, and will provide a comprehensive new baseline against which future changes will be compared. The project will provide a tool for the whole community to use, and the investigators will work with the community to make them aware of the new assets via public presentations, and perhaps via a workshop. The map will have international interest, and will also serve as a tool for environmental managers to draw on as they consider conservation plans. Several undergraduate and graduate students will participate in the project, and one of the co-PIs is a new investigator. The imagery collected is expected to be of interest to the general public in addition to scientific researchers, and venues for outreach such as museum exhibits and the internet will be explored. The proposed work is synergistic with 1) the co-located McMurdo LTER program, and 2) the NCALM facility that is also funded by the Geosciences Directorate.", "east": 166.95825, "geometry": "POINT(163.5318575 -77.747214)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e AIRBORNE LASER SCANNER", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; Not provided; LANDFORMS; NOT APPLICABLE", "locations": "Antarctica", "north": -77.2119, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Levy, Joseph; Gooseff, Michael N.; Fountain, Andrew", "platforms": "Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "OpenTopo", "repositories": "OpenTopo; USAP-DC", "science_programs": null, "south": -78.282528, "title": "Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change", "uid": "p0000076", "west": 160.105465}, {"awards": "1103428 Thurber, Andrew", "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": "McMurdo Spiophanes beds 16s V4 region community composition from sediment cores at McMurdo Station, Antarctia on Sept 9th, 2012 (McMurdo Benthos project); Stable isotopic composition of McMurdo Benthos", "datasets": [{"dataset_uid": "000201", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Stable isotopic composition of McMurdo Benthos", "url": "https://www.bco-dmo.org/dataset/716462"}, {"dataset_uid": "000202", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "McMurdo Spiophanes beds 16s V4 region community composition from sediment cores at McMurdo Station, Antarctia on Sept 9th, 2012 (McMurdo Benthos project)", "url": "https://www.bco-dmo.org/dataset/716443"}], "date_created": "Tue, 10 Oct 2017 00:00:00 GMT", "description": "The biota of the world\u0027s seafloor is fueled by bursts of seasonal primary production. For food-limited sediment communities to persist, a balance must exist between metazoan consumption of and competition with bacteria, a balance which likely changes through the seasons. Polar marine ecosystems are ideal places to study such complex interactions due to stark seasonal shifts between heterotrophic and autotrophic communities, and temperatures that may limit microbial processing of organic matter. The research will test the following hypotheses: 1) heterotrophic bacteria compete with macrofauna for food; 2) as phytoplankton populations decline macrofauna increasingly consume microbial biomass to sustain their populations; and 3) in the absence of seasonal photosynthetic inputs, macrofaunal biodiversity will decrease unless supplied with microbially derived nutrition. Observational and empirical studies will test these hypotheses at McMurdo Station, Antarctica, where a high-abundance macro-infaunal community is adapted to this boom-and-bust cycle of productivity. The investigator will mentor undergraduates from a predominantly minority-serving institution, in the fields of invertebrate taxonomy and biogeochemistry. The general public and young scientists will be engaged through lectures at local K-12 venues and launch of an interactive website. The results will better inform scientists and managers about the effects of climate change on polar ecosystems and the mechanisms of changing productivity patterns on global biodiversity.", "east": 170.0, "geometry": "POINT(167.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.0, "nsf_funding_programs": null, "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -78.0, "title": "PostDoctoral Research Fellowship", "uid": "p0000416", "west": 165.0}, {"awards": "1142085 Alley, Richard", "bounds_geometry": null, "dataset_titles": "Firn-temperature time series in Dronning Maud Land, East Antarctica", "datasets": [{"dataset_uid": "601050", "doi": "10.15784/601050", "keywords": "Antarctica; Borehole Logging; Dronning Maud Land; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Physical Properties; Snow; Temperature", "people": "Muto, Atsu", "repository": "USAP-DC", "science_program": null, "title": "Firn-temperature time series in Dronning Maud Land, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601050"}], "date_created": "Mon, 11 Sep 2017 00:00:00 GMT", "description": "Alley/1142085\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to continue the collection and analyses of firn temperature data from three automated firn thermal profiling units deployed in Dronning Maud Land sector of East Antarctica as part of the Norway-US IPY Traverse project between 2007 and 2009. The intellectual merits of this project are as follows: 1) to constrain and improve the parameterization of firn thermal properties (thermal conductivity and specific heat capacity) that are required for the borehole paleothermometry, 2) to study the change in firn temperature since the deployment of thermal profiling units ~5 years ago and derive the surface temperature trend for that time period, and 3) to compare and contrast the surface temperatures and their trends derived from the measured firn temperatures and satellite thermal infrared data for the past three decades. The project also involves acquiring and deploying an automated system to record transient temperatures at multiple depths in the top 16 meters of the shallow borehole at Dome Fuji, to provide useful data and to prepare for the possibility of conducting temperature-logging in the existing deep (3035 m) and shallow (112 m) boreholes at Dome Fuji in the near future. The preparation of the shallow borehole and the installation of the automated system will be carried out by collaborators from the Japanese Antarctic Research Expedition (JARE) in 2012-13 Antarctic field season. The data collected by this automated system will be used to constrain the thermal properties of upper firn layer at Dome Fuji, as well as comparing with data from other sites, increasing the geographic extent of these studies. The broader impacts of the project include presentation of results at scientific conferences and publication of results in peer-reviewed journals. Public outreach will include targeted work with science teachers and middle school students.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Revealing Late Holocence Climate Variability in Antarctica from Borehole Paleothermometry", "uid": "p0000440", "west": null}, {"awards": "1142122 Miller, Nathan", "bounds_geometry": "POLYGON((166.163 -76.665,166.2635 -76.665,166.364 -76.665,166.4645 -76.665,166.565 -76.665,166.6655 -76.665,166.766 -76.665,166.8665 -76.665,166.967 -76.665,167.0675 -76.665,167.168 -76.665,167.168 -76.782,167.168 -76.899,167.168 -77.016,167.168 -77.133,167.168 -77.25,167.168 -77.367,167.168 -77.484,167.168 -77.601,167.168 -77.718,167.168 -77.835,167.0675 -77.835,166.967 -77.835,166.8665 -77.835,166.766 -77.835,166.6655 -77.835,166.565 -77.835,166.4645 -77.835,166.364 -77.835,166.2635 -77.835,166.163 -77.835,166.163 -77.718,166.163 -77.601,166.163 -77.484,166.163 -77.367,166.163 -77.25,166.163 -77.133,166.163 -77.016,166.163 -76.899,166.163 -76.782,166.163 -76.665))", "dataset_titles": "Antarctic emerald rockcod have the capacity to compensate for warming when uncoupled from CO2-acidification; Physiological and biochemical measurements on Antarctic dragonfish (Gymnodraco acuticeps) from McMurdo Sound; Physiological and biochemical measurements on juvenile Antarctic rockcod (Trematomus bernacchii) from McMurdo Sound; Thermal windows and metabolic performance curves in a developing Antarctic fish", "datasets": [{"dataset_uid": "601039", "doi": "10.15784/601039", "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; CTD Data; Fish; Mcmurdo Sound; Ocean Acidification; Oceans; Physical Oceanography; Ross Sea; Southern Ocean", "people": "Miller, Nathan; Todgham, Anne", "repository": "USAP-DC", "science_program": null, "title": "Antarctic emerald rockcod have the capacity to compensate for warming when uncoupled from CO2-acidification", "url": "https://www.usap-dc.org/view/dataset/601039"}, {"dataset_uid": "601040", "doi": "10.15784/601040", "keywords": "Antarctica; Biota; Fish; Mcmurdo Sound; Oceans; Ross Sea; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Todgham, Anne; Miller, Nathan", "repository": "USAP-DC", "science_program": null, "title": "Thermal windows and metabolic performance curves in a developing Antarctic fish", "url": "https://www.usap-dc.org/view/dataset/601040"}, {"dataset_uid": "601026", "doi": "10.15784/601026", "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; CTD Data; Fish; Mcmurdo Sound; Ocean Acidification; Oceans; Physical Oceanography; Ross Sea; Southern Ocean", "people": "Davis, Brittany; Todgham, Anne; Flynn, Erin; Miller, Nathan", "repository": "USAP-DC", "science_program": null, "title": "Physiological and biochemical measurements on Antarctic dragonfish (Gymnodraco acuticeps) from McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601026"}, {"dataset_uid": "601025", "doi": "10.15784/601025", "keywords": "Antarctica; Biota; Fish; Mcmurdo Sound; Oceans; Ross Sea; Southern Ocean", "people": "Flynn, Erin; Davis, Brittany; Miller, Nathan; Todgham, Anne", "repository": "USAP-DC", "science_program": null, "title": "Physiological and biochemical measurements on juvenile Antarctic rockcod (Trematomus bernacchii) from McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601025"}], "date_created": "Tue, 15 Aug 2017 00:00:00 GMT", "description": "Ocean acidification and increased temperatures are projected to be the primary impacts of global climate change on polar marine ecosystems over the next century. While recent research has focused on the effects of these drivers on calcifying organisms, less is known about how these changes may affect vertebrates. This research will focus on two Antarctic fishes, Trematomus bernacchii and Pagothenia borchgrevinki. Fish eggs and larvae will be collected in McMurdo Sound and reared under different temperature and pH regimes. Modern techniques will be used to examine subsequent changes in physiology, growth, development and gene expression over both short and long timescales. The results will fill a missing gap in our knowledge about the response of non-calcifying organisms to projected changes in pH and temperature. Results will be widely disseminated through publications as well as through presentations at national and international meetings; raw data will also be made available through open-access, web-based databases. This project will support the research and training of three graduate and three undergraduate students. As well, this project will foster the development of two modules on climate change and ocean acidification for an Introduction to Biology course.", "east": 167.168, "geometry": "POINT(166.6655 -77.25)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.665, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Miller, Nathan; Todgham, Anne", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.835, "title": "RUI: Synergistic effects of Ocean Acidification and Warming on Larval Development in Antarctic Fishes", "uid": "p0000411", "west": 166.163}, {"awards": "1246387 Guo, Weifu", "bounds_geometry": "POLYGON((-79.9183333 35.441666667,-55.16316667 35.441666667,-30.40800004 35.441666667,-5.65283341 35.441666667,19.10233322 35.441666667,43.85749985 35.441666667,68.61266648 35.441666667,93.36783311 35.441666667,118.12299974 35.441666667,142.87816637 35.441666667,167.633333 35.441666667,167.633333 25.9255333333,167.633333 16.4093999996,167.633333 6.8932666659,167.633333 -2.6228666678,167.633333 -12.1390000015,167.633333 -21.6551333352,167.633333 -31.1712666689,167.633333 -40.6874000026,167.633333 -50.2035333363,167.633333 -59.71966667,142.87816637 -59.71966667,118.12299974 -59.71966667,93.36783311 -59.71966667,68.61266648 -59.71966667,43.85749985 -59.71966667,19.10233322 -59.71966667,-5.65283341 -59.71966667,-30.40800004 -59.71966667,-55.16316667 -59.71966667,-79.9183333 -59.71966667,-79.9183333 -50.2035333363,-79.9183333 -40.6874000026,-79.9183333 -31.1712666689,-79.9183333 -21.6551333352,-79.9183333 -12.1390000015,-79.9183333 -2.6228666678,-79.9183333 6.8932666659,-79.9183333 16.4093999996,-79.9183333 25.9255333333,-79.9183333 35.441666667))", "dataset_titles": "Clumped isotope composition of modern cold water corals", "datasets": [{"dataset_uid": "000205", "doi": "", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Clumped isotope composition of modern cold water corals", "url": "http://www.earthchem.org/"}], "date_created": "Fri, 07 Jul 2017 00:00:00 GMT", "description": "This proposed research aims to produce high resolution, precise and accurate records of deep water temperatures in the Drake Passage over the past ~40,000 years, by applying the newly developed carbonate clumped isotope thermometer to a unique collection of modern and fossil deep-sea corals, and thus advance the understanding of the role of the Southern Ocean in modulating global climate. In addition, this study will provide further evaluation on the potential of this new thermometer to derive accurate estimates of past ocean temperatures from deep-sea coral skeletons. Funding will support an early-career junior scientist and a graduate student. \u003cbr/\u003e\u003cbr/\u003eDespite its crucial role in modulating global climate, rates and amplitudes of environmental changes in the Southern Ocean are often difficult to constrain. In particular, the knowledge about the deep water temperatures in the Southern Ocean during the last glacial cycle is extremely limited. This results both from the lack of well-dated climate archives for the deep Southern Ocean and from the fact that most existing temperature proxies (e.g. del18O and Mg/Ca of foraminifera and corals) suffer from the biological \u0027vital effects\u0027. The latter is especially problematic; it causes substantial challenges in interpreting these geochemical proxies and can lead to biases equivalent to tens of degrees in temperature estimates. Recent development of carbonate clumped isotope thermometer, holds new promises for reconstructing deep water temperatures in the Southern Ocean, since calibration studies of this thermometer in deep-sea corals suggest it is largely free of vital effects. This proposed research seeks to refine the calibration of carbonate clumped isotope thermometer in deep-sea corals at low temperatures, improve the experimental methods to obtain high precision in temperature estimates, and then apply this thermometer to a unique collection of modern and fossil deep-sea corals collected from the Drake Passage during two recent Office of Polar Programs (OPP)-funded cruises, that have already been dated by radiocarbon and U-series methods. By combining the reconstructed temperatures with the radiocarbon and U-Th ages for these deep-sea corals, this study will explore the relationships between these temperature changes and global climate changes.", "east": 167.633333, "geometry": "POINT(43.85749985 -12.1390000015)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": 35.441666667, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Guo, Weifu", "platforms": "Not provided", "repo": "EarthChem", "repositories": "EarthChem", "science_programs": null, "south": -59.71966667, "title": "Reconstruction of Deep-Water Temperatures in the Drake Passage Over the Last Glacial Cycle: Application of Carbonate Clumped Isotope Thermometer to Absolutely-Dated Deep-Sea Corals", "uid": "p0000389", "west": -79.9183333}, {"awards": "1246463 Burns, Jennifer", "bounds_geometry": "POINT(149 -80)", "dataset_titles": "1970s - 1980s Kooyman-Billups TDR Dive Records from Weddell Seals in McMurdo Sound; Cortisol levels in Weddell seal fur; Seasonal Dive Data ; Specimen logs and observations from Weddell Seal colonies in Erebus Bay, 2013-2017; Weddell Seal Heat Flux Dataset; Weddell seal iron dynamics and oxygen stores across lactation; Weddell Seal Molt Phenology Dataset; Weddell Seal Molt Survey Data; Weddell seal summer diving behavior", "datasets": [{"dataset_uid": "601587", "doi": "10.15784/601587", "keywords": "Aerobic; Antarctica; Dive Capacity; Iron; Mcmurdo Sound; Weddell Seal", "people": "Shero, Michelle", "repository": "USAP-DC", "science_program": null, "title": "Weddell seal iron dynamics and oxygen stores across lactation", "url": "https://www.usap-dc.org/view/dataset/601587"}, {"dataset_uid": "601137", "doi": "10.15784/601137", "keywords": "Antarctica; Biota; Ross Sea; Seals; Southern Ocean; Weddell Seal", "people": "Beltran, Roxanne; Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Weddell seal summer diving behavior", "url": "https://www.usap-dc.org/view/dataset/601137"}, {"dataset_uid": "601027", "doi": "10.15784/601027", "keywords": "Antarctica; Biota; Mcmurdo Sound; Oceans; Ross Sea; Sample/collection Description; Sample/Collection Description; Seals", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Specimen logs and observations from Weddell Seal colonies in Erebus Bay, 2013-2017", "url": "https://www.usap-dc.org/view/dataset/601027"}, {"dataset_uid": "601134", "doi": "10.15784/601134", "keywords": "Antarctica; Biota; Cortisol; Fur; Ross Sea; Seals; Southern Ocean; Visual Observations; Weddell Seal", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Cortisol levels in Weddell seal fur", "url": "https://www.usap-dc.org/view/dataset/601134"}, {"dataset_uid": "601133", "doi": "10.15784/601133", "keywords": "Antarctica; Biota; Ross Sea; Seals; Visual Observations; Weddell Seal", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Weddell Seal Molt Survey Data", "url": "https://www.usap-dc.org/view/dataset/601133"}, {"dataset_uid": "601131", "doi": "10.15784/601131", "keywords": "Antarctica; B-292-M; Biota; Ross Sea; Seals; Southern Ocean; Weddell Seal", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Weddell Seal Molt Phenology Dataset", "url": "https://www.usap-dc.org/view/dataset/601131"}, {"dataset_uid": "601560", "doi": "10.15784/601560", "keywords": "Antarctica; Biota; Diving Behavior; Mcmurdo Sound; Weddell Seal", "people": "Tsai, EmmaLi", "repository": "USAP-DC", "science_program": null, "title": "1970s - 1980s Kooyman-Billups TDR Dive Records from Weddell Seals in McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601560"}, {"dataset_uid": "601338", "doi": "10.15784/601338", "keywords": "Animal Behavior Observation; Antarctica; Biota; Mcmurdo Sound; Ross Sea; Seal Dive Data; Weddell Seal", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Seasonal Dive Data ", "url": "https://www.usap-dc.org/view/dataset/601338"}, {"dataset_uid": "601271", "doi": "10.15784/601271", "keywords": "Antarctica; Heat Flux; Infrared Thermography; Physiological Conditions; Surface Temperatures; Thermoregulation; Weddell Seal", "people": "Walcott, Skyla", "repository": "USAP-DC", "science_program": null, "title": "Weddell Seal Heat Flux Dataset", "url": "https://www.usap-dc.org/view/dataset/601271"}], "date_created": "Wed, 24 May 2017 00:00:00 GMT", "description": "Marine mammals that inhabit high latitude environments have evolved unique mechanisms to execute a suite of energetically-costly life history events (CLHEs) within a relatively short timeframe when conditions are most favorable. Understanding the intrinsic and extrinsic factors that regulate CLHEs is particularly important in species such as Weddell seals, as both reproduction and molt are associated with large reductions in foraging effort, and the timing and outcome of each appears linked with the other. The long-term mark recapture program on Erebus Bay\u0027s Weddell seals provides a unique opportunity to examine CLHEs in a known-history population. The proposed work will monitor physiological condition, pregnancy status, and behavior at various times throughout the year to determine if molt timing is influenced by prior reproductive outcome, and if it, in turn, influences future reproductive success. These data will then be used to address the demographic consequences of trade-offs between CLHEs in Weddell seals. The impact of environmental conditions and CLHE timing on population health will also be modeled so that results can be extended to other climates and species. \u003cbr/\u003e\u003cbr/\u003eAn improved understanding of the interactions between CLHEs and the environment is important in predicting the response of organisms from higher trophic levels to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of graduate students and a post-doctoral researcher and will further foster an extensive public outreach collaboration.", "east": 165.0, "geometry": "POINT(165 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; USAP-DC; Seal Dive Data; Weddell Seal", "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Burns, Jennifer", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "The Cost of A New Fur Coat: Interactions between Molt and Reproduction in Weddell Seals", "uid": "p0000229", "west": 165.0}, {"awards": "0538520 Thiemens, Mark; 0538049 Steig, Eric", "bounds_geometry": "POINT(-112.085 -79.5)", "dataset_titles": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core; WAIS Divide sulfate and nitrate isotopes; WAIS ice core isotope data #387, 385 (full data link not provided)", "datasets": [{"dataset_uid": "601007", "doi": "10.15784/601007", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; Oxygen Isotope; Sulfate; WAIS Divide; WAIS Divide Ice Core", "people": "Alexander, Becky; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide sulfate and nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601007"}, {"dataset_uid": "609479", "doi": "10.7265/N5BG2KXH", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Thiemens, Mark H.", "repository": "USAP-DC", "science_program": null, "title": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609479"}, {"dataset_uid": "002512", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #387, 385 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538520\u003cbr/\u003eThiemens\u003cbr/\u003eThis award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.", "east": -112.085, "geometry": "POINT(-112.085 -79.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Isotope Ratios; Temperature; Sulfate; West Antarctic; Paleoatmosphere; LABORATORY; Ice Core; Ice Core Data; Mass Independent Fractionation; FIELD SURVEYS; Not provided; Accumulation Rate; Oxygen Isotope; FIELD INVESTIGATION; Ice Core Chemistry; Isotope", "locations": "West Antarctic", "north": -79.5, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky; Steig, Eric J.; Thiemens, Mark H.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000020", "west": -112.085}, {"awards": "1245580 Castro, M. Clara", "bounds_geometry": "POINT(162.167 -77.733)", "dataset_titles": "Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases", "datasets": [{"dataset_uid": "600389", "doi": "10.15784/600389", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Critical Zone; Geochemistry; Noble Gas; Paleoclimate; Ross Ice Shelf; Ross Sea; Taylor Valley", "people": "Castro, M. Clara", "repository": "USAP-DC", "science_program": null, "title": "Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases", "url": "https://www.usap-dc.org/view/dataset/600389"}], "date_created": "Mon, 30 Jan 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eNoble gases in groundwater systems can indicate past climates in ice-free regions through estimation of noble gas temperatures. Traditional noble gas temperatures cannot be derived in ice-covered regions where water is not in contact with the atmosphere. The goal of the proposed work is to take advantage of noble gas properties in ice covered lakes at the ice/water interface to develop a new paleoclimate proxy with the potential to be routinely used in both polar and alpine glacial regions. The evolution of the Taylor Valley lakes is intimately connected to the dynamics of nearby glaciers, as well as the advance and retreat of the Ross Ice Shelf, both of which are dictated by climate change. The perennial ice cover of the lakes form at the water/ice interface and sublimate at the top rendering these lakes ideal to test and develop this new proxy. The proposed research involves conducting an extensive noble gas sampling campaign of lake water, stream water, ice covers and glacial ice. This data set, together with data continuously collected in the area will provide a solid basis to develop, test and refine mathematical models capable of accurately describing heavy noble gas concentration profiles as well as their overall inventory in the lakes over time. These will provide information on the occurrence of major climatic events while simultaneously providing temporal constraints on such events. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe findings of this work will be inserted into a new class that the PI has created at the University of Michigan targeted at non-science majors. It will create research opportunities for 1-2 undergraduates each year and will support a PhD student. The outcomes of this research could have strong societal relevance.", "east": 162.167, "geometry": "POINT(162.167 -77.733)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.733, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Castro, M. Clara; Doran, Peter; Kenig, Fabien", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.733, "title": "Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases", "uid": "p0000388", "west": 162.167}, {"awards": "1340905 Doran, Peter", "bounds_geometry": "POLYGON((161 -77,161.3 -77,161.6 -77,161.9 -77,162.2 -77,162.5 -77,162.8 -77,163.1 -77,163.4 -77,163.7 -77,164 -77,164 -77.05,164 -77.1,164 -77.15,164 -77.2,164 -77.25,164 -77.3,164 -77.35,164 -77.4,164 -77.45,164 -77.5,163.7 -77.5,163.4 -77.5,163.1 -77.5,162.8 -77.5,162.5 -77.5,162.2 -77.5,161.9 -77.5,161.6 -77.5,161.3 -77.5,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3,161 -77.25,161 -77.2,161 -77.15,161 -77.1,161 -77.05,161 -77))", "dataset_titles": "Lake Bonney Autonomous Lake Profiler and Samplers (ALPS): Particulate Organic Carbon and Nitrogen Concentrations. doi:10.6073/pasta/0043c1728b4e51879970d59f2d0ce575", "datasets": [{"dataset_uid": "002521", "doi": "", "keywords": null, "people": null, "repository": "LTER", "science_program": null, "title": "Lake Bonney Autonomous Lake Profiler and Samplers (ALPS): Particulate Organic Carbon and Nitrogen Concentrations. doi:10.6073/pasta/0043c1728b4e51879970d59f2d0ce575", "url": "http://www.mcmlter.org/node/3957"}], "date_created": "Fri, 13 Jan 2017 00:00:00 GMT", "description": "EAGER: Collaborative Research: Habitability of Antarctic lakes and detectability of microbial life in icy environments by autonomous year-round instrumentation, is supported by the Antarctic Integrated System Science (AISS) and the Antarctic Organisms and Ecosystems (AOE) programs within the Antarctic Sciences section in the Division of Polar Programs within the Geosciences Directorate of the National Sciences Foundation (NSF). The funds will allow the measurement of year-round properties of the microbes and the surrounding water in Lake Bonney, a lake with four meters of permanent ice cover over forty meters of liquid water in the Dry Valleys of Antarctica. NSF funds will be used to support the deployment, and the science enabled by the deployment, and NASA (the National Aeronautics and Space Administration) funds will be used to purchase the equipment.\u003cbr/\u003e\u003cbr/\u003eIntellectual Merit: This research will be the first to make year-round measurements of the microbial community, and several associated environmental variables, in the continuously liquid portions of Lake Bonney, Antarctica. Three different types of equipment will be deployed in each of the lobes of Lake Bonney. The first instrument is an ITP (an ice-tethered profiler) that will measure physical parameters such as temperature, dissolved oxygen, and chlorophyll throughout the full depth of the liquid water portion of the lake, making measurements at least once each week. The second and third instruments will be used to collect discrete water samples at least every two weeks to determine A) the biological community (assessing metabolic and phylogenetic diversity) and B) the geochemistry (e.g., dissolved organic carbon, and dissolved inorganic nitrogen species). Such samplers have never been used to measure these properties year-round in the Antarctic. Cold temperatures, bottom lake water salinities that are four times greater than the ocean, the thick permanent ice cover, and the lack of sunlight to recharge batteries all present significant challenges for the project, thus classifying the work as an early, high-risk, high-reward activity (the acronym EAGER stands for Early-concept Grants for Exploratory Research).\u003cbr/\u003e\u003cbr/\u003eBroader Impacts: There is much interest in understanding the ecosystems of the Polar regions in an era of climate change. Logistical limitations dictate much of this work only take place in the summer, until new autonomous technologies can open the door for year-round measurements. This award will be the first to attempt year-round microbial sampling in Antarctica. The McMurdo Dry Valleys region is also the site of a Long-Term Ecological Research (LTER) Program, and the research conducted on this project with benefit from, and contribute to, the larger LTER project. The instruments used in the project will be purchased by NASA, so two separate agencies have agreed to explore the feasibility of an early stage project. There will be at least three graduate student trained during the project, and the team will also participate in outreach activities at several venues including the Crow Reservation in Montana.", "east": 164.0, "geometry": "POINT(162.5 -77.25)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Doran, Peter; Takacs-Vesbach, Cristina; Priscu, John", "platforms": "Not provided", "repo": "LTER", "repositories": "LTER", "science_programs": "LTER", "south": -77.5, "title": "EAGER: Collaborative Research: Habitability of Antarctic Lakes and Detectability of Microbial Life in Icy Environments by Aautonomous Year-round Instrumentation", "uid": "p0000326", "west": 161.0}, {"awards": "0539578 Alley, Richard; 0539232 Cuffey, Kurt", "bounds_geometry": "POINT(112.083 -79.467)", "dataset_titles": "Grain Size Full Population Dataset from WDC06A Core; Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole; Temperature Reconstruction at the West Antarctic Ice Sheet Divide; Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data; WAIS Divide Ice Core Vertical Thin Section Low-resolution Digital Imagery; WAIS Divide Surface and Snow-pit Data, 2009-2013; WDC 06A Mean Grain Size Data", "datasets": [{"dataset_uid": "609550", "doi": "10.7265/N5V69GJW", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Cuffey, Kurt M.; Clow, Gary D.", "repository": "USAP-DC", "science_program": null, "title": "Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole", "url": "https://www.usap-dc.org/view/dataset/609550"}, {"dataset_uid": "609654", "doi": "10.7265/N5GM858X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Photo/video; Photo/Video; Thin Sections; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Vertical Thin Section Low-resolution Digital Imagery", "url": "https://www.usap-dc.org/view/dataset/609654"}, {"dataset_uid": "601224", "doi": "10.15784/601224", "keywords": "Antarctic; Antarctica; Bubble Number Density; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; NSF-ICF Microtome and Photography Stage; Paleoclimate; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Fitzpatrick, Joan; Fegyveresi, John; Spencer, Matthew; Alley, Richard; Voigt, Donald E.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data", "url": "https://www.usap-dc.org/view/dataset/601224"}, {"dataset_uid": "601079", "doi": "10.15784/601079", "keywords": "Antarctica; Atmosphere; AWS; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Meteorology; Physical Properties; Snow Pit; Temperature; WAIS Divide; WAIS Divide Ice Core; Weatherstation", "people": "Alley, Richard; Fegyveresi, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Surface and Snow-pit Data, 2009-2013", "url": "https://www.usap-dc.org/view/dataset/601079"}, {"dataset_uid": "609655", "doi": "10.7265/N5VX0DG0", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": null, "title": "Grain Size Full Population Dataset from WDC06A Core", "url": "https://www.usap-dc.org/view/dataset/609655"}, {"dataset_uid": "600377", "doi": "10.15784/600377", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrogen; Paleoclimate; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Cuffey, Kurt M.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Temperature Reconstruction at the West Antarctic Ice Sheet Divide", "url": "https://www.usap-dc.org/view/dataset/600377"}, {"dataset_uid": "609656", "doi": "10.7265/N5MC8X08", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": null, "title": "WDC 06A Mean Grain Size Data", "url": "https://www.usap-dc.org/view/dataset/609656"}], "date_created": "Thu, 12 Jan 2017 00:00:00 GMT", "description": "0539578\u003cbr/\u003eAlley \u003cbr/\u003eThis award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.", "east": 112.083, "geometry": "POINT(112.083 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "LABORATORY; WAIS Divide; Ice Core; Temperature Profiles; FIELD SURVEYS; Bubble Number Density; GROUND-BASED OBSERVATIONS; Wais Divide-project", "locations": "WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Fitzpatrick, Joan; Alley, Richard; Fegyveresi, John; Clow, Gary D.; Cuffey, Kurt M.; Cravens, Eric D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Physical Properties of the WAIS Divide Deep Core", "uid": "p0000038", "west": 112.083}, {"awards": "1043167 White, James; 1043092 Steig, Eric", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Resampling of Deep Polar Ice Cores using Information Theory; 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; WAIS Divide Ice Core Discrete CH4 (80-3403m)", "datasets": [{"dataset_uid": "600169", "doi": "10.15784/600169", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "Jones, Tyler R.; Morris, Valerie; Vaughn, Bruce; White, James", "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/600169"}, {"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Sowers, Todd A.; Brook, Edward", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601365", "doi": "10.15784/601365", "keywords": "Antarctica; Delta 18O; Isotope; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "White, James; Jones, Tyler R.; Garland, Joshua; Vaughn, Bruce; Morris, Valerie", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Resampling of Deep Polar Ice Cores using Information Theory", "url": "https://www.usap-dc.org/view/dataset/601365"}, {"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"}, {"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": "Price, Michael; Garland, Joshua; Bradley, Elizabeth; Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "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"}], "date_created": "Thu, 15 Sep 2016 00:00:00 GMT", "description": "Steig/1043092\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": -79.47, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "White, James; Vaughn, Bruce; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000078", "west": -112.08}, {"awards": "1141877 Aronson, Richard", "bounds_geometry": "POLYGON((-111.18 -49.98,-105.429 -49.98,-99.678 -49.98,-93.927 -49.98,-88.176 -49.98,-82.425 -49.98,-76.674 -49.98,-70.923 -49.98,-65.172 -49.98,-59.421 -49.98,-53.67 -49.98,-53.67 -52.826,-53.67 -55.672,-53.67 -58.518,-53.67 -61.364,-53.67 -64.21,-53.67 -67.056,-53.67 -69.902,-53.67 -72.748,-53.67 -75.594,-53.67 -78.44,-59.421 -78.44,-65.172 -78.44,-70.923 -78.44,-76.674 -78.44,-82.425 -78.44,-88.176 -78.44,-93.927 -78.44,-99.678 -78.44,-105.429 -78.44,-111.18 -78.44,-111.18 -75.594,-111.18 -72.748,-111.18 -69.902,-111.18 -67.056,-111.18 -64.21,-111.18 -61.364,-111.18 -58.518,-111.18 -55.672,-111.18 -52.826,-111.18 -49.98))", "dataset_titles": "Climate Change and Predatory Invasion of the Antarctic Benthos; Expedition Data; Material properties of the exoskeleton of Paralomis birsteini", "datasets": [{"dataset_uid": "001417", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1310"}, {"dataset_uid": "601109", "doi": "10.15784/601109", "keywords": "Antarctica; Biota; Callinectes; Exoskeleton; Fish; Glaciers/ice Sheet; Glaciers/Ice Sheet; Paralomis", "people": "Steffel, Brittan", "repository": "USAP-DC", "science_program": null, "title": "Material properties of the exoskeleton of Paralomis birsteini", "url": "https://www.usap-dc.org/view/dataset/601109"}, {"dataset_uid": "600385", "doi": "10.15784/600385", "keywords": "Antarctica; Antarctic Peninsula; Anvers Island; Benthos; Biota; Camera Tow; LMG1502; Marguerite Bay; NBP1002; NBP1310; Oceans; Photo/video; Photo/Video; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Aronson, Richard", "repository": "USAP-DC", "science_program": null, "title": "Climate Change and Predatory Invasion of the Antarctic Benthos", "url": "https://www.usap-dc.org/view/dataset/600385"}, {"dataset_uid": "600171", "doi": "10.15784/600171", "keywords": "Antarctica; Antarctic Peninsula; Anvers Island; Benthos; Biota; Camera Tow; LMG1502; Marguerite Bay; NBP1002; NBP1310; Oceans; Photo/video; Photo/Video; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Aronson, Richard", "repository": "USAP-DC", "science_program": null, "title": "Climate Change and Predatory Invasion of the Antarctic Benthos", "url": "https://www.usap-dc.org/view/dataset/600171"}], "date_created": "Wed, 14 Sep 2016 00:00:00 GMT", "description": "Elevated temperatures and ocean acidification are both threatening the Southern Ocean. The effects of these environmental changes are poorly understood, but preliminary data suggest that they are driving a biological invasion. Specifically, large populations of skeleton-crushing king crabs, Paralomis birsteini, have been detected off Marguerite Bay on the West Antarctic Peninsula. These crabs appear to be invading the continental shelf region where benthic communities have evolved in the absence of such top-predators. Thus, this invasion could result in a wholesale restructuring of the Antarctic benthic ecosystem. The proposed work seeks to document this invasion and better understand the effects of the introduction of P. birsteini on the ecology of this region. A towed underwater vehicle will be used to photographically image communities, and communities with and without P. birsteini will be compared quantitatively. Additionally, crabs will trapped and various aspects of their morphology and physiology will be assessed. This research is unique in that it will document a biological invasion in real-time and it will therefore enhance our general understandings of the drivers of invasion and resilience in biological communities. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of undergraduate and graduate students and will foster an international collaboration with British scientists. Researchers on this project will participate in outreach thorough the development of K-12 curricular materials.", "east": -53.67, "geometry": "POINT(-82.425 -64.21)", "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 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": "R/V NBP; Not provided", "locations": null, "north": -49.98, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Aronson, Richard", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -78.44, "title": "Collaborative Research: Climate Change and Predatory Invasion of the Antarctic Benthos", "uid": "p0000303", "west": -111.18}, {"awards": "1142173 Bay, Ryan; 1142010 Talghader, Joseph", "bounds_geometry": "POINT(112.085 -79.467)", "dataset_titles": "Optical Fabric and Fiber Logging of Glacial Ice (1142010)", "datasets": [{"dataset_uid": "600172", "doi": "10.15784/600172", "keywords": "Antarctica; Ash Layer; Borehole Camera; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Talghader, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Optical Fabric and Fiber Logging of Glacial Ice (1142010)", "url": "https://www.usap-dc.org/view/dataset/600172"}], "date_created": "Thu, 05 Nov 2015 00:00:00 GMT", "description": "1142010/Talghader\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum.", "east": 112.085, "geometry": "POINT(112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": true, "keywords": "Fabric; Optical Scattering; Not provided; FIELD SURVEYS; Ice Core; Siple Dome; Antarctic; Dust; WAIS Divide; LABORATORY; Crystal Structure; Chronology; FIELD INVESTIGATION; Borehole", "locations": "Antarctic; WAIS Divide; Siple Dome", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Talghader, Joseph; Bay, Ryan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.467, "title": "Optical Fabric and Fiber Logging of Glacial Ice", "uid": "p0000339", "west": 112.085}, {"awards": "1041022 McClintock, James", "bounds_geometry": "POLYGON((-79 -60,-76.4 -60,-73.8 -60,-71.2 -60,-68.6 -60,-66 -60,-63.4 -60,-60.8 -60,-58.2 -60,-55.6 -60,-53 -60,-53 -61,-53 -62,-53 -63,-53 -64,-53 -65,-53 -66,-53 -67,-53 -68,-53 -69,-53 -70,-55.6 -70,-58.2 -70,-60.8 -70,-63.4 -70,-66 -70,-68.6 -70,-71.2 -70,-73.8 -70,-76.4 -70,-79 -70,-79 -69,-79 -68,-79 -67,-79 -66,-79 -65,-79 -64,-79 -63,-79 -62,-79 -61,-79 -60))", "dataset_titles": "Data from Schram et al. 2017 MEPS; Response time data for snails escaping from predatory sea stars; The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica", "datasets": [{"dataset_uid": "601062", "doi": "10.15784/601062", "keywords": "Antarctica; Antarctic Peninsula; Biota; Chemistry:fluid; Chemistry:Fluid; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Schram, Julie; Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Data from Schram et al. 2017 MEPS", "url": "https://www.usap-dc.org/view/dataset/601062"}, {"dataset_uid": "601162", "doi": "10.15784/601162", "keywords": "Antarctica; Benthos; Biota; Oceans; Snail; Southern Ocean; Visual Observations", "people": "Schram, Julie; Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Response time data for snails escaping from predatory sea stars", "url": "https://www.usap-dc.org/view/dataset/601162"}, {"dataset_uid": "600122", "doi": "10.15784/600122", "keywords": "Antarctic Peninsula; Biota; Oceans; Southern Ocean", "people": "Angus, Robert; Amsler, Charles; McClintock, James", "repository": "USAP-DC", "science_program": null, "title": "The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica", "url": "https://www.usap-dc.org/view/dataset/600122"}], "date_created": "Fri, 22 May 2015 00:00:00 GMT", "description": "The research will investigate the individual and combined effects of rising ocean acidification and sea surface temperatures on shallow-water calcified benthic organisms in western Antarctic Peninsular (WAP) marine communities. The Southern Ocean is predicted to become undersaturated in terms of both aragonite and calcite within 50 and 100 years, respectively, challenging calcification processes. Adding to the problem, antarctic calcified benthic marine organisms are more vulnerable to ocean acidification than temperate and tropical species because they are generally weakly calcified. Many antarctic organisms are essentially stenothermal, and those in the West Antarctic Peninsula are being subjected to rising seawater temperatures. The project employs both single-species and multi-species level approaches to evaluating the impacts of rising ocean acidification and seawater temperature on representative calcified and non-calcified macroalgae, on calcified and non-calcified mesograzers, and on a calcified macro-grazer, all of which are important ecological players in the rich benthic communities. Multi-species analysis will focus on the diverse assemblage of amphipods and mesogastropods that are associated with dominant macroalgae that collectively play a key role in community dynamics along the WAP. The project will support undergraduate research, both through NSF programs, as well as home university-based programs, some designed to enhance the representation of minorities in the sciences. The principal investigators also will support and foster graduate education through mentoring of graduate students. Through their highly successful UAB IN ANTARCTICA interactive web program, they will continue to involve large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica.", "east": -53.0, "geometry": "POINT(-66 -65)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Angus, Robert; Amsler, Charles; McClintock, James", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica", "uid": "p0000426", "west": -79.0}, {"awards": "1043217 Zagorodnov, Victor", "bounds_geometry": null, "dataset_titles": "Fiber-Optic Distributed Temperature Sensing at Windless Bight", "datasets": [{"dataset_uid": "609604", "doi": "10.7265/N5V122QS", "keywords": "Antarctica; Ice Shelf; Mcmurdo Sound; Mooring; Oceans; Physical Oceanography; Ross Ice Shelf; Southern Ocean", "people": "Zagorodnov, Victor; Tyler, Scott W.; Holland, David", "repository": "USAP-DC", "science_program": null, "title": "Fiber-Optic Distributed Temperature Sensing at Windless Bight", "url": "https://www.usap-dc.org/view/dataset/609604"}], "date_created": "Tue, 05 May 2015 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eResearchers will explore the use of a distributed temperature sensing monitoring system (DTS), using fiber-optical (FO) technology, as the basis of a sustainable, sub-ice cavity sensing array. FO cable systems, such as may be deployed through a hot-water drilled hole through an ice shelf, passing through the underlying cavity to the sea floor, are capable of measuring temperatures down fiber at 1 meter intervals, and at time frequencies as high as 15 seconds. DTS FO systems operate via optical time domain reflectometry along the fiber waveguide using inelastic backscatter of coherent laser light as a probe beam in the FO environment.