{"dp_type": "Dataset", "free_text": "Strain"}
[{"awards": "2201129 Fischer, Karen", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Wed, 12 Feb 2025 00:00:00 GMT", "description": "This dataset contains the depths of negative velocity gradients that are potentially interpretable as the lithosphere-asthenosphere boundary (LAB) beneath Antarctica, derived from common conversion point stacking of Sp receiver functions. The dataset provides constraints on lithospheric thickness variations, particularly in West Antarctica, where a vertically localized LAB is observed at depths of 70\u2013100 km. In East Antarctica, two zones of well-defined LAB depths are present in regions near the coast at depths of 75-110 km (~140\u02daE) and 90-130 km (~115\u02daE). Interpretation of these results and comparison with prior studies are provided in the associated journal article (see References).", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cryosphere; LAB; Lithosphere; Lithospheric Thickness", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Brown, Sarah; Fischer, Karen", "project_titles": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity", "projects": [{"proj_uid": "p0010339", "repository": "USAP-DC", "title": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Lithospheric thicknesses in Antarctica from Sp receiver functions", "uid": "601899", "west": -180.0}, {"awards": "2201129 Fischer, Karen", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Wed, 12 Feb 2025 00:00:00 GMT", "description": "This dataset contains crustal thickness measurements at 99 individual broadband seismic stations across Antarctica derived from teleseismic Sp waves. Crustal thickness estimates were obtained by measuring the depth of the Sp phase associated with the crust-mantle boundary observed in single-station stacks of Sp receiver functions. The measurements offer new constraints on crustal structure in West and East Antarctica. Comparison with crustal thickness estimates from prior studies are provided in the associated journal article (see References).", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Crust; Cryosphere; Moho", "locations": "Antarctica; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Brown, Sarah; Fischer, Karen", "project_titles": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity", "projects": [{"proj_uid": "p0010339", "repository": "USAP-DC", "title": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Crustal thicknesses in Antarctica from Sp receiver functions", "uid": "601898", "west": -180.0}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-104.9429 -75.1543,-104.92228999999999 -75.1543,-104.90168 -75.1543,-104.88107 -75.1543,-104.86046 -75.1543,-104.83985 -75.1543,-104.81924 -75.1543,-104.79863 -75.1543,-104.77802 -75.1543,-104.75741000000001 -75.1543,-104.7368 -75.1543,-104.7368 -75.16263000000001,-104.7368 -75.17096000000001,-104.7368 -75.17929000000001,-104.7368 -75.18762000000001,-104.7368 -75.19595000000001,-104.7368 -75.20428,-104.7368 -75.21261,-104.7368 -75.22094,-104.7368 -75.22927,-104.7368 -75.2376,-104.75741000000001 -75.2376,-104.77802 -75.2376,-104.79863 -75.2376,-104.81924 -75.2376,-104.83985 -75.2376,-104.86046 -75.2376,-104.88107 -75.2376,-104.90168 -75.2376,-104.92228999999999 -75.2376,-104.9429 -75.2376,-104.9429 -75.22927,-104.9429 -75.22094,-104.9429 -75.21261,-104.9429 -75.20428,-104.9429 -75.19595000000001,-104.9429 -75.18762000000001,-104.9429 -75.17929000000001,-104.9429 -75.17096000000001,-104.9429 -75.16263000000001,-104.9429 -75.1543))"], "date_created": "Mon, 25 Nov 2024 00:00:00 GMT", "description": "Contains ice-penetrating radar data (10 and 400 MHz) from the Thwaites Glacier grounding zone. The main purpose of collecting these data was for safety assessment at a camp put-in; deep (10 MHz) radar data were also collected opportunistically.", "east": -104.7368, "geometry": ["POINT(-104.83985 -75.19595000000001)"], "keywords": "Antarctica; Cryosphere; Grounding Zone; Ice Penetrating Radar; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": -75.1543, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Balco, Greg; Campbell, Seth; Goehring, Brent", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.2376, "title": "Ice-penetrating radar data from the Thwaites Glacier grounding zone", "uid": "601860", "west": -104.9429}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-110.9665 -75.1967,-110.92041 -75.1967,-110.87432 -75.1967,-110.82822999999999 -75.1967,-110.78214 -75.1967,-110.73605 -75.1967,-110.68996 -75.1967,-110.64386999999999 -75.1967,-110.59778 -75.1967,-110.55169000000001 -75.1967,-110.5056 -75.1967,-110.5056 -75.20331,-110.5056 -75.20992000000001,-110.5056 -75.21653,-110.5056 -75.22314,-110.5056 -75.22975,-110.5056 -75.23636,-110.5056 -75.24297,-110.5056 -75.24958,-110.5056 -75.25619,-110.5056 -75.2628,-110.55169000000001 -75.2628,-110.59778 -75.2628,-110.64386999999999 -75.2628,-110.68996 -75.2628,-110.73605 -75.2628,-110.78214 -75.2628,-110.82822999999999 -75.2628,-110.87432 -75.2628,-110.92041 -75.2628,-110.9665 -75.2628,-110.9665 -75.25619,-110.9665 -75.24958,-110.9665 -75.24297,-110.9665 -75.23636,-110.9665 -75.22975,-110.9665 -75.22314,-110.9665 -75.21653,-110.9665 -75.20992000000001,-110.9665 -75.20331,-110.9665 -75.1967))"], "date_created": "Wed, 13 Nov 2024 00:00:00 GMT", "description": "Contains ice-penetrating radar data (10, 100, and 400 MHz) from the north side of the Mt. Murphy massif. Most of these data are closely spaced lines used for reconnaissance and site selection for a subglacial bedrock recovery drilling project very close to the ice margin at the north ridge of Kay Peak, a sub-peak of the massif. In addition, there are several longer exploratory lines that cross the embayment between the massif and the Crosson Ice Shelf, some of which may cross grounding lines. ", "east": -110.5056, "geometry": ["POINT(-110.73605 -75.22975)"], "keywords": "Antarctica; Cryosphere; Mount Murphy", "locations": "Antarctica; Mount Murphy", "north": -75.1967, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Balco, Greg; Campbell, Seth; Goehring, Brent", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.2628, "title": "Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif", "uid": "601834", "west": -110.9665}, {"awards": "1643669 