USAP-DC

{"dp_type": "Project", "free_text": "Chemical Composition"}

[{"awards": "1744961 Olesik, John", "bounds_geometry": "POLYGON((161.711586 -77.75758,161.71322740000002 -77.75758,161.7148688 -77.75758,161.71651020000002 -77.75758,161.7181516 -77.75758,161.719793 -77.75758,161.72143440000002 -77.75758,161.7230758 -77.75758,161.72471720000001 -77.75758,161.7263586 -77.75758,161.728 -77.75758,161.728 -77.75784200000001,161.728 -77.758104,161.728 -77.758366,161.728 -77.758628,161.728 -77.75889000000001,161.728 -77.759152,161.728 -77.75941399999999,161.728 -77.759676,161.728 -77.759938,161.728 -77.7602,161.7263586 -77.7602,161.72471720000001 -77.7602,161.7230758 -77.7602,161.72143440000002 -77.7602,161.719793 -77.7602,161.7181516 -77.7602,161.71651020000002 -77.7602,161.7148688 -77.7602,161.71322740000002 -77.7602,161.711586 -77.7602,161.711586 -77.759938,161.711586 -77.759676,161.711586 -77.75941399999999,161.711586 -77.759152,161.711586 -77.75889000000001,161.711586 -77.758628,161.711586 -77.758366,161.711586 -77.758104,161.711586 -77.75784200000001,161.711586 -77.75758))", "dataset_titles": "Elemental composition of individual nanoparticles and fine particles in 28 Taylor Glacier ice core samples 9000 to 44000 yrs BP; Taylor Glacier Atmospheric Mineral Nanoparticles and Microparticles in Antarctic Ice during the last Climatic Cycle", "datasets": [{"dataset_uid": "200426", "doi": "https://doi.org/10.25921/bd1k-mv46", "keywords": null, "people": null, "repository": "NOAA\u0027s National Centers for Environmental Information World Data Service Paleo archive", "science_program": null, "title": "Taylor Glacier Atmospheric Mineral Nanoparticles and Microparticles in Antarctic Ice during the last Climatic Cycle", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/40380"}, {"dataset_uid": "601879", "doi": "10.15784/601879", "keywords": "Antarctica; Cryosphere; Particle Size; Taylor Glacier", "people": "Carter, Lucas; Olesik, John; Gabrielli, Paolo; Kutuzov, Stanislav; Lomax-Vogt, Madeleine; Sullivan, Ryan; Lowry, Greg", "repository": "USAP-DC", "science_program": null, "title": "Elemental composition of individual nanoparticles and fine particles in 28 Taylor Glacier ice core samples 9000 to 44000 yrs BP", "url": "https://www.usap-dc.org/view/dataset/601879"}], "date_created": "Mon, 06 Jan 2025 00:00:00 GMT", "description": "The main goal of this project is to identify and geochemically characterize atmospheric mineral nanoparticles in pre-industrial Antarctic ice during the last climatic cycle. Recent technological and industrial development is introducing a large number of natural and engineered nanoparticles into Earth\u0027s atmosphere. These constitute a concern for human health, mainly due to their high chemical reactivity. While many atmospheric nanoparticle studies have been performed in modern urban environments, there is essentially no information about their occurrence in a pristine pre-industrial atmosphere. This information is critical, as it constitutes an important benchmark for comparison to the modern atmosphere. Information on nanoparticles from the pre-industrial atmosphere can be obtained from atmospheric mineral nanoparticles that are entrapped in remote pre-industrial Antarctic ice covering the last climatic cycles. Mineral nanoparticles can also affect several climatic processes. First, they directly influence the global energy balance by reflecting solar radiation and indirectly influence through changes in cloud formation (and clouds also reflect solar radiation). Second, atmospheric mineral nanoparticles such as iron oxides could have fertilized the oceans, causing blooms of marine phytoplankton that may have drawn part of the atmospheric carbon dioxide into the oceans during glacial ages (the \"biological pump\"). Third, a significant amount of extraterrestrial material entering the Earth atmosphere is thought to be transported to the poles as nanoparticles called \"meteoric smoke\" that form polar stratospheric clouds implicated in changes of the ozone hole. This project aims to establish the natural background of unknown classes of glacial particles whose size is below the detection limit of the conventional dust analyzers. The team will take advantage of ice samples from the \"horizontal ice core\", already extracted from the remote Taylor Glacier (coastal East Antarctica) covering the last ~44,000 years. These ancient samples are particularly suited to project scope because i) a large ice volume is available ii) the team expects to find a markedly different geochemistry between nanoparticles deposited during the last glacial age and during the current interglacial. A set of advanced techniques including Transmission Electron Microscopy, Single Particle Inductively Coupled Plasma Mass Spectrometry (spICP-MS), spICP-Time of Flight MS, and Field Flow Fractionation will be employed to determine mineral nanoparticle sizes, number/volume, and chemical composition. So far, the elemental composition of dust entrapped in polar ice has been mainly determined by Inductively Coupled Plasma Sector Field Mass Spectrometry and it is generally assumed to be descriptive of the coarse aeolian dust fraction. However, project will test whether or not the determined elemental composition is instead mainly linked to the previously unobserved smaller mineral nanoparticle content. Results on nanoparticles will be compared with a set of new experiments of total dust composition measured by Inductively Coupled Plasma Sector Field Mass Spectrometry, using the same ice samples from Taylor Glacier. 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": 161.728, "geometry": "POINT(161.719793 -77.75889000000001)", "instruments": null, "is_usap_dc": true, "keywords": "MICROPARTICLE CONCENTRATION; Taylor Glacier", "locations": "Taylor Glacier", "north": -77.75758, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Olesik, John", "platforms": null, "repo": "NOAA\u0027s National Centers for Environmental Information World Data Service Paleo archive", "repositories": "NOAA\u0027s National Centers for Environmental Information World Data Service Paleo archive; USAP-DC", "science_programs": null, "south": -77.7602, "title": "Atmospheric Mineral Nanoparticles in Antarctic Ice during the last Climatic Cycle", "uid": "p0010492", "west": 161.711586}, {"awards": "2207011 Granger, Julie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 04 Mar 2024 00:00:00 GMT", "description": "Phytoplankton are microscopic single-celled plants that grow at the sun-lit surface of the ocean. In the Southern Ocean around Antarctica, phytoplankton live in sub-optimal conditions because the amount of iron in seawater is insufficient for growth. Moreover, the chemical composition of Southern Ocean phytoplankton is distinct from that in other ocean regions, with a higher proportion of phosphorus relative to other elements, a characteristic that ultimately influences the distribution of nutrients ocean-wide. The researchers hypothesize that the high phosphorus composition of phytoplankton in the Southern Ocean is caused by their low iron content. Specifically, they postulate that a phosphorus-rich molecule, phytic acid, is synthesized by phytoplankton in order to assist in the storage of iron in designated cellular compartments, such as vacuoles. Recent observations show that some phytoplankton can absorb phytic acid, suggesting that it may be produced by certain species. Phytic acid is pervasive in soils, wherein it aids absorption of iron via plant roots and could similarly help phytoplankton in the Southern Ocean acquire iron via the cell membranes. This project benefits the National Science Foundation\u0027s goals of improving understanding of interactions between the Southern Ocean and the global ocean, of expanding fundamental knowledge of Antarctic biota and associated processes by focusing on phytoplankton species unique to the Antarctic. As part of this project, the Department of Marine Sciences from the College of Liberal Arts and Sciences at the University of Connecticut will sponsor the recruitment, relocation and mentorship of a graduate student under-represented in the sciences. This project aims to determine whether the unusual elemental composition of phytoplankton at the Southern Ocean is a result of anemia. The work will query whether inositol hexakisphosphate (phytic acid) aids Antarctic phytoplankton acquire and store iron, resulting in an elevated fraction of cellular phosphorus relative to other elements. The researchers, including a graduate student, will conduct laboratory culture experiments with phytoplankton strains isolated from the Southern Ocean. They will grow cells in iron- deficient versus iron-replete media to see if their phosphorus content is higher in iron-deficient conditions. They will test whether cells grown with sufficient phosphorus acquire more iron, allowing them to grow better in iron-deficient conditions than cells deriving from phosphorus-poor conditions. They will also query whether cells grown in iron-deficient conditions achieve faster growth rates in the presence of phytic acid. Results will inform the design of CRISPR mutants with which to investigate phosphorus and iron co-metabolism in Antarctic marine phytoplankton. 