\u003cbr/\u003e\u003cbr/\u003eThe introduction of new technologies to the harsh environmental conditions of the Antarctic are often associated with high risk. However, the potential rewards of this approach (e.g. multiyear capability, minimal submerged mechanical or electrical components that may fail, relative simplicity of deployment and measurement principle, yet yielding distributed real time and spatial observation) are attractive enough to conduct a pilot project at a field-ready location (McMurdo). \u003cbr/\u003e\u003cbr/\u003eCurrent indications are that the instability of some of the world\u0027s largest ice sheets located around the Antarctic and Greenland may be caused by the presence of warming, deep ocean waters, shoaling over continental shelves, and melting the underside of floating ice shelves. Additional knowledge of the temporal and spatial variability of the temperature fields underneath terminal ice shelves, such as those draining the West Antarctic Ice Sheet, are needed to accurately project future global climate effects on ice-shelf ocean interactions, and in order to inform societal and technological aspects of adaption to changing sea-level.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e TEMPERATURE LOGGERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "GROUND STATIONS; Not provided; Conservative Temperature; MOORINGS; Ice Shelf Temperature; Ocean Temperature", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Zagorodnov, Victor; Holland, David; Tyler, Scott W.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e MOORINGS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Application of Distributed Temperature Sensors (DTS) for Antarctic Ice Shelves and Cavities", "uid": "p0000183", "west": null}, {"awards": "0944557 Marsh, Adam", "bounds_geometry": "POINT(166 78)", "dataset_titles": "Environmental Genomics of an Antarctic Polychaete #SRP040946", "datasets": [{"dataset_uid": "000223", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Environmental Genomics of an Antarctic Polychaete #SRP040946", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRP040946"}], "date_created": "Tue, 13 Jan 2015 00:00:00 GMT", "description": "Genome-enabled biology provides a foundation for understanding the genetic basis of organism-environment interactions. . The research project links gene expression, genome methylation, and metabolic rates to assess the mechanisms of environmental adaptation (temperature) across multiple generations in a polar, and closely related temperate, polychaete. By comparing these two species, the research will assess how a polar environment shapes responses to environmental stress. This work will produce: 1) a database of full transcriptome (gene specific) profiling data for the polar polychaete cultured at two temperatures; 2) the contribution of genome methylation to the suppression of gene transcription activities; 3) the linkage between shifts in mRNA pools and total cellular activities (as ATP consumption via respiration); 4) an assessment of the inheritance of patterns of gene expression and metabolic activities across three generations; and 5) a simple demographic model of the polar polychaete population dynamics under normal and \u0027global-warming\u0027 temperature scenarios. Broader impacts include two outreach activities. The first is a mentoring program, where African-American undergraduate students spend 1.5 years working on a research project with a UD faculty member (2 summers plus their senior academic year). The second is a children\u0027s display activity at UD?s School of Marine Science \"Coast Day\".", "east": 166.0, "geometry": "POINT(166 -78)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -78.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marsh, Adam G.", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -78.0, "title": "Environmental Genomics in an Antarctic polychaete", "uid": "p0000355", "west": 166.0}, {"awards": "0732906 Nowicki, Sophie; 0732804 McPhee, Miles; 0732869 Holland, David; 0732730 Truffer, Martin", "bounds_geometry": "POINT(-100.728 -75.0427)", "dataset_titles": "Automatic Weather Station Pine Island Glacier; Borehole Temperatures at Pine Island Glacier, Antarctica; Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "datasets": [{"dataset_uid": "609627", "doi": "10.7265/N5T151MV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Pine Island Glacier; Temperature", "people": "Truffer, Martin; Stanton, Timothy", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperatures at Pine Island Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609627"}, {"dataset_uid": "601216", "doi": "10.15784/601216", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Flux; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Pine Island Glacier; Weather Station Data", "people": "Mojica Moncada, Jhon F.; Holland, David", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Automatic Weather Station Pine Island Glacier", "url": "https://www.usap-dc.org/view/dataset/601216"}, {"dataset_uid": "600072", "doi": "10.15784/600072", "keywords": "Antarctica; Atmosphere; Mcmurdo; Meteorology; Oceans; Ross Island; Southern Ocean", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "url": "https://www.usap-dc.org/view/dataset/600072"}], "date_created": "Tue, 30 Dec 2014 00:00:00 GMT", "description": "Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 \u003cbr/\u003eTitle: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica\u003cbr/\u003e\u003cbr/\u003eThe Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the \"Multidisciplinary Study of the Amundsen Sea Embayment\" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded \"Polar Palooza\" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.", "east": -100.728, "geometry": "POINT(-100.728 -75.0427)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": true, "keywords": "West Antarctica; Seismic; LABORATORY; Amundsen Sea; Ocean-Ice Interaction; Remote Sensing; COMPUTERS; FIELD SURVEYS; LANDSAT-8; FIELD INVESTIGATION; Ocean Profiling; AUVS; Sea Level Rise; Stability; Not provided; Deformation; SATELLITES; Ice Movement; GROUND-BASED OBSERVATIONS; Ice Temperature; International Polar Year; Borehole", "locations": "West Antarctica; Amundsen Sea", "north": -75.0427, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-8; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES \u003e SUBSURFACE \u003e AUVS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0427, "title": "Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica", "uid": "p0000043", "west": -100.728}, {"awards": "1354231 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "datasets": [{"dataset_uid": "600140", "doi": "10.15784/600140", "keywords": "Antarctica; Atmosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Model Data; Paleoclimate; Transantarctic Mountains", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/600140"}], "date_created": "Thu, 28 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eNeogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eResults from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "uid": "p0000463", "west": 160.0}, {"awards": "1043265 Deming, Jody", "bounds_geometry": "POLYGON((162.1397 -77.14085,162.828507 -77.14085,163.517314 -77.14085,164.206121 -77.14085,164.894928 -77.14085,165.583735 -77.14085,166.272542 -77.14085,166.961349 -77.14085,167.650156 -77.14085,168.338963 -77.14085,169.02777 -77.14085,169.02777 -77.200745,169.02777 -77.26064,169.02777 -77.320535,169.02777 -77.38043,169.02777 -77.440325,169.02777 -77.50022,169.02777 -77.560115,169.02777 -77.62001,169.02777 -77.679905,169.02777 -77.7398,168.338963 -77.7398,167.650156 -77.7398,166.961349 -77.7398,166.272542 -77.7398,165.583735 -77.7398,164.894928 -77.7398,164.206121 -77.7398,163.517314 -77.7398,162.828507 -77.7398,162.1397 -77.7398,162.1397 -77.679905,162.1397 -77.62001,162.1397 -77.560115,162.1397 -77.50022,162.1397 -77.440325,162.1397 -77.38043,162.1397 -77.320535,162.1397 -77.26064,162.1397 -77.200745,162.1397 -77.14085))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 31 Jul 2014 00:00:00 GMT", "description": "The relatively pristine Antarctic continent with its extensive maritime zone represents a unique location on the planet to investigate the long distance aerial transport and deposition of marine microorganisms. The vast extent of new sea ice that forms each winter around the continent results in large numbers of frost flowers, delicate ice-crystal structures of high salt content that form on the surface of the ice and are readily dispersed by wind. The proposed research builds on earlier work in the Arctic and tests the new hypothesis that wind-borne frost flowers provide an effective mechanism for the transport of marine bacteria over long distances, one that can be uniquely sourced and tracked by the frost flower salt signature in the Antarctic realm. A highly resolved genomic snapshot of the microbial community will be acquired at each stage in the transport path, which will track decreasing fractions of the marine microbial community as it freezes into sea ice, incorporates into frost flowers, converts to aerosols, and ultimately deposits within continental snowpack. En route from sea ice to snowpack, marine bacteria will be exposed to an array of environmental stresses, including high salinity, low temperatures, UV light and potential desiccation. A parallel proteomic analysis will enable an evaluation of the microbial response to these extreme conditions and potential survival mechanisms that allow persistence or eventual colonization of deposition sites across Antarctica. \u003cbr/\u003e\u003cbr/\u003eCurrent understanding of microbes in the Antarctic atmosphere is based on a limited number of microscopic and culture-based assays and a single report of low-resolution 16S RNA gene sequence analysis. The research will broadly impact understanding of atmospheric microbiology, from source to deposition, and various issues of microbial survival, colonization, endemism, and diversity under extreme conditions. In addition to venues that reach the scientific community, the research team will develop a permanent multi-media and artifact-based exhibit on Antarctic Microbial Transport that will be showcased at Seattle\u0027s Pacific Science Center (PSC), which educates nearly a million visitors annually.", "east": 169.02777, "geometry": "POINT(165.583735 -77.440325)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.14085, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Deming, Jody", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -77.7398, "title": "High Resolution Genomic and Proteomic Analyses of a Microbial Transport Mechanism from Antarctic Marine Waters to Permanent Snowpack", "uid": "p0000356", "west": 162.1397}, {"awards": "1019305 Grim, Jeffrey", "bounds_geometry": null, "dataset_titles": "Impact of Rising Oceanic Temperatures on the Embryonic Development of Antarctic Notothenioid Fishes", "datasets": [{"dataset_uid": "600119", "doi": "10.15784/600119", "keywords": "Biota; Fish Logs; LMG1203; LMG1204; LMG1205; Oceans; Pot; Southern Ocean; Trawl", "people": "Grim, Jeffrey", "repository": "USAP-DC", "science_program": null, "title": "Impact of Rising Oceanic Temperatures on the Embryonic Development of Antarctic Notothenioid Fishes", "url": "https://www.usap-dc.org/view/dataset/600119"}], "date_created": "Mon, 10 Feb 2014 00:00:00 GMT", "description": "Survival of Antarctic notothenioid fishes in the context of global climate change will depend upon the impact of rising oceanic temperatures on their embryonic development, yet little is known regarding the molecular mechanisms underlying this complex suite of processes. Many notothenioids are characterized by secondary pelagicism, which enables them to exploit food sources in the water column and is supported in part by skeletal pedomorphism. Here the PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The research objectives are : 1) To quantify and localize ROS production and identify the point(s) of origin of ROS production in embryonic Antarctic fishes that differ in skeletal phenotypes 2) To determine whether the time course of embryogenesis and the extent of osteological development in embryonic Antarctic fishes can be altered by changing the oxidative status of the animal during embryogenesis 3) To evaluate whether transgenic alteration of oxidative status can induce skeletal pedomorphism in a fish model. Broader Impacts will include teaching undergraduate lectures, recruiting undergraduate students to help with lab analyses (and possibly field work), lectures and demonstrations to high school students, and allowing secondary educators access to personal photos and videos of research animals for curriculum development.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Grim, Jeffrey", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "PostDoctoral Research Fellowship", "uid": "p0000482", "west": null}, {"awards": "1043740 Lenczewski, Melissa", "bounds_geometry": "POLYGON((165 -77.5,165.3 -77.5,165.6 -77.5,165.9 -77.5,166.2 -77.5,166.5 -77.5,166.8 -77.5,167.1 -77.5,167.4 -77.5,167.7 -77.5,168 -77.5,168 -77.6,168 -77.7,168 -77.8,168 -77.9,168 -78,168 -78.1,168 -78.2,168 -78.3,168 -78.4,168 -78.5,167.7 -78.5,167.4 -78.5,167.1 -78.5,166.8 -78.5,166.5 -78.5,166.2 -78.5,165.9 -78.5,165.6 -78.5,165.3 -78.5,165 -78.5,165 -78.4,165 -78.3,165 -78.2,165 -78.1,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5))", "dataset_titles": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "datasets": [{"dataset_uid": "600129", "doi": "10.15784/600129", "keywords": "Andrill; Antarctica; Chemistry:fluid; Chemistry:Fluid; Chemistry:rock; Chemistry:Rock; Drilling Fluid; Geochemistry; Mcmurdo; Ross Sea; Sediment Core", "people": "Lenczewski, Melissa", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "url": "https://www.usap-dc.org/view/dataset/600129"}], "date_created": "Mon, 27 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe PI proposes to utilize computer models used by hydrogeologists to establish the fate and transport of contamination and determine the extent of drilling fluid contamination in the ANDRILL SMS core. For these models, previously collected logs of lithology, porosity, fracture density, fracture type, fracture orientation, drilling fluid loss, drilling fluid characteristics and temperature will be used as input parameters. In addition, biodegradation and sorption constants for the drilling fluid will be determined and incorporated into the models. Samples of drilling fluids used during coring as well as the return fluids were collected at the drill site using standard microbiological sampling techniques. Fluids will be tested at in situ temperatures under aerobic and anaerobic conditions to determine biodegradation constants. Sorption will be determined between the drilling fluids and core samples using standard isotherm methods. Geochemical and microbial fingerprints of the fluids and the changes during biodegradation will determine the potential impact of the drilling fluids on the isolated microbial communities and the geochemistry within various subsurface lithologic units beneath the southern McMurdo Sound in Antarctica. The results of this study could potentially provide guidelines on developing less detrimental methods for future exploration, if deemed necessary through this research.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis proposed project will train a graduate student. The methods developed for analyses of samples in this project will serve as a guide for future studies of similar interest and will improve the understanding of ecological impacts of geologic drilling in Antarctica. The results of this study will be used as a reference for comparison with future studies examining newly developed, and improved, sample collection methods in future exploratory drilling projects in pristine environments. The PI is new to Antarctic research.", "east": 168.0, "geometry": "POINT(166.5 -78)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lenczewski, Melissa", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -78.5, "title": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "uid": "p0000468", "west": 165.0}, {"awards": "0944517 Detrich, H. William", "bounds_geometry": "POLYGON((-67.42 -61.2,-66.28 -61.2,-65.14 -61.2,-64 -61.2,-62.86 -61.2,-61.72 -61.2,-60.58 -61.2,-59.44 -61.2,-58.3 -61.2,-57.16 -61.2,-56.02 -61.2,-56.02 -61.71,-56.02 -62.22,-56.02 -62.73,-56.02 -63.24,-56.02 -63.75,-56.02 -64.26,-56.02 -64.77,-56.02 -65.28,-56.02 -65.79,-56.02 -66.3,-57.16 -66.3,-58.3 -66.3,-59.44 -66.3,-60.58 -66.3,-61.72 -66.3,-62.86 -66.3,-64 -66.3,-65.14 -66.3,-66.28 -66.3,-67.42 -66.3,-67.42 -65.79,-67.42 -65.28,-67.42 -64.77,-67.42 -64.26,-67.42 -63.75,-67.42 -63.24,-67.42 -62.73,-67.42 -62.22,-67.42 -61.71,-67.42 -61.2))", "dataset_titles": "Cruise LMG1203; Cruise LMG1205; Cruise LMG1206; GenBank KC594078, FJ914563.1, FJ914564.1, FJ914565.1, FJ896018.1, FJ896019.1, FJ896022.1, FJ896023.1, FJ896024.1, FJ896025.1, FJ896026.1", "datasets": [{"dataset_uid": "000159", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "GenBank KC594078, FJ914563.1, FJ914564.1, FJ914565.1, FJ896018.1, FJ896019.1, FJ896022.1, FJ896023.1, FJ896024.1, FJ896025.1, FJ896026.1", "url": "http://www.ncbi.nlm.nih.gov/genbank/"}, {"dataset_uid": "000160", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Cruise LMG1203", "url": "https://www.rvdata.us/search/cruise/LMG1203"}, {"dataset_uid": "000161", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Cruise LMG1205", "url": "https://www.rvdata.us/search/cruise/LMG1205"}, {"dataset_uid": "000162", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Cruise LMG1206", "url": "https://www.rvdata.us/search/cruise/LMG1206"}], "date_created": "Fri, 20 Dec 2013 00:00:00 GMT", "description": "Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~40-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. The biochemical and physiological challenges facing ectotherms living in the Southern Ocean include the reduction of reaction rates and metabolic fluxes and a pervasive weakening of macromolecular interactions. Yet, Southern Ocean ectotherms are now threatened by warming over periods measured in centuries or less. The proposed research seeks to understand the molecular mechanisms of cold adaptation in Antarctic marine fishes and to assess the physiological capacity of these organisms to resist or compensate for rapid oceanic warming. The P.I. will characterize two important and interacting protein systems, the tubulins that form microtubules and the chaperonin CCT (cytoplasmic chaperonin-containing TCP-1, a family of proteins that assists the folding of the tubulins). Higher-level, integrative responses to global temperature change will be analyzed by studying the thermal dependence of cleavage in Antarctic fish embryos (a microtubule-dependent process). The objectives are (1) to determine the contributions of five novel amino acid substitutions found in Antarctic fish beta-tubulins to microtubule assembly at cold temperature. (2) to compare the functional properties of CCT from testis tissues of Antarctic fishes and mammals. (3) to evaluate the effects of increased temperature on embryogenesis in Antarctic fishes. The research will introduce graduate and REU undergraduate students to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem. The proposed work also will benefit society by developing a cold-functioning chaperonin protein folding system, of great value to the biopharmaceutical and biotechnological industries for use in folding insoluble proteins.", "east": -56.02, "geometry": "POINT(-61.72 -63.75)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -61.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "NCBI GenBank; R2R", "science_programs": null, "south": -66.3, "title": "Microtubule Function, Protein Folding, and Embryogenesis in Antarctic Fishes: An Integrative Approach", "uid": "p0000664", "west": -67.42}, {"awards": "0944743 Buckley, Bradley", "bounds_geometry": "POINT(166.66667 -77.83333)", "dataset_titles": "The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.", "datasets": [{"dataset_uid": "600118", "doi": "10.15784/600118", "keywords": "Biota; Southern Ocean", "people": "Buckley, Bradley", "repository": "USAP-DC", "science_program": null, "title": "The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.", "url": "https://www.usap-dc.org/view/dataset/600118"}], "date_created": "Thu, 19 Dec 2013 00:00:00 GMT", "description": "The research will investigate a novel mechanism by which cold-adapted fishes of the Southern Ocean sense and respond to elevated temperatures. It is hypothesized that sub-lethal heat stress may induce cell cycle arrest and/or programmed cell death through apoptosis. The study will use genome-enabled technologies to examine the environmental control over gene expression in Antarctic species and will build direct mechanistic links between the expression of a specific signaling pathway gene and heat-induced changes in cells. Prior results support the hypothesis that heat stress results in cell cycle arrest and, in some cases, programmed cell death in Antarctic fishes. If so, this represents a novel, modified version of the well-conserved cellular stress response found in essentially all other species and suggests that warming ocean temperatures may have profound cellular and physiological impacts on these extremely stenothermal species. The P.I. conducts outreach activities with the Oregon Museum of Science and Industry, will be involved in developing a science curriculum for the Native American Youth and Family Center (NAYA) Early College Academy in Portland, and supports the educational and professional development of both undergraduate and graduate students at Portland State University.", "east": 166.66667, "geometry": "POINT(166.66667 -77.83333)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.83333, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Buckley, Bradley", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.83333, "title": "The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.", "uid": "p0000493", "west": 166.66667}, {"awards": "0739681 Murray, Alison; 0739698 Doran, Peter", "bounds_geometry": "POINT(161.931 -77.3885)", "dataset_titles": "Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "datasets": [{"dataset_uid": "600080", "doi": "10.15784/600080", "keywords": "Antarctica; Biota; Carbon-14; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Dry Valleys; Geochronology; Ice Core Records; Lake Vida; Microbiology", "people": "Murray, Alison", "repository": "USAP-DC", "science_program": null, "title": "Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/600080"}], "date_created": "Thu, 12 Dec 2013 00:00:00 GMT", "description": "Lake Vida is the largest lake of the McMurdo Dry Valleys, with an approximately 20 m ice cover overlaying a brine of unknown depth with at least 7 times seawater salinity and temperatures below -10 degrees C year-round. Samples of brine collected from ice above the main water body contain 1) the highest nitrous oxide levels of any natural water body on Earth, 2) unusual geochemistry including anomalously high ammonia and iron concentrations, 3) high microbial counts with an unusual proportion (99%) of ultramicrobacteria. The microbial community is unique even compared to other Dry Valley Lakes. The research proposes to enter, for the first time the main brine body below the thick ice of Lake Vida and perform in situ measurements, collect samples of the brine column, and collect sediment cores from the lake bottom for detailed geochemical and microbiological analyses. The results will allow the characterization of present and past life in the lake, assessment of modern and past sedimentary processes, and determination of the lake\u0027s history. The research will be conducted by a multidisciplinary team that will uncover the biogeochemical processes associated with a non-photosynthetic microbial community isolated for a significant period of time. This research will address diversity, adaptive mechanisms and evolutionary processes in the context of the physical evolution of the environment of Lake Vida. Results will be widely disseminated through publications, presentations at national and international meetings, through the Subglacial Antarctic Lake Exploration (SALE) web site and the McMurdo LTER web site. The research will support three graduate students and three undergraduate research assistants. The results will be incorporated into a new undergraduate biogeosciences course at the University of Illinois at Chicago which has an extremely diverse student body, dominated by minorities.", "east": 161.931, "geometry": "POINT(161.931 -77.3885)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.3885, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Murray, Alison; Doran, Peter", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.3885, "title": "Collaborative Research: Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "uid": "p0000485", "west": 161.931}, {"awards": "0739783 Junge, 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": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "datasets": [{"dataset_uid": "600083", "doi": "10.15784/600083", "keywords": "Antarctica; Biota; Microbiology; Oceans; Sea Ice; Southern Ocean", "people": "Junge, Karen", "repository": "USAP-DC", "science_program": null, "title": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "url": "https://www.usap-dc.org/view/dataset/600083"}], "date_created": "Wed, 25 Sep 2013 00:00:00 GMT", "description": "The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation. This research program has two main objectives. The first is to investigate metabolic activities and gene expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (\u003c54C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern if psychrophilic processes of leucine incorporation into proteins, shown to occur to -196C, amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. We will examine extracellular and intracellular processes of psychrophilic activity above and below the eutectic by (i) determining the temperature range of metabolic activities such as DNA synthesis, carbon utilization, respiration and ATP generation using radioactive tracer technology, including a control at liquid helium temperature (-268.9C), (ii) analyzing gene expression in ice using whole genome and microarray analyses and iii) examining the role of exopolymeric substances (EPS) and ice micro-physics for the observed activity using an in-situ microscopy technique. Results of the proposed research can be expected to aid in the determination of cellular and genetic strategies that allow cells to maintain activity at extremely low temperatures within an icy matrix and/or to resume activity again when more growth-permissive conditions are encountered. The research is an interdisciplinary collaboration involving three different institutions with participants in Oceanography, Genomics, and Geophysical Sciences. The proposed activity will support the beginning professional career of a female researcher and will serve as the basis for several undergraduate student laboratory projects.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Junge, Karen", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "uid": "p0000673", "west": -180.0}, {"awards": "0823101 Ducklow, Hugh", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG1301", "datasets": [{"dataset_uid": "001425", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1301"}, {"dataset_uid": "002731", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1301", "url": "https://www.rvdata.us/search/cruise/LMG1301"}], "date_created": "Mon, 24 Jun 2013 00:00:00 GMT", "description": "Since 1990, Palmer LTER (PAL) research has been guided by the hypothesis that variability in the polar marine ecosystem is mechanistically coupled to changes in the annual advance, retreat and spatial extent of sea ice. Since that time, the hypothesis has been modified to incorporate climate migration, i.e. the displacement of a cold, dry polar climate by a warm, moist climate regime in the northern component of the PAL region, producing fundamental changes in food web structure and elemental cycling. The observed northern changes are affecting all trophic levels and elemental cycling, and the primary mechanism of change involves match-mismatch dynamics. The proposed research builds on previous findings, with a new emphasis on process studies and modeling to elucidate the mechanistic links between teleconnections, climate change, physical oceanographic forcing and ecosystem dynamics. The proposed research will examine the hypothesis that regional warming and sea ice decline associated with historical and on-going climate migration in the northern part of the study area have altered key phenological relationships, leading to changes in species distributions, increasing trophic mismatches and changes in habitat, food availability, ecosystem dynamics and biogeochemical cycling. Through targeted process studies linked to numerical model simulations, the research also will test the hypothesis that deep cross-shelf canyons characterizing the core study region are focal areas for ecosystem processes that result in predictable, elevated food resources for top-predators. The effort includes the addition of 3 new PIs: a zooplankton ecologist with expertise in biogeochemical fluxes, a phytoplankton ecologist focusing on bio-optics and autonomous observations using gliders, and a numerical simulation modeler specializing in coupled global models of ocean circulation, plankton ecology and biogeochemical cycles. The program will add trace metal sampling and analysis, moored physical oceanographic sensors, a moored sediment trap in the south, drifting sediment traps and stable carbon (del 13C) and nitrogen (del 15N) isotope analyses. Missions lasting up to 45 days using gliders deployed before, during and after summer cruises will, along with moorings and satellite remote sensing of sea ice, ocean color, sea surface temperatures and wind fields, greatly extend the observational program in space and time. \u003cbr/\u003e\u003cbr/\u003eSince its inception, PAL has been a leader in Information Management to enable knowledge-building within and beyond the Antarctic, oceanographic and LTER communities. PAL has designed and deployed a new information infrastructure with a relational database architecture to facilitate data distribution and sharing. The Education and Outreach program capitalizes on the public\u0027s fascination with Antarctica to promote scientific literacy from kindergarten students to adult citizens concerned with climate change and environmental sustainability. Through communicating results to the public and working with scientific assessment bodies (e.g., IPCC) and Antarctic Treaty parties to protect Earth\u0027s last frontier, PAL researchers contribute to the national scientific agenda and the greater public benefit.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e PROFILERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Ducklow, Hugh", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": "LTER", "south": null, "title": "Palmer, Antarctica Long Term Ecological Research Project", "uid": "p0000874", "west": null}, {"awards": "0538674 Winebrenner, Dale; 0537752 Creyts, Timothy", "bounds_geometry": null, "dataset_titles": "Millennially Averaged Accumulation Rates for Lake Vostok; Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "datasets": [{"dataset_uid": "609501", "doi": "10.7265/N59K485D", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Radar Attenuation Rate; Vostok Ice Core", "people": "Matsuoka, Kenichi; Studinger, Michael S.; Macgregor, Joseph A.", "repository": "USAP-DC", "science_program": null, "title": "Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609501"}, {"dataset_uid": "609500", "doi": "10.7265/N5F769HV", "keywords": "Accumulation Rate; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok", "people": "Matsuoka, Kenichi; Waddington, Edwin D.; Winebrenner, Dale; Macgregor, Joseph A.; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Millennially Averaged Accumulation Rates for Lake Vostok", "url": "https://www.usap-dc.org/view/dataset/609500"}], "date_created": "Thu, 09 Aug 2012 00:00:00 GMT", "description": "0538674\u003cbr/\u003eMatsuoka\u003cbr/\u003eThis award supports a project to evaluate radio-echo intensities in the available SOAR ice-penetrating radar data along grids covering Lake Vostok, and along four regional tracks from Ridge B toward the lake. The project has two objectives; first, it will examine the upper surface of the lake and reflectors hypothesized to be a boundary between the meteoric and accreted ice. They will provide crucial knowledge on the dynamic evolution of the lake. Second, this project will examine a poorly understood echo-free zone within the deep ice in central East Antarctica. This zone may consist of distorted stagnant ice, while its upper boundary may be a shear zone. The SOAR radar data provide a unique resource to examine spatiotemporal water circulation patterns that should be understood in order to select the best direct-sampling strategy to the lake. The Vostok ice core provides a unique opportunity to do this work. First, the path effects, i.e. propagation loss and birefringence, will be derived at the ice-core site using ice temperature, chemistry, and fabric data. Second, lateral variations of the propagation loss will be estimated by tracking chemistry associated with radar-detected isochronous layers, and by inferring temperatures from an ice-flow model that can replicate those layers. Ice-fabric patterns will be inferred from anisotropy in the reflectivity at about 100 radar-track cross-over sites. In terms of broader impacts, a graduate student will be trained to interpret the radar data in the light of radar theory and glaciological context of Lake Vostok and summer workshops for K-12 teachers will be provided in Seattle and New York. This project will contribute to ongoing efforts to study Lake Vostok and will complement the site selection for a North Vostok ice core, which has been proposed by Russia and France as an IPY program.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Airborne Radar Sounding; DHC-6; Salinity; Lake Vostok; Antarctic Ice Sheet; Modeling; FIELD SURVEYS; Model Output; Accumulation Rate; MODELS; Numerical Model; Ice Sheet; Not provided; Hydrostatic; Aerogeophysical; Subglacial; Attenuation Rate; Radar; FIELD INVESTIGATION; Model; Circulation; LABORATORY", "locations": "Lake Vostok; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Matsuoka, Kenichi; Winebrenner, Dale; Creyts, Timothy; Macgregor, Joseph A.; Studinger, Michael S.; Waddington, Edwin D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data", "uid": "p0000090", "west": null}, {"awards": "0739766 Brook, Edward", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "WAIS Divide Ice Core CO2", "datasets": [{"dataset_uid": "609651", "doi": "10.7265/N5DV1GTZ", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Marcott, Shaun; Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core CO2", "url": "https://www.usap-dc.org/view/dataset/609651"}], "date_created": "Wed, 30 May 2012 00:00:00 GMT", "description": "Brook 0739766\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a 25,000-year high-resolution record of atmospheric CO2 from the WAIS Divide ice core. The site has high ice accumulation rate, relatively cold temperatures, and annual layering that should be preserved back to 40,000 years, all prerequisite for preserving a high quality, well-dated CO2 record. The new record will be used to examine relationships between Antarctic climate, Northern Hemisphere climate, and atmospheric CO2 on glacial-interglacial to centennial time scales, at unprecedented temporal resolution. The intellectual merit of the proposed work is simply that CO2 is the most important greenhouse gas that humans directly impact, and understanding the sources, sinks, and controls of atmospheric CO2 is a major goal for the global scientific community. Accurate chronology and detailed records are primary requirements for developing and testing models that explain and predict CO2 variability. The proposed work has several broader impacts. It contributes to the training of a post-doctoral researcher, who will transfer to a research faculty position during the award period and who will participate in graduate teaching and guest lecture in undergraduate courses. An undergraduate researcher will gain valuable lab training and conduct independent research. Bringing the results of\u003cbr/\u003ethe proposed work to the classroom will enrich courses taught by the PI. Outreach efforts will expose pre-college students to ice core research. The proposed work will enhance the laboratory facilities for ice core research at OSU, insuring that the capability for CO2 measurements exists for future projects. All data will be archived at the National Snow and Ice Data Center and other similar archives, per OPP policy. Highly significant results will be disseminated to the news media through OSU?s very effective News and Communications group. Carbon dioxide is the most important greenhouse gas that humans are directly changing. Understanding how CO2 and climate are linked on all time scales is necessary for predicting the future behavior of the carbon cycle and climate system, primarily to insure that the appropriate processes are represented in carbon cycle/climate models. Part of the proposed work emphasizes the relationship of CO2 and abrupt climate change. Understanding how future abrupt change might impact the carbon cycle is an important issue for society.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Carbon Dioxide; FIELD INVESTIGATION; CO2; Wais Divide-project; Ice Core; Antarctica; Climate; Gas Chromatography; Antarctic Ice Core; LABORATORY", "locations": "Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marcott, Shaun; Ahn, Jinho; 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": -79.47, "title": "Atmospheric Carbon Dioxide and Climate Change: The WAIS Divide Ice Core Record", "uid": "p0000044", "west": -112.08}, {"awards": "0635470 Detrich, H. William", "bounds_geometry": "POLYGON((-67.41667 -61.2,-66.27667 -61.2,-65.13667 -61.2,-63.99667 -61.2,-62.85667 -61.2,-61.71667 -61.2,-60.57667 -61.2,-59.43667 -61.2,-58.29667 -61.2,-57.15667 -61.2,-56.01667 -61.2,-56.01667 -61.71,-56.01667 -62.22,-56.01667 -62.73,-56.01667 -63.24,-56.01667 -63.75,-56.01667 -64.26,-56.01667 -64.77,-56.01667 -65.28,-56.01667 -65.79,-56.01667 -66.3,-57.15667 -66.3,-58.29667 -66.3,-59.43667 -66.3,-60.57667 -66.3,-61.71667 -66.3,-62.85667 -66.3,-63.99667 -66.3,-65.13667 -66.3,-66.27667 -66.3,-67.41667 -66.3,-67.41667 -65.79,-67.41667 -65.28,-67.41667 -64.77,-67.41667 -64.26,-67.41667 -63.75,-67.41667 -63.24,-67.41667 -62.73,-67.41667 -62.22,-67.41667 -61.71,-67.41667 -61.2))", "dataset_titles": "Expedition Data; Expedition data of LMG1003; Expedition data of LMG1004; Sequence data", "datasets": [{"dataset_uid": "002684", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1003", "url": "https://www.rvdata.us/search/cruise/LMG1003"}, {"dataset_uid": "000133", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Sequence data", "url": "http://www.ncbi.nlm.nih.gov/genbank/"}, {"dataset_uid": "001508", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0807"}, {"dataset_uid": "001509", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0806"}, {"dataset_uid": "002685", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1004", "url": "https://www.rvdata.us/search/cruise/LMG1004"}], "date_created": "Mon, 06 Sep 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eSince the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~38-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. Because they live at very low and stable temperatures, Antarctic fishes of the suborder Nototheniodei are particularly attractive as models for understanding the mechanisms of biomolecular cold adaptation, or the compensatory restructuring of biochemical and physiological systems to preserve biological function in cold thermal regimes. Two interrelated and potentially co-evolved systems, the tubulins that form microtubules and the chaperonin-containing TCP1 (t-complex protein-1) complex (CCT) that assists the folding of tubulins, provide an unparalleled opportunity to elucidate these mechanisms. This research will yield new and important knowledge regarding: 1) cold adaptation of microtubule assembly and of chaperonin function; and 2) the co-evolutionary origin of tubulin-binding specificity by CCT. The first objective of this proposal is to determine the contributions of five novel amino acid substitutions found in Antarctic fish beta-tubulins to microtubule assembly at cold temperature. The second objective is to establish a chaperonin folding system in vitro using CCT purified from testis tissue of Antarctic fishes and to evaluate its thermal properties and mechanism. The third objective is to evaluate, through phylogenetically controlled contrasts, the hypothesis that CCT and its tubulin substrates from Antarctic fishes have co-evolved to function at cold temperatures. The broader impacts of this proposal include introduction of graduate and REU undergraduate students of Northeastern University to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem. Because much of the research on the biogenesis and function of cold-adapted proteins will be performed in the field at Palmer Station, these students will gain invaluable experience in the practical considerations of expeditionary biological science. The research also will increase knowledge about molecular cold adaptation in one of the Earth\u0027s extreme environments, and hence is relevant to the formulation of refined hypotheses regarding potential extraterrestrial life on Mars or Europa. The cold-functioning chaperonin protein folding system will be of great value to the biopharmaceutical and biotechnological industries for use in folding insoluble proteins.", "east": -56.01667, "geometry": "POINT(-61.71667 -63.