Petrenko, Vasilii", "bounds_geometry": ["POLYGON((112 -66,112.2 -66,112.4 -66,112.6 -66,112.8 -66,113 -66,113.2 -66,113.4 -66,113.6 -66,113.8 -66,114 -66,114 -66.1,114 -66.2,114 -66.3,114 -66.4,114 -66.5,114 -66.6,114 -66.7,114 -66.8,114 -66.9,114 -67,113.8 -67,113.6 -67,113.4 -67,113.2 -67,113 -67,112.8 -67,112.6 -67,112.4 -67,112.2 -67,112 -67,112 -66.9,112 -66.8,112 -66.7,112 -66.6,112 -66.5,112 -66.4,112 -66.3,112 -66.2,112 -66.1,112 -66))"], "date_created": "Thu, 24 Oct 2024 00:00:00 GMT", "description": "This is a data set containing measurements of [14CO] in firn air and ice core samples from Law Dome DE08-OH site, Antarctica. The firn air and ice core samples were collected at Law Dome in December 2018 and January 2019. The [14CO] data represent atmospheric values (with the in situ cosmogenic and procedural components removed). [14CO] measurements were conducted as described in Hmiel et al., 2024 (https://doi.org/10.5194/tc-18-3363-2024). The in situ cosmogenic [14CO] contribution was calculated using parameters and model also described in Hmiel et al. (2024). As [14CO] measurements in ice cores are complex, use of the data in a publication requires contacting Vasilii Petrenko (vasilii.petrenko@rochester.edu) to ensure correct understanding of the data. Depending on nature of use of the data, co-authorship may be appropriate. ", "east": 114.0, "geometry": ["POINT(113 -66.5)"], "keywords": "Antarctica; Carbon-14; Cryosphere; Firn Air; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Law Dome; Snow/ice; Snow/Ice", "locations": "Antarctica; Law Dome", "north": -66.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Petrenko, Vasilii", "project_titles": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "projects": [{"proj_uid": "p0010341", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Law Dome firn air and ice core 14CO concentration", "uid": "601846", "west": 112.0}, {"awards": "2317097 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"], "date_created": "Wed, 02 Oct 2024 00:00:00 GMT", "description": "This data set contains an ice and firn density profile from Winkie Nunatak, West Antarctica. These data were collected when drilling a sub-ice access hole with an Eclipse drill in preparation for Winkie drill collection of subglacial bedrock. ", "east": -99.745, "geometry": ["POINT(-99.769 -74.8635)"], "keywords": "Antarctica; Cryosphere; Density; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Density; Ice Core Records; Snow/ice; Snow/Ice", "locations": "Antarctica", "north": -74.857, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Venturelli, Ryan", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -74.87, "title": "Firn and Ice Density at Winkie Nunatak", "uid": "601838", "west": -99.793}, {"awards": "1853377 Shero, Michelle; 0838892 Burns, Jennifer; 0838937 Costa, Daniel", "bounds_geometry": ["POLYGON((-180 -72,-179.8 -72,-179.6 -72,-179.4 -72,-179.2 -72,-179 -72,-178.8 -72,-178.6 -72,-178.4 -72,-178.2 -72,-178 -72,-178 -72.7,-178 -73.4,-178 -74.1,-178 -74.8,-178 -75.5,-178 -76.2,-178 -76.9,-178 -77.6,-178 -78.3,-178 -79,-178.2 -79,-178.4 -79,-178.6 -79,-178.8 -79,-179 -79,-179.2 -79,-179.4 -79,-179.6 -79,-179.8 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.3,162 -77.6,162 -76.9,162 -76.2,162 -75.5,162 -74.8,162 -74.1,162 -73.4,162 -72.7,162 -72,163.8 -72,165.6 -72,167.4 -72,169.2 -72,171 -72,172.8 -72,174.6 -72,176.4 -72,178.2 -72,-180 -72))"], "date_created": "Fri, 20 Sep 2024 00:00:00 GMT", "description": "Diel vertical migrations (DVM) have been well-documented across numerous taxa, with prey descend through the water column during daylight hours to avoid visual predators and feed at the surface at night. However, the ability of marine mammals such as Weddell seals (Leptonychotes weddellii) to follow prey to depths is likely constrained by limited breath-hold capacities and the physiological consequences of pushing aerobic thresholds. In particular, dives that exceed the aerobic dive limit require exponentially longer surface recuperation times to clear lactate byproducts from circulation. This is time that the animals then cannot spend foraging. In this study, we assess the circadian organization of the Weddell seal\u0027s dive efforts and when animals make their longest/deepest (most \u0027extreme\u0027) dives that far exceed aerobic thresholds. Sixty-two adult Weddell seals were instrumented with satellite linked relay loggers in the Ross Sea to collect behavioral information across the austral winter. Daily activities are likely to shift across the year in a highly-seasonal polar environment, and through this \u0027natural experiment\u0027 we test how free-ranging seals alter foraging behavior during Polar Day and Night (continuous light, LL and dark, DD, respectively) and varying light/dark (LD) cycling across the year.", "east": -178.0, "geometry": ["POINT(172 -75.5)"], "keywords": "Aerobic; Antarctica; Cryosphere; Weddell Seal", "locations": "Antarctica; Antarctica", "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Shero, Michelle", "project_titles": "Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals; Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea", "projects": [{"proj_uid": "p0010369", "repository": "USAP-DC", "title": "Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals"}, {"proj_uid": "p0000661", "repository": "USAP-DC", "title": "Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Weddell seal dive behavior and rhythmicity from 2010-2012 in the Ross Sea", "uid": "601835", "west": 162.0}, {"awards": "1643120 Iverson, Neal", "bounds_geometry": null, "date_created": "Mon, 16 Sep 2024 00:00:00 GMT", "description": "Accurately modeling the deformation of temperate glacier ice, which is at its pressure-melting temperature and contains liquid water at grain boundaries, is essential for predicting ice sheet discharge to the ocean and associated sea-level rise. Central to such modeling is Glen\u2019s flow law, in which strain rate depends on stress raised to a power of n=3-4. In sharp contrast to this nonlinearity, we find by conducting