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": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Dinoflagellates; Iron; United States Of America; Iron Acquisition; Siderophore; TRACE ELEMENTS; Iron Limitation", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Granger, Julie; Lin, Senjie", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Siderophore utilization by dinoflagellates as a strategy for iron acquisition", "uid": "p0010455", "west": -180.0}, {"awards": "0838843 Kurbatov, Andrei; 1745006 Brook, Edward J.; 1744993 Higgins, John; 1744832 Severinghaus, Jeffrey; 1745007 Mayewski, Paul", "bounds_geometry": "POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))", "dataset_titles": "Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills Stable Water Isotopes; CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903; Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903; I-165-M GPR Field Report 2019-2020; MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903; Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "datasets": [{"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Brook, Edward J.; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601896", "doi": "10.15784/601896", "keywords": "Allan Hills; Antarctica; Ch4; CO2; Cryosphere; Glaciology; Glaciology; Ice Core Data; Ice Core Records", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601896"}, {"dataset_uid": "601895", "doi": "10.15784/601895", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Noble Gas", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601895"}, {"dataset_uid": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Shackleton, Sarah; Marks Peterson, Julia; Brook, Edward; Kalk, Michael; Severinghaus, Jeffrey P.; Hishamunda, Valens", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "url": "https://www.usap-dc.org/view/dataset/601878"}, {"dataset_uid": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.; Spaulding, Nicole", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Nesbitt, Ian; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}, {"dataset_uid": "601897", "doi": "10.15784/601897", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciology; Ice Core Data; MOT; Ocean Temperature; Paleoclimate; Xe/Kr", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601897"}], "date_created": "Fri, 27 Aug 2021 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores have been used to directly reconstruct atmospheric composition, and its links to Antarctic and global climate, over the last 800,000 years. Previous field expeditions to the Allan Hills Blue Ice Area, Antarctica, have recovered ice cores that extend as far back as 2.7 million years, by far the oldest polar ice samples yet recovered. These ice cores extend direct observations of atmospheric carbon dioxide and methane concentrations and indirect records of Antarctic climate into a period of Earth\u0027s climate history that represents a plausible geologic analogue to future anthropogenic climate change. The results demonstrate a smaller glacial-interglacial variability of climate and greenhouse gases, and a persistent linkage between Antarctic climate and atmospheric carbon dioxide, between 1 and 2 million years ago. Through this project, the team will return to the Allan Hills Blue Ice Area to recover additional ice cores that date to 2 million years or older. The climate records developed from these ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Project results will help answer questions about issues associated with anthropogenic change including the relationship between temperature change and the mass balance of Antarctic ice and the relationship between atmospheric greenhouse gases and global climate change. Earth has been cooling, and ice sheets expanding, over the past ~52 million years. Superimposed on this cooling are periodic changes in Earth\u0027s climate system driven by variations in the eccentricity, precession, and obliquity of Earth\u0027s orbit around the Sun. Climate reconstructions based on measurements of oxygen isotopes in foraminiferal calcite indicate that, from ~2.8 to 1.2 million years before present (Ma), Earth\u0027s climate system oscillated between glacial and interglacial states every ~40,000 years (the \"40k world\"). Between 1.2-0.8 Ma and continuing to the present, the period of glacial cycles increased in amplitude and lengthened to ~100,000 years (the \"100k world\"). Ice cores preserve ancient air that allows direct reconstructions of atmospheric carbon dioxide and methane. They also archive proxy records of regional climate, mean ocean temperature, global oxygen cycling, and the aridity of nearby continents. Studies of stratigraphically continuous ice cores, extending to 800,000 years before present, have demonstrated that atmospheric carbon dioxide is strongly linked to climate, and it is of great interest to extend the ice-core record into the 40k world. Recent discoveries of well-preserved ice dating from 1.0 to 2.7 Ma from ice cores drilled in the Allan Hills Blue Ice Area (BIA), Antarctica, demonstrate the potential to retrieve stratigraphically discontinuous old ice at shallow depths (\u003c200 meters). This project will continue this work by retrieving new large-volume ice cores and measuring paleoclimate properties in both new and existing ice from the Allan Hills BIA. The experimental objectives are to more fully characterize fundamental properties of the climate system and the carbon cycle during the 40k world. Project results will have implications for Pleistocene climate change, and will provide new constraints on the processes that regulate atmospheric carbon dioxide, methane, and oxygen on geologic timescales. Given a demonstrated age of the ice at the Allan Hills BIA of at least 2 million years, the team will drill additional cores to prospect for ice that predates the initiation of Northern Hemisphere glaciation at the Plio-Pleistocene transition (~2.8 Ma). 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": 159.41667, "geometry": "POINT(159.29167 -76.7)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; SNOW/ICE; Allan Hills; FIELD SURVEYS; USA/NSF; Amd/Us; LABORATORY", "locations": "Allan Hills", "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Brook, Edward J.; Severinghaus, Jeffrey P.; Higgins, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area ", "uid": "p0010253", "west": 159.16667}, {"awards": "1941292 St-Laurent, Pierre; 1941304 Sherrell, Robert; 1941327 Stammerjohn, Sharon; 1941483 Yager, Patricia; 1941308 Fitzsimmons, Jessica", "bounds_geometry": "POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.4,-100 -71.8,-100 -72.2,-100 -72.6,-100 -73,-100 -73.4,-100 -73.8,-100 -74.2,-100 -74.6,-100 -75,-102 -75,-104 -75,-106 -75,-108 -75,-110 -75,-112 -75,-114 -75,-116 -75,-118 -75,-120 -75,-120 -74.6,-120 -74.2,-120 -73.8,-120 -73.4,-120 -73,-120 -72.6,-120 -72.2,-120 -71.8,-120 -71.4,-120 -71))", "dataset_titles": "Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files; Expedition Data of NBP2202; Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica); Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea", "datasets": [{"dataset_uid": "200400", "doi": "10.17882/99231", "keywords": null, "people": null, "repository": "SEANOE", "science_program": null, "title": "Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica)", "url": "https://doi.org/10.17882/99231"}, {"dataset_uid": "601785", "doi": "10.15784/601785", "keywords": "Amundsen Sea; Antarctica; Cryosphere; CTD; NBP2202; Oceanography; R/v Nathaniel B. Palmer", "people": "Stammerjohn, Sharon", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601785"}, {"dataset_uid": "200399", "doi": "10.25773/bt54-sj65", "keywords": null, "people": null, "repository": "William \u0026 Mary ScholarWorks", "science_program": null, "title": "Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files", "url": "https://doi.org/10.25773/bt54-sj65"}, {"dataset_uid": "200311", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2202", "url": "https://www.rvdata.us/search/cruise/NBP2202"}], "date_created": "Fri, 20 Aug 2021 00:00:00 GMT", "description": "Part I: Non-technical summary: The Amundsen Sea is adjacent to the West Antarctic Ice Sheet (WAIS) and hosts the most productive coastal ecosystem in all of Antarctica, with vibrant green waters visible from space and an atmospheric carbon dioxide uptake rate ten times higher than the Southern Ocean average. The region is also an area highly impacted by climate change and glacier ice loss. Upwelling of warm deep water is causing melt under the ice sheet, which is contributing to sea level rise and added nutrient inputs to the region. This is a project that is jointly funded by the National Science Foundation\u2019s Directorate of 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, each Agency funds the proportion of the budget and the investigators associated with its own country. In this collaboration, the US team will undertake biogeochemical sampling alongside a UK-funded physical oceanographic program to evaluate the contribution of micronutrients such as iron from glacial meltwater to ecosystem productivity and carbon cycling. Measurements will be incorporated into computer simulations to examine ecosystem responses to further glacial melting. Results will help predict future impacts on the region and determine whether the climate sensitivity of the Amundsen Sea ecosystem represents the front line of processes generalizable to the greater Antarctic. This study is aligned with the large International Thwaites Glacier Collaboration (ITGC) and will make data available to the full scientific community. The program will provide training for undergraduate, graduate, post-doctoral, and early-career scientists in both science and communication. The team will also develop out-of-school science experiences for middle and high schoolers related to climate change and Antarctica. Part II: Technical summary: The Amundsen Sea hosts the most productive polynya in all of Antarctica, with atmospheric carbon dioxide uptake rates ten times higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet, a process being studied by the International Thwaites Glacier Collaboration. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied. In collaboration with a UK-funded physical oceanographic program, ARTEMIS is using shipboard sampling for trace metals, carbonate system, nutrients, organic matter, and microorganisms, with biogeochemical sensors on autonomous vehicles to gather data needed to understand the impact of the melting ice sheet on both the coastal ecosystem and the regional carbon cycle. These measurements, along with access to the advanced physical oceanographic measurements will allow this team to 1) bridge the gap between biogeochemistry and physics by adding estimates of fluxes and transport of limiting micronutrients; 2) provide biogeochemical context to broaden understanding of the global significance of ocean-ice shelf interactions; 3) determine processes and scales of variability in micronutrient supply that drive the ten-fold increase in carbon dioxide uptake, and 4) identify small-scale processes key to iron and carbon cycling using optimized field sampling. Observations will be integrated into an ocean model to enhance predictive capabilities of regional ocean function. 