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": true, "keywords": "R/V LMG", "locations": null, "north": -61.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "NCBI GenBank; R2R", "science_programs": null, "south": -66.3, "title": "Protein Folding and Function at Cold Temperature: Co-Evolution of the Chaperonin CCT and Tubulins from Antarctic Fishes", "uid": "p0000470", "west": -67.41667}, {"awards": "0839119 Wu, Qian", "bounds_geometry": "POLYGON((-68.1 -63.8,-67.29 -63.8,-66.48 -63.8,-65.67 -63.8,-64.86 -63.8,-64.05 -63.8,-63.24 -63.8,-62.43 -63.8,-61.62 -63.8,-60.81 -63.8,-60 -63.8,-60 -64.1,-60 -64.4,-60 -64.7,-60 -65,-60 -65.3,-60 -65.6,-60 -65.9,-60 -66.2,-60 -66.5,-60 -66.8,-60.81 -66.8,-61.62 -66.8,-62.43 -66.8,-63.24 -66.8,-64.05 -66.8,-64.86 -66.8,-65.67 -66.8,-66.48 -66.8,-67.29 -66.8,-68.1 -66.8,-68.1 -66.5,-68.1 -66.2,-68.1 -65.9,-68.1 -65.6,-68.1 -65.3,-68.1 -65,-68.1 -64.7,-68.1 -64.4,-68.1 -64.1,-68.1 -63.8))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 12 Jul 2010 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project will deploy a new Fabry-Perot interferometer (FPI) at the U.S. Palmer Station located in the Antarctic Peninsula. The FPI will observe mesospheric and thermospheric neutral winds and temperatures using multiple nightglow emissions (OH, 892 nm, 87 km; O 557.7 nm, 97 km; O 630 nm, 250 km; and O2 (0-1) 865 nm, 94 km). The project\u0027s team will collaborate with Australian scientists who operate similar FPI instruments at their Antarctic stations Mawson and Davis to jointly analyze the neutral wind and temperature data distributions over the continent and address the following scientific problems: (1) Thermospheric neutral winds effects on the Weddell Sea Anomaly, (2) Non-migrating tides in the mesosphere and lower thermosphere, (3) Lower thermospheric meridional wind circulation and mesosphere wind shear, (4) High-latitude geomagnetic field effects on the mid-latitude thermosphere, and (4) Conjugacy studies of the mesosphere and thermosphere with the incoherent scatter radar and FPI observations from Millstone Hill, Massachusetts. The fieldwork and analysis efforts associated with this project are highly suitable for involvement and research training of graduate students.", "east": -60.0, "geometry": "POINT(-64.05 -65.3)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e INTERFEROMETERS \u003e FPI", "is_usap_dc": false, "keywords": "GROUND STATIONS; Thermospheric Winds; Fpi", "locations": null, "north": -63.8, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Wu, Qian", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repositories": null, "science_programs": null, "south": -66.8, "title": "Collaborative Research: Thermospheric Neutral Wind Observation from the Antarctic Peninsula", "uid": "p0000472", "west": -68.1}, {"awards": "0801392 Swanson, Brian", "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": "Ice Nucleation by Marine Psychrophiles", "datasets": [{"dataset_uid": "600087", "doi": "10.15784/600087", "keywords": "Biota; Microbiology; Oceans; Raman Spectroscopy; Sea Ice; Sea Surface; Southern Ocean", "people": "Swanson, Brian", "repository": "USAP-DC", "science_program": null, "title": "Ice Nucleation by Marine Psychrophiles", "url": "https://www.usap-dc.org/view/dataset/600087"}], "date_created": "Sat, 26 Jun 2010 00:00:00 GMT", "description": "The primary objective of this research is to investigate polar marine psychrophilic bacteria for their potential to nucleate ice using a combination of microbiological, molecular biological and atmospheric science approaches in the laboratory. Very little is known about how psychrophiles interact and cope with ice or their adaptations to conditions of extreme cold and salinity. This work will involve a series of laboratory experiments using a novel freeze-tube technique for assaying freezing spectra which will provide quantitative information on: (i) the temperature-dependent freezing rates for heterogeneously frozen droplets containing sea-ice bacteria, (ii) the proportional occurrence of ice-nucleation activity versus anti-freeze activity among sea-ice bacterial isolates and (iii) the temperature-dependent freezing rates of bacteria with ice-nucleation activity grown at a range of temperatures and salinities. The compound(s) responsible for the observed activity will be identified, which is an essential step towards the development of an in-situ bacterial ice-nucleation detection assay that can be applied in the field to Antarctic water and cloud samples.\u003cbr/\u003e One of the goals of this work is to better understand survival and cold adaptation processes of polar marine bacteria confronted with freezing conditions in sea ice. Since sea ice strongly impacts polar, as well as the global climates, this research is of significant interest because it will also provide data for accessing the importance of bacterial ice nucleation in the formation of sea ice. These measurements of ice-nucleation rates will be the first high-resolution measurements for psychrophilic marine bacteria. Another goal is to better understand the impact of bacterial ice initiation processes in polar clouds by making high-resolution measurements of nucleation rates for cloud bacteria found over Arctic and Antarctic regions. Initial measurements indicate these bacteria nucleate ice at warmer temperatures and the effect in polar regions may be quite important, since ice can strongly impact cloud dynamics, cloud radiative properties, precipitation formation, and cloud chemistry. If these initial measurements are confirmed, the data collected here will be important for improving the understanding of polar cloud processes and models. A third goal is to better understand the molecular basis of marine bacterial ice nucleation by characterizing the ice-nucleation compound and comparing it with those of known plant-derived ice-nucleating bacteria, which are the only ice-nucleating bacteria examined in detail to date. The proposed activity will support the beginning academic career of a post-doctoral researcher and will serve as the basis for several undergraduate student laboratory projects. Results from this research will be widely published in various scientific journals and outreach venues.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Swanson, Brian", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Ice Nucleation by Marine Psychrophiles", "uid": "p0000195", "west": -180.0}, {"awards": "9909055 Sidell, Bruce", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG0105", "datasets": [{"dataset_uid": "002693", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0105", "url": "https://www.rvdata.us/search/cruise/LMG0105"}, {"dataset_uid": "001869", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0105"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The suborder Notothenoidei is the dominant fish group of the Southern Ocean surrounding Antarctica, both in terms of number of species and biomass. For about fourteen million years, these highly successful fish evolved under stable thermal conditions that result in body temperatures of about zero degrees centigrade throughout their life histories. Evolution this cold environment has led to unusual physiological and biochemical characteristics. In some cases, the characteristics contribute to overcoming constraints of cold temperature on biological processes. In other instances, mutations that probably would have been lethal in warmer, less oxygen-rich environments than the Southern Ocean have been retained in Antarctic fishes. This research project focuses on three major objectives that exploit these unusual conditions to identify mechanisms compatible with normal cellular function at cold temperature and to gain unique insights into the physiological roles of key intracellular proteins. The three lines of study proposed are the molecular basis for the failure of the myoglobin encoding gene to be expressed in certain Antarctic notothenioid fishes, the basis of the substrate specificity of the enzyme fatty acyl-CoA synthetase that is involved in the catabolism of fatty acids, and the functional roles played by different isoforms of creatine phosphokinase in locomotory muscle of Antarctic fish. Results from this study will not only provide insight into the evolutionary biology of the Antarctic notothenioid fishes, but will elucidate important general principles that are applicable to widely different taxa beyond the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sidell, Bruce", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Proteins of Oxygen-Binding and Energy Metabolism in Muscles of Antarctic Fishes: Evolutionary Adjustments to Life at Cold Temperature", "uid": "p0000863", "west": null}, {"awards": "0125890 Sidell, Bruce", "bounds_geometry": "POLYGON((-68.1413 -52.6755,-67.47503 -52.6755,-66.80876 -52.6755,-66.14249 -52.6755,-65.47622 -52.6755,-64.80995 -52.6755,-64.14368 -52.6755,-63.47741 -52.6755,-62.81114 -52.6755,-62.14487 -52.6755,-61.4786 -52.6755,-61.4786 -53.8957,-61.4786 -55.1159,-61.4786 -56.3361,-61.4786 -57.5563,-61.4786 -58.7765,-61.4786 -59.9967,-61.4786 -61.2169,-61.4786 -62.4371,-61.4786 -63.6573,-61.4786 -64.8775,-62.14487 -64.8775,-62.81114 -64.8775,-63.47741 -64.8775,-64.14368 -64.8775,-64.80995 -64.8775,-65.47622 -64.8775,-66.14249 -64.8775,-66.80876 -64.8775,-67.47503 -64.8775,-68.1413 -64.8775,-68.1413 -63.6573,-68.1413 -62.4371,-68.1413 -61.2169,-68.1413 -59.9967,-68.1413 -58.7765,-68.1413 -57.5563,-68.1413 -56.3361,-68.1413 -55.1159,-68.1413 -53.8957,-68.1413 -52.6755))", "dataset_titles": "Expedition Data; Expedition data of LMG0304; Expedition data of LMG0304A", "datasets": [{"dataset_uid": "002708", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0304A", "url": "https://www.rvdata.us/search/cruise/LMG0304A"}, {"dataset_uid": "001596", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0506"}, {"dataset_uid": "001597", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0505"}, {"dataset_uid": "001704", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0304"}, {"dataset_uid": "002707", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0304A", "url": "https://www.rvdata.us/search/cruise/LMG0304A"}, {"dataset_uid": "002706", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0304", "url": "https://www.rvdata.us/search/cruise/LMG0304"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Notothenioid fishes that dominate the fish fauna surrounding Antarctica have been evolving for 10-14 million years at a nearly constant body temperature of ~0C throughout their life histories. As a result, this group of animals is uniquely suited to studies aimed at understanding and identifying features of physiology and biochemistry that result from the process of evolution at cold body temperature. This project has three major objectives aimed at examining adaptations for life in cold environments: \u003cbr/\u003e\u003cbr/\u003e1. Identify the amino acid substitutions in the fatty acid-binding pocket of fatty acyl CoA synthetase (FACS) that explain its substrate specificity. Fatty acids are a major fuel of energy metabolism in Antarctic fishes. FACS catalyzes the condensation of CoASH and fatty acids to fatty acyl CoA esters, a step required for subsequent metabolism of these important compounds. This research may permit us to resolve the specific amino acid substitutions that explain both substrate specificity and preservation of catalytic rate of notothenioid FACS at cold physiological temperatures.\u003cbr/\u003e\u003cbr/\u003e2. Produce a rigorous biochemical and biophysical characterization of the intracellular calcium-binding protein, parvalbumin, from white axial musculature of Antarctic fishes. Parvalbumin plays a pivotal role in facilitating the relaxation phase of fast-contracting muscles and is a likely site of strong selective pressure. Preliminary data strongly indicate that the protein from Antarctic fishes has been modified to ensure function at cold temperature. A suite of physical techniques will be used to determine dissociation constants of Antarctic fish parvalbumins for calcium and magnesium and unidirectional rate constants of ion-dissociation from the protein. Full-length cDNA clones for Antarctic fish parvalbumin(s) will permit deduction of primary amino acid sequence These data will yield insight into structural elements that permit the protein from notothenioid fishes to function at very cold body temperature.\u003cbr/\u003e\u003cbr/\u003e3. Conduct a broad survey of the pattern of cardiac myoglobin expression in the Suborder Notothenoidei. Previous work has indicated a variable pattern of presence or absence of the intracellular oxygen-binding protein, myoglobin (Mb), in hearts of one family of Antarctic notothenioid fishes (Channichthyidae; icefishes). Because Mb is of physiological value in species that express the protein, the observed pattern of interspecific expression has been attributed to unusually low niche competition in the Southern Ocean. This leads to the prediction that similar loss of cardiac Mb should be observed in other notothenioid taxa. This part of the project will survey for the presence and absence of cardiac Mb in as many notothenioid species as possible and, if Mb-lacking species are detected, will extend analyses to determine the mechanism(s) responsible for loss of its expression using molecular biological techniques.", "east": -61.4786, "geometry": "POINT(-64.80995 -58.7765)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.6755, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sidell, Bruce; Detrich, H. William", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.8775, "title": "Cold Body Temperature as an Evolutionary Shaping force in the Physiology of Antarctic Fishes", "uid": "p0000241", "west": -68.1413}, {"awards": "0089451 Detrich, H. William", "bounds_geometry": "POLYGON((-70.907 -52.353,-69.8619 -52.353,-68.8168 -52.353,-67.7717 -52.353,-66.7266 -52.353,-65.6815 -52.353,-64.6364 -52.353,-63.5913 -52.353,-62.5462 -52.353,-61.5011 -52.353,-60.456 -52.353,-60.456 -53.64334,-60.456 -54.93368,-60.456 -56.22402,-60.456 -57.51436,-60.456 -58.8047,-60.456 -60.09504,-60.456 -61.38538,-60.456 -62.67572,-60.456 -63.96606,-60.456 -65.2564,-61.5011 -65.2564,-62.5462 -65.2564,-63.5913 -65.2564,-64.6364 -65.2564,-65.6815 -65.2564,-66.7266 -65.2564,-67.7717 -65.2564,-68.8168 -65.2564,-69.8619 -65.2564,-70.907 -65.2564,-70.907 -63.96606,-70.907 -62.67572,-70.907 -61.38538,-70.907 -60.09504,-70.907 -58.8047,-70.907 -57.51436,-70.907 -56.22402,-70.907 -54.93368,-70.907 -53.64334,-70.907 -52.353))", "dataset_titles": "Expedition Data; Expedition data of LMG0304A", "datasets": [{"dataset_uid": "001869", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0105"}, {"dataset_uid": "001704", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0304"}, {"dataset_uid": "002707", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0304A", "url": "https://www.rvdata.us/search/cruise/LMG0304A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003eOPP-0089451\u003cbr/\u003eP.I. William Detrich\u003cbr/\u003e\u003cbr/\u003e As the Southern Ocean cooled during the past 25 million years, the fishes of Antarctic coastal waters evolved biochemical and physiological adaptations that maintain essential cellular processes such as cytoskeletal function and gene transcription. Their microtubules, for example, assemble and function at body temperatures (-1.8 to +1 oC) well below those of homeotherms and temperate poikilotherms. The long range goals of the proposed research are to determine, at the molecular level, the adaptations that enhance the assembly of microtubules, the function of kinesin motors, and the expression of globin and tubulin genes. The specific objectives are three: 1) to determine the primary sequence changes and posttranslational modifications that contribute to the efficient polymerization of Antarctic fish tubulins at low temperatures; 2) to evaluate the biochemical adaptations required for efficient function of the brain kinesin motor of Antarctic fishes at low temperatures; and 3) to characterize the structure, organization, and promoter-driven expression of globin and tubulin genes from an Antarctic rockcod (Notothenia coriiceps) and a temperate congener (N. angustata). Brain tubulins from Antarctic fishes differ from those of temperate and warm-blooded vertebrates both in unusual primary sequence substitutions (located primarily in lateral loops and the cores of tubulin monomers) and in posttranslational C-terminal glutamylation. Potential primary sequence adaptations of the Antarctic fish tubulins will be tested directly by production of wild-type and site directed tubulin mutants for functional analysis in vitro. The capacity of mutated and wild-type fish tubulins to form \"cold-stable\" microtubules will be determined by measurement of their critical concentrations for assembly and by analysis of their dynamics by video-enhanced microscopy. Three unusual substitutions in the kinesin motor domain of Chionodraco rastrospinosus may enhance mechanochemical activity at low temperature by modifying the binding of ATP and/or the velocity of the motor. To test the functional significance of these changes, the fish residues will be converted individually, and in concert, to those found in mammalian brain kinesin. Reciprocal substitutions will be introduced into the framework of the mammalian kinesin motor domain. After production in Escherichia coli and purification, the functional performance of the mutant motor domains will be evaluated by measurement of the temperature dependence of their ATPase and motility activities. Molecular adaptation of gene expression in N. coriiceps will be analyzed using an a-globin/b-globin gene pair and an a-tubulin gene cluster. Structural features of N. coriiceps globin and tubulin gene regulatory sequences (promoters and enhancers) that support efficient expression will be assessed by transient transfection assay of promoter/luciferase reporter plasmid constructs in inducible erythrocytic and neuronal model cell systems followed by assay of luciferase reporter activity. Together, these studies should reveal the molecular adaptations of Antarctic fishes that maintain efficient cytoskeletal assembly, mechanochemical motor function, and gene expression at low temperatures. In the broadest sense, this research program should advance the molecular understanding of the poikilothermic mode of life.", "east": -60.456, "geometry": "POINT(-65.6815 -58.8047)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.353, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sidell, Bruce; Detrich, H. William", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -65.2564, "title": "Structure, Function, and Expression of Tubulins, Globins, and Microtubule-Dependent Motors from Cold-Adapted Antarctic Fishes", "uid": "p0000591", "west": -70.907}, {"awards": "8915730 Foster, Theodore", "bounds_geometry": "POLYGON((-70.9 -52.3533,-67.79577 -52.3533,-64.69154 -52.3533,-61.58731 -52.3533,-58.48308 -52.3533,-55.37885 -52.3533,-52.27462 -52.3533,-49.17039 -52.3533,-46.06616 -52.3533,-42.96193 -52.3533,-39.8577 -52.3533,-39.8577 -53.78259,-39.8577 -55.21188,-39.8577 -56.64117,-39.8577 -58.07046,-39.8577 -59.49975,-39.8577 -60.92904,-39.8577 -62.35833,-39.8577 -63.78762,-39.8577 -65.21691,-39.8577 -66.6462,-42.96193 -66.6462,-46.06616 -66.6462,-49.17039 -66.6462,-52.27462 -66.6462,-55.37885 -66.6462,-58.48308 -66.6462,-61.58731 -66.6462,-64.69154 -66.6462,-67.79577 -66.6462,-70.9 -66.6462,-70.9 -65.21691,-70.9 -63.78762,-70.9 -62.35833,-70.9 -60.92904,-70.9 -59.49975,-70.9 -58.07046,-70.9 -56.64117,-70.9 -55.21188,-70.9 -53.78259,-70.9 -52.3533))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002310", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9207"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a two-year investigation into the dynamics and processes of deep water mass formation in the western Weddell Sea, combining physical and chemical oceanographic techniques to produce a coherent picture of the importance of this unique region to the structure of the world ocean. In the global context, this area is a major water mass modification site, involving open ocean convective events, the continental margin, and the ice cover. At this time the various water types that combine to form Weddell Sea Deep Water and Antarctic Bottom Water, and the conditions under which these water masses form, are not known well enough to establish direct physical links and volumetric budgets. It is suspected that the outflow from the Weddell Sea is restricted to quite narrow boundary currents flowing near the base of the continental shelf, and consequently may be observed with conventional current meter moorings from the shelf into the deep ocean. Two oceanographic expeditions to the western Weddell Sea are planned as part of this study: the first in the 1990/91, and the second in 1991/92. The objectives will be to measure the flow of newly-formed bottom water and to explore the sinking process of near-surface waters in the open ocean to see how these affect the deep water flows. In the first year the primary objective will be to set out an array of eight current meters in the bottom water core, while a secondary objective will be to grapple for an existing array that was set out in early 1988 but could not be recovered in 1989 because Antarctic Program ship resources had to be diverted to deal with the oil spill at Palmer Station. In the second year the array will be retrieved. Hydrographic cruises in order to define the upper ocean temperatures and salinity structure in the outflow region where unusually large step structures have been found in the past. A chemistry program consistent with the objectives of the World Ocean Circulation Experiment (WOCE) and presently planned experiments in the South Atlantic Ocean, will be integrated into the cruises carried out under this project.", "east": -39.8577, "geometry": "POINT(-55.37885 -59.49975)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.3533, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Foster, Theodore; Foster, Ted", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.6462, "title": "Antarctic Bottom Water Formation", "uid": "p0000654", "west": -70.9}, {"awards": "9908828 Aronson, Richard", "bounds_geometry": "POLYGON((-70.906 -52.350166,-69.4494 -52.350166,-67.9928 -52.350166,-66.5362 -52.350166,-65.0796 -52.350166,-63.623 -52.350166,-62.1664 -52.350166,-60.7098 -52.350166,-59.2532 -52.350166,-57.7966 -52.350166,-56.34 -52.350166,-56.34 -53.6028324,-56.34 -54.8554988,-56.34 -56.1081652,-56.34 -57.3608316,-56.34 -58.613498,-56.34 -59.8661644,-56.34 -61.1188308,-56.34 -62.3714972,-56.34 -63.6241636,-56.34 -64.87683,-57.7966 -64.87683,-59.2532 -64.87683,-60.7098 -64.87683,-62.1664 -64.87683,-63.623 -64.87683,-65.0796 -64.87683,-66.5362 -64.87683,-67.9928 -64.87683,-69.4494 -64.87683,-70.906 -64.87683,-70.906 -63.6241636,-70.906 -62.3714972,-70.906 -61.1188308,-70.906 -59.8661644,-70.906 -58.613498,-70.906 -57.3608316,-70.906 -56.1081652,-70.906 -54.8554988,-70.906 -53.6028324,-70.906 -52.350166))", "dataset_titles": "Expedition Data; Expedition data of NBP0107", "datasets": [{"dataset_uid": "002656", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0107", "url": "https://www.rvdata.us/search/cruise/NBP0107"}, {"dataset_uid": "001962", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0011"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9908828\u003cbr/\u003eAronson\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.\u003cbr/\u003e\u003cbr/\u003eA series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). \u003cbr/\u003e\u003cbr/\u003eSeymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.", "east": -56.34, "geometry": "POINT(-63.623 -58.613498)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP; Hugo Island; R/V LMG; Palmer Deep", "locations": "Hugo Island", "north": -52.350166, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Aronson, Richard; Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.87683, "title": "Global Climate Change and the Evolutionary Ecology of Antarctic Mollusks in the Late Eocene", "uid": "p0000617", "west": -70.906}, {"awards": "0338371 Hallet, Bernard; 0338137 Anderson, John", "bounds_geometry": "POLYGON((-74.59492 -45.98986,-74.072309 -45.98986,-73.549698 -45.98986,-73.027087 -45.98986,-72.504476 -45.98986,-71.981865 -45.98986,-71.459254 -45.98986,-70.936643 -45.98986,-70.414032 -45.98986,-69.891421 -45.98986,-69.36881 -45.98986,-69.36881 -46.835236,-69.36881 -47.680612,-69.36881 -48.525988,-69.36881 -49.371364,-69.36881 -50.21674,-69.36881 -51.062116,-69.36881 -51.907492,-69.36881 -52.752868,-69.36881 -53.598244,-69.36881 -54.44362,-69.891421 -54.44362,-70.414032 -54.44362,-70.936643 -54.44362,-71.459254 -54.44362,-71.981865 -54.44362,-72.504476 -54.44362,-73.027087 -54.44362,-73.549698 -54.44362,-74.072309 -54.44362,-74.59492 -54.44362,-74.59492 -53.598244,-74.59492 -52.752868,-74.59492 -51.907492,-74.59492 -51.062116,-74.59492 -50.21674,-74.59492 -49.371364,-74.59492 -48.525988,-74.59492 -47.680612,-74.59492 -46.835236,-74.59492 -45.98986))", "dataset_titles": "Expedition data of NBP0505; Expedition data of NBP0703; NBP0505 CTD data; NBP0505 sediment core locations", "datasets": [{"dataset_uid": "601363", "doi": "10.15784/601363", "keywords": "Chile; CTD; CTD Data; Depth; Fjord; NBP0505; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Wellner, Julia; Anderson, John", "repository": "USAP-DC", "science_program": null, "title": "NBP0505 CTD data", "url": "https://www.usap-dc.org/view/dataset/601363"}, {"dataset_uid": "002642", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0703", "url": "https://www.rvdata.us/search/cruise/NBP0703"}, {"dataset_uid": "601362", "doi": "10.15784/601362", "keywords": "Chile; Fjord; Marine Geoscience; NBP0505; R/v Nathaniel B. Palmer; Sample/collection Description; Sample/Collection Description; Sediment Core; Sediment Corer; Station List", "people": "Anderson, John; Wellner, Julia", "repository": "USAP-DC", "science_program": null, "title": "NBP0505 sediment core locations", "url": "https://www.usap-dc.org/view/dataset/601362"}, {"dataset_uid": "002609", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0505", "url": "https://www.rvdata.us/search/cruise/NBP0505"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project examines the role of glacier dynamics in glacial sediment yields. The results will shed light on how glacial erosion influences both orogenic processes and produces sediments that accumulate in basins, rich archives of climate variability. Our hypothesis is that erosion rates are a function of sliding speed, and should diminish sharply as the glacier\u0027s basal temperatures drop below the melting point. To test this hypothesis, we will determine sediment accumulation rates from seismic studies of fjord sediments for six tidewater glaciers that range from fast-moving temperate glaciers in Patagonia to slow-moving polar glaciers on the Antarctic Peninsula. Two key themes are addressed for each glacier system: 1) sediment yields and erosion rates by determining accumulation rates within the fjords using seismic profiles and core data, and 2) dynamic properties and basin characteristics of each glacier in order to seek an empirical relationship between glacial erosion rates and ice dynamics. The work is based in Patagonia and the Antarctic Peninsula, ideal natural laboratories for these purposes because the large latitudinal range provides a large range of precipitation and thermal regimes over relatively homogeneous lithologies and tectonic settings. Prior studies of these regions noted significant decreases in glaciomarine sediment accumulations in the fjords to the south. As well, the fjords constitute accessible and nearly perfect natural sediment traps.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this study include inter-disciplinary collaboration with Chilean glaciologists and marine geologists, support for one postdoctoral and three doctoral students, inclusion of undergraduates in research, and outreach to under-represented groups in Earth sciences and K-12 educators. The results of the project will also contribute to a better understanding of the linkages between climate and evolution of all high mountain ranges.", "east": -69.36881, "geometry": "POINT(-71.981865 -50.21674)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e WATER BOTTLES; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP; Penguin Glacier", "locations": null, "north": -45.98986, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Hallet, Bernard; Wellner, Julia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -54.44362, "title": "Collaborative Research: Controls on Sediment Yields from Tidewater Glaciers from Patagonia to Antarctica", "uid": "p0000821", "west": -74.59492}, {"awards": "9908856 Blake, Daniel", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG0309", "datasets": [{"dataset_uid": "001683", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0309"}, {"dataset_uid": "002675", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0309", "url": "https://www.rvdata.us/search/cruise/LMG0309"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.\u003cbr/\u003e\u003cbr/\u003eA series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). \u003cbr/\u003e\u003cbr/\u003eSeymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blake, Daniel", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Global Climate Change and the Evolutionary Ecology of Antarctic Mollusks in the Late Eocene.", "uid": "p0000857", "west": null}, {"awards": "0338248 Takahashi, Taro", "bounds_geometry": "POLYGON((-68.0051 -52.7573,-67.35191 -52.7573,-66.69872 -52.7573,-66.04553 -52.7573,-65.39234 -52.7573,-64.73915 -52.7573,-64.08596 -52.7573,-63.43277 -52.7573,-62.77958 -52.7573,-62.12639 -52.7573,-61.4732 -52.7573,-61.4732 -53.96927,-61.4732 -55.18124,-61.4732 -56.39321,-61.4732 -57.60518,-61.4732 -58.81715,-61.4732 -60.02912,-61.4732 -61.24109,-61.4732 -62.45306,-61.4732 -63.66503,-61.4732 -64.877,-62.12639 -64.877,-62.77958 -64.877,-63.43277 -64.877,-64.08596 -64.877,-64.73915 -64.877,-65.39234 -64.877,-66.04553 -64.877,-66.69872 -64.877,-67.35191 -64.877,-68.0051 -64.877,-68.0051 -63.66503,-68.0051 -62.45306,-68.0051 -61.24109,-68.0051 -60.02912,-68.0051 -58.81715,-68.0051 -57.60518,-68.0051 -56.39321,-68.0051 -55.18124,-68.0051 -53.96927,-68.0051 -52.7573))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001572", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0603"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This proposal is for the continuation and expansion of an underway program on the R/V Laurence M. Gould to measure dissolved carbon dioxide gas (pCO2) along with occasional total carbon dioxide (TCO2) in surface waters on transects of Drake Passage. The added observations include dissolved oxygen, as well as nutrient and carbon-13. The proposed work is similar to the underway measurement program made aboard R/V Nathaniel B. Palmer, and complements similar surface temperature and current data.\u003cbr/\u003eThe Southern Ocean is an important component of the global carbon budget. Low surface temperatures with consequently low vertical stability, ice formation, and high winds produce a very active environment for the exchange of gaseous carbon dioxide between the atmospheric and oceanic reservoirs. The Drake Passage is the narrowest point through which the Antarctic Circumpolar Current and its associated fronts must pass, and is the most efficient location for the measurement of latitudinal gradients of gas exchange. The generated time series will contribute towards two scientific goals: the quantification of the spatial and temporal variability and trends of surface carbon dioxide, oxygen, nutrients and C-13, and an understanding of the dominant processes that contribute to the observed variability.", "east": -61.4732, "geometry": "POINT(-64.73915 -58.81715)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.7573, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Takahashi, Taro", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.877, "title": "Collaborative Research: Processes Driving Spatial and Temporal Variability of Surface pCO2 in the Drake Passage", "uid": "p0000572", "west": -68.0051}, {"awards": "9980379 Baker, Ian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 15 Feb 2010 00:00:00 GMT", "description": "This award is for support for three years of funding to study the effects of impurities on the flow of poly-\u003cbr/\u003ecrystalline ice. It has been known for thirty years that both hydrofluoric acid (HF) and hydrochloric acid (HCl) dramatically decrease the strength of ice and recent work by the author\u0027s group has shown that sulfuric acid (H2SO4) produces a similar reduction in strength. However, these data are for single crystals at strain rates and stresses that far exceed those found in glaciers and ice sheets, and often at concentrations that far exceed those in natural ice. Therefore, it is not known how impurities found in nature affect the flow of polycrystalline ice at slow strain rates. In this research, the effects of nitric acid and sulfuric acid (which are naturally occurring impurities in ice) on the microstructure (dislocation structure, grain boundary structure and location of the acids) and creep of polycrystalline ice (at a range of temperatures and stresses) will be determined. The ice\u0027s response to creep deformation will be studied using a combination of x-ray topography, optical microscopy and scanning electron microscopy. X-ray microanalysis in an environmental scanning electron microscope will be used to study the location of impurities. The structure and creep behavior of the acid-doped ice will be compared with those of both high-purity laboratory-grown ice and ice from Byrd Station, Antarctica. The end-result of this project will be to elucidate the effects of naturally-occurring acid impurities on the mechanical properties of polycrystalline ice under conditions relevant to the deformation of glaciers and ice sheets, including and understanding of how impurities affect the underlying deformation mechanisms.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PARTICLE DETECTORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "Ice Core Data; Ice Core; Microstructure; Ice Sheet; Ice Core Chemistry; Antarctic Ice Sheet; LABORATORY", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Obbard, Rachel", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "The Effects of Impurities on the Flow of Polycrystalline Ice", "uid": "p0000015", "west": null}, {"awards": "0551969 Moran, Amy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 12 Jan 2010 00:00:00 GMT", "description": "This project seeks to understand the evolutionary physiology of reproductive strategies in Southern Ocean marine invertebrates. The fauna of the Southern Ocean has evolved under stable, cold temperatures for approximately 14 million years. These conditions have led to the evolution of unusual physiological and biochemical characteristics, many of which may reflect adaptations to relatively low oxygen availability and high larval oxygen demands. The goal of the proposed projects is to understand latitudinal variation in the function of invertebrate egg masses in relation to oxygen availability and temperature. This relationship is critical to larval survival in the low-temperature, high-oxygen conditions found at high latitudes. In particular, the investigators will: (1) use first principles to model the diffusion of oxygen into egg and embryo masses of Antarctic organisms at environmentally relevant temperatures; (2) test model assumptions by measuring the temperature-dependence of embryonic metabolism and oxygen diffusivity through natural and artificial gels; (3) test model predictions by using oxygen microelectrodes to measure oxygen gradients in both artificial and natural egg masses, and by measuring developmental rates of embryos at different positions in masses; and (4) compare the structure and function of egg masses from the Southern Ocean to those from temperate waters. These components of the study constitute an integrated examination of the evolutionary physiology of egg mass structure and function. Studies of masses endemic to polar conditions will increase the understanding of egg mass evolution across equator-to-pole gradients in temperature and across gradients in oxygen partial pressure. The proposal will support graduate students and will involve several undergraduates in research. The PIs will also design and implement units on polar biology for undergraduate classes at their respective institutions. These educational units will focus on the PIs\u0027 photographs, video footage, experiments, and data from this project. The PIs will use web-linked video and instructional technologies to design and co-teach a new class on polar ecological physiology, will work with local grade school institutions to involve high school students in research, and will develop high school course modules about polar biology.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Moran, Amy", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Effects of Oxygen and Temperature on Egg Mass Function of Southern Ocean Marine Minvertebrates", "uid": "p0000716", "west": null}, {"awards": "0338008 Wemple, Beverley", "bounds_geometry": null, "dataset_titles": "Laboratory Studies of Isotopic Exchange in Snow; Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "datasets": [{"dataset_uid": "609441", "doi": "10.7265/N54X55R2", "keywords": "Snow/ice; Snow/Ice", "people": "Wemple, Beverley C.", "repository": "USAP-DC", "science_program": null, "title": "Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "url": "https://www.usap-dc.org/view/dataset/609441"}, {"dataset_uid": "609445", "doi": "10.7265/N51834DX", "keywords": "Atmosphere; Chemistry:ice; Chemistry:Ice; Snow/ice; Snow/Ice; Snow Sublimation Rate", "people": "Neumann, Thomas A.", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Studies of Isotopic Exchange in Snow", "url": "https://www.usap-dc.org/view/dataset/609445"}], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "This award supports a project to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is of paramount importance to ice core interpretation. Carefully controlled laboratory studies will be conducted at a variety of temperatures to empirically measure the mass transfer coefficient (the rate at which water moves from the solid to the vapor phase) for sublimating snow and to determine the time scale for isotopic equilibration between water vapor and ice. In addition the isotopic fractionation coefficient for vapor derived from sublimating ice will be determined and the results will be used to update existing models of mass transfer and isotopic evolution in firn. It is well known that water vapor moves through firn due to diffusion, free convection and forced convection. Although vapor movement through variably-saturated firn due to these processes has been modeled, because of a lack of laboratory data the mass transfer coefficient had to be estimated. Field studies have documented the magnitudes of post-depositional changes, but field studies do not permit rigorous analysis of the relative importance of the many processes which are likely to act in natural snow packs. The results of these laboratory investigations will be broadly applicable to a number of studies and will allow for improvement of existing physically-based models of post-depositional isotopic change, isotopic diffusion in firn, and vapor motion in firn. A major component of this project will be the design and fabrication of the necessary, novel experimental apparatus, which will be facilitated by existing technical expertise, cold room facilities, and laboratory equipment at CRREL. This project is a necessary step toward a quantitative understanding of the isotopic effects of water vapor movement in firn. The proposed work has broader impacts in several different areas. The modeling results will be applicable to a wide range of studies of water in the polar environment, including studies of wind-blown or drifting snow. The proposed collaborative study will partially support a Dartmouth graduate student for three years. This project will also provide support for a young first-time NSF investigator at the University of Vermont. Undergraduate students from Dartmouth will be involved in the research through the Women in Science Project and undergraduate students at the University of Vermont will be supported through the Research Experiences for Undergraduates program. The principal investigators and graduate student will continue their tradition of k-12 school outreach by giving science lessons and talks in local schools each year. Research results will be disseminated through scientific conferences, journal publications, and institutional seminars.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e SNOW TUBE; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HYGROMETERS \u003e HYGROMETERS", "is_usap_dc": true, "keywords": "Snow Accumulation; Snow Chemistry; Snow Melt; Snowfall; Snow Water Equivalent; LABORATORY; Seasonal Snow Cover; Not provided; Snow; Sublimation Rate; FIELD SURVEYS; FIELD INVESTIGATION", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Neumann, Thomas A.; Wemple, Beverley C.