large-scale, shear-deformation experiments to tertiary creep that temperate ice is linear-viscous (n\u22481.0) over common ranges of liquid water content and stress expected near glacier beds and in ice stream margins. This linearity is likely caused by diffusive pressure-melting and refreezing at grain boundaries and could help stabilize modeled responses of ice sheets to shrinkage-induced stress increases.", "east": null, "geometry": null, "keywords": "Antarctica; Cryosphere", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Iverson, Neal", "project_titles": "NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice", "projects": [{"proj_uid": "p0010197", "repository": "USAP-DC", "title": "NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Tertiary creep rates of temperate ice containing greater than 0.7% liquid water", "uid": "601833", "west": null}, {"awards": "0087144 Conway, Howard", "bounds_geometry": ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"], "date_created": "Mon, 22 Jul 2024 00:00:00 GMT", "description": "Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\\sim3000$ and $\\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly.", "east": -130.0, "geometry": ["POINT(-140 -84.25)"], "keywords": "Antarctica; Cryosphere; Siple Coast", "locations": "Antarctica; Siple Coast", "north": -83.5, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hoffman, Andrew; Conway, Howard; Christianson, Knut", "project_titles": "Glacial History of Ridge AB, West Antarctica", "projects": [{"proj_uid": "p0010470", "repository": "USAP-DC", "title": "Glacial History of Ridge AB, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Impulse HF radar data from Conway Ridge", "uid": "601810", "west": -150.0}, {"awards": "2042495 Blackburn, Terrence; 1644171 Blackburn, Terrence", "bounds_geometry": ["POLYGON((161.9 -77.65,161.96 -77.65,162.02 -77.65,162.08 -77.65,162.14000000000001 -77.65,162.2 -77.65,162.26 -77.65,162.32 -77.65,162.38 -77.65,162.44 -77.65,162.5 -77.65,162.5 -77.66000000000001,162.5 -77.67,162.5 -77.68,162.5 -77.69,162.5 -77.7,162.5 -77.71000000000001,162.5 -77.72,162.5 -77.73,162.5 -77.74,162.5 -77.75,162.44 -77.75,162.38 -77.75,162.32 -77.75,162.26 -77.75,162.2 -77.75,162.14000000000001 -77.75,162.08 -77.75,162.02 -77.75,161.96 -77.75,161.9 -77.75,161.9 -77.74,161.9 -77.73,161.9 -77.72,161.9 -77.71000000000001,161.9 -77.7,161.9 -77.69,161.9 -77.68,161.9 -77.67,161.9 -77.66000000000001,161.9 -77.65))"], "date_created": "Mon, 01 Jul 2024 00:00:00 GMT", "description": "This dataset contains uranium and thorium isotopic compositions (U-234, U-235, U-238, Th-230, Th-232) and major element compositions (Al, K, Na, Ca, Fe, Mn, reported as oxides) for silicate sediments from glaciogenic drifts associated with advances of Taylor Glacier in Taylor Valley, Antarctica. Isotopic measurements were obtained by ID-TIMS in the Keck Isotope Facility at UC Santa Cruz and elemental measurements were obtained by ICP-OES in the Plasma Analytical Laboratory. All measurements include fully propagated analytical and systematic (e.g. isotopic tracer) uncertainties. Chemical index of alteration was calculated from major element data. Prior to measurements, sediments were sieved to \u2264125 \u03bcm grain sizes, separated into quartz-feldspar-rich and clay-rich aliquots by hydraulic settling, and subjected to sequential chemical extractions (\"leaching\") prior to silicate digestion.", "east": 162.5, "geometry": ["POINT(162.2 -77.7)"], "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "locations": "Taylor Valley; Taylor Glacier; Antarctica", "north": -77.65, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Edwards, Graham; Piccione, Gavin; Blackburn, Terrence; Tulaczyk, Slawek", "project_titles": "Collaborative Research: Reconstructing East Antarctica\u2019s Past Response to Climate using Subglacial Precipitates; U-Series Comminution Age Constraints on Taylor Valley Erosion", "projects": [{"proj_uid": "p0010192", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing East Antarctica\u2019s Past Response to Climate using Subglacial Precipitates"}, {"proj_uid": "p0010243", "repository": "USAP-DC", "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.75, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "uid": "601806", "west": 161.9}, {"awards": "2218402 Fegyveresi, John", "bounds_geometry": ["POLYGON((-148.812 -79.467,-143.7458 -79.467,-138.67960000000002 -79.467,-133.6134 -79.467,-128.5472 -79.467,-123.48100000000001 -79.467,-118.41480000000001 -79.467,-113.3486 -79.467,-108.28240000000001 -79.467,-103.21620000000001 -79.467,-98.15 -79.467,-98.15 -80.52029999999999,-98.15 -81.5736,-98.15 -82.6269,-98.15 -83.6802,-98.15 -84.73349999999999,-98.15 -85.7868,-98.15 -86.8401,-98.15 -87.8934,-98.15 -88.94669999999999,-98.15 -90,-103.2162 -90,-108.28240000000001 -90,-113.3486 -90,-118.41480000000001 -90,-123.48100000000001 -90,-128.5472 -90,-133.6134 -90,-138.6796 -90,-143.7458 -90,-148.812 -90,-148.812 -88.94669999999999,-148.812 -87.8934,-148.812 -86.8401,-148.812 -85.7868,-148.812 -84.73349999999999,-148.812 -83.6802,-148.812 -82.6269,-148.812 -81.5736,-148.812 -80.52029999999999,-148.812 -79.467))"], "date_created": "Thu, 16 May 2024 00:00:00 GMT", "description": "This data set includes all measurements and observations used in conjunction with NSF funded project 2218402 - \"EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site\". Data is directly related to the Masters Thesis of NAU graduate student Samantha Barnett", "east": -98.15, "geometry": ["POINT(-123.48100000000001 -84.73349999999999)"], "keywords": "Antarctica; Brittle Ice; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Glaciology; Ice Core; Ice Core Records; Ice Core Records; Physical Properties; Simple Dome; Siple Dome; South Pole; SPICEcore; Subgrain Boundaries; WAIS Divide", "locations": "Simple Dome; South Pole; WAIS Divide; Antarctica; Siple Dome; WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fegyveresi, John; Barnett, Samantha", "project_titles": "EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site.", "projects": [{"proj_uid": "p0010378", "repository": "USAP-DC", "title": "EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -90.0, "title": "Multi-Site