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": -100.0, "geometry": "POINT(-110 -73)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; USA/NSF; USAP-DC; AMD; Amundsen Sea; Amd/Us; SHIPS", "locations": "Amundsen Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "SEANOE", "repositories": "R2R; SEANOE; USAP-DC; William \u0026 Mary ScholarWorks", "science_programs": "Thwaites (ITGC)", "south": -75.0, "title": "NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)", "uid": "p0010249", "west": -120.0}, {"awards": "1744871 Robinson, Rebecca", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Diatom assemblage from IODP Site U1357; Diatom-bound and bulk sedimentary N isotopes from ODP Site 1098, Western Antarctic Peninsula; Diatom-bound and bulk sedimentary nitrogen isotopes from IODP Site U1357; Dissolved nutrients, cell counts, and nitrogen isotope measurements from Chaetoceros socialis culture experiments; ODP Site 1098 deglacial diatom assemblage; Sediment chemistry of ODP Site 1098", "datasets": [{"dataset_uid": "601818", "doi": "10.15784/601818", "keywords": "Antarctica; Cryosphere; Geochemistry; Sediment; Wilkes Land", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblage from IODP Site U1357", "url": "https://www.usap-dc.org/view/dataset/601818"}, {"dataset_uid": "601727", "doi": "10.15784/601727", "keywords": "Antarctica", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Dissolved nutrients, cell counts, and nitrogen isotope measurements from Chaetoceros socialis culture experiments", "url": "https://www.usap-dc.org/view/dataset/601727"}, {"dataset_uid": "601816", "doi": "10.15784/601816", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Geochemistry; Sediment", "people": "Dove, Isabel; Jones, Colin; Kelly, Roger; Robinson, Rebecca", "repository": "USAP-DC", "science_program": null, "title": "Diatom-bound and bulk sedimentary N isotopes from ODP Site 1098, Western Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601816"}, {"dataset_uid": "601778", "doi": "10.15784/601778", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Sediment chemistry of ODP Site 1098", "url": "https://www.usap-dc.org/view/dataset/601778"}, {"dataset_uid": "601817", "doi": "10.15784/601817", "keywords": "Antarctica; Cryosphere; Wilkes Land", "people": "Dove, Isabel; Kelly, Roger; Robinson, Rebecca", "repository": "USAP-DC", "science_program": null, "title": "Diatom-bound and bulk sedimentary nitrogen isotopes from IODP Site U1357", "url": "https://www.usap-dc.org/view/dataset/601817"}, {"dataset_uid": "601777", "doi": "10.15784/601777", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Sediment Core Data", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "ODP Site 1098 deglacial diatom assemblage", "url": "https://www.usap-dc.org/view/dataset/601777"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "The chemical composition of diatom fossils in the Southern Ocean provides information about the environmental history of Antarctica, including sea ice extent, biological production, and ocean nutrient distribution. The sea ice zone is an important habitat for a group of diatoms, largely from the genus Chaetoceros, that have a unique life cycle stage under environmental stress, when they produce a structure called a resting spore. Resting spores are meant to reseed the surface ocean when conditions are more favorable. The production of these heavy resting spores tends to remove significant amounts of carbon and silicon, essential nutrients, out of the surface ocean. As a result, this group has the potential to remove carbon from the surface ocean and can impact the sedimentary record scientists use to reconstruct environmental change. This project explores the role of resting spores in the sedimentary record using the nitrogen isotopic signature of these fossils and how those measurements are used to estimate carbon cycle changes. The work will include laboratory incubations of these organisms to answer if and how the chemistry of the resting spores differs from that of a typical diatom cell. The incubation results will be used to evaluate nutrient drawdown in sea ice environments during two contrasting intervals in earth history, the last ice age and the warm Pliocene. This work should have significant impact on how the scientific community considers the impact of seasonal sea ice cover in the Southern Ocean in terms of how it responds to and regulates global climate. The project provides training and research opportunities for undergraduate and graduate students. Ongoing research efforts in Antarctic earth sciences will be disseminated through an interactive display at the home institution. The work proposed here will address uncertainties in how Chaetoceros resting spores record surface nutrient conditions in their nitrogen stable isotopic composition, the relative impact of their specific signal with respect to the full sedimentary assemblage, and their potential to bias or enhance environmental reconstructions in the sea ice zone. Measurements of nitrogen stable isotopes of nitrate, biomass, and diatom-bound nitrogen and silicon-to-nitrogen ratios of individual species grown in the laboratory will be used to quantify how resting spores record nutrient drawdown in the water column and to what degree their signature is biased toward low nutrient conditions. These relationships will be used to inform diatom-bound nitrogen isotope reconstructions of nutrient drawdown from a Pliocene coastal polyna and an open ocean core that spans the last glacial maximum. This proposal capitalizes on the availability of Southern Ocean isolates of Chaetoceros spp. collected in 2017 for the proposed culture work and archived sediment cores and/or existing data. 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": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USAP-DC; Antarctica; ISOTOPES; MARINE SEDIMENTS; LABORATORY; USA/NSF; NITROGEN; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Rebecca", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The nitrogen isotopic composition of diatom resting spores in Southern Ocean sediments: A source of bias and/or paleoenvironmental information?", "uid": "p0010234", "west": -180.0}, {"awards": "1643494 Saal, Alberto", "bounds_geometry": "POLYGON((-68.074 -57.345,-66.6033 -57.345,-65.1326 -57.345,-63.6619 -57.345,-62.1912 -57.345,-60.7205 -57.345,-59.2498 -57.345,-57.7791 -57.345,-56.3084 -57.345,-54.8377 -57.345,-53.367 -57.345,-53.367 -58.12517,-53.367 -58.90534,-53.367 -59.68551,-53.367 -60.46568,-53.367 -61.24585,-53.367 -62.02602,-53.367 -62.80619,-53.367 -63.58636,-53.367 -64.36653,-53.367 -65.1467,-54.8377 -65.1467,-56.3084 -65.1467,-57.7791 -65.1467,-59.2498 -65.1467,-60.7205 -65.1467,-62.1912 -65.1467,-63.6619 -65.1467,-65.1326 -65.1467,-66.6033 -65.1467,-68.074 -65.1467,-68.074 -64.36653,-68.074 -63.58636,-68.074 -62.80619,-68.074 -62.02602,-68.074 -61.24585,-68.074 -60.46568,-68.074 -59.68551,-68.074 -58.90534,-68.074 -58.12517,-68.074 -57.345))", "dataset_titles": "Major, trace elements contents and radiogenic isotopes of erupted lavas Antarctic Peninsula and Phoenix Ridge", "datasets": [{"dataset_uid": "601519", "doi": "10.15784/601519", "keywords": "Antarctica; Antarctic Peninsula; Chemical Composition; Chemistry:rock; Chemistry:Rock; Geochemistry; Isotope Data; Trace Elements", "people": "Saal, Alberto", "repository": "USAP-DC", "science_program": null, "title": "Major, trace elements contents and radiogenic isotopes of erupted lavas Antarctic Peninsula and Phoenix Ridge", "url": "https://www.usap-dc.org/view/dataset/601519"}], "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "The Earth\u0027s mantle influences the movement of tectonic plates and volcanism on the surface. One way to understand the composition and nature of the Earth\u0027s mantle is by studying the chemistry of basalts, which originate by volcanic eruptions of partially melting mantle rocks. This study will establish the budget and distribution of volatile elements (hydrogen, carbon, fluorine, chlorine, sulfur) in volcanic basalts to better understand the composition of the Earth\u0027s interior. Volatiles influence mantle melting, magma crystallization, magma migration and volcanic eruptions. Their abundances and spatial distribution provide important constraints on models of mantle flow and temperature. Moreover, volatiles are key constituents of the Earth\u0027s atmosphere and oceans. Establishing the cycles of volatiles between the Earth\u0027s interior and surface is of fundamental importance to understand the long-term evolution of our planet. This project supports a graduate student and research scientist at Brown University. It promotes the collaboration with geochemists from eleven institutions representing six different countries: USA, Germany, United Kingdom, Argentina, South Korea and Japan, and utilizes several NSF-funded USA analytical facilities. Communication of results will occur through: 1) peer-reviewed journals, presentations at conferences and invited university lectures, 2) hands-on science learning activities for local elementary and high school classes, and 3) outreach to the general audience through public lectures. Over the last 60 years of funded research, the Antarctic Peninsula and nearby ocean ridges have been extensively investigated providing information on the origin of the magmatism, and the composition, structure, temperature and evolution of the lithospheric and asthenospheric mantle. Diverse hypotheses have been proposed for the origin of the magmatism in the Antarctic Peninsula, from flux melting of the mantle wedge during devolatilization of the subducted Phoenix plate, to adiabatic decompression melting of a carbonated and hydrous asthenosphere, to melting of a volatile-rich metasomatized subcontinental lithospheric mantle. All proposed hypotheses invoke the role of volatiles. Surprisingly, data on the volatile contents of basalts and mantle from this region are non-existent. This is a significant omission from the geochemical data set, given the important role volatile elements play in the generation and composition of magmas