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow and Firn", "uid": "p0000132", "west": null}, {"awards": "0437887 Sidell, Bruce", "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": "Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis; Expedition Data; Expedition data of LMG0705; Expedition data of LMG0706", "datasets": [{"dataset_uid": "002712", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0705", "url": "https://www.rvdata.us/search/cruise/LMG0705"}, {"dataset_uid": "001534", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0705"}, {"dataset_uid": "002713", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0706", "url": "https://www.rvdata.us/search/cruise/LMG0706"}, {"dataset_uid": "600039", "doi": "10.15784/600039", "keywords": "Biota; Oceans; Pot; Sample/collection Description; Sample/Collection Description; Southern Ocean; Trawl", "people": "Sidell, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis", "url": "https://www.usap-dc.org/view/dataset/600039"}], "date_created": "Sun, 06 Dec 2009 00:00:00 GMT", "description": "The polar ocean presently surrounding Antarctica is the coldest, most thermally stable marine environment on earth. Because oxygen solubility in seawater is inversely proportional to temperature, the cold Antarctic seas are an exceptionally oxygen-rich aquatic habitat. Eight families of a single perciform suborder, the Notothenioidei, dominate the present fish fauna surrounding Antarctica. Notothenioids account for approximately 35% of fish species and 90% of fish biomass south of the Antarctic Polar Front. Radiation of closely related notothenioid species thus has occurred rapidly and under a very unusual set of conditions: relative oceanographic isolation from other faunas due to circumpolar currents and deep ocean trenches surrounding the continent, chronically, severely cold water temperatures, very high oxygen availability, very low levels of niche competition in a Southern Ocean depauperate of species subsequent to a dramatic crash in species diversity of fishes that occurred sometime between the mid-Tertiary and present. These features make Antarctic notothenioid fishes an uniquely attractive group for the study of physiological and biochemical adaptations to cold body temperature. \u003cbr/\u003eFew distinctive features of Antarctic fishes are as unique as the pattern of expression of oxygen-binding proteins in one notothenioid family, the Channichthyidae (Antarctic icefishes). All channichthyid icefishes lack the circulating oxygen-binding protein, hemoglobin (Hb); the intracellular oxygen-binding protein, myoglobin (Mb) is not uniformly expressed in species of this family. Both proteins are normally considered essential for adequate delivery of oxygen to aerobically poised tissues of animals. To compensate for the absence of Hb, icefishes have developed large hearts, rapidly circulate a large blood volume and possess elaborate vasculature of larger lumenal diameter than is seen in red-blooded fishes. Loss of Mb expression in oxidative muscles correlates with dramatic elevation in density of mitochondria within the cell, although each individual organelle is less densely packed with respiratory proteins. \u003cbr/\u003eWithin the framework of oxygen movement, the adaptive significance of greater vascular density and mitochondrial populations is understandable but mechanisms underlying development of these characteristics remain unknown. The answer may lie in another major function of both Hb and Mb, degradation of the ubiquitous bioactive compound, nitric oxide (NO). The research will test the hypothesis that loss of hemoprotein expression in icefishes has resulted in an increase in levels of NO that mediate modification of vascular systems and expansion of mitochondrial populations in oxidative tissues. The objectives of the proposal are to quantify the vascular density of retinas in +Hb and -Hb notothenioid species, to characterize NOS isoforms and catalytic activity in retina and cardiac muscle of Antarctic notothenioid fishes, to evaluate level of expression of downstream factors implicated in angiogenesis (in retinal tissue) and mitochondrial biogenesis (in cardiac muscle), and to determine whether inhibition of NOS in vivo results in regression of angiogenic and mitochondrial biogenic responses in icefishes. Broader impacts range from basic biology, through training of young scientists, to enhanced understanding of clinically relevant biomedical processes.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS", "is_usap_dc": true, "keywords": "R/V LMG; Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sidell, Bruce", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis.", "uid": "p0000527", "west": -180.0}, {"awards": "0538630 Severinghaus, Jeffrey", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 01 Apr 2009 00:00:00 GMT", "description": "0538630\u003cbr/\u003eSeveringhaus\u003cbr/\u003eThis award supports a project to produce the first record of Kr/N2 in the paleo-atmosphere as measured in air bubbles trapped in ice cores. These measurements may be indicative of past variations in mean ocean temperature. Knowing the mean ocean temperature in the past will give insight into past variations in deep ocean temperature, which remain poorly understood. Deep ocean temperature variations are important for understanding the mechanisms of climate change. Krypton is highly soluble in water, and its solubility varies with temperature, with higher solubilities at colder water temperatures. A colder ocean during the last glacial period would therefore hold more krypton than today\u0027s ocean. Because the total amount of krypton in the ocean-atmosphere system is constant, the increase in the krypton inventory in the glacial ocean should cause a resultant decrease in the atmospheric inventory of krypton. The primary goal of this work is to develop the use of Kr/N2 as an indicator of paleo-oceanic mean temperature. This will involve improving the analytical technique for the Kr/N2 measurement itself, and measuring the Kr/N2 in air bubbles in ice from the last glacial maximum (LGM) and the late Holocene in the Vostok and GISP2 ice cores. This provides an estimate of LGM mean ocean temperature change, and allows for a comparison between previous estimates of deep ocean temperature during the LGM. The Vostok ice core is ideal for this purpose because of the absence of melt layers, which compromise the krypton and xenon signal. Another goal is to improve precision on the Xe/N2 measurement, which could serve as a second, independent proxy of ocean temperature change. A mean ocean temperature time series during this transition may help to explain these observations. Additionally, the proposed work will measure the Kr/N2 from marine isotope stage (MIS) 3 in the GISP2 ice core. Knowing the past ocean temperature during MIS 3 will help to constrain sea level estimates during this time period. The broader impacts of the proposed work: are that it will provide the first estimate of the extent and timing of mean ocean temperature change in the past. This will help to constrain previously proposed mechanisms of climate change involving large changes in deep ocean temperature. This project will also support the education of a graduate student. The PI gives interviews and talks to the media and public about climate change, and the work will enhance these outreach activities. Finally, the work will occur during the International Polar Year (IPY), and will underscore the unique importance of the polar regions for understanding the global atmosphere and ocean system.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Paleoatmospheric Krypton and Xenon Abundances from Trapped Air in Polar Ice as Indicators of Past Mean Ocean Temperature", "uid": "p0000553", "west": null}, {"awards": "0436190 Eastman, 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": "Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes", "datasets": [{"dataset_uid": "600038", "doi": "10.15784/600038", "keywords": "Biota; NBP0404; Oceans; R/v Nathaniel B. Palmer; Southern Ocean", "people": "Eastman, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes", "url": "https://www.usap-dc.org/view/dataset/600038"}], "date_created": "Mon, 30 Mar 2009 00:00:00 GMT", "description": "Patterns of biodiversity, as revealed by basic research in organismal biology, may be derived from ecological and evolutionary processes expressed in unique settings, such as Antarctica. The polar regions and their faunas are commanding increased attention as declining species diversity, environmental change, commercial fisheries, and resource management are now being viewed in a global context. Commercial fishing is known to have a direct and pervasive effect on marine biodiversity, and occurs in the Southern Ocean as far south as the Ross Sea. \u003cbr/\u003eThe nature of fish biodiversity in the Antarctic is different than in all other ocean shelf areas. Waters of the Antarctic continental shelf are ice covered for most of the year and water temperatures are nearly constant at -1.5 C. In these waters components of the phyletically derived Antarctic clade of Notothenioids dominate fish diversity. In some regions, including the southwestern Ross Sea, Notothenioids are overwhelmingly dominant in terms of number of species, abundance, and biomass. Such dominance by a single taxonomic group is unique among shelf faunas of the world. In the absence of competition from a taxonomically diverse fauna, Notothenioids underwent a habitat or depth related diversification keyed to the utilization of unfilled niches in the water column, especially pelagic or partially pelagic zooplanktivory and piscivory. This has been accomplished in the absence of a swim bladder for buoyancy control. They also may form a special type of adaptive radiation known as a species flock, which is an assemblage of a disproportionately high number of related species that have evolved rapidly within a defined area where most species are endemic. Diversification in buoyancy is the hallmark of the notothenioid radiation. Buoyancy is the feature of notothenioid biology that determines whether a species lives on the substrate, in the water column or both. Buoyancy also influences other key aspects of life history including swimming, feeding and reproduction and thus has implications for the role of the species in the ecosystem. \u003cbr/\u003eWith similarities to classic evolutionary hot spots, the Antarctic shelf and its Notothenioid radiation merit further exploration. The 2004 \"International Collaborative Expedition to collect and study Fish Indigenous to Sub-Antarctic Habitats,\" or, \"ICEFISH,\" provided a platform for collection of notothenioid fishes from sub-Antarctic waters between South America and Africa, which will be examined in this project. This study will determine buoyancy for samples of all notothenioid species captured during the ICEFISH cruise. This essential aspect of the biology is known for only 19% of the notothenioid fauna. Also, the gross and microscopic anatomy of brains and sense organs of the phyletically basal families Bovichtidae, Eleginopidae, and of the non-Antarctic species of the primarily Antarctic family Nototheniidae will be examined. The fish biodiversity and endemicity in poorly known localities along the ICEFISH cruise track, seamounts and deep trenches will be quantified. Broader impacts include improved information for comprehending and conserving biodiversity, a scientific and societal priority.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Eastman, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes", "uid": "p0000106", "west": -180.0}, {"awards": "0228842 Grew, Edward", "bounds_geometry": "POLYGON((76 -69.3,76.05 -69.3,76.1 -69.3,76.15 -69.3,76.2 -69.3,76.25 -69.3,76.3 -69.3,76.35 -69.3,76.4 -69.3,76.45 -69.3,76.5 -69.3,76.5 -69.32,76.5 -69.34,76.5 -69.36,76.5 -69.38,76.5 -69.4,76.5 -69.42,76.5 -69.44,76.5 -69.46,76.5 -69.48,76.5 -69.5,76.45 -69.5,76.4 -69.5,76.35 -69.5,76.3 -69.5,76.25 -69.5,76.2 -69.5,76.15 -69.5,76.1 -69.5,76.05 -69.5,76 -69.5,76 -69.48,76 -69.46,76 -69.44,76 -69.42,76 -69.4,76 -69.38,76 -69.36,76 -69.34,76 -69.32,76 -69.3))", "dataset_titles": "Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?", "datasets": [{"dataset_uid": "600030", "doi": "10.15784/600030", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Geochronology; Solid Earth", "people": "Grew, Edward", "repository": "USAP-DC", "science_program": null, "title": "Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?", "url": "https://www.usap-dc.org/view/dataset/600030"}], "date_created": "Tue, 10 Mar 2009 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role and fate of Boron in high-grade metamorphic rocks of the Larsemann Hills region of Antarctica. Trace elements provide valuable information on the changes sedimentary rocks undergo as temperature and pressure increase during burial. One such element, boron, is particularly sensitive to increasing temperature because of its affinity for aqueous fluids, which are lost as rocks are buried. Boron contents of unmetamorphosed pelitic sediments range from 20 to over 200 parts per million, but rarely exceed 5 parts per million in rocks subjected to conditions of the middle and lower crust, that is, temperatures of 700 degrees C or more in the granulite-facies, which is characterized by very low water activities at pressures of 5 to 10 kbar (18-35 km burial). Devolatization reactions with loss of aqueous fluid and partial melting with removal of melt have been cited as primary causes for boron depletion under granulite-facies conditions. Despite the pervasiveness of both these processes, rocks rich in boron are locally found in the granulite-facies, that is, there are mechanisms for retaining boron during the metamorphic process. The Larsemann Hills, Prydz Bay, Antarctica, are a prime example. More than 20 lenses and layered bodies containing four borosilicate mineral species crop out over a 50 square kilometer area, which thus would be well suited for research on boron-rich granulite-facies metamorphic rocks. \u003cbr/\u003e\u003cbr/\u003eWhile most investigators have focused on the causes for loss of boron, this work will investigate how boron is retained during high-grade metamorphism. Field observations and mapping in the Larsemann Hills, chemical analyses of minerals and their host rocks, and microprobe age dating will be used to identify possible precursors and deduce how the precursor materials recrystallized into borosilicate rocks under granulite-facies conditions. The working hypothesis is that high initial boron content facilitates retention of boron during metamorphism because above a certain threshold boron content, a mechanism \"kicks in\" that facilitates retention of boron in metamorphosed rocks. For example, in a rock with large amounts of the borosilicate tourmaline, such as stratabound tourmalinite, the breakdown of tourmaline to melt could result in the formation of prismatine and grandidierite, two borosilicates found in the Larsemann Hills. This situation is rarely observed in rocks with modest boron content, in which breakdown of tourmaline releases boron into partial melts, which in turn remove boron when they leave the system. Stratabound tourmalinite is associated with manganese-rich quartzite, phosphorus-rich rocks and sulfide concentrations that could be diagnostic for recognizing a tourmalinite protolith in a highly metamorphosed complex where sedimentary features have been destroyed by deformation. Because partial melting plays an important role in the fate of boron during metamorphism, our field and laboratory research will focus on the relationship between the borosilicate units, granite pegmatites and other granitic intrusives. The results of our study will provide information on cycling of boron at deeper levels in the Earth\u0027s crust and on possible sources of boron for granites originating from deep-seated rocks.\u003cbr/\u003e\u003cbr/\u003eAn undergraduate student will participate in the electron microprobe age-dating of monazite and xenotime as part of a senior project, thereby integrating the proposed research into the educational mission of the University of Maine. In response to a proposal for fieldwork, the Australian Antarctic Division, which maintains Davis station near the Larsemann Hills, has indicated that they will support the Antarctic fieldwork.", "east": 76.5, "geometry": "POINT(76.25 -69.4)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION", "locations": null, "north": -69.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Grew, Edward", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.5, "title": "Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?", "uid": "p0000431", "west": 76.0}, {"awards": "0440602 Saltzman, Eric; 0440509 Battle, Mark; 0440498 White, James; 0440701 Severinghaus, Jeffrey; 0440759 Sowers, Todd; 0440615 Brook, Edward", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica; Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core; Methane Isotopes from the WAIS Divide Ice Core; Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A; WAIS ice core Methane Data, Carbon Dioxide Data", "datasets": [{"dataset_uid": "609638", "doi": "10.7265/N56971HF", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Severinghaus, Jeffrey P.; Orsi, Anais J.", "repository": "USAP-DC", "science_program": null, "title": "Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A", "url": "https://www.usap-dc.org/view/dataset/609638"}, {"dataset_uid": "609412", "doi": "10.7265/N5251G40", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core", "people": "Saltzman, Eric", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609412"}, {"dataset_uid": "609435", "doi": "10.7265/N5J67DW0", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Methane Isotopes from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609435"}, {"dataset_uid": "609493", "doi": "10.7265/N5319SV3", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph; Taylor, Kendrick C.; Sowers, Todd A.; Brook, Edward J.; Mitchell, Logan E", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS ice core Methane Data, Carbon Dioxide Data", "url": "https://www.usap-dc.org/view/dataset/609493"}, {"dataset_uid": "601357", "doi": "10.15784/601357", "keywords": "Antarctica; Atmospheric Gases; Gas Measurement; Ice Core; Ice Core Gas Records; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core", "url": "https://www.usap-dc.org/view/dataset/601357"}], "date_created": "Tue, 03 Feb 2009 00:00:00 GMT", "description": "This award supports a project to measure the elemental and isotopic composition of firn air and occluded air in shallow boreholes and ice cores from the WAIS Divide site, the location of a deep ice-coring program planned for 2006-07 and subsequent seasons. The three primary objectives are: 1) to establish the nature of firn air movement and trapping at the site to aid interpretations of gas data from the deep core; 2) to expand the suite of atmospheric trace gas species that can be measured in ice and replicate existing records of other species; and 3) to inter-calibrate all collaborating labs to insure that compositional and isotopic data sets are inter-comparable. The program will be initiated with a shallow drilling program during the 05/06 field season which will recover two 300+m cores and firn air samples. The ice core and firn air will provide more than 700 years of atmospheric history that will be used to address a number of important questions related to atmospheric change over this time period. The research team consists of six US laboratories that also plan to participate in the deep core program. This collaborative research program has a number of advantages. First, the scientists will be able to coordinate sample allocation a priori to maximize the resolution and overlap of records of interrelated species. Second, sample registration will be exact, allowing direct comparison of all records. Third, a coherent data set will be produced at the same time and all PI.s will participate in interpreting and publishing the results. This will insure that the best possible understanding of gas records at the WAIS Divide site will be achieved, and that all work necessary to interpret the deep core is conducted in a timely fashion. The collaborative structure created by the proposal will encourage sharing of techniques, equipment, and ideas between the laboratories. The research will identify impacts of various industrial/agricultural activities and help to distinguish them from natural variations, and will include species for which there are no long records of anthropogenic impact. The work will also help to predict future atmospheric loadings. The project will contribute to training scientists at several levels, including seven undergraduates, two graduate students and one post doctoral fellow.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GC-MS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e SPECTROMETERS \u003e SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; WAIS Divide; Firn; LABORATORY; Ice Core; Firn Air Isotope Measurements; Shallow Firn Air; FIELD INVESTIGATION; Ice Core Gas Records; GROUND-BASED OBSERVATIONS; Firn Isotopes; Wais Divide-project; Gas Data; Polar Firn Air; Not provided; Trace Gas Species; Trapped Gases; West Antarctic Ice Sheet; Deep Core; Ice Sheet; Gas; Firn Air Isotopes; FIELD SURVEYS; Air Samples; Atmospheric Gases; Isotope; Cores; Atmosphere; Ice Core Data; Surface Temperatures; Firn Air; Borehole; Antarctica", "locations": "West Antarctic Ice Sheet; Antarctica; WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Battle, Mark; Mischler, John; Saltzman, Eric; Aydin, Murat; White, James; Brook, Edward J.; Orsi, Anais J.; Severinghaus, Jeffrey P.; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site", "uid": "p0000368", "west": -112.085}, {"awards": "0229546 MacAyeal, Douglas", "bounds_geometry": "POINT(-178 -78)", "dataset_titles": "collection of nascent rift images and description of station deployment; Continuous GPS (static) Data from the Ross Ice Shelf, Antarctica; Giant Icebergs of the Ross Sea, in situ Drift and Weather Measurements, Antarctica; Iceberg Firn Temperatures, Antarctica; Iceberg Harmonic Tremor, Seismometer Data, Antarctica; Iceberg Satellite imagery from stations and ice shelves (full data link not provided); Iceberg Tiltmeter Measurements, Antarctica; Ice Shelf Rift Time-Lapse Photography, Antarctica; Incorporated Research Institutions for Seismology; Nascent Iceberg Webcam Images available during the deployment period; Ross Ice Shelf Firn Temperature, Antarctica; The files contain a short header (number of data samples, sample rate, start time, stop time, channel title)The time series data then follow the header above.; This site mirrors the NSIDC website archive.", "datasets": [{"dataset_uid": "609353", "doi": "10.7265/N5GF0RFF", "keywords": "Glaciology; Iceberg; Oceans; Ross Ice Shelf; Sea Ice; Southern Ocean; Tiltmeter", "people": "Bliss, Andrew; MacAyeal, Douglas; Kim, Young-Jin", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Tiltmeter Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609353"}, {"dataset_uid": "609351", "doi": "10.7265/N5QV3JGV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Photo/video; Photo/Video; Ross Ice Shelf", "people": "MacAyeal, Douglas; Brunt, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Ice Shelf Rift Time-Lapse Photography, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609351"}, {"dataset_uid": "609350", "doi": "10.7265/N5VM496K", "keywords": "AWS; Glaciology; GPS; Iceberg; Meteorology; Oceans; Ross Sea; Sea Ice; Southern Ocean; Weatherstation", "people": "Aster, Richard; Okal, Emile; Bassis, Jeremy; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Giant Icebergs of the Ross Sea, in situ Drift and Weather Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609350"}, {"dataset_uid": "609349", "doi": "10.7265/N5445JD6", "keywords": "Geology/Geophysics - Other; Glaciology; Iceberg; Oceans; Ross Sea; Sea Ice; Seismometer; Southern Ocean", "people": "Okal, Emile; MacAyeal, Douglas; Aster, Richard; Bassis, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Harmonic Tremor, Seismometer Data, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609349"}, {"dataset_uid": "609347", "doi": "10.7265/N57W694M", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ross Ice Shelf; Southern Ocean", "people": "Brunt, Kelly; King, Matthew; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Continuous GPS (static) Data from the Ross Ice Shelf, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609347"}, {"dataset_uid": "609354", "doi": "10.7265/N5BP00Q3", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ross Ice Shelf; Snow/ice; Snow/Ice; Temperature", "people": "Muto, Atsu; Sergienko, Olga; MacAyeal, Douglas; Scambos, Ted", "repository": "USAP-DC", "science_program": null, "title": "Ross Ice Shelf Firn Temperature, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609354"}, {"dataset_uid": "001598", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The files contain a short header (number of data samples, sample rate, start time, stop time, channel title)The time series data then follow the header above.", "url": "http://nsidc.org"}, {"dataset_uid": "001639", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "collection of nascent rift images and description of station deployment", "url": "http://thistle.org/nascent/index.shtml"}, {"dataset_uid": "001684", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "This site mirrors the NSIDC website archive.", "url": "http://uwamrc.ssec.wisc.edu/"}, {"dataset_uid": "001685", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Incorporated Research Institutions for Seismology", "url": "http://www.iris.edu/data/sources.htm"}, {"dataset_uid": "002568", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Iceberg Satellite imagery from stations and ice shelves (full data link not provided)", "url": "http://amrc.ssec.wisc.edu/"}, {"dataset_uid": "002504", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Nascent Iceberg Webcam Images available during the deployment period", "url": "https://amrc.ssec.wisc.edu/data/iceberg.html"}, {"dataset_uid": "609352", "doi": "10.7265/N5M61H55", "keywords": "Glaciology; Iceberg; Oceans; Ross Ice Shelf; Sea Ice; Snow/ice; Snow/Ice; Southern Ocean; Temperature", "people": "Sergienko, Olga; Thom, Jonathan; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Firn Temperatures, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609352"}], "date_created": "Fri, 19 Sep 2008 00:00:00 GMT", "description": "This award supports the study of the drift and break-up of Earth\u0027s largest icebergs, which were recently released into the Ross Sea of Antarctica as a result of calving from the Ross Ice Shelf. The scientific goals of the study are to determine the physics of iceberg motion within the dynamic context of ocean currents, winds, and sea ice, which determine the forces that drive iceberg motion, and the relationship between the iceberg and geographically and topographically determined pinning points on which the iceberg can ground. In addition, the processes by which icebergs influence the local environments (e.g., sea ice conditions near Antarctica, access to penguin rookeries, air-sea heat exchange and upwelling at iceberg margins, nutrient fluxes) will be studied. The processes by which icebergs generate globally far-reaching ocean acoustic signals that are detected within the global seismic (earthquake) sensing networks will also be studied. A featured element of the scientific research activity will be a field effort to deploy automatic weather stations, seismometer arrays and GPS-tracking stations on several of the largest icebergs presently adrift, or about to be adrift, in the Ross Sea. Data generated and relayed via satellite to home institutions in the Midwest will motivate theoretical analysis and computer simulation; and will be archived on an \"iceberg\" website (http://amrc.ssec.wisc.edu/amrc/iceberg.html) for access by scientists and the general public. At the most broad level, the study is justified by the fact that icebergs released by the Antarctic ice sheet represent the largest movements of fresh water within the natural environment (e.g., several of the icebergs to be studied, B15, C19 and others calved since 2000 CE, represent over 6000 cubic kilometers of fresh water-an amount roughly equivalent to 100 years of the flow of the Nile River). A better understanding of the impact of iceberg drift through the environment, and particularly the impact on ocean stratification and mixing, is essential to the understanding of the abrupt global climate changes witnessed by proxy during the ice age and of concern under conditions of future greenhouse warming. On a more specific level, the study will generate a knowledge base useful for the better management of Antarctic logistical resources (e.g., the shipping lanes to McMurdo Station) that can occasionally be influenced by adverse effects icebergs have on sea ice conditions.", "east": -178.0, "geometry": "POINT(-178 -78)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HUMIDITY SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e TEMPERATURE LOGGERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e TEMPERATURE PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "SEISMOLOGICAL STATIONS; Pressure; AWS; Velocity Measurements; Firn Temperature Measurements; Ice Velocity; Seismology; Ice Sheet Elevation; Harmonic Tremor; Ice Shelf Temperature; Wind Speed; Iceberg; Ice Surface Elevation; Non-Volcanic Tremor; Not provided; Antarctic; Iceberg Tremor; Solar Radiation; Antarctic Ice Sheet; Ross Ice Shelf; Elevation; GPS; Temperature Profiles; Ice Shelf Rift Camera; GROUND STATIONS; Latitude; GROUND-BASED OBSERVATIONS; Ice Shelf Weather; FIELD INVESTIGATION; ARWS; Surface Elevation; Ice Shelf Flow; Antarctica; FIELD SURVEYS; Camera; Seismometer; Iceberg Weather (aws); Ice Movement; Photo; Wind Direction; Iceberg Snow Accumulation; Tremor And Slow Slip Events; AWS Climate Data; Location; Iceberg Drift; Iceberg Collisions; Iceberg Tilt; Atmospheric Pressure; Iceberg Seismicity; Firn Temperature", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; Ross Ice Shelf", "north": -78.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Okal, Emile; Aster, Richard; Bassis, Jeremy; Kim, Young-Jin; Bliss, Andrew; Sergienko, Olga; Thom, Jonathan; Scambos, Ted; Muto, Atsu; Brunt, Kelly; King, Matthew; Parker, Tim; Okal, Marianne; Cathles, Mac; MacAyeal, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e ARWS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "AMRDC; IRIS; NSIDC; Project website; USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research of Earth\u0027s Largest Icebergs", "uid": "p0000117", "west": -178.0}, {"awards": "0536870 Rogers, Scott", "bounds_geometry": "POINT(-106.8 -72.4667)", "dataset_titles": "Comprehensive Biological Study of Vostok Accretion Ice", "datasets": [{"dataset_uid": "600052", "doi": "10.15784/600052", "keywords": "Antarctica; Biota; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrothermal Vent; Lake Vostok; Microbes; Subglacial Lake", "people": "Rogers, Scott O.", "repository": "USAP-DC", "science_program": null, "title": "Comprehensive Biological Study of Vostok Accretion Ice", "url": "https://www.usap-dc.org/view/dataset/600052"}], "date_created": "Tue, 02 Sep 2008 00:00:00 GMT", "description": "The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. The will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons.", "east": -106.8, "geometry": "POINT(-106.8 -72.4667)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -72.4667, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rogers, Scott O.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.4667, "title": "Comprehensive Biological Study of Vostok Accretion Ice", "uid": "p0000566", "west": -106.8}, {"awards": "0238281 Marsh, Adam", "bounds_geometry": "POLYGON((163 -77,163.4 -77,163.8 -77,164.2 -77,164.6 -77,165 -77,165.4 -77,165.8 -77,166.2 -77,166.6 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.6 -78,166.2 -78,165.8 -78,165.4 -78,165 -78,164.6 -78,164.2 -78,163.8 -78,163.4 -78,163 -78,163 -77.9,163 -77.8,163 -77.7,163 -77.6,163 -77.5,163 -77.4,163 -77.3,163 -77.2,163 -77.1,163 -77))", "dataset_titles": "Marine Invertebrates of McMurdo Sound", "datasets": [{"dataset_uid": "600034", "doi": "10.15784/600034", "keywords": "Antarctica; Biota; Mcmurdo Sound; Oceans; Photo/video; Photo/Video; Southern Ocean", "people": "Marsh, Adam G.", "repository": "USAP-DC", "science_program": null, "title": "Marine Invertebrates of McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/600034"}], "date_created": "Mon, 09 Jun 2008 00:00:00 GMT", "description": "Although the cold ocean ecosystems comprise seventy-two percent of the biosphere on Earth by volume, they remain sparsely inhabited and relatively unexploited, particularly in terms of metazoan phyla. Consequently, the few animals that can exist at this border of intracellular freezing represent ideal systems for exploring genomic-level processes of environmental adaptations. Understanding life at a margin of the biosphere is likely to convey significant insights into the essential genomic processes necessary for survival under intense selection pressures. This study of adaptive mechanisms in genomic networks focuses on an experimental system that faces a formidable challenge for viability at low water temperatures: embryonic development at sea water temperatures of -1.8 o C in two Antarctic echinoderms, the sea star Odontaster validus and the sea urchin Sterechinus neumayeri. The project strategy will quantify temperature effects on gene expression and protein turnover networks during early development using a Bayesian network analysis to identify clusters of genes and proteins whose expression levels are associated in fixed, synergistic interactions. Ultimately, there is a simple question to be addressed: Is it more or less difficult (complex) for an embryo to develop in an extreme environment? To answer this question, the research plan will decipher network topologies and subnet structuring to uncover gene connectivity patterns associated with embryo development in this polar environment. This is the new area of Environmental Genomics that the PI will explore by expanding his research experience into computational network analyses. Overall, there is a significant need for integrative biologists in the future development of environmental sciences, particularly for the application of genomic-scale technologies to answer ecological-scale questions. The educational goals of this CAREER proposal are focused at two levels in terms of interesting young students in the developing field of environmental genomics: 1) increasing the racial diversity of the scientists attracted to environmental research, and 2) increasing the awareness of career opportunities within environmental research.\u003cbr/\u003eThese educational objectives are incorporated into the research plan to engage students with the excitement of working in an extreme environment such as Antarctica and to interest them in the insights that genome-level research can reveal about how organisms are adapted to specific habitats. Working in a remote, extreme environment such as Antarctica is always a challenge. However, the adventurous nature of the work can be utilized to establish educational and outreach components of high interest to both undergraduate students and the public in general. The proposed plan will bring the experience of working in Antarctica to a larger audience through several means. These include the following: the project theme of environmental genomics will be incorporated into a new Bioinformatics curriculum currently being developed at the University of Delaware; an intern program will be implemented to involved minority undergraduate students in summer research in the United States and then to bring the students to Antarctica to participate in the research; and a K-12 education program will bring the excitement of working in Antarctica to the classrooms of thousands of children (U.S. and international) through a program produced with the Marine Science Public Education Office at the University of Delaware.", "east": 167.0, "geometry": "POINT(165 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS", "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marsh, Adam G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "CAREER: Genomic Networks for Cold-Adaptation in Embryos of Polar Marine Invertebrates", "uid": "p0000240", "west": 163.0}, {"awards": "0337656 Lee, Richard", "bounds_geometry": "POLYGON((-64.1 -64.75,-64.085 -64.75,-64.07 -64.75,-64.055 -64.75,-64.04 -64.75,-64.025 -64.75,-64.01 -64.75,-63.995 -64.75,-63.98 -64.75,-63.965 -64.75,-63.95 -64.75,-63.95 -64.757,-63.95 -64.764,-63.95 -64.771,-63.95 -64.778,-63.95 -64.785,-63.95 -64.792,-63.95 -64.799,-63.95 -64.806,-63.95 -64.813,-63.95 -64.82,-63.965 -64.82,-63.98 -64.82,-63.995 -64.82,-64.01 -64.82,-64.025 -64.82,-64.04 -64.82,-64.055 -64.82,-64.07 -64.82,-64.085 -64.82,-64.1 -64.82,-64.1 -64.813,-64.1 -64.806,-64.1 -64.799,-64.1 -64.792,-64.1 -64.785,-64.1 -64.778,-64.1 -64.771,-64.1 -64.764,-64.1 -64.757,-64.1 -64.75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 06 Jun 2008 00:00:00 GMT", "description": "Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. \u003cbr/\u003eOverwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. \u003cbr/\u003eThis project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.", "east": -63.95, "geometry": "POINT(-64.025 -64.785)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.75, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Denlinger, David; Lee, Richard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -64.82, "title": "Physiological and Molecular Mechanisms of Stress Tolerance in a Polar Insect", "uid": "p0000742", "west": -64.1}, {"awards": "0230469 Wise, Sherwood", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 31 Jul 2007 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports the development of a standardized diatom image catalog or database. Diatoms are considered by many to be the most important microfossil group used today in the study of Antarctic Cenozoic marine deposits south of the Polar Front, from the near shore to deep sea. These microfossils, with walls of silica called frustules, are produced by single-celled plants (algae of the Class Bacillariophyceae) in a great variety of forms. Consequently, they have great biostratigraphic importance in the Southern Ocean and elsewhere for determining the age of marine sediments. Also, paleoclimatic and paleoceanographic studies increasingly rely on fossil diatom data. Changing biogeographic distributions of given taxa indicate shifting paleoecological conditions and provide evidence of the surface productivity and temperatures of ancient oceans. The generality of conclusions, though, is limited by variation in species concepts among workers. The broad research community relies, directly or indirectly, on the accurate identification of diatom species. Current technology can be used to greatly improve upon the standard references that have been used in making these identifications.\u003cbr/\u003e\u003cbr/\u003eThis project will develop an interactive digital-image catalog of modern and Cenozoic fossil diatoms of the Southern Ocean called \"DiatomWare\" for use by specialists and educators as an aid in rapid, accurate, and consistent species identification. As such, this will be a researcher\u0027s resource. It will be especially useful where it is not possible to maintain standard library resources such as onboard research vessels or at remote stations such as McMurdo Station. Major Antarctic geological drilling initiatives such as the new SHALDRIL project and the pending ANDRILL project will benefit from this product because they will rely heavily on diatom biostratigraphy to achieve their research objectives. The DiatomWare image database will be modeled on NannoWare, which was released in October 2002 on CD-ROM as a publication of the International Nannoplankton Association. BugCam will be adapted and modified as necessary to run the DiatomWare database, which can then be run from desktop or laptop computers. Images and text for the database will be scanned from the literature or captured in digital form from light or scanning electron microscopes.\u003cbr/\u003e\u003cbr/\u003eThe software interface will include a number of data fields that can be accessed by the click of a mouse button. Primary information will be the images and descriptions of the holotypes. In addition, representative images of paratypes or hypotypes will be included whenever possible in plain transmitted, differential interference contrast light and, when available, as drawings and SEM images. Also included will be a 35-word or less English diagnosis (\"mini-description\"), the biostratigraphic range in terms of zones and linear time, bibliographic references, lists of species considered junior synonyms, and similar species. The list of similar species will be cross-referenced with their respective image files to enable quick access for direct visual comparison on the viewing screen. Multiple images can be brought to the viewing screen simultaneously, and a zoom feature will permit image examination at a wide range of magnifications. Buttons will allow range charts, a bibliography, and key public-domain publications from the literature to be called up from within the program. The DiatomWare/BugCam package will be distributed at a nominal cost through a major nonprofit society via CD-ROM and free to Internet users on the Worldwide Web. Quality control measures will include critical review of the finalized database by a network of qualified specialists. The completed database will include descriptions and images of between 350 and 400 species, including fossil as well as modern forms that have no fossil record.\u003cbr/\u003e\u003cbr/\u003eThe development of the proposed diatom image database will be important to all research fields that depend on accurate biostratigraphic dating and paleoenvironmental interpretation of Antarctic marine sediments and plankton. The database will also serve as a valuable teaching tool for micropaleontology students and their professors, will provide a rapid means of keying down species for micropaleontologists of varying experience and background, and will promote a uniformity of taxonomic concepts since it will be developed and continuously updated with the advice of a community of nannofossil fossil experts. Broad use of the database is anticipated since it will be widely available through the Internet and on CD-ROM for use on personal computers that do not require large amounts of memory, costly specialized programs, or additional hardware.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wise, Sherwood", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "DiatomWare: An Interactive Digital Image Catalog for Antarctic Cenozoic Diatoms", "uid": "p0000062", "west": null}, {"awards": "9909436 Farley, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 11 Jul 2007 00:00:00 GMT", "description": "9909436 \u003cbr/\u003eFarley\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an investigation of the uplift history of the Dry Valleys segment of the Transantarctic Mountains. The overall goal is to further constrain the exhumation history of the Transantarctic Mountains by using the newly developed apatite (U-Th)/He dating method on samples collected in vertical profiles. This approach, combined with existing apatite fission track information will constrain the rate and patterns of exhumation across the Transantarctic Mountains since their inception as a rift-flank uplift in the early Cenozoic.