Brittle Ice Data and Measurements", "uid": "601786", "west": -148.812}, {"awards": "2200448 Simms, Alexander", "bounds_geometry": null, "date_created": "Fri, 10 May 2024 00:00:00 GMT", "description": "Radiocarbon dating is arguably the most common method for dating Quaternary deposits. However, accurate age assignments using radiocarbon dating are dependent on knowing the radiocarbon reservoir. For the coastal waters across Antarctica, the radiocarbon reservoirs show significant variation, ranging from 700 to 6,000 years depending on the material dated and the period in question. In this study, we examine the radiocarbon reservoir age for the shallow waters of the Southern Ocean using 23 whale bones salvaged from whaling stations operating on or near the Western Antarctic Peninsula between 1904 and 1916. The species origin of the bones had been identified previously as humpback, fin, or blue whales using sequences of mitochondrial (mt)DNA. We find an average reservoir age of 1050 +/- 135 years for these 23 whale bones, with a \u003c100 year difference in the reservoir age value by species. A comparison between our results and other studies through the Holocene suggest that the Southern Ocean surface water radiocarbon reservoir age has not significantly changed for the last 14,000 years. Combining our new ages with existing data sets provides insight to the stability of the Southern Ocean marine radiocarbon reservoir age, enhancing our understanding of ocean ventilation and upwelling dynamics throughout the Holocene.", "east": null, "geometry": null, "keywords": "Antarctica; C-14; Cryosphere; Radiocarbon Dates; Whale Bone; Whales", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Divola, Claire; Simms, Alexander; Sremba, Angela; Baker, C. Scott; Friedlaender, Ari; Southon, John", "project_titles": "New constraints on 14C reservoirs around the Antarctic Peninsula and the Southern Ocean based on historically-harvested whale bones", "projects": [{"proj_uid": "p0010457", "repository": "USAP-DC", "title": "New constraints on 14C reservoirs around the Antarctic Peninsula and the Southern Ocean based on historically-harvested whale bones"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Constraining the Radiocarbon Reservoir Age for the Southern Ocean Using Whale Bones Salvaged from Early 20th Century Whaling Stations", "uid": "601784", "west": null}, {"awards": "1914698 Hansen, Samantha", "bounds_geometry": ["POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))"], "date_created": "Wed, 24 Jan 2024 00:00:00 GMT", "description": "Recent investigations in polar environments have examined solid-Earth-ice-sheet feedbacks and have emphasized that glacial isostatic adjustment, tectonic, and geothermal forcings exert first-order control on the physical conditions at and below the ice-bed interface and must be taken into account when evaluating ice-sheet evolution. However, the solid-Earth structure beneath much of Antarctica is still poorly constrained given the sparse distribution of seismic stations across the continent and the generally low seismicity rate. One region of particular interest is the Wilkes Subglacial Basin (WSB) in East Antarctica. During the mid-Pliocene warm period, the WSB may have contributed 3-4 m to the estimated 20 m rise in sea-level, indicating that this region could also play an important role in future warming scenarios. However, the WSB may have experienced notable bedrock uplift since the Pliocene; therefore, past geologic inferences of instability may not serve as a simple analogue for the future.\r\n\r\nUsing records of ambient seismic noise recorded by both temporary and long-term seismic networks, along with a full-waveform tomographic inversion technique, we have developed improved images of the lithospheric structure beneath East Antarctica, including the WSB. Empirical Green\u2019s Functions with periods between 40 and 340 s have been extracted using a frequency-time normalization technique, and a finite-difference approach with a spherical grid has been employed to numerically model synthetic seismograms. Associated sensitivity kernels have also been constructed using a scattering integral method. Our results suggest the WSB is underlain by slow seismic velocities, with faster seismic structure beneath the adjacent Transantarctic Mountains and the Belgica Subglacial Highlands. This may indicate that the WSB is associated with a region of thinner lithosphere, possibly associated with prior continental rifting. The seismic heterogeneity highlighted in our model could have significant implications for understanding the geodynamic origin of WSB topography and its influence on ice-sheet behavior.\r\n\r\nThe model file and associated plotting scripts are provided.", "east": 180.0, "geometry": ["POINT(135 -77.5)"], "keywords": "Ambient Noise; Antarctica; East Antarctica; Geoscientificinformation; Seismic Tomography; Seismology", "locations": "Antarctica; East Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Hansen, Samantha; Emry, Erica", "project_titles": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)", "projects": [{"proj_uid": "p0010204", "repository": "USAP-DC", "title": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Full Waveform Ambient Noise Tomography for East Antarctica", "uid": "601763", "west": 90.0}, {"awards": "2023303 Purkey, Sarah", "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))"], "date_created": "Tue, 31 Oct 2023 00:00:00 GMT", "description": "A global CFC Data product is derived used the Time-Corrected Method (TCM) in order to estimate CFCs and SF6 ocean concentration back to 1940. The Green\u0027s functions (GFs), describing the steady-state transport from the surface to the ocean interior, is solved, constrained by observations. From the GFs, we reconstruct global tracer concentrations (and associated uncertainties) in the ocean interior at annual resolution (1940\u20132021). The spatial resolution includes 50 neutral density levels that span the water column along World Ocean Circulation Experiment/Global Ocean Ship-Based Hydrographic Investigations Program lines. ", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; CFCs; GLODAP; Ocean