and their sources. The focus of our research is to examine the regional variations in volatile contents (C, H, F, S, Cl) in geochemically well-characterized Pliocene-recent basalts from the Antarctic Peninsula and Phoenix ridge. Our goal is to establish the budget and distribution of volatiles in the mantle to understand 1) the processes responsible for the generation of chemically diverse basalts in close spatial and temporal proximity and 2) the nature (lithology, composition and temperature) of the heterogeneous mantle source beneath the Antarctic Peninsula and Phoenix ridge.", "east": -53.367, "geometry": "POINT(-60.7205 -61.24585)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; USA/NSF; USAP-DC; TRACE ELEMENTS; MAJOR ELEMENTS; Amd/Us; LABORATORY; ROCKS/MINERALS/CRYSTALS; Magmatic Volatiles; AMD", "locations": "Antarctic Peninsula", "north": -57.345, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Saal, Alberto", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.1467, "title": "Magmatic Volatiles, Unraveling the Reservoirs and Processes of the Volcanism in the Antarctic Peninsula", "uid": "p0010196", "west": -68.074}, {"awards": "1744550 Amsler, Charles; 1744570 Galloway, Aaron; 1744602 Iken, Katrin; 1744584 Klein, Andrew", "bounds_geometry": "POLYGON((-70 -61,-69 -61,-68 -61,-67 -61,-66 -61,-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-60 -61.772,-60 -62.544,-60 -63.316,-60 -64.088,-60 -64.86,-60 -65.632,-60 -66.404,-60 -67.176,-60 -67.948,-60 -68.72,-61 -68.72,-62 -68.72,-63 -68.72,-64 -68.72,-65 -68.72,-66 -68.72,-67 -68.72,-68 -68.72,-69 -68.72,-70 -68.72,-70 -67.948,-70 -67.176,-70 -66.404,-70 -65.632,-70 -64.86,-70 -64.088,-70 -63.316,-70 -62.544,-70 -61.772,-70 -61))", "dataset_titles": "Average global horizontal solar irradiance at study sites; Carbon and nitrogen isotope data along a gradient at the Antarctic Peninsula; Chemical composition data for Desmarestia menziesii; Chemical composition data for Himantothallus grandifolius; Chemical composition data for Iridaea ; Chemical composition data for Sarcopeltis antarctica ; Computed fetch for project study sites; Five year mean annual and summer sea ice concentration grids for the Western Antarctic Peninsula from AMSR2, National Ice Center Charts and the Sea Ice Index ; Gridded sea ice concentrations from National Ice Center (NIC) Charts 2014-2019 for Western Antarctic Peninsula ; Initial release of code and data associated with Whippo et al. (2024) Fatty acid profiles and stable isotope composition of Antarctic macroalgae: A baseline for a combined biomarker approach in food web studies.; Landsat Sea Ice/Cloud classifications surrounding project study sites; Latitude and longitude data for project study sites; LMG1904 expedition data; Macroalgal species collected along horizontal transect components ; Modelled Solar Irradiance for Western Antarctic Pennisula; Sea Ice Concentration Timeseries for study sites; Underwater transect videos used for community analyses; Underwater video transect community analysis data; VIIRS KD(490) diffuse attenuation coefficients for study sites", "datasets": [{"dataset_uid": "601642", "doi": "10.15784/601642", "keywords": "Antarctica; Antarctic Peninsula; Biota; LMG1904; R/v Laurence M. Gould; Sea Ice Concentration", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Sea Ice Concentration Timeseries for study sites", "url": "https://www.usap-dc.org/view/dataset/601642"}, {"dataset_uid": "601654", "doi": "10.15784/601654", "keywords": "Antarctica; Antarctic Peninsula; GIS; LANDSAT; LMG1904; Remote Sensing; R/v Laurence M. Gould", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Landsat Sea Ice/Cloud classifications surrounding project study sites", "url": "https://www.usap-dc.org/view/dataset/601654"}, {"dataset_uid": "601883", "doi": "10.15784/601883", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Macroalgae", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Chemical composition data for Himantothallus grandifolius", "url": "https://www.usap-dc.org/view/dataset/601883"}, {"dataset_uid": "601882", "doi": "10.15784/601882", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Macroalgae", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Chemical composition data for Desmarestia menziesii", "url": "https://www.usap-dc.org/view/dataset/601882"}, {"dataset_uid": "601619", "doi": "10.15784/601619", "keywords": "Antarctica; Antarctic Peninsula; Benthic Communities; Biota; Macroalgae; Macroinvertebrates; Oceans; Video Transects", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Underwater video transect community analysis data", "url": "https://www.usap-dc.org/view/dataset/601619"}, {"dataset_uid": "200402", "doi": "10.5281/zenodo.10524919", "keywords": null, "people": null, "repository": "Zendo", "science_program": null, "title": "Initial release of code and data associated with Whippo et al. (2024) Fatty acid profiles and stable isotope composition of Antarctic macroalgae: A baseline for a combined biomarker approach in food web studies.", "url": "https://zenodo.org/records/10524920"}, {"dataset_uid": "601653", "doi": "10.15784/601653", "keywords": "Antarctica; Antarctic Peninsula; Biota; Carbon; Carbon Isotopes; LMG1904; Nitrogen Isotopes; Oceans", "people": "Iken, Katrin", "repository": "USAP-DC", "science_program": null, "title": "Carbon and nitrogen isotope data along a gradient at the Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601653"}, {"dataset_uid": "601610", "doi": "10.15784/601610", "keywords": "Antarctica; Antarctic Peninsula; Benthic Communities; Biota; Macroalgae; Macroinvertebrates; Oceans; Video Transects", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Underwater transect videos used for community analyses", "url": "https://www.usap-dc.org/view/dataset/601610"}, {"dataset_uid": "601641", "doi": "10.15784/601641", "keywords": "Antarctica; Average Global Horizontal Solar Irradiance; Biota; LMG1904; R/v Laurence M. Gould", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Average global horizontal solar irradiance at study sites", "url": "https://www.usap-dc.org/view/dataset/601641"}, {"dataset_uid": "601643", "doi": "10.15784/601643", "keywords": "Antarctica; Antarctic Peninsula; LMG1904; National Ice Center Charts; R/v Laurence M. Gould; Sea Ice Concentration", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Gridded sea ice concentrations from National Ice Center (NIC) Charts 2014-2019 for Western Antarctic Peninsula ", "url": "https://www.usap-dc.org/view/dataset/601643"}, {"dataset_uid": "601330", "doi": "10.15784/601330", "keywords": "Antarctica; Antarctic Peninsula; Biota; LMG1904; R/v Laurence M. Gould; Sample Location", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Latitude and longitude data for project study sites", "url": "https://www.usap-dc.org/view/dataset/601330"}, {"dataset_uid": "601639", "doi": "10.15784/601639", "keywords": "Antarctica; Antarctic Peninsula; Biota; Fetch; LMG1904; R/v Laurence M. Gould", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Computed fetch for project study sites", "url": "https://www.usap-dc.org/view/dataset/601639"}, {"dataset_uid": "601725", "doi": "10.15784/601725", "keywords": "Antarctica; Antarctic Peninsula", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Macroalgal species collected along horizontal transect components ", "url": "https://www.usap-dc.org/view/dataset/601725"}, {"dataset_uid": "200147", "doi": "10.7284/908260", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG1904 expedition data", "url": "https://www.rvdata.us/search/cruise/LMG1904"}, {"dataset_uid": "601640", "doi": "10.15784/601640", "keywords": "Antarctica; Biota; Diffuse Attenuation Coefficient; LMG1904; R/v Laurence M. Gould; Turbidity", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "VIIRS KD(490) diffuse attenuation coefficients for study sites", "url": "https://www.usap-dc.org/view/dataset/601640"}, {"dataset_uid": "601885", "doi": "10.15784/601885", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Macroalgae", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Chemical composition data for Sarcopeltis antarctica ", "url": "https://www.usap-dc.org/view/dataset/601885"}, {"dataset_uid": "601884", "doi": "10.15784/601884", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Macroalgae", "people": "Amsler, Charles", "repository": "USAP-DC", "science_program": null, "title": "Chemical composition data for Iridaea ", "url": "https://www.usap-dc.org/view/dataset/601884"}, {"dataset_uid": "601651", "doi": "10.15784/601651", "keywords": "Antarctica; Antarctic Peninsula; Biota; GIS; GIS Data; LMG1904; R/v Laurence M. Gould; Solar Radiation", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Modelled Solar Irradiance for Western Antarctic Pennisula", "url": "https://www.usap-dc.org/view/dataset/601651"}, {"dataset_uid": "601649", "doi": "10.15784/601649", "keywords": "Antarctica; Antarctic Peninsula; LMG1904; National Ice Center Charts; Sea Ice Concentration", "people": "Klein, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Five year mean annual and summer sea ice concentration grids for the Western Antarctic Peninsula from AMSR2, National Ice Center Charts and the Sea Ice Index ", "url": "https://www.usap-dc.org/view/dataset/601649"}], "date_created": "Thu, 04 Jun 2020 00:00:00 GMT", "description": "The western Antarctic Peninsula has become a model for understanding cold water communities and how they may be changing in Antarctica and elsewhere. Brown macroalgae (seaweeds) form extensive undersea forests in the northern portion of this region where they play a key role in providing both physical structure and a food (carbon) source for shallow water communities. Yet between Anvers Island (64 degrees S latitude) and Adelaide Island (67 S latitude) these macroalgae become markedly less abundant and diverse. This is probably because the habitat to the south is covered by more sea ice for a longer period, and the sea ice reduces the amount of light that reaches the algae. The reduced macroalgal cover undoubtedly impacts other organisms in the food web, but the ways in which it alters sea-floor community processes and organization is unknown. This project will quantitatively document the macroalgal communities