\u003cbr/\u003e\u003cbr/\u003eThis project will complement other projects and build on previous interpretations of the exhumation and tectonic history determined using apatite fission track thermochronology. It will bridge the gap between information on erosion rates determined from fission track thermochronology and from cosmogenic surface exposure dating and integrate the exhumation history of the mountains with their landscape evolution. As such, the results from this project will address an outstanding problem in Antarctic science; namely the stability of the East Antarctic Ice Sheet, and the timing of the transition from a \"warm\" dynamic ice sheet to a cold polar ice sheet. Highly relevant to this issue is the landscape evolution of the Transantarctic Mountains because many diverse lines of evidence for the rate of landscape evolution have been used to argue for a dynamic ice sheet up until either the Pliocene (the \"dynamic\" ice sheet model) or the middle Miocene (the \"stable\" ice sheet model). Understanding the past stability or dynamic fluctuations of the East Antarctic ice sheet with respect to the climate record is, of course, important for understanding how the present ice sheet may respond to global warming.\u003cbr/\u003e\u003cbr/\u003eThe specific objective of this project is to determine apatite (U-Th)/He age versus elevation trends for a number of vertical profiles from locations within the Transantarctic Mountain front and across the structural grain of the range. Fission track data already exist for all of these profiles, with apatite fission track ages ranging from 150-30 Ma. The greater precision of the (U-Th)/He technique and the fact it records information at lower temperatures (closure temperature of ~70 degrees Celsius; limits of 40-85 degrees Celsius for the He partial retention zone) will allow examination of the exhumation history of the TAM in more detail from ca 130 Ma to ~20 Ma. Another facet is to examine areas where Cretaceous exhumation is recorded and areas where the fission track profiles indicate periods of thermal and tectonic stability and minimal erosion throughout the Cretaceous. The variation of timing of the onset of more rapid exhumation accompanying uplift and formation of the Transantarctic Mountains in the early Cenozoic will also be examined.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Farley, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Exhumation of the Transantarctic Mountains: Constraints from (U-Th)/He Dating of Apatites", "uid": "p0000281", "west": null}, {"awards": "0233303 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.\u003cbr/\u003eThis award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.\u003cbr/\u003eA better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Ice Sheet; Basal Melting; Ice Shelf Meltwater; Not provided; Oceanography; Ice Velocity; Glaciology; Sea Level Rise; Ice Sheet Stability; Mass; Ross Ice Sheet; Numerical Model; Basal Freezing; Ice Cavity Circulations; George VI Ice Shelf; Outflow", "locations": "Ross Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Melting and Calving of Antarctic Ice Shelves", "uid": "p0000730", "west": null}, {"awards": "9615502 Harrison, William", "bounds_geometry": "POINT(-148.822 -81.655)", "dataset_titles": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "datasets": [{"dataset_uid": "609214", "doi": "10.7265/N5HH6H00", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Strain; WAISCORES", "people": "Elsberg, Daniel; Pettit, Erin; Zumberge, Mark; Waddington, Edwin D.; Harrison, William; Morack, James", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "url": "https://www.usap-dc.org/view/dataset/609214"}], "date_created": "Thu, 22 Feb 2007 00:00:00 GMT", "description": "This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the \"vertical strain rate\" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.", "east": -148.822, "geometry": "POINT(-148.822 -81.655)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e STRAIN GAUGE WHEATSTONE BRIDGE", "is_usap_dc": true, "keywords": "Ice Core Data; GROUND-BASED OBSERVATIONS; Antarctica; USAP-DC; Ice Core; Ice Analysis; Ice Flow; Ice Deformation; Antarctic Ice Sheet; West Antarctic Ice Sheet; Vertical Strain Rate; Ice Sheet; Glaciology; West Antarctica; Ice; Ice Movement", "locations": "Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet", "north": -81.655, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Harrison, William; Morack, James; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.655, "title": "Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome", "uid": "p0000601", "west": -148.822}, {"awards": "9526566 Bindschadler, Robert", "bounds_geometry": null, "dataset_titles": "Decadal-Length Composite West Antarctic Air Temperature Records", "datasets": [{"dataset_uid": "609097", "doi": "10.7265/N55D8PS0", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Meteorology; Temperature; West Antarctica", "people": "Stearns, Charles R.; Shuman, Christopher A.", "repository": "USAP-DC", "science_program": null, "title": "Decadal-Length Composite West Antarctic Air Temperature Records", "url": "https://www.usap-dc.org/view/dataset/609097"}], "date_created": "Tue, 28 Nov 2006 00:00:00 GMT", "description": "This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SMMR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SSM/I", "is_usap_dc": true, "keywords": "West Antarctica; Near-Surface Air Temperatures; Surface Temperatures; Special Sensor Microwave/imager; Passive Microwave Brightness Temperatures; Scanning Multichannel Microwave Radiometer; SSM/I; SSMR; AWS Byrd Station; NIMBUS-7; Emissivity Modeling; Antarctica; West Antarctic Ice Sheet; Not provided; DMSP; AWS Siple; Automated Weather Station; AWS Lynn; AWS Lettau; AWS", "locations": "Antarctica; West Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bindschadler, Robert; Shuman, Christopher A.; Stearns, Charles R.", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e DEFENSE METEOROLOGICAL SATELLITE PROGRAM (DMSP) \u003e DMSP; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NIMBUS \u003e NIMBUS-7", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Passive Microwave Remote Sensing for Paleoclimate Indicators at Siple Dome, Antarctica", "uid": "p0000191", "west": null}, {"awards": "0230448 Severinghaus, Jeffrey; 0230260 Bender, Michael", "bounds_geometry": "POLYGON((-75.34 86.6,-68.742 86.6,-62.144 86.6,-55.546 86.6,-48.948 86.6,-42.35 86.6,-35.752 86.6,-29.154 86.6,-22.556 86.6,-15.958 86.6,-9.36 86.6,-9.36 83.618,-9.36 80.636,-9.36 77.654,-9.36 74.672,-9.36 71.69,-9.36 68.708,-9.36 65.726,-9.36 62.744,-9.36 59.762,-9.36 56.78,-15.958 56.78,-22.556 56.78,-29.154 56.78,-35.752 56.78,-42.35 56.78,-48.948 56.78,-55.546 56.78,-62.144 56.78,-68.742 56.78,-75.34 56.78,-75.34 59.762,-75.34 62.744,-75.34 65.726,-75.34 68.708,-75.34 71.69,-75.34 74.672,-75.34 77.654,-75.34 80.636,-75.34 83.618,-75.34 86.6))", "dataset_titles": "Firn Air Inert Gas and Oxygen Observations from Siple Dome, 1996, and the South Pole, 2001; Trapped Gas Composition and Chronology of the Vostok Ice Core", "datasets": [{"dataset_uid": "609311", "doi": "10.7265/N5P26W12", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Lake Vostok; Paleoclimate; Vostok; Vostok Ice Core", "people": "Suwa, Makoto; Bender, Michael", "repository": "USAP-DC", "science_program": null, "title": "Trapped Gas Composition and Chronology of the Vostok Ice Core", "url": "https://www.usap-dc.org/view/dataset/609311"}, {"dataset_uid": "609290", "doi": "10.7265/N5FJ2DQC", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciology; Paleoclimate; Siple Dome; Snow/ice; Snow/Ice; South Pole", "people": "Battle, Mark; Bender, Michael; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Firn Air Inert Gas and Oxygen Observations from Siple Dome, 1996, and the South Pole, 2001", "url": "https://www.usap-dc.org/view/dataset/609290"}], "date_created": "Wed, 18 Jan 2006 00:00:00 GMT", "description": "High latitude deep ice cores contain fundamental records of polar temperatures, atmospheric dust loads (and continental aridity), greenhouse gas concentrations, the status of the biosphere, and other essential properties of past environments. An accurate chronology for these records is needed if their significance is to be fully realized. The dating challenge has stimulated efforts at orbital tuning. In this approach, one varies a timescale, within allowable limits, to optimize the match between a paleoenvironmental property and a curve of insolation through time. The ideal property would vary with time due to direct insolation forcing. It would be unaffected by complex climate feedbacks and teleconnections, and it would give a clean record with high signal/noise ratio. It is argued strongly that the O2/N2 ratio of ice core trapped gases is such a property, and evidence is presented that this property, whose atmospheric ratio is nearly constant, is tied to local summertime insolation. This award will support a project to analyze the O2/N2 ratios at 1 kyr intervals from ~ 115-400 ka in the Vostok ice core. Ancillary measurements will be made of Ar/N2, and Ne/N2 and heavy noble gas ratios, in order to understand bubble close-off fractionation and its manifestation in the Vostok trapped gas record. O2/N2 variations will be matched with summertime insolation at Vostok to achieve a high-accuracy chronology for the Vostok core. The Vostok and other correlatable climate records will then be reexamined to improve our understanding of the dynamics of Pleistocene climate change.", "east": 106.8, "geometry": "POINT(106.8 -72.4667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Paleoclimate; Siple Dome; Ice Age; Shallow Firn Air; Firn Air Isotope Measurements; Polar Firn Air; Ice Sample Gas Integrity; Oxygen Isotope; Noble Gas; Ice Core Gas Records; Atmospheric Gases; Trapped Gases; Not provided; LABORATORY; Vostok; Firn Air Isotopes; Thermal Fractionation; Ice Core Chemistry; Trapped Air Bubbles; Ice Core; Antarctica; South Pole; Ice Core Data; GROUND-BASED OBSERVATIONS; Gas Age; Firn Isotopes", "locations": "Antarctica; Vostok; Siple Dome; South Pole", "north": -72.4667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Battle, Mark; Bender, Michael; Suwa, Makoto; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -72.4667, "title": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core", "uid": "p0000257", "west": 106.8}, {"awards": "0125276 Albert, Mary; 0125570 Scambos, Ted", "bounds_geometry": null, "dataset_titles": "Access AGDC data online by navigating to Data Sets. Data sets are arranged by Principal Investigators. Access data that are combined into multiple data sets, or compiled products.; AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation; GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation; Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation; The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "datasets": [{"dataset_uid": "609299", "doi": "10.7265/N5639MPD", "keywords": "Antarctica; East Antarctic Plateau; Glaciology; Physical Properties; Snow/ice; Snow/Ice", "people": "Courville, Zoe; Cathles, Mac; Albert, Mary R.", "repository": "USAP-DC", "science_program": null, "title": "Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609299"}, {"dataset_uid": "001343", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "url": "https://nsidc.org/data/agdc/"}, {"dataset_uid": "609282", "doi": "10.7265/N5Q23X5F", "keywords": "Antarctica; East Antarctic Plateau; Glaciology; GPR; GPS; Navigation; Paleoclimate; Snow/ice; Snow/Ice", "people": "Bauer, Rob; Scambos, Ted", "repository": "USAP-DC", "science_program": null, "title": "GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609282"}, {"dataset_uid": "001669", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access AGDC data online by navigating to Data Sets. Data sets are arranged by Principal Investigators. Access data that are combined into multiple data sets, or compiled products.", "url": "http://nsidc.org/data/agdc_investigators.html"}, {"dataset_uid": "609283", "doi": "10.7265/N5K935F3", "keywords": "Antarctica; Atmosphere; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meteorology; Snow/ice; Snow/Ice", "people": "Fahnestock, Mark; Bauer, Rob; Haran, Terry; Scambos, Ted", "repository": "USAP-DC", "science_program": null, "title": "AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609283"}], "date_created": "Wed, 04 Jan 2006 00:00:00 GMT", "description": "This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e SNOWPACK TEMPERATURE PROBE; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PERMEAMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e AIR PERMEAMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e ARGOS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e WIND PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e DENSIOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e BALANCE", "is_usap_dc": true, "keywords": "Internal Layering; ICESAT; Vapor-Redeposition; Antarctic; Wind Speed; FIELD INVESTIGATION; Surface Morphology; Antarctica; GROUND-BASED OBSERVATIONS; ARWS; Polar Firn Air; Microstructure; Gas Diffusivity; WEATHER STATIONS; Surface Temperatures; RADARSAT-2; Ice Core; Wind Direction; AWS; Ice Sheet; Snow Pit; Dunefields; Climate Record; Megadunes; GROUND STATIONS; METEOROLOGICAL STATIONS; Antarctic Ice Sheet; Density; Atmospheric Pressure; Firn Permeability; FIELD SURVEYS; Radar; Permeability; Field Survey; Firn Temperature Measurements; Snow Megadunes; Thermal Conductivity; LANDSAT; Firn; Ice Core Interpretation; East Antarctic Plateau; Not provided; Surface Winds; Sublimation; Snow Density; Ice Climate Record; Glaciology; Snow Permeability; Air Temperature; Paleoenvironment; Automated Weather Station", "locations": "Antarctica; Antarctic Ice Sheet; Antarctic; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Courville, Zoe; Cathles, Mac; Scambos, Ted; Bauer, Rob; Fahnestock, Mark; Haran, Terry; Shuman, Christopher A.; Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e ARWS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e WEATHER STATIONS; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-2", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation", "uid": "p0000587", "west": null}, {"awards": "0338359 Saltzman, Eric", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br); Antarctic Ice Cores: Methyl Chloride and Methyl Bromide; Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core; Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples", "datasets": [{"dataset_uid": "601357", "doi": "10.15784/601357", "keywords": "Antarctica; Atmospheric Gases; Gas Measurement; Ice Core; Ice Core Gas Records; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core", "url": "https://www.usap-dc.org/view/dataset/601357"}, {"dataset_uid": "609313", "doi": "10.7265/N5DN430Q", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; ITASE; Paleoclimate; Siple Dome Ice Core; South Pole; SPRESSO; SPRESSO Ice Core", "people": "Saltzman, Eric; Aydin, Murat; Williams, Margaret; Tatum, Cheryl", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Cores: Methyl Chloride and Methyl Bromide", "url": "https://www.usap-dc.org/view/dataset/609313"}, {"dataset_uid": "609279", "doi": "10.7265/N53B5X3G", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br)", "url": "https://www.usap-dc.org/view/dataset/609279"}, {"dataset_uid": "609131", "doi": "10.7265/N5P848VP", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples", "url": "https://www.usap-dc.org/view/dataset/609131"}], "date_created": "Wed, 16 Nov 2005 00:00:00 GMT", "description": "This award supports the analysis, in Antarctic ice cores, of the ozone depleting substances methyl bromide (CH3Br) and methyl chloride (CH3Cl), and the sulfur-containing gas, carbonyl sulfide (OCS). The broad scientific goal is to assess the level and variability of these gases in the preindustrial atmosphere. This information will allow testing of current models for sources and sinks of these gases from the atmosphere, and to indirectly assess the impact of anthropogenic activities on their biogeochemical cycles. Longer-term records will shed light on the climatic sensitivity of the atmospheric burden of these gases, and ultimately on the biogeochemical processes controlling them. These gases are present in ice at parts per trillion levels, and the current database consists entirely of a small number of measurements made in from a shallow ice core from Siple Dome, Antarctica. This project will involve studies of ice core samples from three Antarctic sites: Siple Station, Siple Dome, and South Pole. The sampling strategy is designed to accomplish several objectives: 1) to verify the atmospheric mixing ratios previously observed in shallow Siple Dome ice for OCS, CH3Br, and CH3Cl at sites with very different accumulation rates and surface temperatures; 2) to obtain a well-dated, high resolution record from a high accumulation rate site (Siple Station), that can provide overlap in mean gas age with Antarctic firn air samples; 3) explore Holocene variability in trace gas mixing ratios; and 4) to make the first measurements of these trace gases in Antarctic glacial ice. In terms of broader impact on society, this research will help to provide a stronger scientific basis for policy decisions regulating the production and use of ozone-depleting and climate-active gases. Specifically, the methyl bromide results will contribute to the current debate on the impact of recent regulation (via the Montreal Protocol and its Amendments) on atmospheric levels. Determination of pre-industrial atmospheric variability of ozone-depleting substances will help place more realistic constraints on scenarios used for future projections of stratospheric ozone and its climatic impacts. This research will involve the participation of both graduate and undergraduate students.", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core Gas Records; Carbonyl Sulfide; Siple Coast; Chloride; Trapped Gases; Snow; Ice Core Chemistry; Chromatography; Siple; GROUND STATIONS; Atmospheric Gases; Ozone Depletion; AWS Siple; Ice Sheet; Ice Core Data; Antarctica; Glaciology; West Antarctica; Atmospheric Chemistry; Ice Core; Stratigraphy; LABORATORY; Methane; Mass Spectrometer; GROUND-BASED OBSERVATIONS; WAISCORES; Msa; Mass Spectrometry; Not provided; Siple Dome; Gas Measurement", "locations": "Antarctica; Siple Coast; Siple Dome; West Antarctica; Siple", "north": -81.65, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Saltzman, Eric; Aydin, Murat; Williams, Margaret; Tatum, Cheryl", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.65, "title": "Methyl chloride and methyl bromide in Antarctic ice cores", "uid": "p0000032", "west": -148.81}, {"awards": "9909167 Rust, David", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": "Solar Magnetograms and Filtergrams", "datasets": [{"dataset_uid": "600022", "doi": "", "keywords": null, "people": "Rust, David M.", "repository": "USAP-DC", "science_program": null, "title": "Solar Magnetograms and Filtergrams", "url": "https://www.usap-dc.org/view/dataset/600022"}], "date_created": "Wed, 19 Oct 2005 00:00:00 GMT", "description": "This award provides funding for one year of data analysis of the solar images produced by the Flare Genesis Experiment telescope during a long-duration balloon flight over Antarctica in early 2000, near the peak of solar activity for this solar cycle. The telescope produced many thousands of images and maps of solar magnetic fields with unprecedented resolution. It is expected that the detailed analysis of the data will improve understanding of how energy stored in solar magnetic fields is converted to high temperatures and velocities associated with solar activity. \u003cbr/\u003e\u003cbr/\u003eThis project is jointly supported by NASA, NSF/OPP and NSF/ATM.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -62.83, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Rust, David M.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Flare Genesis Experiment", "uid": "p0000245", "west": -180.0}, {"awards": "0087235 Grew, Edward", "bounds_geometry": "POLYGON((42 -64,43.2 -64,44.4 -64,45.6 -64,46.8 -64,48 -64,49.2 -64,50.4 -64,51.6 -64,52.8 -64,54 -64,54 -64.4,54 -64.8,54 -65.2,54 -65.6,54 -66,54 -66.4,54 -66.8,54 -67.2,54 -67.6,54 -68,52.8 -68,51.6 -68,50.4 -68,49.2 -68,48 -68,46.8 -68,45.6 -68,44.4 -68,43.2 -68,42 -68,42 -67.6,42 -67.2,42 -66.8,42 -66.4,42 -66,42 -65.6,42 -65.2,42 -64.8,42 -64.4,42 -64))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Aug 2004 00:00:00 GMT", "description": "0087235\u003cbr/\u003eGrew\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role of beryllium in lower crustal partial melting events. The formation of granitic liquids by partial melting deep in the Earth\u0027s crust is one of the major topics of research in igneous and metamorphic petrology today. One aspect of this sphere of research is the beginning of the process, specifically, the geochemical interaction between melts and source rocks before the melt has left the source area. One example of anatexis in metamorphic rocks affected by conditions found deep in the Earth\u0027s crust is pegmatite in the Archean ultrahigh temperature granulite-facies Napier Complex of Enderby Land, East Antarctica. Peak conditions for this granulite-facies metamorphism are estimated to have reached nearly 1100 Degrees Celsius and 11 kilobar, that is, conditions in the Earth\u0027s lower crust in Archean time. The proposed research is a study of the Napier Complex pegmatites with an emphasis on the minerals and geochemistry of beryllium. This element, which is estimated to constitute 3 ppm of the Earth\u0027s upper crust, is very rarely found in any significant concentrations in metamorphic rocks subjected to conditions of the Earth\u0027s lower crust. Structural, geochronological, and mineralogical studies will be carried out to test the hypothesis that the beryllium pegmatites resulted from anatexis of their metapelitic host rocks during the ultrahigh-temperature metamorphic event in the late Archean. Host rocks will be analyzed for major and trace elements. Minerals will be analyzed by the electron microprobe for major constituents including fluorine and by the ion microprobe for lithium, beryllium and boron. The analytical data will be used to determine how beryllium and other trace constituents were extracted from host rocks under ultrahigh-temperature conditions and subsequently concentrated in the granitic melt, eventually to crystallize out in a pegmatite as beryllian sapphirine and khmaralite, minerals not found in pegmatites elsewhere. Mineral compositions and assemblages will be used to determine the evolution and conditions of crystallization and recrystallization of the pegmatites and their host rocks during metamorphic episodes following the ultrahigh-temperature event. Monazite will be analyzed for lead, thorium and uranium to date the ages of these events. Because fluorine is instrumental in mobilizing beryllium, an undergraduate student will study the magnesium fluorphosphate wagnerite in the pegmatites in order to estimate fluorine activity in the melt as part of a senior project. The results of the present project will provide important insights on the melting process in general and on the geochemical behavior of beryllium in particular under the high temperatures and low water activities characteristic of the Earth\u0027s lower crust.", "east": 54.0, "geometry": "POINT(48 -66)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ION MICROPROBES", "is_usap_dc": false, "keywords": "Metamorphism; Li; Be; Pegmatitic Leucosomes; Partial Melting; Lithium; Granulites; Napier Complex; Boron; Beryllium; Mineralogy; Not provided; Continental Crust", "locations": "Napier Complex", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Grew, Edward", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -68.0, "title": "Beryllium in Antarctic Ultrahigh-Temperature Granulite-Facies Rocks and its Role in Partial Melting of the Lower Continental Crust", "uid": "p0000370", "west": 42.0}, {"awards": "9419128 Stearns, Charles", "bounds_geometry": null, "dataset_titles": "Three-Hourly Antarctic Automatic Weather Station Data, 1980-2000", "datasets": [{"dataset_uid": "609111", "doi": "", "keywords": "Antarctica; Atmosphere; AWS; Weatherstation", "people": "Stearns, Charles R.; Weidner, George A.; Lazzara, Matthew; Keller, Linda M.", "repository": "USAP-DC", "science_program": null, "title": "Three-Hourly Antarctic Automatic Weather Station Data, 1980-2000", "url": "https://www.usap-dc.org/view/dataset/609111"}], "date_created": "Mon, 18 Aug 2003 00:00:00 GMT", "description": "9419128 Stearns This is a project to maintain and augment as necessary, the network of nearly fifty automatic weather stations established on the Antarctic continent and on several surrounding islands. These weather stations measure surface wind, pressure, temperature, humidity, and in some instances other atmospheric variables, such as snow accumulation and incident solar radiation, and report these via satellite to a number of ground stations. The data are used for operational weather forecasting in support of the United States Antarctic program, for climatological records, and for research purposes. The AWS network, which began as a small-scale program in 1980, has been extremely reliable and has proven indispensable for both forecasting and research purposes. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e BAROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HUMIDITY SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "Surface Temperature Measurements; USAP-DC; Atmospheric Pressure; Automated Weather Station; Surface Winds; Near-Surface Air Temperatures; Surface Wind Speed Measurements; Atmospheric Humidity Measurements; AWS; Not provided; Snow Temperature; Surface Temperatures; Antarctica; Snow Temperature Measurements", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lazzara, Matthew; Stearns, Charles R.; Weidner, George A.; Keller, Linda M.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Continuation for the Antarctic Automatic Weather Station Climate Program 1995-1998", "uid": "p0000151", "west": null}, {"awards": "9980538 Lohmann, Kyger", "bounds_geometry": "POINT(-56 -64)", "dataset_titles": "Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica", "datasets": [{"dataset_uid": "600019", "doi": "", "keywords": null, "people": "Lohmann, Kyger", "repository": "USAP-DC", "science_program": null, "title": "Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600019"}], "date_created": "Mon, 11 Jun 2001 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research for construction of a long-term record of climate during the late Cretaceous and early Paleogene to assess the annual seasonality in temperature on the coastal margin of Antarctica. Stable isotope and element compositions of well-preserved bivalve shells collected on Seymour Island will be the primary source of data used to reconstruct paleoenvironmental conditions. Seasonal temperature records collected through high-resolution sampling along growth structures in bivalve shells will allow seasonality to be assessed during different climate states and during periods of rapid climate change. In addition, high stratigraphic resolution will enable this project to detect the presence and frequency of short-lived thermal excursions that may have extended to such high latitudes.\u003cbr/\u003e\u003cbr/\u003eTo compile a reliable temporal record of paleoclimate, two major avenues of investigation will be undertaken: 1) precise stratigraphic (and therefore, temporal) placement of fossils over a large geographic area will be employed through the use of a graphical technique employing geometric projections; 2) stable isotope and elemental analyses will be performed to derive paleotemperatures and to evaluate diagenetic alteration of shell materials. To provide realistic comparisons of paleotemperatures across stratigraphic horizons, this study will focus on a single taxon, thus avoiding complications due to the mixing of faunal assemblages that have been encountered in previous studies of this region.\u003cbr/\u003e\u003cbr/\u003eThe near-shore marine fossil record on Seymour Island provides a unique opportunity to address many questions about the Antarctic paleoenvironment, including the relation between seasonality and different climate states, the influence of climate on biogeographic distribution of specific taxa, the effect of ice-volume changes on the stable isotope record from the late Cretaceous through the Eocene, and the plausibility of high-latitude bottom water formation during this time interval. In particular, information that will be collected concerning patterns of seasonality and the presence (or absence) of short-lived thermal excursions will be extremely valuable to an understanding of the response of high latitude sites during climate transitions from globally cool to globally warm conditions.", "east": -56.0, "geometry": "POINT(-56 -64)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided; Bivalves; Geochemical Composition; Carbon Isotopes; Climate", "locations": null, "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE \u003e EOCENE", "persons": "Lohmann, Kyger; Barrera, Enriqueta", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.0, "title": "Evolution of Sea Surface Temperatures in the Coastal Antarctic Paleoenvironment During the Late Cretaceous and Paleogene", "uid": "p0000613", "west": -56.0}]
X
X
Help on the Results MapX
This window can be dragged by its header, and can be resized from the bottom right corner.
The Results Map and the Results Table
The Results Map displays the centroids of the geographic bounds of all the results returned by the search.
Results that are displayed in the current map view will be highlighted in blue and brought to the top of the Results Table.
As the map is panned or zoomed, the highlighted rows in the table will update.
If you click on a centroid on the map, it will turn yellow and display a popup with details for that project/dataset - including a link to the landing page.
The bounds for the project(s)/dataset(s) selected will be displayed in red.
The selected result(s) will be highlighted in red and brought to the top of the table.
The default table sorting order is: Selected, Visible, Date (descending), but this can be changed by clicking on column headers in the table.
Selecting Show on Map for an individual row will both display the geographic bounds for that result on a mini map, and also display the bounds
and highlight the centroid on the Results Map.
Clicking the 'Show boundaries' checkbox at the top of the Results Map will display all the bounds for the filtered results.
Defining a search area on the Results Map
If you click on the Rectangle or Polygon icons in the top right of the Results Map, you can define a search area which will be added to any other
search criteria already selected.
After you have drawn a polygon, you can edit it using the Edit Geometry dropdown in the search form at the top.
Clicking Clear in the map will clear any drawn polygon.
Clicking Search in the map, or Search on the form will have the same effect.
The returned results will be any projects/datasets with bounds that intersect the polygon.
Use the Exclude project/datasets checkbox to exclude any projects/datasets that cover the whole Antarctic region.
Viewing map layers on the Results Map
Clicking the Layers button - the blue square in the top left of the Results Map - will display a list of map layers you can add or remove
from the currently displayed map view.
Older retrieved projects from AMD. Warning: many have incomplete information.
To sort the table of search results, click the header of the column you wish to search by. To sort by multiple columns, hold down the shift key whilst selecting the sort columns in order.
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's 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.
Part I, Non-technical Abstract <br/>Concerns 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.<br/><br/>Part 2, Technical Abstract<br/><br/>New 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.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctic animals face tremendous threats as Antarctic ice sheets melt and temperatures rise. About 34 million years ago, when Antarctica began to cool, most species of fish became locally extinct. A group called the notothenioids, however, survived due to the evolution of antifreeze. The group eventually split into over 120 species. Why did this group of Antarctic fishes evolve into so many species? One possible reason why a single population splits into two species relates to sex genes and sex chromosomes. Diverging species often have either different sex determining genes (genes that specify whether an individual’s gonads become ovaries or testes) or have different sex chromosomes (chromosomes that differ between males and females within a species, like the human X and Y chromosomes). We know the sex chromosomes of only a few notothenioid species and know the genetic basis for sex determination in none of them.
The aims of this research are to: 1) identify sex chromosomes in species representing every major group of Antarctic notothenioid fish; 2) discover possible sex determining genes in every major group of Antarctic notothenioid fish; and 3) find sex chromosomes and possible sex determining genes in two groups of temperate, warmer water, notothenioid fish. These warmer water fish include groups that never experienced the frigid Southern Ocean and groups that had ancestors inhabiting Antarctic oceans that later adjusted to warmer waters. This project will help explain the mechanisms that led to the division of a group of species threatened by climate change. This information is critical to conserve declining populations of Antarctic notothenioids, which are major food sources for other Antarctic species such as bird and seals.
The project will offer a diverse group of undergraduates the opportunity to develop a permanent exhibit at the Eugene Science Center Museum. The exhibit will describe the Antarctic environment and explain its rapid climate change. It will also introduce the continent’s bizarre fishes that live below the freezing point of water. The project will collaborate with the university’s Science and Comics Initiative and students in the English Department’s Comics Studies Minor to prepare short graphic novels explaining Antarctic biogeography, icefish specialties, and the science of this project as it develops.
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—viscous flow—is 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 “Glen’s law”, that describes ice flow rate as a function of temperature and stress. Glen’s 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, “superplastic” 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.
Polycrystalline ice samples with grain sizes ranging from 5 µm to 1000 µm will be fabricated and deformed in the PI’s laboratory at WHOI, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of −30°C to −10°C, 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.
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. <br/><br/>The 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's 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.
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°C 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.
These 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:
(R1) Can local winds account for the observed 2021/2022 sea ice loss, or are remote sea surface temperature (SST) anomalies a necessary ingredient?
(R2) Are sea ice conditions over 2022-2024 likely to remain anomalously low?
(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?
The 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.
Siddoway, Christine; Thomson, Stuart; Teyssier, Christian
No project link provided
in progress
No project link provided
in progress
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 >800° C to 300° 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's 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.
Analyzing 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.
The methods used for the research include:
•Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling, applied to the timing and characterizatio episodes of glacial erosional incision.
•Single-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.
Students 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's Gulf Coast Core Repository, and the OSU Marine and Geology Repository. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
As plate tectonics pushed Antarctica into a polar position, by ~34 million years ago, the continent and its surrounding Southern Ocean (SO) became geographically and thermally isolated by the Antarctic Circumpolar Current. Terrestrial and marine glaciation followed, resulting in extinctions as well as the survival and radiation of unique flora and fauna. The notothenioid fish survived and arose from a common ancestral stock into tax with 120 species that dominates today's SO fish fauna. The Notothenioids evolved adaptive traits including novel antifreeze proteins for survival in extreme cold, but also suffered seemingly adverse trait loss including red blood cells in the icefish family, and the ability to mount cellular responses to mitigate heat stress ? otherwise ubiquitous across all life. This project aims to understand how the notothenoid genomes have changed and contributed to their evolution in the cold. The project will sequence, analyze and compare the genomes of two strategic pairs of notothenioid fishes representing both red-blooded and white-blooded species. Each pair will consist of one Antarctic species and one that has readapted to the temperate waters of S. America or New Zealand. The project will also compare the Antarctic species genomes to a genome of the closet non-Antarctic relative representing the temperate notothenioid ancestor. The work aims to uncover the mechanisms that enabled the adaptive evolution of this ecologically vital group of fish in the freezing Southern Ocean, and shed light on their adaptability to a warming world. The finished genomes will be made available to promote and advance Antarctic research and the project will host a symposium of Polar researchers to discuss the cutting edge developments regarding of genomic adaptations in the polar region.<br/>Despite subzero, icy conditions that are perilous to teleost fish, the fish fauna of the isolated Southern Ocean (SO) surrounding Antarctica is remarkably bountiful. A single teleost group - the notothenioid fishes - dominate the fauna, comprising over 120 species that arose from a common ancestor. When Antarctica became isolated and SO temperatures began to plunge in early Oligocene, the prior temperate fishes became extinct. The ancestor of Antarctic notothenioids overcame forbidding polar conditions and, absent niche competition, it diversified and filled the SO. How did notothenioids adapt to freezing environmental selection pressures and achieve such extraordinary success? And having specialized to life in chronic cold for 30 myr, can they evolve in pace with today's warming climate to stay viable? Past studies of Antarctic notothenioid evolutionary adaptation have discovered various remarkable traits including the key, life-saving antifreeze proteins. But life specialized to cold also led to paradoxical trait changes such as the loss of the otherwise universal heat shock response, and of the O2-transporting hemoglobin and red blood cells in the icefish family. A few species interestingly regained abilities to live in temperate waters following the escape of their ancestor out of the freezing SO. <br/>This proposed project is the first major effort to advance the field from single trait studies to understanding the full spectrum of genomic and genetic responses to climatic and environmental change during notothenioid evolution, and to evaluate their adaptability to continuing climate change. To this end, the project will sequence the genomes of four key species that embody genomic responses to different thermal selection regimes during notothenioids' evolutionary history, and by comparative analyses of genomic structure, architecture and content, deduce the responding changes. Specifically, the project will (i) obtain whole genome assemblies of the red-blooded T. borchgrevinki and the S. American icefish C. esox; (ii) using the finished genomes from (i) as template, obtain assemblies of the New Zealand notothenioid N. angustata, and the white-blooded icefish C. gunnari, representing a long (11 myr) and recent (1 myr) secondarily temperate evolutionary history respectively. Genes that are under selection in the temperate environment but not in the Antarctic environment can be inferred to be directly necessary for that environment and the reverse is also true for genes under selection in the Antarctic but not in the temperate environment. Further, genes important for survival in temperate waters will show parallel selection between N. angustata and C. esox despite the fact that the two fish left the Antarctic at far separated time points. Finally, gene families that expanded due to strong selection within the cold Antarctic should show a degradation of duplicates in the temperate environment. The project will test these hypotheses using a number of techniques to compare the content and form of genes, the structure of the chromosomes containing those genes, and through the identification of key characters, such as selfish genetic elements, introns, and structural variants.
To obtain observations of temporal variability of firn processes in Antarctica, we designed a cost-efficient, reliable, and easily deployable firn monitoring system capable of operating with little or no maintenance over a period of several seasons. The prototype station was installed in December 2017 in the vicinity of the geographical South Pole and at a short distance from the Amundsen-Scott South Pole Research Station in Antarctica. The data presented was acquired between December of 2017 and January of 2020. During the first year, of the months without sunlight the longest period without SMB measurements was 22 days, yielding enough measurements to obtain monthly estimates of every variable. During the polar night of 2019, a technical issue related to extreme cold prevented the data logger attached to the CRNCs to record correctly so the sensor was placed under a stand-by mode until the 2nd of December 2019 when temperatures raised. Firn compaction, temperature and wind were recorded continuously during the 2-year period with the exception of a couple of weeks during the Austral winter. The project finalized in January 2020 and the system was taken down on January 15th.