Model; Ocean Ventilation; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "persons": "Cimoli, Laura; Purkey, Sarah; Gebbie, Jack", "project_titles": "Collaborative Research: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters?", "projects": [{"proj_uid": "p0010220", "repository": "USAP-DC", "title": "Collaborative Research: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Ocean CFC reconstructed data product", "uid": "601752", "west": -180.0}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(-112.05 -79.28)"], "date_created": "Fri, 20 Oct 2023 00:00:00 GMT", "description": "Major gas components of air data set, containing d15N, d18O of O2, dO2/N2, and dAr/N2 from the WAIS Divide ice core at high resolution. These data are used to constrain surface temperature, biosphere oxygen cycling, and firn thickness through the past \u003e60 kyr.", "east": -112.05, "geometry": ["POINT(-112.05 -79.28)"], "keywords": "Antarctica; Delta 15N; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Gas Records; Ice Core Records; Isotope; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; WAIS; WAIS Divide", "locations": "Antarctica; WAIS Divide; WAIS", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.", "project_titles": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "projects": [{"proj_uid": "p0000036", "repository": "USAP-DC", "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "d15N and d18O of air in the WAIS Divide ice core", "uid": "601747", "west": -112.05}, {"awards": "1643798 Emry, Erica; 1643873 Hansen, Samantha", "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))"], "date_created": "Mon, 16 Oct 2023 00:00:00 GMT", "description": "This dataset provides the shear wave velocity model resulting from a full-waveform inversion that was constrained using long-period empirical Green\u0027s functions extracted from ambient seismic noise. These results were presented by Emry and Hansen at the 2022 Fall Meeting of the American Geophysical Union.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Ambient Seismic Noise; Antarctica; Full-Waveform Inversion; Seismic Tomography; Shear Wave Velocity; Solid Earth", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Emry, Erica", "project_titles": "Collaborative Research: Imaging Seismic Heterogeneity within the Antarctic Mantle with Full Waveform Ambient Noise Tomography", "projects": [{"proj_uid": "p0010139", "repository": "USAP-DC", "title": "Collaborative Research: Imaging Seismic Heterogeneity within the Antarctic Mantle with Full Waveform Ambient Noise Tomography"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Shear Wave Velocity of the Antarctic Upper Mantle from Full Waveform Inversion and Long Period Ambient Seismic Noise", "uid": "601744", "west": -180.0}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POINT(-110.96038 -75.21526)"], "date_created": "Mon, 10 Jul 2023 00:00:00 GMT", "description": "Included in this dataset are in situ carbon-14 concentrations for a series of bedrock cores recovered from the subglacial extension of Kay Peak, a grounding-line-proximal ridge of the volcanic edifice Mount Murphy (near Thwaites and Pope glaciers). Concentrations measured in these bedrock samples have been used in the associated publication to demonstrate that the Thwaites-Pope glacier system was thinner in the Holocene than it is today. ", "east": -110.96038, "geometry": ["POINT(-110.96038 -75.21526)"], "keywords": "Antarctica; Cosmogenic Radionuclides; Mount Murphy; Subglacial Bedrock", "locations": "Antarctica; Mount Murphy", "north": -75.21526, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Venturelli, Ryan; Goehring, Brent; Balco, Gregory", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.21526, "title": "In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers", "uid": "601705", "west": -110.96038}, {"awards": "1643716 Buizert, Christo", "bounds_geometry": ["POLYGON((-180 -67,-144 -67,-108 -67,-72 -67,-36 -67,0 -67,36 -67,72 -67,108 -67,144 -67,180 -67,180 -69.3,180 -71.6,180 -73.9,180 -76.2,180 -78.5,180 -80.8,180 -83.1,180 -85.4,180 -87.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.7,-180 -85.4,-180 -83.1,-180 -80.8,-180 -78.5,-180 -76.2,-180 -73.9,-180 -71.6,-180 -69.3,-180 -67))"], "date_created": "Mon, 22 May 2023 00:00:00 GMT", "description": "We have reconstructed the atmospheric N2O mole fraction and its isotopic composition by combining data from ice cores, firn air, and atmospheric samples. The mole fraction reconstruction extends back to 1000 CE using ice cores, firn air, and atmospheric sampling; and the isotopic reconstruction extends back to 1900 CE using only firn air data. We have incorporated both newly measured and previously published data. We present new data for the mole fraction, d15Nbulk, d18O, and d15NSP values from the Styx (East Antarctica) firn air, and mole fraction from the North Greenland Eemian Ice drilling Project (NEEM) firn air. We have used published records from the Styx and NEEM ice cores, direct atmospheric measurements from the NOAA global sampling network, and firn air data, giving a total of 11 sites for N2O mole fraction, 12 sites for d15Nbulk, 11 sites for d18O, and 8 sites for d15NSP values.\r\n", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctic; Antarctica; Anthropogenic Emission; Atmosphere; Greenhouse Gas; Greenland; Ice Core Data; Nitrification And Denitrification Processes; Nitrous Oxide; Site-Specific 15N Isotopomer; Styx Glacier", "locations": "Antarctic; Greenland; Antarctica; Styx Glacier", "north": -67.