at multiple sites between Anvers and Adelaide Islands using a combination of SCUBA diving, video surveys, and algal collections. Sea ice cover, light levels, and other environmental parameters on community structure will be modelled to determine which factors have the largest influence. Impacts on community structure, food webs, and carbon flow will be assessed through a mixture of SCUBA diving and video surveys. Broader impacts include the training of graduate students and a postdoctoral researcher, as well as numerous informal public education activities including lectures, presentations to K-12 groups, and a variety of social media-based outreach. Macroalgal communities are more abundance and diverse to the north along the Western Antarctic Peninsula, perhaps due to the greater light availability that is associated with shorter period of sea-ice cover. This project will determine the causes and community level consequence of this variation in algal community structure. First, satellite data on sea ice extent and water turbidity will be used to select study sites between 64 S and 69 S where the extent of annual sea ice cover is the primary factor influencing subsurface light levels. Then, variations in macroalgal cover across these study sites will be determined by video line-transect surveys conducted by SCUBA divers. The health, growth, and physiological status of species found at the different sites will be determined by quadrat sampling. The relative importance of macroalgal-derived carbon to the common invertebrate consumers in the foodweb will be assessed with stable isotope and fatty acid biomarker techniques. This will reveal how variation in macroalgal abundance and species composition across the sea ice cover gradient impacts sea floor community composition and carbon flow throughout the food web. In combination, this work will facilitate predictions of how the ongoing reductions in extent and duration of sea ice cover that is occurring in the region as a result of global climate change will impact the structure of nearshore benthic communities. 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": -60.0, "geometry": "POINT(-65 -64.86)", "instruments": null, "is_usap_dc": true, "keywords": "COASTAL; R/V LMG; MACROALGAE (SEAWEEDS); BENTHIC; USAP-DC; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -61.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Amsler, Charles; McClintock, James; Iken, Katrin; Galloway, Aaron; Klein, Andrew", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "USAP-DC", "repositories": "R2R; USAP-DC; Zendo", "science_programs": null, "south": -68.72, "title": "Collaborative Research: Sea ice as a driver of Antarctic benthic macroalgal community composition and nearshore trophic connectivity", "uid": "p0010104", "west": -70.0}, {"awards": "1543313 VanTongeren, Jill", "bounds_geometry": null, "dataset_titles": "U-Pb ages and mineral compositions from Dufek Intrusion", "datasets": [{"dataset_uid": "601132", "doi": "10.15784/601132", "keywords": "Antarctica; Chemical Composition; Chemistry:rock; Chemistry:Rock; Crystallization; Dufek Complex; Geochemistry; Magma Chamber Procesess; Mass Spectrometry; Rocks; Snow/ice; Snow/Ice; Solid Earth; TIMS; Volcanic Deposits", "people": "VanTongeren, Jill", "repository": "USAP-DC", "science_program": null, "title": "U-Pb ages and mineral compositions from Dufek Intrusion", "url": "https://www.usap-dc.org/view/dataset/601132"}], "date_created": "Mon, 29 Oct 2018 00:00:00 GMT", "description": "The solidified remnants of large magma bodies within the continental crust hold the key to understanding the chemical and physical evolution of volcanic provinces through time. These deposits also commonly contain some of the world\u0027s most important ore deposits. Exposed deposits in South Africa, Greenland, USA, Canada, and Antarctica have led researchers to propose that the bigger the magma body, the faster it will crystallize. While this might seem counter-intuitive (typically it is thought that more magma = hotter = harder to cool), the comparison of these exposures show that bigger magma chambers maintain a molten top that is always in contact with the colder crust; whereas smaller magma chambers insulate themselves by crystallizing at the margins. The process is similar to the difference between a large cup of coffee with no lid, and a smaller cup of coffee held in a thermos. The large unprotected cup of coffee will cool down much faster than that held in the thermos. This research project of VanTongeren and Schoene will use previously collected rocks from the large (~8-9 km thick) Dufek Intrusion in Antarctica to precisely quantify how fast the magma chamber crystallized, and compare that rate to the much smaller magma chamber exposed in the Skaergaard Intrusion of E. Greenland. The work is an important step towards improving our understanding of time-scales associated with the thermal and chemical evolution of nearly all magma chambers on Earth, which will ultimately lead to better predictions of volcanic hazards globally. The work will also yield important insights into the timescales and conditions necessary for developing vast magmatic ore deposits, which is essential to the platinum and steel industries in the USA and abroad. Based on observations of solidification fronts in six of the world\u0027s most completely exposed layered mafic intrusions, it was recently proposed that bigger magma chambers must crystallize faster than small magma chambers. While this is initially counter-intuitive, the hypothesis falls out of simple heat balance equations and the observation that the thickness of cumulates at the roofs of such intrusions is negatively proportional to the size of the intrusion. In this study, VanTongeren and Schoene will directly test the hypothesis that bigger magma chambers crystallize faster by applying high precision U-Pb zircon geochronology on 5-10 samples throughout the large Dufek Intrusion of Antarctica. Due to uncertainties in even the highest-precision ID-TIMS analyses, the Dufek Intrusion of Antarctica is the only large layered mafic intrusion on Earth where this research can be accomplished. VanTongeren and Schoene will place the geochronological measurements of the Dufek Intrusion into a comprehensive petrologic framework by linking zircon crystallization to other liquidus phases using mineral geochemistry, zircon saturation models, and petrologic models for intrusion crystallization. The research has the potential to radically change the way that we understand the formation and differentiation of large magma bodies within the shallow crust. Layered intrusions are typically thought to cool and crystallize over very long timescales allowing for significant differentiation of the magmas and reorganization of the cumulate rocks. If the \u0027bigger magma chambers crystallize faster hypothesis\u0027 holds this could reduce the calculated solidification time scales of the early earth and lunar magma oceans and have important implications for magma chamber dynamics of active intraplate volcanism and long-lived continental arcs. Furthermore, while the Dufek Intrusion is one of only two large layered intrusions exposed on Earth, very little is known about its petrologic evolution. The detailed geochemical and petrologic work of VanTongeren and Schoene based on analyses of previously collected samples will provide important observations with which to compare the Dufek and other large magma chambers.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "VanTongeren, Jill", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Testing the Hypothesis that Bigger Magma Chambers Crystallize Faster", "uid": "p0000135", "west": null}, {"awards": "1443263 Higgins, John; 1443306 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Allan Hills ice water stable isotope record for dD, d18O; Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores; Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores; Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores; Greenhouse gas composition in the Allan Hills S27 ice core; Methane concentration in Allan Hills ice cores; Stable isotope composition of the trapped air in the Allan Hills S27 ice core; Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "datasets": [{"dataset_uid": "601203", "doi": "10.15784/601203", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Chemistry:ice; Chemistry:Ice; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenhouse Gas; Ice; Ice Core Data; Ice Core Gas Records; Methane; Snow/ice; Snow/Ice", "people": "Bender, Michael; Brook, Edward J.; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Methane concentration in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601203"}, {"dataset_uid": "601201", "doi": "10.15784/601201", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Argon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Gas Records; Krypton; Mass Spectrometer; Noble Gas; Snow/ice; Snow/Ice; Xenon", "people": "Yan, Yuzhen; Ng, Jessica; Higgins, John; Severinghaus, Jeffrey P.; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601201"}, {"dataset_uid": "601128", "doi": "10.15784/601128", "keywords": "Allan Hills; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Mass Spectrometry; Stable Water Isotopes", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Introne, Douglas; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601128"}, {"dataset_uid": "601129", "doi": "10.15784/601129", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Isotope Data; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Introne, Douglas; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601129"}, {"dataset_uid": "601130", "doi": "10.15784/601130", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Gas Records; Ice Core Records; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Introne, Douglas; Kurbatov, Andrei V.; Mayewski, Paul A.