The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington's annual Polar Science Weekend in Seattle, and art-science collaboration.<br/><br/>This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a "Raymond Bump") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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.<br/><br/> 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.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
We studied the molecular evolution and physiology of two types of ion channels: voltage gated potassium channels and transient receptor potential (TRP) channels. We also studied the molecular evolution and expression of water-passing channels, the aquaporins, to determine if these show signs of evolutionary change in notothenioids.
We noted apparent amino acid substitutions at a number of sites in a muscle-expressing
potassium channel (Kv1.3). We were surprised to find that although the AAs at these sites
appeared highly conserved in teleosts and even in tetrapods, reverting them singly, in pairs,
or all together back to the ancestral condition had no effect on the biophysical properties of
the channels that we measured (voltage-sensitivity; rate of activation) at room temperature
as well as over a range of temperatures down to 4oC.
The results for the TRP channels and aquaporins can be accessed in their publications. York and Zakon (2022) in Genome Biology and Evolution, and two forthcoming papers.
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.<br/><br/>This 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.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Salvatore, Mark; Gooseff, Michael N.; Sokol, Eric; Barrett, John
No dataset link provided
Part I: Non-technical description:
Water 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.
Part II: Technical description:
Terrestrial 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.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
ANDRILL is a scientific drilling program to investigate Antarctica's 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's 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's ocean-climate system. <br/><br/>This 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's 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.<br/><br/>The 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's complex tectonic history.<br/><br/>The broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society's 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. <br/><br/>As key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica's ice sheets are important to society's 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's climatic future.
The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina.
The PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master’s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics.
The Mid-Pleistocene Transition (MPT; ~1.25–0.7 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’s 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 (2.6–0.7 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.
Due to persistent cold temperatures, geographical isolation, and resulting evolutionary distinctness of Southern Ocean fauna, the study of Antarctic reducing habitats has the potential to fundamentally alter our understanding of the biologic processes that inhibit greenhouse gas emissions from our oceans. Marine methane, a greenhouse gas 25x as potent as carbon dioxide for warming our atmosphere, is currently a minor component of atmospheric forcing due to the microbial oxidation of methane within the oceans. Based on studies of persistent deep-sea seeps at mid- and northern latitudes we have learned that bacteria and archaea create a ‘sediment filter’ that oxidizes methane prior to its release. As increasing global temperatures have and will continue to alter the rate and variance of methane release, the ability of the microbial filter to respond to fluctuations in methane cycles is a critical yet unexplored avenue of research. Antarctica contains vast reservoirs of methane, equivalent to all of the permafrost in the Arctic, and yet we know almost nothing about the fauna that may mitigate its release, as until recently, we had not discovered an active methane seep.
In 2012, a methane seep was discovered in the Ross Sea, Antarctica that formed in 2011 providing the first opportunity to study an active Antarctic methane-fueled habitat and simultaneously the impact of microbial succession on the oxidation of methane, a critical ecosystem service. Previous work has shown that after 5 years of seepage, the community was at an early stage of succession and unable to mitigate the release of methane from the seafloor. In addition, additional areas of seepage had begun nearby. This research aims to quantify the community trajectory of these seeps in relation to their role in the Antarctic Ecosystem, from greenhouse gas mitigation through supporting the food web. Through the application of genomic and transcriptomic approaches, taxa involved in methane cycling and genes activated by the addition of methane will be identified and contrasted with those from other geographical locations. These comparisons will elucidate how taxa have evolved and adapted to the polar environment.
This research uses a ‘genome to ecosystem’ approach to advance our understanding of organismal and systems ecology in Antarctica. By quantifying the trajectory of community succession following the onset of methane emission, the research will decipher temporal shifts in biodiversity/ecosystem function relationships. Phylogenomic approaches focusing on taxa involved in methane cycling will advance the burgeoning field of microbial biogeography on a continent where earth’s history may have had a profound yet unquantified impact on microbial evolution. Further, the research will empirically quantify the role of chemosynthesis as a form of export production from seeps and in non-seep habitats in the nearshore Ross Sea benthos, informing our understanding of Antarctic carbon cycling.
The frequency and severity of hypoxic events are increasing in marine and freshwater environments worldwide with climate warming, threatening the health of aquatic ecosystems and the viability of fish populations. The Southern Ocean surrounding Antarctica has historically been a stable, icy-cold, and oxygen-rich environment, but is now warming at an unprecedented rate and faster than all other regions in the Southern hemisphere. Evolution at sub-zero temperatures has equipped Antarctic fishes with traits allowing them to thrive in frigid waters, but has diminished their resilience to warming. Presently little is known about the ability of Antarctic fishes to withstand hypoxic conditions that often accompany warming. This research will investigate the hypoxia tolerance of four species of Antarctic fishes, including two species of icefishes that lack the oxygen-carrying protein, hemoglobin, which may compromise their ability to oxygenate tissues under hypoxic conditions. The hypoxia tolerance of Antarctic fish species will be compared to that of a related fish species inhabiting coastal regions of South America. Physiological and biochemical responses to hypoxia will be evaluated and compared amongst the five species to bolster our predictions of the capacity of Antarctic fishes to cope with a changing environment. This research will provide training opportunities for undergraduate and graduate students, and a postdoctoral research fellow. A year-long seminar series hosted by the Aquarium of the Pacific will feature female scientists who work in Antarctica to inspire youth in the greater Los Angeles area to pursue careers in science.
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 ‘bathtub rings’ 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 (<50 m). 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.
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.
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.
Sea 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.
Overview</br>
It 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‐coring 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.
This 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.
</br></br>
Intellectual Merits</br>
The 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‐coring 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‐based logging technology, developed previously for Siple Dome borehole logging.
</br></br>
Broader Impact</br>
Laser 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‐high 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.
This 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‐on 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.
This proposal does not involve field work.
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's institution, the project will also encourage engagement of citizen scientists through its website.
The 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.
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.
To 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.
At present, Antarctica’s 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’s glaciers. Totten Glacier, located on the Sabrina Coast, East Antarctica is presently retreating. Totten’s 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.
Undersea forests of seaweeds dominate the shallow waters of the central and northern coast of the western Antarctic Peninsula and provide critical structural habitat and carbon resources (food) for a host of marine organisms. Most of the seaweeds are chemically defended against herbivores yet support very high densities of herbivorous shrimp-like grazers (crustaceans, primarily amphipods) which greatly benefit their hosts by consuming filamentous and microscopic algae that otherwise overgrow the seaweeds. The amphipods benefit from the association with the chemically defended seaweeds by gaining an associational refuge from fish predation. The project builds on recent work that has demonstrated that several species of amphipods that are key members of crustacean assemblages associated with the seaweeds suffer significant mortality when chronically exposed to increased seawater acidity (reduced pH) and elevated temperatures representative of near-future oceans. By simulating these environmental conditions in the laboratory at Palmer Station, Antarctica, the investigators will test the overall hypothesis that ocean acidification will play a significant role in structuring crustacean assemblages associated with seaweeds. Broader impacts include expanding fundamental knowledge of the impacts of global climate change by focusing on a geographic region of the earth uniquely susceptible to climate change. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This includes training graduate students and early career scientists with an emphasis on diversity, presentations to K-12 groups and the general public, and a variety of social media-based outreach programs.
The project will compare population and assemblage-wide impacts of natural (ambient) and carbon dioxide enriched seawater on assemblages of seaweed-associated crustacean grazers. Based on prior results, it is likely that some species will be relative "winners" and some will be relative "losers" under the changed conditions. The project will then aim to carry out measurements of growth, calcification, mineralogy, the incidence of molts, and biochemical and energetic body composition for two key amphipod "winners" and two key amphipod "losers". These measurements will allow an assessment of what factors drive species-specific enhanced or diminished performance under conditions of ocean acidification and sea surface warming. The project will expand on what little is known about prospective impacts of changing conditions on benthic marine Crustacea, in Antarctica, a taxonomic group that faces the additional physiological stressor of molting. The project is likely to provide additional insight on the indirect regulation of the seaweeds that comprise Antarctic undersea forests that provide key architectural components of the coastal marine ecosystem.
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.
This 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 (> 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.
This investigation will reconstruct past behavior of the East Antarctic Ice Sheet during periods of warmer-than-present climate, such as the Pliocene, in order to better project the likely response of Earth's largest ice sheet to anthropogenic warming. Containing the equivalent of ~55 m sea-level rise, the future evolution of the East Antarctic Ice Sheet has clear societal ramifications on a global scale as temperatures continue to rise. Therefore, determining ice-sheet sensitivity to climate on the scale predicted for the next two centuries is a matter of increasing urgency, particularly in light of evidence suggesting the East Antarctic Ice Sheet is more dynamic than previously thought. This research will provide a terrestrial geologic record of long-term ice-sheet behavior from sites immediately adjacent the East Antarctic Ice Sheet in the Transantarctic Mountains, with which the project will help ascertain how the ice sheet responded to past warm periods. The project will focus primarily on the Pliocene warm period, 5 to 3 million years ago, as this represents the closest analogue to 21st Century climate conditions.<br/><br/>The proposed research will investigate glacial deposits corresponding to the East Antarctic Ice Sheet in the central Transantarctic Mountains in order to expand the geologic record of past ice-sheet behavior. The overarching research objectives are to improve understanding of the East Antarctic Ice Sheet's configuration during periods of warmer-than-present climate, such as the Pliocene warm period, and to determine whether the ice sheet underwent significant volume changes or remained relatively stable in response to warming. To address these goals, the investigation will map and date glacial deposits preserved at mountain sites immediately adjacent the ice sheet. Specifically, we will: (i) employ multiple cosmogenic nuclides (10Be, 26Al, 21Ne) to establish more fully ice-thickness histories for the upper Shackleton and Beardmore Glaciers, where they exit the ice sheet; (ii) use this record to identify periods during which the East Antarctic Ice Sheet was at least as extensive as today; and (iii) use these data to assess long-term ice-sheet variability in East Antarctica, with particular emphasis on Pliocene warm episodes. This research will require Antarctic fieldwork, glacial-geologic mapping, and cosmogenic surface-exposure dating.
The Earth's climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from 'greenhouse' to 'icehouse' 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.<br/><br/>The 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.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The transition of young from parental care to independence is a critical stage in the life of many animals. Surviving this stage can be especially challenging for polar mammals where the extreme cold requires extra energy to keep warm, rather than using the majority of energy for growth, development and physical activities. Young Weddell seals (Leptonychotes weddellii) have only weeks to develop the capabilities to survive both on top of the sea ice and within the -1.9°C seawater where they can forage for food. The project seeks to better understand how Weddell seal pups rapidly develop (within weeks) the capacity to transition between these two extreme environments (that differ greatly in their abilities to conduct heat) and how they budget their energy during the transition. Though the biology and physiology of adult Weddell seals is well studied, the energetic and physiological strategies of pups during development is still unclear. Understanding factors that may affect survival at critical life history events is essential for better understanding factors that might affect marine mammal populations. Weddell seals are the southernmost breeding mammal and are easily recognizable as quintessential Antarctic seals. Determining potential vulnerabilities at critical life stages to change in the Antarctic environment will facilitate the researchers' ability to not only gain public interest but also communicate how research is revealing ways in which changes are occurring at the poles and how these changes may affect polar ecosystems. By collaborating with the Marine Mammal Center, the project will directly reach the public, through curricular educational materials and public outreach that will impact over 100,000 visitors annually.<br/><br/>To elucidate the physiological strategies that facilitate the survival of Weddell seal pups from birth to independence, the proposed study examines the development of their thermoregulation and diving capability. To achieve this, the project will determine the mechanisms that Weddell seal pups use to maintain a stable, warm body temperature in air and in water and then examine the development of diving capability as the animals prepare for independent foraging. The researchers will take a fully integrative approach- making assessments from proteins to tissues to the whole-animal level- when investigating both these objectives. To assess the development of thermoregulatory capability, researchers will quantify body insulation, resting metabolic rates in air and in water, muscle thermogenesis (shivering), and body surface temperatures in the field. The project will also assess the development of dive capability by quantifying oxygen storage capacities and measuring early dive behavior. To identify possible cellular mechanisms for how Weddell seals navigate this trade-off during development, the program will quantify several key developmental regulators of increased hypoxic capacity (HIF, VEGF and EPO) using qPCR, as well as follow the proteomic changes of adipose and muscle tissue, which will include abundance changes of metabolic, antioxidant, cytoskeletal, and Ca2+-regulating proteins. The study of the physiological development leading up to the transition to independence in pinnipeds will help researchers better predict the effects of climate change on the distribution and abundance of this species and how this will affect other trophic levels. Environmental changes that alter habitat suitability have been shown to decrease population health, specifically because of declines in juvenile survival.
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.
In Antarctica, millions of years of freezing have led to the development of hundreds of meters of thick permafrost (i.e., frozen ground). Recent research demonstrated that this slow freezing has trapped and concentrated water into local and regional briny aquifers, many times more salty than seawater. Because salt depresses the freezing point of water, these saline brines are able to persist as liquid water at temperatures well below the normal freezing point of freshwater. Such unusual groundwater systems may support microbial life, supply nutrients to coastal ocean and ice-covered lakes, and influence motion of glaciers. These briny aquifers also represent potential terrestrial analogs for deep life habitats on other planets, such as Mars, and provide a testing ground for the search for extraterrestrial water. Whereas much effort has been invested in understanding the physics, chemistry, and biology of surface and near-surface waters in cold polar regions, it has been comparably difficult to investigate deep subsurface aquifers in such settings. Airborne ElectroMagnetics (AEM) subsurface imaging provides an efficient way for mapping salty groundwater. An international collaboration with the University of Aarhus in Denmark will enable knowledge and skill transfer in AEM techniques that will enhance US polar research capabilities and provide US undergraduates and graduate students with unique training experiences. This project will survey over 1000 km2 of ocean and land near McMurdo Station in Antarctica, and will reveal if cold polar deserts hide a subsurface pool of liquid water. This will have significant implications for understanding cold polar glaciers, ice-covered lakes, frozen ground, and polar microbiology as well as for predictions of their response to future change. Improvements in permafrost mapping techniques and understanding of permafrost and of underlying groundwaters will benefit human use of high polar regions in the Antarctic and the Arctic.<br/><br/>The project will provide the first integrative system-scale overview of subsurface water distribution and hydrological connectivity in a partly ice-free coastal region of Antarctica, the McMurdo Dry Valleys. Liquid water is relatively scarce in this environment but plays an outsized role by influencing, and integrating, biological, biogeochemical, glaciological, and geological processes. Whereas surface hydrology and its role in ecosystem processes has been thoroughly studied over the last several decades, it has been difficult to map out and characterize subsurface water reservoirs and to understand their interactions with regional lakes, glaciers, and coastal waters. The proposed project builds on the "proof-of-concept" use of AEM technology in 2011. Improvements in sensor and data processing capabilities will result in about double the depth of penetration of the subsurface during the new data collection when compared to the 2011 proof-of-concept survey, which reached depths of 300-400m. The first field season will focus on collecting deep soundings with a ground-based system in key locations where: (i) independent constraints on subsurface structure exist from past drilling projects, and (ii) the 2011 resistivity dataset indicates the need for deeper penetration and high signal-to-noise ratios achievable only with a ground-based system. The regional airborne survey will take place during the second field season and will yield subsurface electrical resistivity data from across several valleys of different sizes and different ice cover fractions.
Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer
No dataset link provided
Part I: Nontechnical
Scientists study the Earth's 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's 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 ºC 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.
Part II: Technical Description
The mid-Pliocene Warm Period (3–3.3 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.
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.
To 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.
High 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’s Thesis. The project also provide partial support to a postdoctoral scholar obtaining cosmogenic neon measurements and for training and mentoring the graduate student's 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's 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.
Ice cores contain detailed accounts of Earth's 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's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctic notothenioid fishes exhibit two adaptive traits to survive in frigid temperatures. The first of these is the production of anti-freeze proteins in their blood and tissues. The second is a system-wide ability to perform cellular and physiological functions at extremely cold temperatures.The proposal goals are to show how Antarctic fishes use these characteristics to avoid freezing, and which additional genes are turned on, or suppressed in order for these fishes to maintain normal physiological function in extreme cold temperatures. Progressively colder habitats are encountered in the high latitude McMurdo Sound and Ross Shelf region, along with somewhat milder near?shore water environments in the Western Antarctic Peninsula (WAP). By quantifying the extent of ice crystals invading and lodging in the spleen, the percentage of McMurdo Sound fish during austral summer (Oct-Feb) will be compared to the WAP intertidal fish during austral winter (Jul-Sep) to demonstrate their capability and extent of freeze avoidance. Resistance to ice entry in surface epithelia (e.g. skin, gill and intestinal lining) is another expression of the adaptation of these fish to otherwise lethally freezing conditions.<br/><br/>The adaptive nature of a uniquely characteristic polar genome will be explored by the study of the transcriptome (the set of expressed RNA transcripts that constitutes the precursor to set of proteins expressed by an entire genome). Three notothenioid species (E.maclovinus, D. Mawsoni and C. aceratus) will be analysed to document evolutionary genetic changes (both gain and loss) shaped by life under extreme chronic cold. A differential gene expression (DGE) study will be carried out on these different species to evaluate evolutionary modification of tissue-wide response to heat challenges. The transcriptomes and other sequencing libraries will contribute to de novo ice-fish genome sequencing efforts.
In the past, Earth's climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth's atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth's climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record.<br/><br/>The primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.
Understanding how groups of organisms respond to climate change is fundamentally important to assessing the impacts of human activities as well as understanding how past climatic shifts have shaped biological diversity over deep stretches of time. The fishes occupying the near-shore marine habitats around Antarctica are dominated by one group of closely related species called notothenioids. It appears dramatic changes in Antarctic climate were important in the origin and evolutionary diversification of this economically important lineage of fishes. Deposits of fossil fishes in Antarctica that were formed when the continent was experiencing milder temperatures show that the area was home to a much more diverse array of fish lineages. Today the waters of the Southern Ocean are very cold, and often below freezing, but notothenioids fishes exhibit a number of adaptions to live in this harsh set of marine habitats, including the presence of anti-freeze proteins. This research project will collect DNA sequences from hundreds of genes to infer the genealogical relationships of nearly all 124 notothenioid species, and use mathematical techniques to estimate the ages of species and lineages. Knowledge on the timing of evolutionary divergence in notothenioids will allow investigators to assess if timing of previous major climatic shifts in Antarctica are correlated with key events in the formation of the modern Southern Ocean fish fauna. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The project will support educational outreach activities to teenager groups and to the general public through a natural history museum exhibit and other public lectures. It will provide professional training opportunities for graduate students and a postdoctoral research scholar. <br/><br/>Adaptive radiation, where lineages experience high rates of evolutionary diversification coincident with ecological divergence, is mostly studied in island ecosystems. Notothenioids dominate the fish fauna of the Southern Ocean and exhibit antifreeze glycoproteins that allow occupation of the subzero waters. Notothenioids are noted as one of the only examples of adaptive radiation among marine fishes, but the evolutionary history of diversification and radiation into different ecological habitats is poorly understood. This research will generate a species phylogeny (evolutionary history) for nearly all of the 124 recognized notothenioid species to investigate the mechanisms of adaptive radiation in this lineage. The phylogeny is inferred from approximately 350 genes sampled using next generation DNA sequencing and related techniques. Morphometric data are taken for museum specimens to investigate the tempo of morphological diversification and to determine if there are correlations between rates of lineage diversification and the origin of morphological disparity. The patterns of lineage, morphological, and ecological diversification in the notothenioid radiation will be compared to the paleoclimatic record to determine if past instances of global climate change have shaped the evolutionary diversification of this lineage of polar-adapted fishes.
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.<br/><br/>Antarctic 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.
Intellectual Merit: <br/>Opening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. <br/><br/>Broader impacts: <br/>A graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.A network of four continuous Global Navigational Satellite Systems (GNSS) receivers was installed on the bedrock of South Georgia in the Southern Ocean in 2013 and 2014. An additional receiver on a concrete foundation provides a tie to a tide gauge, part of the United Kingdom South Atlantic Tide Gauge Network. The GNSS receivers have already provided data suggesting that the South Georgia microcontinent (SGM) is moving independent of both the South American plate to the north and the Scotia plate to the south. The data also demonstrate that the SGM is being uplifted.
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's 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
closed captioning.
Since 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.
This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment.<br/><br/>Past research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.
The project will integrate analyses of fish physiology, protein production and genetics to determine if regulation of molecular chaperones (a class of proteins that facilitate the proper folding of proteins in a cell) has been permanently lost in a key fish species (Trematomus bernacchii) inhabiting the Southern Ocean. To do so, efforts will be undertaken to analyze chaperones in these fishes and how elevated temperatures impact protein turnover and protein damage. These studies should more definitively determine if the interruption of chaperone function is environmentally controlled (which could suggest these fish could benefit in some form by increasing sea surface temperatures) or if there is complete loss of chaperone function due to a change in its structure through evolutionary processes (which would suggest these fish are less likely to be able to adapt to warming). In addition to filling key gaps in our knowledge about the diversity and evolution of fishes in the southern ocean and the potential impacts changing temperatures might have on fish populations, the project will support the training of undergraduate and graduate students at an RUI institution. Specifically, activities and content directly related to this project's aims will be incorporated into the undergraduate curriculum at Sonoma State University in an effort to increase undergraduate participation in research, especially with respect to underrepresented groups.<br/><br/>The project has specific aims to perform a comparative analysis of nucleotide divergence resulting in non-synonymous amino acid changes in the trans-regulatory elements, namely members of the heat shock factor (HSF) family of transcription factors, in T. bernacchii and N. angustata. The project will also utilize metabolic labeling of newly synthesized proteins from isolated hepatocytes to monitor protein turnover rates in fish acclimated to both -1.5 and +4 °C for an extended period. Changes in chaperoning capacity and levels of damaged proteins will be quantified in multiple tissues to gain a better understanding of the cellular requirements for maintaining protein homeostasis under long-term acclimations to +4 °C. In combination, the work will help answer questions regarding divergence in these fishes as well a fundamental information regarding protein structure and function that may also have bio-medical implications.
Abstract<br/>During 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. <br/><br/>Technical Description<br/>This 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.
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
PR 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.
The one place on Earth consistently showing increases in sea ice area, duration, and concentration is the Ross Sea in Antarctica. Satellite imagery shows about half of the Ross Sea increases are associated with changes in the austral fall, when the new sea ice is forming. The most pronounced changes are also located near polynyas, which are areas of open ocean surrounded by sea ice. To understand the processes driving the sea ice increase, and to determine if the increase in sea ice area is also accompanied by a change in ice thickness, this project will conduct an oceanographic cruise to the polynyas of the Ross Sea in April and May, 2017, which is the austral fall. The team will deploy state of the art research tools including unmanned airborne systems (UASs, commonly called drones), autonomous underwater vehicles (AUVs), and remotely operated underwater vehicles (ROVs). Using these tools and others, the team will study atmospheric, oceanic, and sea ice properties and processes concurrently. A change in sea ice production will necessarily change the ocean water below, which may have significant consequences for global ocean circulation patterns, a topic of international importance. All the involved institutions will be training students, and all share the goal of expanding climate literacy in the US, emphasizing the role high latitudes play in the Earth's dynamic climate.<br/><br/>The main goal of the project is to improve estimates of sea ice production and water mass transformation in the Ross Sea. The team will fully capture the spatial and temporal changes in air-ice-ocean interactions when they are initiated in the austral fall, and then track the changes into the winter and spring using ice buoys, and airborne mapping with the newly commissioned IcePod instrument system, which is deployed on the US Antarctic Program's LC-130 fleet. The oceanographic cruise will include stations in and outside of both the Terra Nova Bay and Ross Ice Shelf polynyas. Measurements to be made include air-sea boundary layer fluxes of heat, freshwater, and trace gases, radiation, and meteorology in the air; ice formation processes, ice thickness, snow depth, mass balance, and ice drift within the sea ice zone; and temperature, salinity, and momentum in the ocean below. Following collection of the field data, the team will improve both model parameterizations of air-sea-ice interactions and remote sensing algorithms. Model parameterizations are needed to determine if sea-ice production has increased in crucial areas, and if so, why (e.g., stronger winds or fresher oceans). The remote sensing validation will facilitate change detection over wider areas and verify model predictions over time. Accordingly this project will contribute to the international Southern Ocean Observing System (SOOS) goal of measuring essential climate variables continuously to monitor the state of the ocean and ice cover into the future.
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's 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's ancient climate and what we can learn from it.<br/><br/>Antarctica 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.
Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~40-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. As circum-Antarctic coastal temperatures declined during this period from ~20°C to the modern -1.9 to +2.0°C (reached ~8-10 million years ago), the psychrophilic (cold-loving) ectotherms of the Southern Ocean evolved compensatory molecular, cellular, and physiological traits that enabled them to maintain normal metabolic function at cold temperatures. Today, these organisms are threatened by rapid warming of the Southern Ocean over periods measured in centuries (as much as 5°C/100 yr), a timeframe so short that re-adaptation and/or acclimatization to the "new warm" may not be possible. Thus, the long-term goals of this research project are: 1) to understand the biochemical and physiological capacities of the embryos of Antarctic notothenioid fish to resist or compensate for rapid oceanic warming; and 2) to assess the genetic toolkit available to support the acclimatization and adaptation of Antarctic notothenioid embryos to their warming habitat. The specific aims of this work are: 1) to determine the capacity of the chaperonin complex of notothenioid fishes to assist protein folding at temperatures between -4 and +20°C; and 2) to evaluate the genetic responses of notothenioid embryos, measured as global differential gene transcription, to temperature challenge, with -1.9°C as the "normal" control and +4 and +10°C as high temperature insults.
The physiology of embryonic development of marine stenotherms under future climate change scenarios is an important but understudied problem. This project will provide valuable insights into the capacity of Antarctic fish embryos to acclimatize and adapt to plausible climate change scenarios by examining multiple levels of biological organization, from the biochemical to the organismal. The results should also be broadly applicable to understanding the impact of global warming on marine biota worldwide. The research will also introduce graduate and undergraduate students to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem.
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 >1°C 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° - 10°C 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.
Beginning with the earliest expeditions to the poles, scientists have noted that many polar taxa grow to unusually large body sizes, a phenomenon now known as 'polar gigantism.' Although scientists have been interested in polar giants for many years, many questions still remain about the biology of this significant form of polar diversity. This award from the Antarctic Organisms and Ecosystems program within the Polar Sciences Division at the National Science Foundation will investigate the respiratory and biomechanical mechanisms underlying polar gigantism in Antarctic pycnogonids (commonly known as sea spiders). The project will use a series of manipulative experiments to investigate the effects of temperature and oxygen availability on respiratory capacity and biomechanical strength, and will compare Antarctic sea spiders to related species from temperate and tropical regions. The research will provide insight into the ability of polar giants to withstand the warming polar ocean temperatures associated with climate change.<br/><br/>The prevailing hypothesis to explain the evolution of gigantism invokes shifts in respiratory relationships in extremely cold ocean waters: in the cold, oxygen is more plentiful while at the same time metabolic rates are very low. Together these effects alleviate constraints on oxygen supply that restrict organisms living in warmer waters. Respiratory capacity must evolve in the context of adaptive tradeoffs, so for organisms including pycnogonids there must be tradeoffs between respiratory capacity and resistance to biomechanical stresses. The investigators will test a novel hypothesis that respiratory challenges are not associated with particular body sizes, and will answer the following questions: What are the dynamics of oxygen transport and consumption in Antarctic pycnogonids; how do structural features related to oxygen diffusion trade off with requirements for body support and locomotion; how does body size influence vulnerability to environmental hypoxia and to temperature-oxygen interactions; and does the cold-driven high oxygen availability in the Antarctic raise the limit on body size by reducing trade-offs between diffusivity and structural integrity? The research will explore the effects of increased ocean temperatures upon organisms that have different body sizes. In addition, it will provide training for graduate and undergraduate students affiliated with universities in EPSCOR states.
This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth's orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no field work in Antarctica.
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.<br/><br/>Ice-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.
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.
Collaborative Research: THE MCMURDO DRY VALLEYS: A Landscape on the Threshold of Change is supported by the Antarctic Integrated System Science (AISS) program in the Antarctic Sciences Section of the Division of Polar Programs within the Geosciences Directorate of the National Sciences Foundation (NSF). The funds will support the collection of state-of-the-art high resolution LIDAR (combining the terms light and radar) imagery of the Dry Valleys of Antarctica in the 2014/2015 Antarctic field season, with LIDAR data collection and processing being provided by the NSF-supported NCALM (National Center for Airborne Laser Mapping) facility. LIDAR images collected in 2014/2015 will be compared to images from 2001 in order to detect decadal change. Additional fieldwork will look at the distribution of buried massive ice, and the impacts that major changes like slumping are having on the biota. All field data will be used to improve models on energy balance, and hydrology.<br/><br/>Intellectual Merit: There have been dramatic changes over the past decade in the McMurdo Dry Valleys: rivers are incising by more than three meters, and thermokarst slumps are appearing near several streams and lakes. These observations have all been made by researchers in the field, but none of the changes have been mapped on a valley-wide scale. This award will provide a new baseline map for the entire Dry Valley system, with high-resolution imagery provided for the valley floors, and lower resolution imagery available for the higher elevation areas that are undergoing less change. The project will test the idea that sediment-covered ice is associated with the most dramatic changes, due to differential impacts of the increased solar radiation on sediment-covered compared to clean ice, and despite the current trend of slightly cooling air temperatures within the Dry Valleys. Information collected on the topography, coupled with the GPR determined buried ice distributions, will also be incorporated into improved energy and hydrological models. In addition to providing the new high-resolution digital elevation model (DEM), the project will ultimately result in identification of areas that are susceptible to sediment-enhanced melt-driven change, providing a powerful prediction tool for the impacts of climate change.<br/><br/>Broader Impacts: The new DEM will be immediately useful to a wide range of disciplines, and will provide a comprehensive new baseline against which future changes will be compared. The project will provide a tool for the whole community to use, and the investigators will work with the community to make them aware of the new assets via public presentations, and perhaps via a workshop. The map will have international interest, and will also serve as a tool for environmental managers to draw on as they consider conservation plans. Several undergraduate and graduate students will participate in the project, and one of the co-PIs is a new investigator. The imagery collected is expected to be of interest to the general public in addition to scientific researchers, and venues for outreach such as museum exhibits and the internet will be explored. The proposed work is synergistic with 1) the co-located McMurdo LTER program, and 2) the NCALM facility that is also funded by the Geosciences Directorate.
The biota of the world's seafloor is fueled by bursts of seasonal primary production. For food-limited sediment communities to persist, a balance must exist between metazoan consumption of and competition with bacteria, a balance which likely changes through the seasons. Polar marine ecosystems are ideal places to study such complex interactions due to stark seasonal shifts between heterotrophic and autotrophic communities, and temperatures that may limit microbial processing of organic matter. The research will test the following hypotheses: 1) heterotrophic bacteria compete with macrofauna for food; 2) as phytoplankton populations decline macrofauna increasingly consume microbial biomass to sustain their populations; and 3) in the absence of seasonal photosynthetic inputs, macrofaunal biodiversity will decrease unless supplied with microbially derived nutrition. Observational and empirical studies will test these hypotheses at McMurdo Station, Antarctica, where a high-abundance macro-infaunal community is adapted to this boom-and-bust cycle of productivity. The investigator will mentor undergraduates from a predominantly minority-serving institution, in the fields of invertebrate taxonomy and biogeochemistry. The general public and young scientists will be engaged through lectures at local K-12 venues and launch of an interactive website. The results will better inform scientists and managers about the effects of climate change on polar ecosystems and the mechanisms of changing productivity patterns on global biodiversity.
Alley/1142085<br/><br/>This award supports a project to continue the collection and analyses of firn temperature data from three automated firn thermal profiling units deployed in Dronning Maud Land sector of East Antarctica as part of the Norway-US IPY Traverse project between 2007 and 2009. The intellectual merits of this project are as follows: 1) to constrain and improve the parameterization of firn thermal properties (thermal conductivity and specific heat capacity) that are required for the borehole paleothermometry, 2) to study the change in firn temperature since the deployment of thermal profiling units ~5 years ago and derive the surface temperature trend for that time period, and 3) to compare and contrast the surface temperatures and their trends derived from the measured firn temperatures and satellite thermal infrared data for the past three decades. The project also involves acquiring and deploying an automated system to record transient temperatures at multiple depths in the top 16 meters of the shallow borehole at Dome Fuji, to provide useful data and to prepare for the possibility of conducting temperature-logging in the existing deep (3035 m) and shallow (112 m) boreholes at Dome Fuji in the near future. The preparation of the shallow borehole and the installation of the automated system will be carried out by collaborators from the Japanese Antarctic Research Expedition (JARE) in 2012-13 Antarctic field season. The data collected by this automated system will be used to constrain the thermal properties of upper firn layer at Dome Fuji, as well as comparing with data from other sites, increasing the geographic extent of these studies. The broader impacts of the project include presentation of results at scientific conferences and publication of results in peer-reviewed journals. Public outreach will include targeted work with science teachers and middle school students.
Ocean acidification and increased temperatures are projected to be the primary impacts of global climate change on polar marine ecosystems over the next century. While recent research has focused on the effects of these drivers on calcifying organisms, less is known about how these changes may affect vertebrates. This research will focus on two Antarctic fishes, Trematomus bernacchii and Pagothenia borchgrevinki. Fish eggs and larvae will be collected in McMurdo Sound and reared under different temperature and pH regimes. Modern techniques will be used to examine subsequent changes in physiology, growth, development and gene expression over both short and long timescales. The results will fill a missing gap in our knowledge about the response of non-calcifying organisms to projected changes in pH and temperature. Results will be widely disseminated through publications as well as through presentations at national and international meetings; raw data will also be made available through open-access, web-based databases. This project will support the research and training of three graduate and three undergraduate students. As well, this project will foster the development of two modules on climate change and ocean acidification for an Introduction to Biology course.
This proposed research aims to produce high resolution, precise and accurate records of deep water temperatures in the Drake Passage over the past ~40,000 years, by applying the newly developed carbonate clumped isotope thermometer to a unique collection of modern and fossil deep-sea corals, and thus advance the understanding of the role of the Southern Ocean in modulating global climate. In addition, this study will provide further evaluation on the potential of this new thermometer to derive accurate estimates of past ocean temperatures from deep-sea coral skeletons. Funding will support an early-career junior scientist and a graduate student. <br/><br/>Despite its crucial role in modulating global climate, rates and amplitudes of environmental changes in the Southern Ocean are often difficult to constrain. In particular, the knowledge about the deep water temperatures in the Southern Ocean during the last glacial cycle is extremely limited. This results both from the lack of well-dated climate archives for the deep Southern Ocean and from the fact that most existing temperature proxies (e.g. del18O and Mg/Ca of foraminifera and corals) suffer from the biological 'vital effects'. The latter is especially problematic; it causes substantial challenges in interpreting these geochemical proxies and can lead to biases equivalent to tens of degrees in temperature estimates. Recent development of carbonate clumped isotope thermometer, holds new promises for reconstructing deep water temperatures in the Southern Ocean, since calibration studies of this thermometer in deep-sea corals suggest it is largely free of vital effects. This proposed research seeks to refine the calibration of carbonate clumped isotope thermometer in deep-sea corals at low temperatures, improve the experimental methods to obtain high precision in temperature estimates, and then apply this thermometer to a unique collection of modern and fossil deep-sea corals collected from the Drake Passage during two recent Office of Polar Programs (OPP)-funded cruises, that have already been dated by radiocarbon and U-series methods. By combining the reconstructed temperatures with the radiocarbon and U-Th ages for these deep-sea corals, this study will explore the relationships between these temperature changes and global climate changes.
Marine mammals that inhabit high latitude environments have evolved unique mechanisms to execute a suite of energetically-costly life history events (CLHEs) within a relatively short timeframe when conditions are most favorable. Understanding the intrinsic and extrinsic factors that regulate CLHEs is particularly important in species such as Weddell seals, as both reproduction and molt are associated with large reductions in foraging effort, and the timing and outcome of each appears linked with the other. The long-term mark recapture program on Erebus Bay's Weddell seals provides a unique opportunity to examine CLHEs in a known-history population. The proposed work will monitor physiological condition, pregnancy status, and behavior at various times throughout the year to determine if molt timing is influenced by prior reproductive outcome, and if it, in turn, influences future reproductive success. These data will then be used to address the demographic consequences of trade-offs between CLHEs in Weddell seals. The impact of environmental conditions and CLHE timing on population health will also be modeled so that results can be extended to other climates and species. <br/><br/>An improved understanding of the interactions between CLHEs and the environment is important in predicting the response of organisms from higher trophic levels to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of graduate students and a post-doctoral researcher and will further foster an extensive public outreach collaboration.
0538520<br/>Thiemens<br/>This award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.