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Ghosh, Sambit; Toyoda, Sakae ; Buizert, Christo ; Langenfelds, Ray L ; Yoshida, Naohiro ; Joong Kim, Seong; Ahn, Jinho ; Etheridge, David", "project_titles": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "projects": [{"proj_uid": "p0010341", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Concentration and isotopic composition of atmospheric N2O over the last century", "uid": "601693", "west": -180.0}, {"awards": "2130663 Neff, Peter", "bounds_geometry": null, "date_created": "Thu, 18 May 2023 00:00:00 GMT", "description": "Final report of the 2021 Antarctic Subsea Cable Workshop, held virtually June 29 - July 1. The National Science Foundation (NSF)-funded workshop addressed questions around the value and feasibility of deploying a new optical fiber submarine cable system that would supply high-speed internet connectivity to McMurdo Station to address the severe network bandwidth bottlenecks that currently constrain scientific research in Antarctica.", "east": null, "geometry": null, "keywords": "Antarctica; Communication; Internet; Report", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Polar Cyberinfrastructure", "persons": "Andreasen, Julia; Roop, Heidi A; Pundsack, Jonathan W; Howe, Bruce; Jacobs, Gwen; Lassner, David; Yoshimi, Garrett; Timm, Kristin; Neff, Peter", "project_titles": "2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science", "projects": [{"proj_uid": "p0010389", "repository": "USAP-DC", "title": "2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Antarctic Subsea Cable Workshop Report", "uid": "601691", "west": null}, {"awards": "2317097 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"], "date_created": "Fri, 24 Mar 2023 00:00:00 GMT", "description": "This data set contains unprocessed radar profiles collected with a GSSI 200 MHz Hyperstacking antenna near Winkie Nunatak, West Antarctica. This data was collected to estimate depth-to-bedrock along a subglacial ridge line at depths between 20 - 120 meters. ", "east": -99.745, "geometry": ["POINT(-99.769 -74.8635)"], "keywords": "Antarctica; Ice Penetrating Radar; Pine Island Glacier; Subglacial Bedrock", "locations": "Antarctica; Pine Island Glacier", "north": -74.857, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Braddock, Scott", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -74.87, "title": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica", "uid": "601677", "west": -99.793}, {"awards": "1644197 Simms, Alexander", "bounds_geometry": null, "date_created": "Mon, 19 Dec 2022 00:00:00 GMT", "description": "This dataset consists of the location, elevation, and age of samples obtained from Joinville Island along the Antarctic Peninsula", "east": null, "geometry": null, "keywords": "Antarctica; Joinville Island; Raised Beaches; Sea Level", "locations": "Antarctica; Joinville Island", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Simms, Alexander", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Radiocarbon Ages from Beaches on Joinville Island, Antarctic Peninsula", "uid": "601634", "west": null}, {"awards": "1644197 Simms, Alexander", "bounds_geometry": null, "date_created": "Mon, 19 Dec 2022 00:00:00 GMT", "description": "This dataset includes ground-penetrating radar (GPR) data collected on Livingston Island in the Antarctic Peninsula.", "east": null, "geometry": null, "keywords": "Antarctica; Joinville Island", "locations": "Antarctica; Joinville Island", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Simms, Alexander", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Ground-Penetrating Radar data from Livingston Island in the Antarctic Peninsula", "uid": "601633", "west": null}, {"awards": "1644197 Simms, Alexander", "bounds_geometry": null, "date_created": "Mon, 19 Dec 2022 00:00:00 GMT", "description": "This dataset provides the raw and processed ground-penetrating radar (GPR) data collected on Joinville Island in the Antarctic Peninsula. ", "east": null, "geometry": null, "keywords": "Antarctica; Joinville Island", "locations": "Antarctica; Joinville Island", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Simms, Alexander", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Ground Penetrating Radar Profiles from Beaches on Joinville Island, Antarctic Peninsula", "uid": "601632", "west": null}, {"awards": "1643248 Hall, Brenda", "bounds_geometry": ["POLYGON((163.2 -78.1,163.26 -78.1,163.32 -78.1,163.38 -78.1,163.44 -78.1,163.5 -78.1,163.56 -78.1,163.62 -78.1,163.68 -78.1,163.74 -78.1,163.8 -78.1,163.8 -78.11999999999999,163.8 -78.14,163.8 -78.16,163.8 -78.17999999999999,163.8 -78.19999999999999,163.8 -78.22,163.8 -78.24,163.8 -78.25999999999999,163.8 -78.28,163.8 -78.3,163.74 -78.3,163.68 -78.3,163.62 -78.3,163.56 -78.3,163.5 -78.3,163.44 -78.3,163.38 -78.3,163.32 -78.3,163.26 -78.3,163.2 -78.3,163.2 -78.28,163.2 -78.25999999999999,163.2 -78.24,163.2 -78.22,163.2 -78.19999999999999,163.2 -78.17999999999999,163.2 -78.16,163.2 -78.14,163.2 -78.11999999999999,163.2 -78.1))"], "date_created": "Tue, 18 Oct 2022 00:00:00 GMT", "description": "This dataset contains radiocarbon dates of subfossil algal mats associated with Ross Sea drift near Walcott and Howchin Glaciers, southern Royal Society Range. These dates constrain the age of Ross Sea drift in this region. ", "east": 163.8, "geometry": ["POINT(163.5 -78.19999999999999)"], "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Howchin Glacier; Radiocarbon; Radiocarbon Dates; Ross Sea Drift; Royal Society Range; Walcott Glacier", "locations": "Antarctica; Royal Society Range; Ross Sea Drift; Walcott Glacier; Howchin Glacier", "north": -78.1, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Hall, Brenda", "project_titles": "Response of the Antarctic Ice Sheet to the last great global warming", "projects": [{"proj_uid": "p0010301", "repository": "USAP-DC", "title": "Response of the Antarctic Ice Sheet to the last great global warming"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "Walcott Glacier area radiocarbon data", "uid": "601615", "west": 163.2}, {"awards": "1643248 Hall, Brenda", "bounds_geometry": ["POLYGON((163 -78.1,163.07 -78.1,163.14 -78.1,163.21 -78.1,163.28 -78.1,163.35 -78.1,163.42 -78.1,163.48999999999998 -78.1,163.56 -78.1,163.63 -78.1,163.7 -78.1,163.7 -78.13,163.7 -78.16,163.7 -78.19,163.7 -78.22,163.7 -78.25,163.7 -78.28,163.7 -78.31,163.7 -78.34,163.7 -78.37,163.7 -78.4,163.63 -78.4,163.56 -78.4,163.48999999999998 -78.4,163.42 -78.4,163.35 -78.4,163.28 -78.4,163.21 -78.4,163.14 -78.4,163.07 -78.4,163 -78.4,163 -78.37,163 -78.34,163 -78.31,163 -78.28,163 -78.25,163 -78.22,163 -78.19,163 -78.16,163 -78.13,163 -78.1))"], "date_created": "Mon, 17 Oct 2022 00:00:00 GMT", "description": "This dataset contains radiocarbon dates of subfossil algal mats associated with Ross