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601130"}, {"dataset_uid": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Higgins, John; Bender, Michael; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601483"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Severinghaus, Jeffrey P.; Introne, Douglas; Mayewski, Paul A.; Brook, Edward; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Brook, Edward; Introne, Douglas; Higgins, John; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Yan, Yuzhen; Higgins, John; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable isotope composition of the trapped air in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601512"}, {"dataset_uid": "601425", "doi": "10.15784/601425", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Ice Core; Methane", "people": "Brook, Edward J.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Greenhouse gas composition in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601425"}, {"dataset_uid": "601202", "doi": "10.15784/601202", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Carbon Dioxide; Carbon Isotopes; Chemistry:ice; Chemistry:Ice; CO2; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Gas Records; Ice Core Records; Mass Spectrometer; Mass Spectrometry; Methane; Snow/ice; Snow/Ice", "people": "Brook, Edward J.; Bender, Michael; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601202"}], "date_created": "Thu, 18 Oct 2018 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores permit the direct reconstruction of atmospheric composition and allow us to link greenhouse gases and global climate over the last 800,000 years. Previous field expeditions to the Allan Hills blue ice area, Antarctica, have recovered ice cores that date to one million years, the oldest ice cores yet recovered from Antarctica. These records have revealed that interglacial CO2 concentrations decreased by 800,000 years ago and that, in the warmer world 1 million years ago, CO2 and Antarctic temperature were linked as during the last 800,000 years. This project will return to the Allan Hills blue ice area to recover additional ice cores that date to 1 million years or older. The climate records developed from the drilled ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Our results will help answer questions about issues associated with anthropogenic change. These include the relationship between temperature change and the mass balance of Antarctic ice; precipitation and aridity variations associated with radiatively forced climate change; and the climate significance of sea ice extent. The project will entrain two graduate students and a postdoctoral scholar, and will conduct outreach including workshops to engage teachers in carbon science and ice cores. Between about 2.8-0.9 million years ago, Earth\u0027s climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth\u0027s spin axis. Much is known about the \"40,000-year\" world from studies of deep-sea sediments, but our understanding of climate change during this period is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of ancient ice from the Main Ice Field, Allan Hills, Antarctica. During previous field seasons we recovered ice extending, discontinuously, from 0.1-1.0 million years old. Ice was dated by measuring the 40Ar/38Ar (Argon) ratio of the trapped gases. Our discovery of million year-old ice demonstrates that there is gas-record-quality ice from the 40,000-year world in the Allan Hills Main Ice Field. We have identified two different sites, each overlying bedrock at ~ 200 m depth, that are attractive targets for coring ice dating to 1 million years and older. This project aims to core the ice at these two sites, re-occupy a previous site with million year-old ice and drill it down to the bedrock, and generate 10-20 short (~10-meter) cores in areas where our previous work and terrestrial meteorite ages suggest ancient surface ice. We plan to date the ice using the 40Ar/38Ar ages of trapped Argon. We also plan to characterize the continuity of our cores by measuring the deuterium and oxygen isotope ratios in the ice, methane, ratios of Oxygen and Argon to Nitrogen in trapped gas, the Nitrogen-15 isotope (d15N) of Nitrogen, and the Oxygen-18 isotope (d18O) of Oxygen. As the ice may be stratigraphically disturbed, these measurements will provide diagnostic properties for assessing the continuity of the ice-core records. Successful retrieval of ice older than one million years will provide the opportunity for follow-up work to measure the CO2 concentration and other properties within the ice to inform on the temperature history of the Allan Hills region, dust sources and source-area aridity, moisture sources, densification conditions, global average ocean temperature, and greenhouse gas concentrations. We will analyze the data in the context of leading hypotheses of the 40,000-year world and the Mid-Pleistocene Transition to the 100,000-year world. We expect to advance understanding of climate dynamics during these periods.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Allan Hills; USA/NSF; FIELD INVESTIGATION; USAP-DC; Ice Core; LABORATORY", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": null, "title": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area", "uid": "p0000760", "west": null}, {"awards": "0838970 Foreman, Christine", "bounds_geometry": "POINT(161.667 -77.117)", "dataset_titles": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "datasets": [{"dataset_uid": "600104", "doi": "10.15784/600104", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology", "people": "Foreman, Christine", "repository": "USAP-DC", "science_program": null, "title": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600104"}], "date_created": "Fri, 10 Oct 2014 00:00:00 GMT", "description": "Dissolved organic matter (DOM) comprises a significant pool of Earth\u0027s organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls\u0027 schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer.", "east": 161.667, "geometry": "POINT(161.667 -77.117)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Foreman, Christine", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "uid": "p0000458", "west": 161.667}, {"awards": "0944078 Albert, Mary", "bounds_geometry": "POINT(112.05 79.28)", "dataset_titles": "Firn Permeability and Density at WAIS Divide", "datasets": [{"dataset_uid": "609602", "doi": "10.7265/N57942NT", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Albert, Mary R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Firn Permeability and Density at WAIS Divide", "url": "https://www.usap-dc.org/view/dataset/609602"}], "date_created": "Fri, 15 Aug 2014 00:00:00 GMT", "description": "This award supports a project to investigate the transformations from snow to firn to ice and the underlying physics controlling firn\u0027s ability to store atmospheric samples from the past. Senior researchers, a graduate student, and several undergraduates will make high-resolution measurements of both the diffusivity and permeability profiles of firn cores from several sites in Antarctica and correlate the results with their microstructures quantified using advanced materials characterization techniques (scanning electron microscopy and x-ray computed tomography). The use of cores from different sites will enable us to examine the influence of different local climate conditions on the firn structure. We will use the results to help interpret existing measurements of firn air chemical composition at several sites where firn air measurements exist. There are three closely-linked goals of this project: to quantify the dependence of interstitial transport properties on firn microstructure from the surface down to the pore close-off depth, to determine at what depths bubbles form and entrap air, and investigate the extent to which these features exhibit site-to-site differences, and to use the measurements of firn air composition and firn structure to better quantify the differences between atmospheric composition (present and past), and the air trapped in both the firn and in air bubbles within ice by comparing the results of the proposed work with firn air measurements that have been made at the WAIS Divide and Megadunes sites. The broader impacts of this project are that the study will this study will enable us to elucidate the fundamental controls on the metamorphism of firn microstructure and its impact on processes of gas entrapment that are important to understanding ice core evidence of past atmospheric composition and climate change. The project will form the basis for the graduate research of a PhD student at Dartmouth, with numerous opportunities for undergraduate involvement in cold room measurements and outreach. The investigators have a track record of successfully mentoring women students, and will build on this experience. In conjunction with local earth science teachers, and graduate and undergraduate students will design a teacher-training module on the role of the Polar Regions in climate change. Once developed and tested, this module will be made available to the broader polar research community for their use with teachers in their communities.