Intellectual Merit: <br/>Noble gases in groundwater systems can indicate past climates in ice-free regions through estimation of noble gas temperatures. Traditional noble gas temperatures cannot be derived in ice-covered regions where water is not in contact with the atmosphere. The goal of the proposed work is to take advantage of noble gas properties in ice covered lakes at the ice/water interface to develop a new paleoclimate proxy with the potential to be routinely used in both polar and alpine glacial regions. The evolution of the Taylor Valley lakes is intimately connected to the dynamics of nearby glaciers, as well as the advance and retreat of the Ross Ice Shelf, both of which are dictated by climate change. The perennial ice cover of the lakes form at the water/ice interface and sublimate at the top rendering these lakes ideal to test and develop this new proxy. The proposed research involves conducting an extensive noble gas sampling campaign of lake water, stream water, ice covers and glacial ice. This data set, together with data continuously collected in the area will provide a solid basis to develop, test and refine mathematical models capable of accurately describing heavy noble gas concentration profiles as well as their overall inventory in the lakes over time. These will provide information on the occurrence of major climatic events while simultaneously providing temporal constraints on such events. <br/><br/>Broader impacts: <br/>The findings of this work will be inserted into a new class that the PI has created at the University of Michigan targeted at non-science majors. It will create research opportunities for 1-2 undergraduates each year and will support a PhD student. The outcomes of this research could have strong societal relevance.
EAGER: Collaborative Research: Habitability of Antarctic lakes and detectability of microbial life in icy environments by autonomous year-round instrumentation, is supported by the Antarctic Integrated System Science (AISS) and the Antarctic Organisms and Ecosystems (AOE) programs within the Antarctic Sciences section in the Division of Polar Programs within the Geosciences Directorate of the National Sciences Foundation (NSF). The funds will allow the measurement of year-round properties of the microbes and the surrounding water in Lake Bonney, a lake with four meters of permanent ice cover over forty meters of liquid water in the Dry Valleys of Antarctica. NSF funds will be used to support the deployment, and the science enabled by the deployment, and NASA (the National Aeronautics and Space Administration) funds will be used to purchase the equipment.<br/><br/>Intellectual Merit: This research will be the first to make year-round measurements of the microbial community, and several associated environmental variables, in the continuously liquid portions of Lake Bonney, Antarctica. Three different types of equipment will be deployed in each of the lobes of Lake Bonney. The first instrument is an ITP (an ice-tethered profiler) that will measure physical parameters such as temperature, dissolved oxygen, and chlorophyll throughout the full depth of the liquid water portion of the lake, making measurements at least once each week. The second and third instruments will be used to collect discrete water samples at least every two weeks to determine A) the biological community (assessing metabolic and phylogenetic diversity) and B) the geochemistry (e.g., dissolved organic carbon, and dissolved inorganic nitrogen species). Such samplers have never been used to measure these properties year-round in the Antarctic. Cold temperatures, bottom lake water salinities that are four times greater than the ocean, the thick permanent ice cover, and the lack of sunlight to recharge batteries all present significant challenges for the project, thus classifying the work as an early, high-risk, high-reward activity (the acronym EAGER stands for Early-concept Grants for Exploratory Research).<br/><br/>Broader Impacts: There is much interest in understanding the ecosystems of the Polar regions in an era of climate change. Logistical limitations dictate much of this work only take place in the summer, until new autonomous technologies can open the door for year-round measurements. This award will be the first to attempt year-round microbial sampling in Antarctica. The McMurdo Dry Valleys region is also the site of a Long-Term Ecological Research (LTER) Program, and the research conducted on this project with benefit from, and contribute to, the larger LTER project. The instruments used in the project will be purchased by NASA, so two separate agencies have agreed to explore the feasibility of an early stage project. There will be at least three graduate student trained during the project, and the team will also participate in outreach activities at several venues including the Crow Reservation in Montana.
0539578<br/>Alley <br/>This award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.
Steig/1043092<br/><br/>This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
Elevated temperatures and ocean acidification are both threatening the Southern Ocean. The effects of these environmental changes are poorly understood, but preliminary data suggest that they are driving a biological invasion. Specifically, large populations of skeleton-crushing king crabs, Paralomis birsteini, have been detected off Marguerite Bay on the West Antarctic Peninsula. These crabs appear to be invading the continental shelf region where benthic communities have evolved in the absence of such top-predators. Thus, this invasion could result in a wholesale restructuring of the Antarctic benthic ecosystem. The proposed work seeks to document this invasion and better understand the effects of the introduction of P. birsteini on the ecology of this region. A towed underwater vehicle will be used to photographically image communities, and communities with and without P. birsteini will be compared quantitatively. Additionally, crabs will trapped and various aspects of their morphology and physiology will be assessed. This research is unique in that it will document a biological invasion in real-time and it will therefore enhance our general understandings of the drivers of invasion and resilience in biological communities. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of undergraduate and graduate students and will foster an international collaboration with British scientists. Researchers on this project will participate in outreach thorough the development of K-12 curricular materials.
1142010/Talghader<br/><br/>This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum.
The research will investigate the individual and combined effects of rising ocean acidification and sea surface temperatures on shallow-water calcified benthic organisms in western Antarctic Peninsular (WAP) marine communities. The Southern Ocean is predicted to become undersaturated in terms of both aragonite and calcite within 50 and 100 years, respectively, challenging calcification processes. Adding to the problem, antarctic calcified benthic marine organisms are more vulnerable to ocean acidification than temperate and tropical species because they are generally weakly calcified. Many antarctic organisms are essentially stenothermal, and those in the West Antarctic Peninsula are being subjected to rising seawater temperatures. The project employs both single-species and multi-species level approaches to evaluating the impacts of rising ocean acidification and seawater temperature on representative calcified and non-calcified macroalgae, on calcified and non-calcified mesograzers, and on a calcified macro-grazer, all of which are important ecological players in the rich benthic communities. Multi-species analysis will focus on the diverse assemblage of amphipods and mesogastropods that are associated with dominant macroalgae that collectively play a key role in community dynamics along the WAP. The project will support undergraduate research, both through NSF programs, as well as home university-based programs, some designed to enhance the representation of minorities in the sciences. The principal investigators also will support and foster graduate education through mentoring of graduate students. Through their highly successful UAB IN ANTARCTICA interactive web program, they will continue to involve large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica.
Abstract<br/><br/>Researchers will explore the use of a distributed temperature sensing monitoring system (DTS), using fiber-optical (FO) technology, as the basis of a sustainable, sub-ice cavity sensing array. FO cable systems, such as may be deployed through a hot-water drilled hole through an ice shelf, passing through the underlying cavity to the sea floor, are capable of measuring temperatures down fiber at 1 meter intervals, and at time frequencies as high as 15 seconds. DTS FO systems operate via optical time domain reflectometry along the fiber waveguide using inelastic backscatter of coherent laser light as a probe beam in the FO environment.<br/><br/>The introduction of new technologies to the harsh environmental conditions of the Antarctic are often associated with high risk. However, the potential rewards of this approach (e.g. multiyear capability, minimal submerged mechanical or electrical components that may fail, relative simplicity of deployment and measurement principle, yet yielding distributed real time and spatial observation) are attractive enough to conduct a pilot project at a field-ready location (McMurdo). <br/><br/>Current indications are that the instability of some of the world's largest ice sheets located around the Antarctic and Greenland may be caused by the presence of warming, deep ocean waters, shoaling over continental shelves, and melting the underside of floating ice shelves. Additional knowledge of the temporal and spatial variability of the temperature fields underneath terminal ice shelves, such as those draining the West Antarctic Ice Sheet, are needed to accurately project future global climate effects on ice-shelf ocean interactions, and in order to inform societal and technological aspects of adaption to changing sea-level.
Genome-enabled biology provides a foundation for understanding the genetic basis of organism-environment interactions. . The research project links gene expression, genome methylation, and metabolic rates to assess the mechanisms of environmental adaptation (temperature) across multiple generations in a polar, and closely related temperate, polychaete. By comparing these two species, the research will assess how a polar environment shapes responses to environmental stress. This work will produce: 1) a database of full transcriptome (gene specific) profiling data for the polar polychaete cultured at two temperatures; 2) the contribution of genome methylation to the suppression of gene transcription activities; 3) the linkage between shifts in mRNA pools and total cellular activities (as ATP consumption via respiration); 4) an assessment of the inheritance of patterns of gene expression and metabolic activities across three generations; and 5) a simple demographic model of the polar polychaete population dynamics under normal and 'global-warming' temperature scenarios. Broader impacts include two outreach activities. The first is a mentoring program, where African-American undergraduate students spend 1.5 years working on a research project with a UD faculty member (2 summers plus their senior academic year). The second is a children's display activity at UD?s School of Marine Science "Coast Day".
Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 <br/>Title: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica<br/><br/>The Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. <br/><br/>Broader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the "Multidisciplinary Study of the Amundsen Sea Embayment" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded "Polar Palooza" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.
Intellectual Merit: <br/>Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. <br/><br/>Broader impacts: <br/>Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.
The relatively pristine Antarctic continent with its extensive maritime zone represents a unique location on the planet to investigate the long distance aerial transport and deposition of marine microorganisms. The vast extent of new sea ice that forms each winter around the continent results in large numbers of frost flowers, delicate ice-crystal structures of high salt content that form on the surface of the ice and are readily dispersed by wind. The proposed research builds on earlier work in the Arctic and tests the new hypothesis that wind-borne frost flowers provide an effective mechanism for the transport of marine bacteria over long distances, one that can be uniquely sourced and tracked by the frost flower salt signature in the Antarctic realm. A highly resolved genomic snapshot of the microbial community will be acquired at each stage in the transport path, which will track decreasing fractions of the marine microbial community as it freezes into sea ice, incorporates into frost flowers, converts to aerosols, and ultimately deposits within continental snowpack. En route from sea ice to snowpack, marine bacteria will be exposed to an array of environmental stresses, including high salinity, low temperatures, UV light and potential desiccation. A parallel proteomic analysis will enable an evaluation of the microbial response to these extreme conditions and potential survival mechanisms that allow persistence or eventual colonization of deposition sites across Antarctica. <br/><br/>Current understanding of microbes in the Antarctic atmosphere is based on a limited number of microscopic and culture-based assays and a single report of low-resolution 16S RNA gene sequence analysis. The research will broadly impact understanding of atmospheric microbiology, from source to deposition, and various issues of microbial survival, colonization, endemism, and diversity under extreme conditions. In addition to venues that reach the scientific community, the research team will develop a permanent multi-media and artifact-based exhibit on Antarctic Microbial Transport that will be showcased at Seattle's Pacific Science Center (PSC), which educates nearly a million visitors annually.
Survival of Antarctic notothenioid fishes in the context of global climate change will depend upon the impact of rising oceanic temperatures on their embryonic development, yet little is known regarding the molecular mechanisms underlying this complex suite of processes. Many notothenioids are characterized by secondary pelagicism, which enables them to exploit food sources in the water column and is supported in part by skeletal pedomorphism. Here the PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The research objectives are : 1) To quantify and localize ROS production and identify the point(s) of origin of ROS production in embryonic Antarctic fishes that differ in skeletal phenotypes 2) To determine whether the time course of embryogenesis and the extent of osteological development in embryonic Antarctic fishes can be altered by changing the oxidative status of the animal during embryogenesis 3) To evaluate whether transgenic alteration of oxidative status can induce skeletal pedomorphism in a fish model. Broader Impacts will include teaching undergraduate lectures, recruiting undergraduate students to help with lab analyses (and possibly field work), lectures and demonstrations to high school students, and allowing secondary educators access to personal photos and videos of research animals for curriculum development.
Intellectual Merit: <br/>The PI proposes to utilize computer models used by hydrogeologists to establish the fate and transport of contamination and determine the extent of drilling fluid contamination in the ANDRILL SMS core. For these models, previously collected logs of lithology, porosity, fracture density, fracture type, fracture orientation, drilling fluid loss, drilling fluid characteristics and temperature will be used as input parameters. In addition, biodegradation and sorption constants for the drilling fluid will be determined and incorporated into the models. Samples of drilling fluids used during coring as well as the return fluids were collected at the drill site using standard microbiological sampling techniques. Fluids will be tested at in situ temperatures under aerobic and anaerobic conditions to determine biodegradation constants. Sorption will be determined between the drilling fluids and core samples using standard isotherm methods. Geochemical and microbial fingerprints of the fluids and the changes during biodegradation will determine the potential impact of the drilling fluids on the isolated microbial communities and the geochemistry within various subsurface lithologic units beneath the southern McMurdo Sound in Antarctica. The results of this study could potentially provide guidelines on developing less detrimental methods for future exploration, if deemed necessary through this research.<br/><br/>Broader impacts: <br/>This proposed project will train a graduate student. The methods developed for analyses of samples in this project will serve as a guide for future studies of similar interest and will improve the understanding of ecological impacts of geologic drilling in Antarctica. The results of this study will be used as a reference for comparison with future studies examining newly developed, and improved, sample collection methods in future exploratory drilling projects in pristine environments. The PI is new to Antarctic research.
Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~40-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. The biochemical and physiological challenges facing ectotherms living in the Southern Ocean include the reduction of reaction rates and metabolic fluxes and a pervasive weakening of macromolecular interactions. Yet, Southern Ocean ectotherms are now threatened by warming over periods measured in centuries or less. The proposed research seeks to understand the molecular mechanisms of cold adaptation in Antarctic marine fishes and to assess the physiological capacity of these organisms to resist or compensate for rapid oceanic warming. The P.I. will characterize two important and interacting protein systems, the tubulins that form microtubules and the chaperonin CCT (cytoplasmic chaperonin-containing TCP-1, a family of proteins that assists the folding of the tubulins). Higher-level, integrative responses to global temperature change will be analyzed by studying the thermal dependence of cleavage in Antarctic fish embryos (a microtubule-dependent process). The objectives are (1) to determine the contributions of five novel amino acid substitutions found in Antarctic fish beta-tubulins to microtubule assembly at cold temperature. (2) to compare the functional properties of CCT from testis tissues of Antarctic fishes and mammals. (3) to evaluate the effects of increased temperature on embryogenesis in Antarctic fishes. The research will introduce graduate and REU undergraduate students to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem. The proposed work also will benefit society by developing a cold-functioning chaperonin protein folding system, of great value to the biopharmaceutical and biotechnological industries for use in folding insoluble proteins.
The research will investigate a novel mechanism by which cold-adapted fishes of the Southern Ocean sense and respond to elevated temperatures. It is hypothesized that sub-lethal heat stress may induce cell cycle arrest and/or programmed cell death through apoptosis. The study will use genome-enabled technologies to examine the environmental control over gene expression in Antarctic species and will build direct mechanistic links between the expression of a specific signaling pathway gene and heat-induced changes in cells. Prior results support the hypothesis that heat stress results in cell cycle arrest and, in some cases, programmed cell death in Antarctic fishes. If so, this represents a novel, modified version of the well-conserved cellular stress response found in essentially all other species and suggests that warming ocean temperatures may have profound cellular and physiological impacts on these extremely stenothermal species. The P.I. conducts outreach activities with the Oregon Museum of Science and Industry, will be involved in developing a science curriculum for the Native American Youth and Family Center (NAYA) Early College Academy in Portland, and supports the educational and professional development of both undergraduate and graduate students at Portland State University.
Lake Vida is the largest lake of the McMurdo Dry Valleys, with an approximately 20 m ice cover overlaying a brine of unknown depth with at least 7 times seawater salinity and temperatures below -10 degrees C year-round. Samples of brine collected from ice above the main water body contain 1) the highest nitrous oxide levels of any natural water body on Earth, 2) unusual geochemistry including anomalously high ammonia and iron concentrations, 3) high microbial counts with an unusual proportion (99%) of ultramicrobacteria. The microbial community is unique even compared to other Dry Valley Lakes. The research proposes to enter, for the first time the main brine body below the thick ice of Lake Vida and perform in situ measurements, collect samples of the brine column, and collect sediment cores from the lake bottom for detailed geochemical and microbiological analyses. The results will allow the characterization of present and past life in the lake, assessment of modern and past sedimentary processes, and determination of the lake's history. The research will be conducted by a multidisciplinary team that will uncover the biogeochemical processes associated with a non-photosynthetic microbial community isolated for a significant period of time. This research will address diversity, adaptive mechanisms and evolutionary processes in the context of the physical evolution of the environment of Lake Vida. Results will be widely disseminated through publications, presentations at national and international meetings, through the Subglacial Antarctic Lake Exploration (SALE) web site and the McMurdo LTER web site. The research will support three graduate students and three undergraduate research assistants. The results will be incorporated into a new undergraduate biogeosciences course at the University of Illinois at Chicago which has an extremely diverse student body, dominated by minorities.
The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation. This research program has two main objectives. The first is to investigate metabolic activities and gene expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (<54C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern if psychrophilic processes of leucine incorporation into proteins, shown to occur to -196C, amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. We will examine extracellular and intracellular processes of psychrophilic activity above and below the eutectic by (i) determining the temperature range of metabolic activities such as DNA synthesis, carbon utilization, respiration and ATP generation using radioactive tracer technology, including a control at liquid helium temperature (-268.9C), (ii) analyzing gene expression in ice using whole genome and microarray analyses and iii) examining the role of exopolymeric substances (EPS) and ice micro-physics for the observed activity using an in-situ microscopy technique. Results of the proposed research can be expected to aid in the determination of cellular and genetic strategies that allow cells to maintain activity at extremely low temperatures within an icy matrix and/or to resume activity again when more growth-permissive conditions are encountered. The research is an interdisciplinary collaboration involving three different institutions with participants in Oceanography, Genomics, and Geophysical Sciences. The proposed activity will support the beginning professional career of a female researcher and will serve as the basis for several undergraduate student laboratory projects.
Since 1990, Palmer LTER (PAL) research has been guided by the hypothesis that variability in the polar marine ecosystem is mechanistically coupled to changes in the annual advance, retreat and spatial extent of sea ice. Since that time, the hypothesis has been modified to incorporate climate migration, i.e. the displacement of a cold, dry polar climate by a warm, moist climate regime in the northern component of the PAL region, producing fundamental changes in food web structure and elemental cycling. The observed northern changes are affecting all trophic levels and elemental cycling, and the primary mechanism of change involves match-mismatch dynamics. The proposed research builds on previous findings, with a new emphasis on process studies and modeling to elucidate the mechanistic links between teleconnections, climate change, physical oceanographic forcing and ecosystem dynamics. The proposed research will examine the hypothesis that regional warming and sea ice decline associated with historical and on-going climate migration in the northern part of the study area have altered key phenological relationships, leading to changes in species distributions, increasing trophic mismatches and changes in habitat, food availability, ecosystem dynamics and biogeochemical cycling. Through targeted process studies linked to numerical model simulations, the research also will test the hypothesis that deep cross-shelf canyons characterizing the core study region are focal areas for ecosystem processes that result in predictable, elevated food resources for top-predators. The effort includes the addition of 3 new PIs: a zooplankton ecologist with expertise in biogeochemical fluxes, a phytoplankton ecologist focusing on bio-optics and autonomous observations using gliders, and a numerical simulation modeler specializing in coupled global models of ocean circulation, plankton ecology and biogeochemical cycles. The program will add trace metal sampling and analysis, moored physical oceanographic sensors, a moored sediment trap in the south, drifting sediment traps and stable carbon (del 13C) and nitrogen (del 15N) isotope analyses. Missions lasting up to 45 days using gliders deployed before, during and after summer cruises will, along with moorings and satellite remote sensing of sea ice, ocean color, sea surface temperatures and wind fields, greatly extend the observational program in space and time. <br/><br/>Since its inception, PAL has been a leader in Information Management to enable knowledge-building within and beyond the Antarctic, oceanographic and LTER communities. PAL has designed and deployed a new information infrastructure with a relational database architecture to facilitate data distribution and sharing. The Education and Outreach program capitalizes on the public's fascination with Antarctica to promote scientific literacy from kindergarten students to adult citizens concerned with climate change and environmental sustainability. Through communicating results to the public and working with scientific assessment bodies (e.g., IPCC) and Antarctic Treaty parties to protect Earth's last frontier, PAL researchers contribute to the national scientific agenda and the greater public benefit.
0538674<br/>Matsuoka<br/>This award supports a project to evaluate radio-echo intensities in the available SOAR ice-penetrating radar data along grids covering Lake Vostok, and along four regional tracks from Ridge B toward the lake. The project has two objectives; first, it will examine the upper surface of the lake and reflectors hypothesized to be a boundary between the meteoric and accreted ice. They will provide crucial knowledge on the dynamic evolution of the lake. Second, this project will examine a poorly understood echo-free zone within the deep ice in central East Antarctica. This zone may consist of distorted stagnant ice, while its upper boundary may be a shear zone. The SOAR radar data provide a unique resource to examine spatiotemporal water circulation patterns that should be understood in order to select the best direct-sampling strategy to the lake. The Vostok ice core provides a unique opportunity to do this work. First, the path effects, i.e. propagation loss and birefringence, will be derived at the ice-core site using ice temperature, chemistry, and fabric data. Second, lateral variations of the propagation loss will be estimated by tracking chemistry associated with radar-detected isochronous layers, and by inferring temperatures from an ice-flow model that can replicate those layers. Ice-fabric patterns will be inferred from anisotropy in the reflectivity at about 100 radar-track cross-over sites. In terms of broader impacts, a graduate student will be trained to interpret the radar data in the light of radar theory and glaciological context of Lake Vostok and summer workshops for K-12 teachers will be provided in Seattle and New York. This project will contribute to ongoing efforts to study Lake Vostok and will complement the site selection for a North Vostok ice core, which has been proposed by Russia and France as an IPY program.
Brook 0739766<br/><br/>This award supports a project to create a 25,000-year high-resolution record of atmospheric CO2 from the WAIS Divide ice core. The site has high ice accumulation rate, relatively cold temperatures, and annual layering that should be preserved back to 40,000 years, all prerequisite for preserving a high quality, well-dated CO2 record. The new record will be used to examine relationships between Antarctic climate, Northern Hemisphere climate, and atmospheric CO2 on glacial-interglacial to centennial time scales, at unprecedented temporal resolution. The intellectual merit of the proposed work is simply that CO2 is the most important greenhouse gas that humans directly impact, and understanding the sources, sinks, and controls of atmospheric CO2 is a major goal for the global scientific community. Accurate chronology and detailed records are primary requirements for developing and testing models that explain and predict CO2 variability. The proposed work has several broader impacts. It contributes to the training of a post-doctoral researcher, who will transfer to a research faculty position during the award period and who will participate in graduate teaching and guest lecture in undergraduate courses. An undergraduate researcher will gain valuable lab training and conduct independent research. Bringing the results of<br/>the proposed work to the classroom will enrich courses taught by the PI. Outreach efforts will expose pre-college students to ice core research. The proposed work will enhance the laboratory facilities for ice core research at OSU, insuring that the capability for CO2 measurements exists for future projects. All data will be archived at the National Snow and Ice Data Center and other similar archives, per OPP policy. Highly significant results will be disseminated to the news media through OSU?s very effective News and Communications group. Carbon dioxide is the most important greenhouse gas that humans are directly changing. Understanding how CO2 and climate are linked on all time scales is necessary for predicting the future behavior of the carbon cycle and climate system, primarily to insure that the appropriate processes are represented in carbon cycle/climate models. Part of the proposed work emphasizes the relationship of CO2 and abrupt climate change. Understanding how future abrupt change might impact the carbon cycle is an important issue for society.
Abstract<br/><br/>Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~38-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. Because they live at very low and stable temperatures, Antarctic fishes of the suborder Nototheniodei are particularly attractive as models for understanding the mechanisms of biomolecular cold adaptation, or the compensatory restructuring of biochemical and physiological systems to preserve biological function in cold thermal regimes. Two interrelated and potentially co-evolved systems, the tubulins that form microtubules and the chaperonin-containing TCP1 (t-complex protein-1) complex (CCT) that assists the folding of tubulins, provide an unparalleled opportunity to elucidate these mechanisms. This research will yield new and important knowledge regarding: 1) cold adaptation of microtubule assembly and of chaperonin function; and 2) the co-evolutionary origin of tubulin-binding specificity by CCT. The first objective of this proposal is to determine the contributions of five novel amino acid substitutions found in Antarctic fish beta-tubulins to microtubule assembly at cold temperature. The second objective is to establish a chaperonin folding system in vitro using CCT purified from testis tissue of Antarctic fishes and to evaluate its thermal properties and mechanism. The third objective is to evaluate, through phylogenetically controlled contrasts, the hypothesis that CCT and its tubulin substrates from Antarctic fishes have co-evolved to function at cold temperatures. The broader impacts of this proposal include introduction of graduate and REU undergraduate students of Northeastern University to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem. Because much of the research on the biogenesis and function of cold-adapted proteins will be performed in the field at Palmer Station, these students will gain invaluable experience in the practical considerations of expeditionary biological science. The research also will increase knowledge about molecular cold adaptation in one of the Earth's extreme environments, and hence is relevant to the formulation of refined hypotheses regarding potential extraterrestrial life on Mars or Europa. The cold-functioning chaperonin protein folding system will be of great value to the biopharmaceutical and biotechnological industries for use in folding insoluble proteins.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project will deploy a new Fabry-Perot interferometer (FPI) at the U.S. Palmer Station located in the Antarctic Peninsula. The FPI will observe mesospheric and thermospheric neutral winds and temperatures using multiple nightglow emissions (OH, 892 nm, 87 km; O 557.7 nm, 97 km; O 630 nm, 250 km; and O2 (0-1) 865 nm, 94 km). The project's team will collaborate with Australian scientists who operate similar FPI instruments at their Antarctic stations Mawson and Davis to jointly analyze the neutral wind and temperature data distributions over the continent and address the following scientific problems: (1) Thermospheric neutral winds effects on the Weddell Sea Anomaly, (2) Non-migrating tides in the mesosphere and lower thermosphere, (3) Lower thermospheric meridional wind circulation and mesosphere wind shear, (4) High-latitude geomagnetic field effects on the mid-latitude thermosphere, and (4) Conjugacy studies of the mesosphere and thermosphere with the incoherent scatter radar and FPI observations from Millstone Hill, Massachusetts. The fieldwork and analysis efforts associated with this project are highly suitable for involvement and research training of graduate students.
The primary objective of this research is to investigate polar marine psychrophilic bacteria for their potential to nucleate ice using a combination of microbiological, molecular biological and atmospheric science approaches in the laboratory. Very little is known about how psychrophiles interact and cope with ice or their adaptations to conditions of extreme cold and salinity. This work will involve a series of laboratory experiments using a novel freeze-tube technique for assaying freezing spectra which will provide quantitative information on: (i) the temperature-dependent freezing rates for heterogeneously frozen droplets containing sea-ice bacteria, (ii) the proportional occurrence of ice-nucleation activity versus anti-freeze activity among sea-ice bacterial isolates and (iii) the temperature-dependent freezing rates of bacteria with ice-nucleation activity grown at a range of temperatures and salinities. The compound(s) responsible for the observed activity will be identified, which is an essential step towards the development of an in-situ bacterial ice-nucleation detection assay that can be applied in the field to Antarctic water and cloud samples.<br/> One of the goals of this work is to better understand survival and cold adaptation processes of polar marine bacteria confronted with freezing conditions in sea ice. Since sea ice strongly impacts polar, as well as the global climates, this research is of significant interest because it will also provide data for accessing the importance of bacterial ice nucleation in the formation of sea ice. These measurements of ice-nucleation rates will be the first high-resolution measurements for psychrophilic marine bacteria. Another goal is to better understand the impact of bacterial ice initiation processes in polar clouds by making high-resolution measurements of nucleation rates for cloud bacteria found over Arctic and Antarctic regions. Initial measurements indicate these bacteria nucleate ice at warmer temperatures and the effect in polar regions may be quite important, since ice can strongly impact cloud dynamics, cloud radiative properties, precipitation formation, and cloud chemistry. If these initial measurements are confirmed, the data collected here will be important for improving the understanding of polar cloud processes and models. A third goal is to better understand the molecular basis of marine bacterial ice nucleation by characterizing the ice-nucleation compound and comparing it with those of known plant-derived ice-nucleating bacteria, which are the only ice-nucleating bacteria examined in detail to date. The proposed activity will support the beginning academic career of a post-doctoral researcher and will serve as the basis for several undergraduate student laboratory projects. Results from this research will be widely published in various scientific journals and outreach venues.
The suborder Notothenoidei is the dominant fish group of the Southern Ocean surrounding Antarctica, both in terms of number of species and biomass. For about fourteen million years, these highly successful fish evolved under stable thermal conditions that result in body temperatures of about zero degrees centigrade throughout their life histories. Evolution this cold environment has led to unusual physiological and biochemical characteristics. In some cases, the characteristics contribute to overcoming constraints of cold temperature on biological processes. In other instances, mutations that probably would have been lethal in warmer, less oxygen-rich environments than the Southern Ocean have been retained in Antarctic fishes. This research project focuses on three major objectives that exploit these unusual conditions to identify mechanisms compatible with normal cellular function at cold temperature and to gain unique insights into the physiological roles of key intracellular proteins. The three lines of study proposed are the molecular basis for the failure of the myoglobin encoding gene to be expressed in certain Antarctic notothenioid fishes, the basis of the substrate specificity of the enzyme fatty acyl-CoA synthetase that is involved in the catabolism of fatty acids, and the functional roles played by different isoforms of creatine phosphokinase in locomotory muscle of Antarctic fish. Results from this study will not only provide insight into the evolutionary biology of the Antarctic notothenioid fishes, but will elucidate important general principles that are applicable to widely different taxa beyond the Antarctic.
Notothenioid fishes that dominate the fish fauna surrounding Antarctica have been evolving for 10-14 million years at a nearly constant body temperature of ~0C throughout their life histories. As a result, this group of animals is uniquely suited to studies aimed at understanding and identifying features of physiology and biochemistry that result from the process of evolution at cold body temperature. This project has three major objectives aimed at examining adaptations for life in cold environments: <br/><br/>1. Identify the amino acid substitutions in the fatty acid-binding pocket of fatty acyl CoA synthetase (FACS) that explain its substrate specificity. Fatty acids are a major fuel of energy metabolism in Antarctic fishes. FACS catalyzes the condensation of CoASH and fatty acids to fatty acyl CoA esters, a step required for subsequent metabolism of these important compounds. This research may permit us to resolve the specific amino acid substitutions that explain both substrate specificity and preservation of catalytic rate of notothenioid FACS at cold physiological temperatures.<br/><br/>2. Produce a rigorous biochemical and biophysical characterization of the intracellular calcium-binding protein, parvalbumin, from white axial musculature of Antarctic fishes. Parvalbumin plays a pivotal role in facilitating the relaxation phase of fast-contracting muscles and is a likely site of strong selective pressure. Preliminary data strongly indicate that the protein from Antarctic fishes has been modified to ensure function at cold temperature. A suite of physical techniques will be used to determine dissociation constants of Antarctic fish parvalbumins for calcium and magnesium and unidirectional rate constants of ion-dissociation from the protein. Full-length cDNA clones for Antarctic fish parvalbumin(s) will permit deduction of primary amino acid sequence These data will yield insight into structural elements that permit the protein from notothenioid fishes to function at very cold body temperature.<br/><br/>3. Conduct a broad survey of the pattern of cardiac myoglobin expression in the Suborder Notothenoidei. Previous work has indicated a variable pattern of presence or absence of the intracellular oxygen-binding protein, myoglobin (Mb), in hearts of one family of Antarctic notothenioid fishes (Channichthyidae; icefishes). Because Mb is of physiological value in species that express the protein, the observed pattern of interspecific expression has been attributed to unusually low niche competition in the Southern Ocean. This leads to the prediction that similar loss of cardiac Mb should be observed in other notothenioid taxa. This part of the project will survey for the presence and absence of cardiac Mb in as many notothenioid species as possible and, if Mb-lacking species are detected, will extend analyses to determine the mechanism(s) responsible for loss of its expression using molecular biological techniques.
Abstract<br/>OPP-0089451<br/>P.I. William Detrich<br/><br/> As the Southern Ocean cooled during the past 25 million years, the fishes of Antarctic coastal waters evolved biochemical and physiological adaptations that maintain essential cellular processes such as cytoskeletal function and gene transcription. Their microtubules, for example, assemble and function at body temperatures (-1.8 to +1 oC) well below those of homeotherms and temperate poikilotherms. The long range goals of the proposed research are to determine, at the molecular level, the adaptations that enhance the assembly of microtubules, the function of kinesin motors, and the expression of globin and tubulin genes. The specific objectives are three: 1) to determine the primary sequence changes and posttranslational modifications that contribute to the efficient polymerization of Antarctic fish tubulins at low temperatures; 2) to evaluate the biochemical adaptations required for efficient function of the brain kinesin motor of Antarctic fishes at low temperatures; and 3) to characterize the structure, organization, and promoter-driven expression of globin and tubulin genes from an Antarctic rockcod (Notothenia coriiceps) and a temperate congener (N. angustata). Brain tubulins from Antarctic fishes differ from those of temperate and warm-blooded vertebrates both in unusual primary sequence substitutions (located primarily in lateral loops and the cores of tubulin monomers) and in posttranslational C-terminal glutamylation. Potential primary sequence adaptations of the Antarctic fish tubulins will be tested directly by production of wild-type and site directed tubulin mutants for functional analysis in vitro. The capacity of mutated and wild-type fish tubulins to form "cold-stable" microtubules will be determined by measurement of their critical concentrations for assembly and by analysis of their dynamics by video-enhanced microscopy. Three unusual substitutions in the kinesin motor domain of Chionodraco rastrospinosus may enhance mechanochemical activity at low temperature by modifying the binding of ATP and/or the velocity of the motor. To test the functional significance of these changes, the fish residues will be converted individually, and in concert, to those found in mammalian brain kinesin. Reciprocal substitutions will be introduced into the framework of the mammalian kinesin motor domain. After production in Escherichia coli and purification, the functional performance of the mutant motor domains will be evaluated by measurement of the temperature dependence of their ATPase and motility activities. Molecular adaptation of gene expression in N. coriiceps will be analyzed using an a-globin/b-globin gene pair and an a-tubulin gene cluster. Structural features of N. coriiceps globin and tubulin gene regulatory sequences (promoters and enhancers) that support efficient expression will be assessed by transient transfection assay of promoter/luciferase reporter plasmid constructs in inducible erythrocytic and neuronal model cell systems followed by assay of luciferase reporter activity. Together, these studies should reveal the molecular adaptations of Antarctic fishes that maintain efficient cytoskeletal assembly, mechanochemical motor function, and gene expression at low temperatures. In the broadest sense, this research program should advance the molecular understanding of the poikilothermic mode of life.
This project is a two-year investigation into the dynamics and processes of deep water mass formation in the western Weddell Sea, combining physical and chemical oceanographic techniques to produce a coherent picture of the importance of this unique region to the structure of the world ocean. In the global context, this area is a major water mass modification site, involving open ocean convective events, the continental margin, and the ice cover. At this time the various water types that combine to form Weddell Sea Deep Water and Antarctic Bottom Water, and the conditions under which these water masses form, are not known well enough to establish direct physical links and volumetric budgets. It is suspected that the outflow from the Weddell Sea is restricted to quite narrow boundary currents flowing near the base of the continental shelf, and consequently may be observed with conventional current meter moorings from the shelf into the deep ocean. Two oceanographic expeditions to the western Weddell Sea are planned as part of this study: the first in the 1990/91, and the second in 1991/92. The objectives will be to measure the flow of newly-formed bottom water and to explore the sinking process of near-surface waters in the open ocean to see how these affect the deep water flows. In the first year the primary objective will be to set out an array of eight current meters in the bottom water core, while a secondary objective will be to grapple for an existing array that was set out in early 1988 but could not be recovered in 1989 because Antarctic Program ship resources had to be diverted to deal with the oil spill at Palmer Station. In the second year the array will be retrieved. Hydrographic cruises in order to define the upper ocean temperatures and salinity structure in the outflow region where unusually large step structures have been found in the past. A chemistry program consistent with the objectives of the World Ocean Circulation Experiment (WOCE) and presently planned experiments in the South Atlantic Ocean, will be integrated into the cruises carried out under this project.
9908828<br/>Aronson<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.<br/><br/>A series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). <br/><br/>Seymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.