Sea drift in Pyramid Trough. These dates constrain the age of Ross Sea drift in this region. The dataset also includes dates of modern algae.", "east": 163.7, "geometry": ["POINT(163.35 -78.25)"], "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pyramid Trough; Radiocarbon; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "locations": "Royal Society Range; Antarctica; Ross Sea Drift; Pyramid Trough", "north": -78.1, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Hall, Brenda", "project_titles": "Response of the Antarctic Ice Sheet to the last great global warming", "projects": [{"proj_uid": "p0010301", "repository": "USAP-DC", "title": "Response of the Antarctic Ice Sheet to the last great global warming"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.4, "title": "Pyramid Trough Radiocarbon Data", "uid": "601614", "west": 163.0}, {"awards": "1643664 Severinghaus, Jeffrey", "bounds_geometry": null, "date_created": "Tue, 16 Aug 2022 00:00:00 GMT", "description": "This data set comprises measurements of noble and inert gases in the firn at the DE08-OH site sampled in 2018-2019 near the summit of Law Dome, Antarctica. The data show the expected gravitational enrichment of heavy isotopes with depth, somewhat attenuated by the high accumulation rate and a near-surface well-mixed zone (convective zone), and the \"lock-in\" horizon at 68 m depth. As seen at many other sites, the heavy isotope of oxygen 18O is depleted progressively with depth within the lock-in zone due to faster gas permeation of 16O16O relative to 18O16O from compressed air bubbles.", "east": null, "geometry": null, "keywords": "Antarctica; Firn; Firn Density; Gravitational Settling; Inert Gases; Law Dome", "locations": "Law Dome; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.", "project_titles": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "projects": [{"proj_uid": "p0010341", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2", "uid": "601598", "west": null}, {"awards": "1643664 Severinghaus, Jeffrey", "bounds_geometry": null, "date_created": "Tue, 16 Aug 2022 00:00:00 GMT", "description": "This data set consists of high-precision krypton and argon isotope measurements, along with 15N and 18O of O2. This data tests the hypothesis that the 2nd order parameter 86Krexcess (86Kr/82Kr - 40Ar/36Ar) serves as a proxy indicator of past storminess, via atmospheric pressure changes that cause barometric pumping in the firn and hence greater gravitational disequilibrium in the heavier Kr atom than in Ar. These measurements were made as part of the US-Australian Law Dome DE08-OH campaign in 2018-2019. Nitrogen and dioxygen isotopes were also measured.", "east": null, "geometry": null, "keywords": "Antarctica; Ice Core; Law Dome; Noble Gas", "locations": "Antarctica; Law Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.", "project_titles": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "projects": [{"proj_uid": "p0010341", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy", "uid": "601597", "west": null}, {"awards": "1543245 Rynearson, Tatiana", "bounds_geometry": ["POLYGON((-179 -59,-167.7 -59,-156.4 -59,-145.1 -59,-133.8 -59,-122.5 -59,-111.19999999999999 -59,-99.89999999999999 -59,-88.6 -59,-77.3 -59,-66 -59,-66 -60.9,-66 -62.8,-66 -64.7,-66 -66.6,-66 -68.5,-66 -70.4,-66 -72.3,-66 -74.2,-66 -76.1,-66 -78,-77.3 -78,-88.6 -78,-99.9 -78,-111.2 -78,-122.5 -78,-133.8 -78,-145.10000000000002 -78,-156.4 -78,-167.7 -78,-179 -78,-179 -76.1,-179 -74.2,-179 -72.3,-179 -70.4,-179 -68.5,-179 -66.6,-179 -64.7,-179 -62.8,-179 -60.900000000000006,-179 -59))"], "date_created": "Mon, 27 Jun 2022 00:00:00 GMT", "description": "This dataset includes records of the specific growth rates measured for 43 clonal diatom strains originally isolated during the research cruise NBP-1701 across the Pacific sector of the Southern Ocean during December 2016-January 2017. Strains were grown under continuous light (130 \u00b5mol m-2\u00a0s-1) at up to 8 temperatures that span all or most of each strain\u2019s thermal niche width, from 0-12 degrees C, which encompasses each strain\u2019s optimum temperature for growth. Strains have been molecularly identified to species via 18S Sanger sequencing. Data include the following information for each record: Internal lab strain reference ID, date collected, latitude, longitude, Southern Ocean region, species, tested temperature, replicate number and specific growth rate. Data are provided in comma-separated values (csv) format.", "east": -66.0, "geometry": ["POINT(-122.5 -68.5)"], "keywords": "Antarctica; Biota; NBP1701; Phytoplankton; R/v Nathaniel B. Palmer; Specific Growth Rate; Thermal Optimum Temperature", "locations": "Antarctica", "north": -59.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Bishop, Ian", "project_titles": "NSFGEO-NERC: Evolutionary Response of Southern Ocean Diatoms to Environmental Change", "projects": [{"proj_uid": "p0000850", "repository": "USAP-DC", "title": "NSFGEO-NERC: Evolutionary Response of Southern Ocean Diatoms to Environmental Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Specific growth rate measurements for 43 Southern Ocean diatoms", "uid": "601586", "west": -179.0}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-105 -73,-104.5 -73,-104 -73,-103.5 -73,-103 -73,-102.5 -73,-102 -73,-101.5 -73,-101 -73,-100.5 -73,-100 -73,-100 -73.1,-100 -73.2,-100 -73.3,-100 -73.4,-100 -73.5,-100 -73.6,-100 -73.7,-100 -73.8,-100 -73.9,-100 -74,-100.5 -74,-101 -74,-101.5 -74,-102 -74,-102.5 -74,-103 -74,-103.5 -74,-104 -74,-104.5 -74,-105 -74,-105 -73.9,-105 -73.8,-105 -73.7,-105 -73.6,-105 -73.5,-105 -73.4,-105 -73.3,-105 -73.2,-105 -73.1,-105 -73))"], "date_created": "Mon, 11 Apr 2022 00:00:00 GMT", "description": "This dataset includes radiocarbon dates and elevations of organic samples in raised beaches in the Edwards, Lindsey, and Schaefer Islands. It also includes a limited number of cosmogenic exposure-age data of bedrock from these islands.", "east": -100.0, "geometry": ["POINT(-102.5 -73.5)"], "keywords": "Antarctica; Pine Island Bay; Radiocarbon; Raised Beaches", "locations": "Antarctica; Pine Island Bay; Pine Island Bay", "north": -73.