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e MICROTOMOGRAPHY; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "Firn Air; FIELD SURVEYS; Physics; GROUND-BASED OBSERVATIONS; Antarctica; Megadunes; Tomography; Wais Divide-project; Firn Core; FIELD INVESTIGATION; Not provided; Firn Permeability; LABORATORY; Visual Observations; Ice; Firn; WAIS Divide; Microstructure; Density", "locations": "Antarctica; WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; 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 GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "Firn Metamorphism: Microstructure and Physical Properties", "uid": "p0000049", "west": -112.05}, {"awards": "0902957 Robinson, Laura", "bounds_geometry": "POLYGON((-70.5 -54.5,-66.95 -54.5,-63.4 -54.5,-59.85 -54.5,-56.3 -54.5,-52.75 -54.5,-49.2 -54.5,-45.65 -54.5,-42.1 -54.5,-38.55 -54.5,-35 -54.5,-35 -55.2,-35 -55.9,-35 -56.6,-35 -57.3,-35 -58,-35 -58.7,-35 -59.4,-35 -60.1,-35 -60.8,-35 -61.5,-38.55 -61.5,-42.1 -61.5,-45.65 -61.5,-49.2 -61.5,-52.75 -61.5,-56.3 -61.5,-59.85 -61.5,-63.4 -61.5,-66.95 -61.5,-70.5 -61.5,-70.5 -60.8,-70.5 -60.1,-70.5 -59.4,-70.5 -58.7,-70.5 -58,-70.5 -57.3,-70.5 -56.6,-70.5 -55.9,-70.5 -55.2,-70.5 -54.5))", "dataset_titles": "LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals", "datasets": [{"dataset_uid": "600111", "doi": "10.15784/600111", "keywords": "Biota; Corals; Drake Passage; Geochronology; NBP0805; Oceans; Paleoclimate; Radiocarbon; Southern Ocean", "people": "Robinson, Laura", "repository": "USAP-DC", "science_program": null, "title": "LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals", "url": "https://www.usap-dc.org/view/dataset/600111"}], "date_created": "Tue, 28 Jun 2011 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The proposal seeks funds to continue a follow-up analytical work of deep-sea corals collected in the Drake Passage during a research cruise. The project\u0027s goal is paleo-climate research looking to constrain the depth structure and time evolution of the radiocarbon content of the Southern Ocean during the glacial and deglaciation. Radiocarbon is a versatile tracer of past climate; its radioactive decay provides an internal clock with which to assess the rates of processes, and it can be used to trace the movement of carbon through the Earth\u0027s system. It enters the ocean through air-sea gas exchange, so processes that limits this will, therefore, reduce the radiocarbon content of both surface and deep waters. The Southern Ocean is a critical location for exchange of heat and carbon between the deep-ocean and atmospheric reservoirs, and the deep waters formed there fill large volumes of the global deep and intermediate oceans. As strong currents tend to scour away sediments, carbonate preservation is limited, and radiocarbon reservoir ages are poorly constrained, many traditional paleoceanographic techniques become impractical. It is proposed to alleviate these difficulties analyzing the chemical composition of deep-sea coral skeletons. Their aragonitic skeletons can be precisely dated using U-series decay, and when coupled with radiocarbon analyses will allow to calculate the C14/C12 ratio of the past water column.", "east": -35.0, "geometry": "POINT(-52.75 -58)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -54.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Laura", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.5, "title": "LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals", "uid": "p0000519", "west": -70.5}, {"awards": "0538495 Albert, Mary; 0537532 Liston, Glen; 0963924 Steig, Eric; 0538416 McConnell, Joseph; 0538103 Scambos, Ted; 0538422 Hamilton, Gordon", "bounds_geometry": "POLYGON((-180 -72.01667,-161.74667 -72.01667,-143.49334 -72.01667,-125.24001 -72.01667,-106.98668 -72.01667,-88.73335 -72.01667,-70.48002 -72.01667,-52.22669 -72.01667,-33.97336 -72.01667,-15.72003 -72.01667,2.5333 -72.01667,2.5333 -73.815003,2.5333 -75.613336,2.5333 -77.411669,2.5333 -79.210002,2.5333 -81.008335,2.5333 -82.806668,2.5333 -84.605001,2.5333 -86.403334,2.5333 -88.201667,2.5333 -90,-15.72003 -90,-33.97336 -90,-52.22669 -90,-70.48002 -90,-88.73335 -90,-106.98668 -90,-125.24001 -90,-143.49334 -90,-161.74667 -90,180 -90,162.25333 -90,144.50666 -90,126.75999 -90,109.01332 -90,91.26665 -90,73.51998 -90,55.77331 -90,38.02664 -90,20.27997 -90,2.5333 -90,2.5333 -88.201667,2.5333 -86.403334,2.5333 -84.605001,2.5333 -82.806668,2.5333 -81.008335,2.5333 -79.210002,2.5333 -77.411669,2.5333 -75.613336,2.5333 -73.815003,2.5333 -72.01667,20.27997 -72.01667,38.02664 -72.01667,55.77331 -72.01667,73.51998 -72.01667,91.26665 -72.01667,109.01332 -72.01667,126.75999 -72.01667,144.50666 -72.01667,162.25333 -72.01667,-180 -72.01667))", "dataset_titles": "Ice Core Chemistry from the Norwegian-U.S. Scientific Traverse of East Antarctica, IPY 2007-2009; Norwegian-U.S. Scientific Traverse of East Antarctica; This data set contains data from the publication Steig et al., Nature Geoscience, vol. 6, pages 372\u00e2\u20ac\u201c375 (doi:10.1038/ngeo1778), which includes isotope data from the Norway-US traverse in East Antarctica.", "datasets": [{"dataset_uid": "001305", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "This data set contains data from the publication Steig et al., Nature Geoscience, vol. 6, pages 372\u00e2\u20ac\u201c375 (doi:10.1038/ngeo1778), which includes isotope data from the Norway-US traverse in East Antarctica.", "url": "http://nsidc.org/data/nsidc-0536.html"}, {"dataset_uid": "609520", "doi": "10.7265/N5H41PC9", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; East Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Chemistry from the Norwegian-U.S. Scientific Traverse of East Antarctica, IPY 2007-2009", "url": "https://www.usap-dc.org/view/dataset/609520"}, {"dataset_uid": "000112", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Norwegian-U.S. Scientific Traverse of East Antarctica", "url": "http://traverse.npolar.no/"}], "date_created": "Wed, 23 Feb 2011 00:00:00 GMT", "description": "This award supports a project of scientific investigations along two overland traverses in East Antarctica: one going from the Norwegian Troll Station (72deg. S, 2deg. E) to the United States South Pole Station (90deg. S, 0deg. E) in 2007-2008; and a return traverse starting at South Pole Station and ending at Troll Station by a different route in 2008-2009. The project will investigate climate change in East Antarctica, with the goals of understanding climate variability in Dronning Maud Land of East Antarctica on time scales of years to centuries and determining the surface and net mass balance of the ice sheet in this sector to understand its impact on sea level. The project will also investigate the impact of atmospheric and oceanic variability and human activities on the chemical composition of firn and ice in the region, and will revisit areas and sites first explored by traverses in the 1960\u0027s, for detection of possible changes and to establish benchmark datasets for future research efforts. In terms of broader impacts, the results of this study will add to understanding of climate variability in East Antarctica and its contribution to global sea level change. The project includes international exchange of graduate students between the institutions involved and international education of undergraduate students through classes taught by the PI\u0027s at UNIS in Svalbard. It involves extensive outreach to the general public both in Scandinavia and North America through the press, television, science museums, children\u0027s literature, and web sites. Active knowledge sharing and collaboration between pioneers in Antarctic glaciology from Norway and the US, with the international group of scientists and students involved in this project, provide a unique opportunity to explore the changes that half a century have made in climate proxies from East Antarctica, scientific tools, and the culture and people of science. The project is relevant to the International Polar Year (IPY) since it is a genuine collaboration between nations: the scientists involved have complementary expertise, and the logistics involved relies on assets unique to each nation. It is truly an endeavor that neither nation could accomplish alone. This project is a part of the Trans- Antarctic Scientific Traverse Expeditions Ice Divide of East Antarctica (TASTE-IDEA) which is also part of IPY.", "east": 2.5333, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; 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 RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; East Antarctic Plateau; FIXED OBSERVATION STATIONS; Glaciology; LABORATORY; FIELD SURVEYS; Permeability; Ice Core; Climate Variability; Firn; Accumulation Rate; Mass Balance; Snow; Gravity; Ice Sheet; GROUND-BASED OBSERVATIONS; Traverse; Not provided; Antarctic; Ice Core Chemistry; Antarctica; Density", "locations": "Antarctica; Antarctic; East Antarctic Plateau", "north": -72.01667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Courville, Zoe; Bell, Eric; Liston, Glen; Scambos, Ted; Hamilton, Gordon S.; McConnell, Joseph; Albert, Mary R.; Steig, Eric J.", "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 FIXED OBSERVATION STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NSIDC", "repositories": "NSIDC; Project website; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Norwegian-United States IPY Scientific Traverse: Climate Variability and Glaciology in East Antarctica", "uid": "p0000095", "west": 2.5333}, {"awards": "0440478 Tang, Kam", "bounds_geometry": "POINT(166.66267 -77.85067)", "dataset_titles": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "datasets": [{"dataset_uid": "600043", "doi": "10.15784/600043", "keywords": "Biota; McMurdo Sound; Oceans; Phytoplankton; Ross Sea; Southern Ocean; Zooplankton", "people": "Tang, Kam; Smith, Walker", "repository": "USAP-DC", "science_program": null, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "url": "https://www.usap-dc.org/view/dataset/600043"}], "date_created": "Mon, 04 May 2009 00:00:00 GMT", "description": "Phaeocystis Antarctica is a widely distributed phytoplankton that forms dense blooms and aggregates in the Southern Ocean. This phytoplankton and plays important roles in polar ecology and biogeochemistry, in part because it is a dominant primary producer, a main component of organic matter vertical fluxes, and the principal producer of volatile organic sulfur in the region. Yet P. Antarctica is also one of the lesser known species in terms of its physiology, life history and trophic relationships with other organisms; furthermore, information collected on other Phaeocystis species and from different locations may not be applicable to P. Antarctica in the Ross Sea. P. Antarctica occurs mainly as two morphotypes: solitary cells and mucilaginous colonies, which differ significantly in size, architecture and chemical composition. Relative dominance between solitary cells and colonies determines not only the size spectrum of the population, but also its carbon dynamics, nutrient uptake and utilization. Conventional thinking of the planktonic trophic processes is also challenged by the fact that colony formation could effectively alter the predator-prey interactions and interspecific competition. However, the factors that regulate the differences between solitary and colonial forms of P. Antarctica are not well-understood. The research objective of this proposal is therefore to address these over-arching questions:\u003cbr/\u003eo Do P. Antarctica solitary cells and colonies differ in growth, composition and\u003cbr/\u003ephotosynthetic rates?