This project examines the role of glacier dynamics in glacial sediment yields. The results will shed light on how glacial erosion influences both orogenic processes and produces sediments that accumulate in basins, rich archives of climate variability. Our hypothesis is that erosion rates are a function of sliding speed, and should diminish sharply as the glacier's basal temperatures drop below the melting point. To test this hypothesis, we will determine sediment accumulation rates from seismic studies of fjord sediments for six tidewater glaciers that range from fast-moving temperate glaciers in Patagonia to slow-moving polar glaciers on the Antarctic Peninsula. Two key themes are addressed for each glacier system: 1) sediment yields and erosion rates by determining accumulation rates within the fjords using seismic profiles and core data, and 2) dynamic properties and basin characteristics of each glacier in order to seek an empirical relationship between glacial erosion rates and ice dynamics. The work is based in Patagonia and the Antarctic Peninsula, ideal natural laboratories for these purposes because the large latitudinal range provides a large range of precipitation and thermal regimes over relatively homogeneous lithologies and tectonic settings. Prior studies of these regions noted significant decreases in glaciomarine sediment accumulations in the fjords to the south. As well, the fjords constitute accessible and nearly perfect natural sediment traps.<br/><br/>The broader impacts of this study include inter-disciplinary collaboration with Chilean glaciologists and marine geologists, support for one postdoctoral and three doctoral students, inclusion of undergraduates in research, and outreach to under-represented groups in Earth sciences and K-12 educators. The results of the project will also contribute to a better understanding of the linkages between climate and evolution of all high mountain ranges.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.<br/><br/>A series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). <br/><br/>Seymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.
This proposal is for the continuation and expansion of an underway program on the R/V Laurence M. Gould to measure dissolved carbon dioxide gas (pCO2) along with occasional total carbon dioxide (TCO2) in surface waters on transects of Drake Passage. The added observations include dissolved oxygen, as well as nutrient and carbon-13. The proposed work is similar to the underway measurement program made aboard R/V Nathaniel B. Palmer, and complements similar surface temperature and current data.<br/>The Southern Ocean is an important component of the global carbon budget. Low surface temperatures with consequently low vertical stability, ice formation, and high winds produce a very active environment for the exchange of gaseous carbon dioxide between the atmospheric and oceanic reservoirs. The Drake Passage is the narrowest point through which the Antarctic Circumpolar Current and its associated fronts must pass, and is the most efficient location for the measurement of latitudinal gradients of gas exchange. The generated time series will contribute towards two scientific goals: the quantification of the spatial and temporal variability and trends of surface carbon dioxide, oxygen, nutrients and C-13, and an understanding of the dominant processes that contribute to the observed variability.
This award is for support for three years of funding to study the effects of impurities on the flow of poly-<br/>crystalline ice. It has been known for thirty years that both hydrofluoric acid (HF) and hydrochloric acid (HCl) dramatically decrease the strength of ice and recent work by the author's group has shown that sulfuric acid (H2SO4) produces a similar reduction in strength. However, these data are for single crystals at strain rates and stresses that far exceed those found in glaciers and ice sheets, and often at concentrations that far exceed those in natural ice. Therefore, it is not known how impurities found in nature affect the flow of polycrystalline ice at slow strain rates. In this research, the effects of nitric acid and sulfuric acid (which are naturally occurring impurities in ice) on the microstructure (dislocation structure, grain boundary structure and location of the acids) and creep of polycrystalline ice (at a range of temperatures and stresses) will be determined. The ice's response to creep deformation will be studied using a combination of x-ray topography, optical microscopy and scanning electron microscopy. X-ray microanalysis in an environmental scanning electron microscope will be used to study the location of impurities. The structure and creep behavior of the acid-doped ice will be compared with those of both high-purity laboratory-grown ice and ice from Byrd Station, Antarctica. The end-result of this project will be to elucidate the effects of naturally-occurring acid impurities on the mechanical properties of polycrystalline ice under conditions relevant to the deformation of glaciers and ice sheets, including and understanding of how impurities affect the underlying deformation mechanisms.
This project seeks to understand the evolutionary physiology of reproductive strategies in Southern Ocean marine invertebrates. The fauna of the Southern Ocean has evolved under stable, cold temperatures for approximately 14 million years. These conditions have led to the evolution of unusual physiological and biochemical characteristics, many of which may reflect adaptations to relatively low oxygen availability and high larval oxygen demands. The goal of the proposed projects is to understand latitudinal variation in the function of invertebrate egg masses in relation to oxygen availability and temperature. This relationship is critical to larval survival in the low-temperature, high-oxygen conditions found at high latitudes. In particular, the investigators will: (1) use first principles to model the diffusion of oxygen into egg and embryo masses of Antarctic organisms at environmentally relevant temperatures; (2) test model assumptions by measuring the temperature-dependence of embryonic metabolism and oxygen diffusivity through natural and artificial gels; (3) test model predictions by using oxygen microelectrodes to measure oxygen gradients in both artificial and natural egg masses, and by measuring developmental rates of embryos at different positions in masses; and (4) compare the structure and function of egg masses from the Southern Ocean to those from temperate waters. These components of the study constitute an integrated examination of the evolutionary physiology of egg mass structure and function. Studies of masses endemic to polar conditions will increase the understanding of egg mass evolution across equator-to-pole gradients in temperature and across gradients in oxygen partial pressure. The proposal will support graduate students and will involve several undergraduates in research. The PIs will also design and implement units on polar biology for undergraduate classes at their respective institutions. These educational units will focus on the PIs' photographs, video footage, experiments, and data from this project. The PIs will use web-linked video and instructional technologies to design and co-teach a new class on polar ecological physiology, will work with local grade school institutions to involve high school students in research, and will develop high school course modules about polar biology.
This award supports a project to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is of paramount importance to ice core interpretation. Carefully controlled laboratory studies will be conducted at a variety of temperatures to empirically measure the mass transfer coefficient (the rate at which water moves from the solid to the vapor phase) for sublimating snow and to determine the time scale for isotopic equilibration between water vapor and ice. In addition the isotopic fractionation coefficient for vapor derived from sublimating ice will be determined and the results will be used to update existing models of mass transfer and isotopic evolution in firn. It is well known that water vapor moves through firn due to diffusion, free convection and forced convection. Although vapor movement through variably-saturated firn due to these processes has been modeled, because of a lack of laboratory data the mass transfer coefficient had to be estimated. Field studies have documented the magnitudes of post-depositional changes, but field studies do not permit rigorous analysis of the relative importance of the many processes which are likely to act in natural snow packs. The results of these laboratory investigations will be broadly applicable to a number of studies and will allow for improvement of existing physically-based models of post-depositional isotopic change, isotopic diffusion in firn, and vapor motion in firn. A major component of this project will be the design and fabrication of the necessary, novel experimental apparatus, which will be facilitated by existing technical expertise, cold room facilities, and laboratory equipment at CRREL. This project is a necessary step toward a quantitative understanding of the isotopic effects of water vapor movement in firn. The proposed work has broader impacts in several different areas. The modeling results will be applicable to a wide range of studies of water in the polar environment, including studies of wind-blown or drifting snow. The proposed collaborative study will partially support a Dartmouth graduate student for three years. This project will also provide support for a young first-time NSF investigator at the University of Vermont. Undergraduate students from Dartmouth will be involved in the research through the Women in Science Project and undergraduate students at the University of Vermont will be supported through the Research Experiences for Undergraduates program. The principal investigators and graduate student will continue their tradition of k-12 school outreach by giving science lessons and talks in local schools each year. Research results will be disseminated through scientific conferences, journal publications, and institutional seminars.
The polar ocean presently surrounding Antarctica is the coldest, most thermally stable marine environment on earth. Because oxygen solubility in seawater is inversely proportional to temperature, the cold Antarctic seas are an exceptionally oxygen-rich aquatic habitat. Eight families of a single perciform suborder, the Notothenioidei, dominate the present fish fauna surrounding Antarctica. Notothenioids account for approximately 35% of fish species and 90% of fish biomass south of the Antarctic Polar Front. Radiation of closely related notothenioid species thus has occurred rapidly and under a very unusual set of conditions: relative oceanographic isolation from other faunas due to circumpolar currents and deep ocean trenches surrounding the continent, chronically, severely cold water temperatures, very high oxygen availability, very low levels of niche competition in a Southern Ocean depauperate of species subsequent to a dramatic crash in species diversity of fishes that occurred sometime between the mid-Tertiary and present. These features make Antarctic notothenioid fishes an uniquely attractive group for the study of physiological and biochemical adaptations to cold body temperature. <br/>Few distinctive features of Antarctic fishes are as unique as the pattern of expression of oxygen-binding proteins in one notothenioid family, the Channichthyidae (Antarctic icefishes). All channichthyid icefishes lack the circulating oxygen-binding protein, hemoglobin (Hb); the intracellular oxygen-binding protein, myoglobin (Mb) is not uniformly expressed in species of this family. Both proteins are normally considered essential for adequate delivery of oxygen to aerobically poised tissues of animals. To compensate for the absence of Hb, icefishes have developed large hearts, rapidly circulate a large blood volume and possess elaborate vasculature of larger lumenal diameter than is seen in red-blooded fishes. Loss of Mb expression in oxidative muscles correlates with dramatic elevation in density of mitochondria within the cell, although each individual organelle is less densely packed with respiratory proteins. <br/>Within the framework of oxygen movement, the adaptive significance of greater vascular density and mitochondrial populations is understandable but mechanisms underlying development of these characteristics remain unknown. The answer may lie in another major function of both Hb and Mb, degradation of the ubiquitous bioactive compound, nitric oxide (NO). The research will test the hypothesis that loss of hemoprotein expression in icefishes has resulted in an increase in levels of NO that mediate modification of vascular systems and expansion of mitochondrial populations in oxidative tissues. The objectives of the proposal are to quantify the vascular density of retinas in +Hb and -Hb notothenioid species, to characterize NOS isoforms and catalytic activity in retina and cardiac muscle of Antarctic notothenioid fishes, to evaluate level of expression of downstream factors implicated in angiogenesis (in retinal tissue) and mitochondrial biogenesis (in cardiac muscle), and to determine whether inhibition of NOS in vivo results in regression of angiogenic and mitochondrial biogenic responses in icefishes. Broader impacts range from basic biology, through training of young scientists, to enhanced understanding of clinically relevant biomedical processes.
0538630<br/>Severinghaus<br/>This award supports a project to produce the first record of Kr/N2 in the paleo-atmosphere as measured in air bubbles trapped in ice cores. These measurements may be indicative of past variations in mean ocean temperature. Knowing the mean ocean temperature in the past will give insight into past variations in deep ocean temperature, which remain poorly understood. Deep ocean temperature variations are important for understanding the mechanisms of climate change. Krypton is highly soluble in water, and its solubility varies with temperature, with higher solubilities at colder water temperatures. A colder ocean during the last glacial period would therefore hold more krypton than today's ocean. Because the total amount of krypton in the ocean-atmosphere system is constant, the increase in the krypton inventory in the glacial ocean should cause a resultant decrease in the atmospheric inventory of krypton. The primary goal of this work is to develop the use of Kr/N2 as an indicator of paleo-oceanic mean temperature. This will involve improving the analytical technique for the Kr/N2 measurement itself, and measuring the Kr/N2 in air bubbles in ice from the last glacial maximum (LGM) and the late Holocene in the Vostok and GISP2 ice cores. This provides an estimate of LGM mean ocean temperature change, and allows for a comparison between previous estimates of deep ocean temperature during the LGM. The Vostok ice core is ideal for this purpose because of the absence of melt layers, which compromise the krypton and xenon signal. Another goal is to improve precision on the Xe/N2 measurement, which could serve as a second, independent proxy of ocean temperature change. A mean ocean temperature time series during this transition may help to explain these observations. Additionally, the proposed work will measure the Kr/N2 from marine isotope stage (MIS) 3 in the GISP2 ice core. Knowing the past ocean temperature during MIS 3 will help to constrain sea level estimates during this time period. The broader impacts of the proposed work: are that it will provide the first estimate of the extent and timing of mean ocean temperature change in the past. This will help to constrain previously proposed mechanisms of climate change involving large changes in deep ocean temperature. This project will also support the education of a graduate student. The PI gives interviews and talks to the media and public about climate change, and the work will enhance these outreach activities. Finally, the work will occur during the International Polar Year (IPY), and will underscore the unique importance of the polar regions for understanding the global atmosphere and ocean system.
Patterns of biodiversity, as revealed by basic research in organismal biology, may be derived from ecological and evolutionary processes expressed in unique settings, such as Antarctica. The polar regions and their faunas are commanding increased attention as declining species diversity, environmental change, commercial fisheries, and resource management are now being viewed in a global context. Commercial fishing is known to have a direct and pervasive effect on marine biodiversity, and occurs in the Southern Ocean as far south as the Ross Sea. <br/>The nature of fish biodiversity in the Antarctic is different than in all other ocean shelf areas. Waters of the Antarctic continental shelf are ice covered for most of the year and water temperatures are nearly constant at -1.5 C. In these waters components of the phyletically derived Antarctic clade of Notothenioids dominate fish diversity. In some regions, including the southwestern Ross Sea, Notothenioids are overwhelmingly dominant in terms of number of species, abundance, and biomass. Such dominance by a single taxonomic group is unique among shelf faunas of the world. In the absence of competition from a taxonomically diverse fauna, Notothenioids underwent a habitat or depth related diversification keyed to the utilization of unfilled niches in the water column, especially pelagic or partially pelagic zooplanktivory and piscivory. This has been accomplished in the absence of a swim bladder for buoyancy control. They also may form a special type of adaptive radiation known as a species flock, which is an assemblage of a disproportionately high number of related species that have evolved rapidly within a defined area where most species are endemic. Diversification in buoyancy is the hallmark of the notothenioid radiation. Buoyancy is the feature of notothenioid biology that determines whether a species lives on the substrate, in the water column or both. Buoyancy also influences other key aspects of life history including swimming, feeding and reproduction and thus has implications for the role of the species in the ecosystem. <br/>With similarities to classic evolutionary hot spots, the Antarctic shelf and its Notothenioid radiation merit further exploration. The 2004 "International Collaborative Expedition to collect and study Fish Indigenous to Sub-Antarctic Habitats," or, "ICEFISH," provided a platform for collection of notothenioid fishes from sub-Antarctic waters between South America and Africa, which will be examined in this project. This study will determine buoyancy for samples of all notothenioid species captured during the ICEFISH cruise. This essential aspect of the biology is known for only 19% of the notothenioid fauna. Also, the gross and microscopic anatomy of brains and sense organs of the phyletically basal families Bovichtidae, Eleginopidae, and of the non-Antarctic species of the primarily Antarctic family Nototheniidae will be examined. The fish biodiversity and endemicity in poorly known localities along the ICEFISH cruise track, seamounts and deep trenches will be quantified. Broader impacts include improved information for comprehending and conserving biodiversity, a scientific and societal priority.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role and fate of Boron in high-grade metamorphic rocks of the Larsemann Hills region of Antarctica. Trace elements provide valuable information on the changes sedimentary rocks undergo as temperature and pressure increase during burial. One such element, boron, is particularly sensitive to increasing temperature because of its affinity for aqueous fluids, which are lost as rocks are buried. Boron contents of unmetamorphosed pelitic sediments range from 20 to over 200 parts per million, but rarely exceed 5 parts per million in rocks subjected to conditions of the middle and lower crust, that is, temperatures of 700 degrees C or more in the granulite-facies, which is characterized by very low water activities at pressures of 5 to 10 kbar (18-35 km burial). Devolatization reactions with loss of aqueous fluid and partial melting with removal of melt have been cited as primary causes for boron depletion under granulite-facies conditions. Despite the pervasiveness of both these processes, rocks rich in boron are locally found in the granulite-facies, that is, there are mechanisms for retaining boron during the metamorphic process. The Larsemann Hills, Prydz Bay, Antarctica, are a prime example. More than 20 lenses and layered bodies containing four borosilicate mineral species crop out over a 50 square kilometer area, which thus would be well suited for research on boron-rich granulite-facies metamorphic rocks. <br/><br/>While most investigators have focused on the causes for loss of boron, this work will investigate how boron is retained during high-grade metamorphism. Field observations and mapping in the Larsemann Hills, chemical analyses of minerals and their host rocks, and microprobe age dating will be used to identify possible precursors and deduce how the precursor materials recrystallized into borosilicate rocks under granulite-facies conditions. The working hypothesis is that high initial boron content facilitates retention of boron during metamorphism because above a certain threshold boron content, a mechanism "kicks in" that facilitates retention of boron in metamorphosed rocks. For example, in a rock with large amounts of the borosilicate tourmaline, such as stratabound tourmalinite, the breakdown of tourmaline to melt could result in the formation of prismatine and grandidierite, two borosilicates found in the Larsemann Hills. This situation is rarely observed in rocks with modest boron content, in which breakdown of tourmaline releases boron into partial melts, which in turn remove boron when they leave the system. Stratabound tourmalinite is associated with manganese-rich quartzite, phosphorus-rich rocks and sulfide concentrations that could be diagnostic for recognizing a tourmalinite protolith in a highly metamorphosed complex where sedimentary features have been destroyed by deformation. Because partial melting plays an important role in the fate of boron during metamorphism, our field and laboratory research will focus on the relationship between the borosilicate units, granite pegmatites and other granitic intrusives. The results of our study will provide information on cycling of boron at deeper levels in the Earth's crust and on possible sources of boron for granites originating from deep-seated rocks.<br/><br/>An undergraduate student will participate in the electron microprobe age-dating of monazite and xenotime as part of a senior project, thereby integrating the proposed research into the educational mission of the University of Maine. In response to a proposal for fieldwork, the Australian Antarctic Division, which maintains Davis station near the Larsemann Hills, has indicated that they will support the Antarctic fieldwork.
This award supports a project to measure the elemental and isotopic composition of firn air and occluded air in shallow boreholes and ice cores from the WAIS Divide site, the location of a deep ice-coring program planned for 2006-07 and subsequent seasons. The three primary objectives are: 1) to establish the nature of firn air movement and trapping at the site to aid interpretations of gas data from the deep core; 2) to expand the suite of atmospheric trace gas species that can be measured in ice and replicate existing records of other species; and 3) to inter-calibrate all collaborating labs to insure that compositional and isotopic data sets are inter-comparable. The program will be initiated with a shallow drilling program during the 05/06 field season which will recover two 300+m cores and firn air samples. The ice core and firn air will provide more than 700 years of atmospheric history that will be used to address a number of important questions related to atmospheric change over this time period. The research team consists of six US laboratories that also plan to participate in the deep core program. This collaborative research program has a number of advantages. First, the scientists will be able to coordinate sample allocation a priori to maximize the resolution and overlap of records of interrelated species. Second, sample registration will be exact, allowing direct comparison of all records. Third, a coherent data set will be produced at the same time and all PI.s will participate in interpreting and publishing the results. This will insure that the best possible understanding of gas records at the WAIS Divide site will be achieved, and that all work necessary to interpret the deep core is conducted in a timely fashion. The collaborative structure created by the proposal will encourage sharing of techniques, equipment, and ideas between the laboratories. The research will identify impacts of various industrial/agricultural activities and help to distinguish them from natural variations, and will include species for which there are no long records of anthropogenic impact. The work will also help to predict future atmospheric loadings. The project will contribute to training scientists at several levels, including seven undergraduates, two graduate students and one post doctoral fellow.
This award supports the study of the drift and break-up of Earth's largest icebergs, which were recently released into the Ross Sea of Antarctica as a result of calving from the Ross Ice Shelf. The scientific goals of the study are to determine the physics of iceberg motion within the dynamic context of ocean currents, winds, and sea ice, which determine the forces that drive iceberg motion, and the relationship between the iceberg and geographically and topographically determined pinning points on which the iceberg can ground. In addition, the processes by which icebergs influence the local environments (e.g., sea ice conditions near Antarctica, access to penguin rookeries, air-sea heat exchange and upwelling at iceberg margins, nutrient fluxes) will be studied. The processes by which icebergs generate globally far-reaching ocean acoustic signals that are detected within the global seismic (earthquake) sensing networks will also be studied. A featured element of the scientific research activity will be a field effort to deploy automatic weather stations, seismometer arrays and GPS-tracking stations on several of the largest icebergs presently adrift, or about to be adrift, in the Ross Sea. Data generated and relayed via satellite to home institutions in the Midwest will motivate theoretical analysis and computer simulation; and will be archived on an "iceberg" website (http://amrc.ssec.wisc.edu/amrc/iceberg.html) for access by scientists and the general public. At the most broad level, the study is justified by the fact that icebergs released by the Antarctic ice sheet represent the largest movements of fresh water within the natural environment (e.g., several of the icebergs to be studied, B15, C19 and others calved since 2000 CE, represent over 6000 cubic kilometers of fresh water-an amount roughly equivalent to 100 years of the flow of the Nile River). A better understanding of the impact of iceberg drift through the environment, and particularly the impact on ocean stratification and mixing, is essential to the understanding of the abrupt global climate changes witnessed by proxy during the ice age and of concern under conditions of future greenhouse warming. On a more specific level, the study will generate a knowledge base useful for the better management of Antarctic logistical resources (e.g., the shipping lanes to McMurdo Station) that can occasionally be influenced by adverse effects icebergs have on sea ice conditions.
The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. The will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons.
Although the cold ocean ecosystems comprise seventy-two percent of the biosphere on Earth by volume, they remain sparsely inhabited and relatively unexploited, particularly in terms of metazoan phyla. Consequently, the few animals that can exist at this border of intracellular freezing represent ideal systems for exploring genomic-level processes of environmental adaptations. Understanding life at a margin of the biosphere is likely to convey significant insights into the essential genomic processes necessary for survival under intense selection pressures. This study of adaptive mechanisms in genomic networks focuses on an experimental system that faces a formidable challenge for viability at low water temperatures: embryonic development at sea water temperatures of -1.8 o C in two Antarctic echinoderms, the sea star Odontaster validus and the sea urchin Sterechinus neumayeri. The project strategy will quantify temperature effects on gene expression and protein turnover networks during early development using a Bayesian network analysis to identify clusters of genes and proteins whose expression levels are associated in fixed, synergistic interactions. Ultimately, there is a simple question to be addressed: Is it more or less difficult (complex) for an embryo to develop in an extreme environment? To answer this question, the research plan will decipher network topologies and subnet structuring to uncover gene connectivity patterns associated with embryo development in this polar environment. This is the new area of Environmental Genomics that the PI will explore by expanding his research experience into computational network analyses. Overall, there is a significant need for integrative biologists in the future development of environmental sciences, particularly for the application of genomic-scale technologies to answer ecological-scale questions. The educational goals of this CAREER proposal are focused at two levels in terms of interesting young students in the developing field of environmental genomics: 1) increasing the racial diversity of the scientists attracted to environmental research, and 2) increasing the awareness of career opportunities within environmental research.<br/>These educational objectives are incorporated into the research plan to engage students with the excitement of working in an extreme environment such as Antarctica and to interest them in the insights that genome-level research can reveal about how organisms are adapted to specific habitats. Working in a remote, extreme environment such as Antarctica is always a challenge. However, the adventurous nature of the work can be utilized to establish educational and outreach components of high interest to both undergraduate students and the public in general. The proposed plan will bring the experience of working in Antarctica to a larger audience through several means. These include the following: the project theme of environmental genomics will be incorporated into a new Bioinformatics curriculum currently being developed at the University of Delaware; an intern program will be implemented to involved minority undergraduate students in summer research in the United States and then to bring the students to Antarctica to participate in the research; and a K-12 education program will bring the excitement of working in Antarctica to the classrooms of thousands of children (U.S. and international) through a program produced with the Marine Science Public Education Office at the University of Delaware.
Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. <br/>Overwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. <br/>This project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports the development of a standardized diatom image catalog or database. Diatoms are considered by many to be the most important microfossil group used today in the study of Antarctic Cenozoic marine deposits south of the Polar Front, from the near shore to deep sea. These microfossils, with walls of silica called frustules, are produced by single-celled plants (algae of the Class Bacillariophyceae) in a great variety of forms. Consequently, they have great biostratigraphic importance in the Southern Ocean and elsewhere for determining the age of marine sediments. Also, paleoclimatic and paleoceanographic studies increasingly rely on fossil diatom data. Changing biogeographic distributions of given taxa indicate shifting paleoecological conditions and provide evidence of the surface productivity and temperatures of ancient oceans. The generality of conclusions, though, is limited by variation in species concepts among workers. The broad research community relies, directly or indirectly, on the accurate identification of diatom species. Current technology can be used to greatly improve upon the standard references that have been used in making these identifications.<br/><br/>This project will develop an interactive digital-image catalog of modern and Cenozoic fossil diatoms of the Southern Ocean called "DiatomWare" for use by specialists and educators as an aid in rapid, accurate, and consistent species identification. As such, this will be a researcher's resource. It will be especially useful where it is not possible to maintain standard library resources such as onboard research vessels or at remote stations such as McMurdo Station. Major Antarctic geological drilling initiatives such as the new SHALDRIL project and the pending ANDRILL project will benefit from this product because they will rely heavily on diatom biostratigraphy to achieve their research objectives. The DiatomWare image database will be modeled on NannoWare, which was released in October 2002 on CD-ROM as a publication of the International Nannoplankton Association. BugCam will be adapted and modified as necessary to run the DiatomWare database, which can then be run from desktop or laptop computers. Images and text for the database will be scanned from the literature or captured in digital form from light or scanning electron microscopes.<br/><br/>The software interface will include a number of data fields that can be accessed by the click of a mouse button. Primary information will be the images and descriptions of the holotypes. In addition, representative images of paratypes or hypotypes will be included whenever possible in plain transmitted, differential interference contrast light and, when available, as drawings and SEM images. Also included will be a 35-word or less English diagnosis ("mini-description"), the biostratigraphic range in terms of zones and linear time, bibliographic references, lists of species considered junior synonyms, and similar species. The list of similar species will be cross-referenced with their respective image files to enable quick access for direct visual comparison on the viewing screen. Multiple images can be brought to the viewing screen simultaneously, and a zoom feature will permit image examination at a wide range of magnifications. Buttons will allow range charts, a bibliography, and key public-domain publications from the literature to be called up from within the program. The DiatomWare/BugCam package will be distributed at a nominal cost through a major nonprofit society via CD-ROM and free to Internet users on the Worldwide Web. Quality control measures will include critical review of the finalized database by a network of qualified specialists. The completed database will include descriptions and images of between 350 and 400 species, including fossil as well as modern forms that have no fossil record.<br/><br/>The development of the proposed diatom image database will be important to all research fields that depend on accurate biostratigraphic dating and paleoenvironmental interpretation of Antarctic marine sediments and plankton. The database will also serve as a valuable teaching tool for micropaleontology students and their professors, will provide a rapid means of keying down species for micropaleontologists of varying experience and background, and will promote a uniformity of taxonomic concepts since it will be developed and continuously updated with the advice of a community of nannofossil fossil experts. Broad use of the database is anticipated since it will be widely available through the Internet and on CD-ROM for use on personal computers that do not require large amounts of memory, costly specialized programs, or additional hardware.
9909436 <br/>Farley<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an investigation of the uplift history of the Dry Valleys segment of the Transantarctic Mountains. The overall goal is to further constrain the exhumation history of the Transantarctic Mountains by using the newly developed apatite (U-Th)/He dating method on samples collected in vertical profiles. This approach, combined with existing apatite fission track information will constrain the rate and patterns of exhumation across the Transantarctic Mountains since their inception as a rift-flank uplift in the early Cenozoic.<br/><br/>This project will complement other projects and build on previous interpretations of the exhumation and tectonic history determined using apatite fission track thermochronology. It will bridge the gap between information on erosion rates determined from fission track thermochronology and from cosmogenic surface exposure dating and integrate the exhumation history of the mountains with their landscape evolution. As such, the results from this project will address an outstanding problem in Antarctic science; namely the stability of the East Antarctic Ice Sheet, and the timing of the transition from a "warm" dynamic ice sheet to a cold polar ice sheet. Highly relevant to this issue is the landscape evolution of the Transantarctic Mountains because many diverse lines of evidence for the rate of landscape evolution have been used to argue for a dynamic ice sheet up until either the Pliocene (the "dynamic" ice sheet model) or the middle Miocene (the "stable" ice sheet model). Understanding the past stability or dynamic fluctuations of the East Antarctic ice sheet with respect to the climate record is, of course, important for understanding how the present ice sheet may respond to global warming.<br/><br/>The specific objective of this project is to determine apatite (U-Th)/He age versus elevation trends for a number of vertical profiles from locations within the Transantarctic Mountain front and across the structural grain of the range. Fission track data already exist for all of these profiles, with apatite fission track ages ranging from 150-30 Ma. The greater precision of the (U-Th)/He technique and the fact it records information at lower temperatures (closure temperature of ~70 degrees Celsius; limits of 40-85 degrees Celsius for the He partial retention zone) will allow examination of the exhumation history of the TAM in more detail from ca 130 Ma to ~20 Ma. Another facet is to examine areas where Cretaceous exhumation is recorded and areas where the fission track profiles indicate periods of thermal and tectonic stability and minimal erosion throughout the Cretaceous. The variation of timing of the onset of more rapid exhumation accompanying uplift and formation of the Transantarctic Mountains in the early Cenozoic will also be examined.
Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.<br/>This award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.<br/>A better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.
This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the "vertical strain rate" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.
This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.
High latitude deep ice cores contain fundamental records of polar temperatures, atmospheric dust loads (and continental aridity), greenhouse gas concentrations, the status of the biosphere, and other essential properties of past environments. An accurate chronology for these records is needed if their significance is to be fully realized. The dating challenge has stimulated efforts at orbital tuning. In this approach, one varies a timescale, within allowable limits, to optimize the match between a paleoenvironmental property and a curve of insolation through time. The ideal property would vary with time due to direct insolation forcing. It would be unaffected by complex climate feedbacks and teleconnections, and it would give a clean record with high signal/noise ratio. It is argued strongly that the O2/N2 ratio of ice core trapped gases is such a property, and evidence is presented that this property, whose atmospheric ratio is nearly constant, is tied to local summertime insolation. This award will support a project to analyze the O2/N2 ratios at 1 kyr intervals from ~ 115-400 ka in the Vostok ice core. Ancillary measurements will be made of Ar/N2, and Ne/N2 and heavy noble gas ratios, in order to understand bubble close-off fractionation and its manifestation in the Vostok trapped gas record. O2/N2 variations will be matched with summertime insolation at Vostok to achieve a high-accuracy chronology for the Vostok core. The Vostok and other correlatable climate records will then be reexamined to improve our understanding of the dynamics of Pleistocene climate change.
This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.
This award supports the analysis, in Antarctic ice cores, of the ozone depleting substances methyl bromide (CH3Br) and methyl chloride (CH3Cl), and the sulfur-containing gas, carbonyl sulfide (OCS). The broad scientific goal is to assess the level and variability of these gases in the preindustrial atmosphere. This information will allow testing of current models for sources and sinks of these gases from the atmosphere, and to indirectly assess the impact of anthropogenic activities on their biogeochemical cycles. Longer-term records will shed light on the climatic sensitivity of the atmospheric burden of these gases, and ultimately on the biogeochemical processes controlling them. These gases are present in ice at parts per trillion levels, and the current database consists entirely of a small number of measurements made in from a shallow ice core from Siple Dome, Antarctica. This project will involve studies of ice core samples from three Antarctic sites: Siple Station, Siple Dome, and South Pole. The sampling strategy is designed to accomplish several objectives: 1) to verify the atmospheric mixing ratios previously observed in shallow Siple Dome ice for OCS, CH3Br, and CH3Cl at sites with very different accumulation rates and surface temperatures; 2) to obtain a well-dated, high resolution record from a high accumulation rate site (Siple Station), that can provide overlap in mean gas age with Antarctic firn air samples; 3) explore Holocene variability in trace gas mixing ratios; and 4) to make the first measurements of these trace gases in Antarctic glacial ice. In terms of broader impact on society, this research will help to provide a stronger scientific basis for policy decisions regulating the production and use of ozone-depleting and climate-active gases. Specifically, the methyl bromide results will contribute to the current debate on the impact of recent regulation (via the Montreal Protocol and its Amendments) on atmospheric levels. Determination of pre-industrial atmospheric variability of ozone-depleting substances will help place more realistic constraints on scenarios used for future projections of stratospheric ozone and its climatic impacts. This research will involve the participation of both graduate and undergraduate students.
This award provides funding for one year of data analysis of the solar images produced by the Flare Genesis Experiment telescope during a long-duration balloon flight over Antarctica in early 2000, near the peak of solar activity for this solar cycle. The telescope produced many thousands of images and maps of solar magnetic fields with unprecedented resolution. It is expected that the detailed analysis of the data will improve understanding of how energy stored in solar magnetic fields is converted to high temperatures and velocities associated with solar activity. <br/><br/>This project is jointly supported by NASA, NSF/OPP and NSF/ATM.
0087235<br/>Grew<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role of beryllium in lower crustal partial melting events. The formation of granitic liquids by partial melting deep in the Earth's crust is one of the major topics of research in igneous and metamorphic petrology today. One aspect of this sphere of research is the beginning of the process, specifically, the geochemical interaction between melts and source rocks before the melt has left the source area. One example of anatexis in metamorphic rocks affected by conditions found deep in the Earth's crust is pegmatite in the Archean ultrahigh temperature granulite-facies Napier Complex of Enderby Land, East Antarctica. Peak conditions for this granulite-facies metamorphism are estimated to have reached nearly 1100 Degrees Celsius and 11 kilobar, that is, conditions in the Earth's lower crust in Archean time. The proposed research is a study of the Napier Complex pegmatites with an emphasis on the minerals and geochemistry of beryllium. This element, which is estimated to constitute 3 ppm of the Earth's upper crust, is very rarely found in any significant concentrations in metamorphic rocks subjected to conditions of the Earth's lower crust. Structural, geochronological, and mineralogical studies will be carried out to test the hypothesis that the beryllium pegmatites resulted from anatexis of their metapelitic host rocks during the ultrahigh-temperature metamorphic event in the late Archean. Host rocks will be analyzed for major and trace elements. Minerals will be analyzed by the electron microprobe for major constituents including fluorine and by the ion microprobe for lithium, beryllium and boron. The analytical data will be used to determine how beryllium and other trace constituents were extracted from host rocks under ultrahigh-temperature conditions and subsequently concentrated in the granitic melt, eventually to crystallize out in a pegmatite as beryllian sapphirine and khmaralite, minerals not found in pegmatites elsewhere. Mineral compositions and assemblages will be used to determine the evolution and conditions of crystallization and recrystallization of the pegmatites and their host rocks during metamorphic episodes following the ultrahigh-temperature event. Monazite will be analyzed for lead, thorium and uranium to date the ages of these events. Because fluorine is instrumental in mobilizing beryllium, an undergraduate student will study the magnesium fluorphosphate wagnerite in the pegmatites in order to estimate fluorine activity in the melt as part of a senior project. The results of the present project will provide important insights on the melting process in general and on the geochemical behavior of beryllium in particular under the high temperatures and low water activities characteristic of the Earth's lower crust.
9419128 Stearns This is a project to maintain and augment as necessary, the network of nearly fifty automatic weather stations established on the Antarctic continent and on several surrounding islands. These weather stations measure surface wind, pressure, temperature, humidity, and in some instances other atmospheric variables, such as snow accumulation and incident solar radiation, and report these via satellite to a number of ground stations. The data are used for operational weather forecasting in support of the United States Antarctic program, for climatological records, and for research purposes. The AWS network, which began as a small-scale program in 1980, has been extremely reliable and has proven indispensable for both forecasting and research purposes. ***
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research for construction of a long-term record of climate during the late Cretaceous and early Paleogene to assess the annual seasonality in temperature on the coastal margin of Antarctica. Stable isotope and element compositions of well-preserved bivalve shells collected on Seymour Island will be the primary source of data used to reconstruct paleoenvironmental conditions. Seasonal temperature records collected through high-resolution sampling along growth structures in bivalve shells will allow seasonality to be assessed during different climate states and during periods of rapid climate change. In addition, high stratigraphic resolution will enable this project to detect the presence and frequency of short-lived thermal excursions that may have extended to such high latitudes.<br/><br/>To compile a reliable temporal record of paleoclimate, two major avenues of investigation will be undertaken: 1) precise stratigraphic (and therefore, temporal) placement of fossils over a large geographic area will be employed through the use of a graphical technique employing geometric projections; 2) stable isotope and elemental analyses will be performed to derive paleotemperatures and to evaluate diagenetic alteration of shell materials. To provide realistic comparisons of paleotemperatures across stratigraphic horizons, this study will focus on a single taxon, thus avoiding complications due to the mixing of faunal assemblages that have been encountered in previous studies of this region.<br/><br/>The near-shore marine fossil record on Seymour Island provides a unique opportunity to address many questions about the Antarctic paleoenvironment, including the relation between seasonality and different climate states, the influence of climate on biogeographic distribution of specific taxa, the effect of ice-volume changes on the stable isotope record from the late Cretaceous through the Eocene, and the plausibility of high-latitude bottom water formation during this time interval. In particular, information that will be collected concerning patterns of seasonality and the presence (or absence) of short-lived thermal excursions will be extremely valuable to an understanding of the response of high latitude sites during climate transitions from globally cool to globally warm conditions.