\u003cbr/\u003eo How do nutrients and grazers affect colony development and size distribution of P. \u003cbr/\u003eAntarctica?\u003cbr/\u003eo How do nutrients and grazers act synergistically to affect the long-term population\u003cbr/\u003edynamics of P. Antarctica? Experiments will be conducted in the McMurdo station with natural P. Antarctica assemblages and co-occurring grazers. Laboratory experiments will be conducted to study size-specific growth and photosynthetic rates of P. Antarctica, size-specific grazing mortality due to microzooplankton and mesozooplankton, the effects of macronutrients on the (nitrogen compounds) relative dominance of solitary cells and colonies, and the effects of micronutrient (Fe) and grazing related chemical signals on P. Antarctica colony development. Because this species is of critical importance in the Southern Ocean, and because this research will provide critical information on factors that regulate the role of P.Antarctica in food webs and biogeochemical cycles, a major gap in knowledge will be addressed. This project will train two marine science PhD students. The investigators will also collaborate with the School of Education and a marine science museum to communicate polar science to a broader audience.", "east": 166.66267, "geometry": "POINT(166.66267 -77.85067)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.85067, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Tang, Kam; Smith, Walker", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.85067, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial forms of Phaeocystis antarctica", "uid": "p0000214", "west": 166.66267}, {"awards": "0230452 Severinghaus, Jeffrey", "bounds_geometry": "POINT(124.5 -80.78)", "dataset_titles": "Antarctic megadunes", "datasets": [{"dataset_uid": "000191", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Antarctic megadunes", "url": "http://nsidc.org/antarctica/megadunes/"}], "date_created": "Wed, 27 Sep 2006 00:00:00 GMT", "description": "This award supports a study of the chemical composition of air in the snow layer (firn) in a region of \"megadunes\" near Vostok station, Antarctica. It will test the hypothesis that a deep \"convective zone\" of vigorous wind-driven mixing can prevent gas fractionation in the upper one-third of the polar firn layer. In the megadunes, ultralow snow accumulation rates lead to structural changes (large grains, pipes, and cracks) that make the permeability of firn to air movement orders of magnitude higher than normal. The unknown thickness of the convective zone has hampered the interpretation of ice core 15N/14N and 40Ar/36Ar ratios as indicators of past firn thickness, which is a key constraint on the climatically important variables of temperature, accumulation rate, and gas age-ice age difference. Studying this \"extreme end-member\" example will better define the role of the convective zone in gas reconstructions. This study will pump air from a profile of ~20 depths in the firn, to definitively test for the presence of a convective zone based on the fit of observed 15 N/14N and 40Ar/36Ar to a molecular- and eddy-diffusion model. Permeability measurements on the core and 2-D air flow modeling (in collaboration with M. Albert) will permit a more physically realistic interpretation of the isotope data and will relate mixing vigor to air velocities. A new proxy indicator of convective zone thickness will be tested on firn and ice core bubble air, based on the principle that isotopes of slow-diffusing heavy noble gases (Kr, Xe) should be more affected by convection than isotopes of fast-diffusing N2 . These tools will be applied to a test of the hypothesis that the megadunes and a deep convective zone existed at the Vostok site during glacial periods, which would explain the anomalously low 15N/14N and 40Ar/36Ar in the Vostok ice core glacial periods. The broader impacts of this work include 1) clarification of phase relationships of greenhouse gases and temperature in ice core records, with implications for understanding of past and future climates, 2) education of one graduate student, and 3) building of collaborative relationships with five investigators.", "east": 124.5, "geometry": "POINT(124.5 -80.78)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS", "is_usap_dc": false, "keywords": "Antarctica; Methane; Carbon-14; Permeability; CO2; Firn Core; FIELD SURVEYS; Deuterium Excess; GROUND-BASED OBSERVATIONS; LABORATORY; Isotope; Ice Core Density; Firn Air; Megadunes; Ice Core; Not provided; FIELD INVESTIGATION", "locations": "Antarctica", "north": -80.78, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bauer, Rob; Albert, Mary R.; Severinghaus, Jeffrey P.", "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": "NSIDC", "repositories": "NSIDC", "science_programs": null, "south": -80.78, "title": "How Thick Is the Convective Zone: A Study of Firn Air in the Megadunes Near Vostok, Antarctica", "uid": "p0000097", "west": 124.5}, {"awards": "9615554 Fitzpatrick, Joan", "bounds_geometry": null, "dataset_titles": "Digital Images of Thin Sections from Siple Dome; Digital Imaging for Siple Dome Ice Core Analysis, Antarctica", "datasets": [{"dataset_uid": "609127", "doi": "10.7265/N59Z92T4", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Digital Images of Thin Sections from Siple Dome", "url": "https://www.usap-dc.org/view/dataset/609127"}, {"dataset_uid": "609413", "doi": "10.7265/N5XG9P2G", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core", "people": "Alley, Richard; Spencer, Matthew; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Digital Imaging for Siple Dome Ice Core Analysis, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609413"}], "date_created": "Wed, 14 May 2003 00:00:00 GMT", "description": "This award is for support for two years to develop the technology and methodology for digitizing the photographs and analyzing the thin sections from ice cores. In addition, the application of digital technology for whole-core stratigraphy, using digital photography, image enhancement and image processing will be investigated. The thin section analysis will be piloted with samples already in hand from the Taylor Dome ice core. If successful, these techniques will be applied to samples from the Siple Dome ice core, in cooperation with Principal Investigators already funded to retrieve and examine these sections. The original digital images with all original data annotation files will be distributed to Siple Dome principal investigators for their use in the interpretation of their own data. All software and hardware acquired for this project will become part of the permanent equipment inventory at the U.S. National Ice Core Laboratory and will be available for use by clients at the facility.", "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 CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Antarctica; Glaciology; Ice Sheet; Siple; Ice Core; Stratigraphy; GROUND STATIONS; Siple Dome; WAISCORES; Trapped Air Bubbles; Photo; Snow; Density; Volcanic Deposits; Not provided; Ice Core Data; GROUND-BASED OBSERVATIONS; Siple Coast; Chemical Composition", "locations": "Siple Dome; Antarctica; Siple; Siple Coast", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fitzpatrick, Joan; Alley, Richard; Spencer, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Digital Imaging for Ice Core Analysis", "uid": "p0000011", "west": null}, {"awards": "9527262 Gow, Anthony", "bounds_geometry": null, "dataset_titles": "Physical and Structural Properties of the Siple Dome Ice Cores", "datasets": [{"dataset_uid": "609128", "doi": "10.7265/N5668B34", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Meese, Deb; Gow, Tony", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Physical and Structural Properties of the Siple Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609128"}], "date_created": "Wed, 14 May 2003 00:00:00 GMT", "description": "This award is for support for a program to investigate the visual stratigraphy, index physical properties, relaxation characteristics and crystalline structure of ice cores from Siple Dome, West Antarctica. This investigation will include measurements of a time-priority nature that must be initiated at the drill site on freshly-drilled cores. This will be especially true of cores from the brittle ice zone, which is expected to comprise a significant fraction of the ice core. The brittle zone includes ice in which relaxation , resulting from the release of confining pressure is maximized and leads to significant changes in the mechanical condition of the core that must be considered in relation to the processing and analysis of ice samples for entrapped gas and chemical studies. This relaxation will be monitored via precision density measurements made initially at the drill site and repeated at intervals back in the U.S. Other studies will include measurement of the annual layering in the core to as great a depth as visual stratigraphy can be deciphered, crystal size measurements as a function of depth and age, c-axis fabric studies, and analysis of the physical properties of any debris-bearing basal ice and its relationship to the underlying bedrock. Only through careful documentation and analysis of these key properties can we hope to accurately assess the dynamic state of the ice and the age-depth relationships essential to deciphering the paleoclimate record at this location.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Siple Dome; Antarctica; Stratigraphy; Ice Sheet; GROUND-BASED OBSERVATIONS; Density; Siple; Chemical Composition; Volcanic Deposits; Siple Coast; WAISCORES; Not provided; GROUND STATIONS; Pico; Ice Core; Tephra; Fabric; Glaciology; Snow", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Gow, Tony; Meese, Deb", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Physical and Structural Properties of the Siple Dome Core", "uid": "p0000064", "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. 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. 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.", "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}]

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