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Braddock, Scott; Hall, Brenda", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -74.0, "title": "Pine Island Bay Relative Sea-Level Data", "uid": "601554", "west": -105.0}, {"awards": "1644197 Simms, Alexander; 1643868 DeWitt, Regina", "bounds_geometry": ["POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))"], "date_created": "Fri, 11 Mar 2022 00:00:00 GMT", "description": "sediment and rock samples were collected on Joinville and Livingston Islands for OSL dating; feldspar separates were prepared; data set includes Electron microprobe analysis of selected feldspar extracts; includes bmp and tif with elemental maps plus elemental concentrations and Ca:Na:K ratios for feldspar analysis", "east": -55.0, "geometry": ["POINT(-60 -63)"], "keywords": "Antarctica; Geochronology; Joinville Island; Livingston Island; OSL dating; Raised Beaches", "locations": "Livingston Island; Joinville Island; Antarctica", "north": -61.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "DeWitt, Regina", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Electron Microprobe Analysis of feldspar separates from rock and sediment OSL samples from Joinville and Livingston Island Beaches", "uid": "601531", "west": -65.0}, {"awards": "1644197 Simms, Alexander; 1643868 DeWitt, Regina", "bounds_geometry": ["POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))"], "date_created": "Fri, 11 Mar 2022 00:00:00 GMT", "description": "detailed results for rock and sediment OSL ages; De calculation; dose rate calculation, fading, signal measurement", "east": -55.0, "geometry": ["POINT(-60 -63)"], "keywords": "Antarctica; Geochronology; Joinville Island; Livingston Island; OSL dating; Raised Beaches", "locations": "Antarctica; Livingston Island; Joinville Island", "north": -61.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "DeWitt, Regina", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Joinville and Livingston Islands - rock and sediment OSL ages", "uid": "601534", "west": -65.0}, {"awards": "1644197 Simms, Alexander; 1643868 DeWitt, Regina", "bounds_geometry": ["POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))"], "date_created": "Fri, 11 Mar 2022 00:00:00 GMT", "description": "raw OSL data for rock and sediment samples collected on Joinville and Livingston Islands", "east": -55.0, "geometry": ["POINT(-60 -63)"], "keywords": "Antarctica; Geochronology; Joinville Island; Livingston Island; OSL dating; Raised Beaches", "locations": "Livingston Island; Joinville Island; Antarctica", "north": -61.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "DeWitt, Regina", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "OSL data - Joinville and Livingston Islands - Raw data", "uid": "601532", "west": -65.0}, {"awards": "1341464 Robinson, Rebecca", "bounds_geometry": ["POLYGON((-170.4 -60.8,-170.36 -60.8,-170.32 -60.8,-170.28 -60.8,-170.24 -60.8,-170.2 -60.8,-170.16 -60.8,-170.12 -60.8,-170.08 -60.8,-170.04 -60.8,-170 -60.8,-170 -61.34,-170 -61.88,-170 -62.42,-170 -62.96,-170 -63.5,-170 -64.04,-170 -64.58,-170 -65.12,-170 -65.66,-170 -66.2,-170.04 -66.2,-170.08 -66.2,-170.12 -66.2,-170.16 -66.2,-170.2 -66.2,-170.24 -66.2,-170.28 -66.2,-170.32 -66.2,-170.36 -66.2,-170.4 -66.2,-170.4 -65.66,-170.4 -65.12,-170.4 -64.58,-170.4 -64.04,-170.4 -63.5,-170.4 -62.96,-170.4 -62.42,-170.4 -61.88,-170.4 -61.34,-170.4 -60.8))"], "date_created": "Mon, 14 Feb 2022 00:00:00 GMT", "description": "Tracking variations in the surface ocean supply and demand of nitrate, a key marine nutrient, can help constrain the contribution of biological production in driving past climate shifts. The nitrogen isotopic composition (as \u03b415N) of organic matter in marine sediments is a proxy for surface ocean nitrate supply and demand over time but it may be subject to alteration during sinking and burial. The isotopic composition of nitrogen contained in the shells, or frustules, of diatoms (\u03b415NDB) is protected and is therefore a potentially more robust tracer of nitrate use in the past. Here we show that \u03b415NDB in Southern Ocean community cultures does not depend on species composition. We found the \u03b5DB (= biomass \u03b415N - \u03b415NDB) of the community growouts was -4.8 \u00b1 0.8\u2030, more than 10\u2030 different from previous monospecific growouts, but statistically indistinguishable from previous Southern Ocean and North Pacific surface ocean observations. The two community growouts, seeded with populations from 66\u00b0 and 61\u00b0S, had distinct community compositions but indistinguishable \u03b5DB, suggesting species composition does not primarily set \u03b415NDB values in the Southern Ocean. Our results demonstrate that under nitrate-replete conditions, \u03b415NDB values of frustules sinking from the surface ocean robustly track surface ocean nitrate \u03b415N values and therefore nitrate supply and demand. ", "east": -170.0, "geometry": ["POINT(-170.2 -63.5)"], "keywords": "Antarctica; Nitrogen Isotopes; Oceans; Paleoproxies; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -60.8, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Jones, Colin; Robinson, Rebecca; Brzezinski, Mark; Riesselman, Christina; Closset, Ivia; Kelly, Roger; Robinson, Rebecca ", "project_titles": "Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump", "projects": [{"proj_uid": "p0010083", "repository": "USAP-DC", "title": "Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -66.2, "title": "Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy", "uid": "601522", "west": -170.4}, {"awards": "1738942 Wellner, Julia", "bounds_geometry": ["POLYGON((-107.38 -74.64,-107.065 -74.64,-106.75 -74.64,-106.435 -74.64,-106.12 -74.64,-105.805 -74.64,-105.49 -74.64,-105.175 -74.64,-104.86 -74.64,-104.545 -74.64,-104.23 -74.64,-104.23 -74.683,-104.23 -74.726,-104.23 -74.769,-104.23 -74.812,-104.23 -74.855,-104.23 -74.898,-104.23 -74.941,-104.23 -74.984,-104.23 -75.027,-104.23 -75.07,-104.545 -75.07,-104.86 -75.07,-105.175 -75.07,-105.49 -75.07,-105.805 -75.07,-106.12 -75.07,-106.435 -75.07,-106.75 -75.07,-107.065 -75.07,-107.38 -75.07,-107.38 -75.027,-107.38 -74.984,-107.38 -74.941,-107.38 -74.898,-107.38 -74.855,-107.38 -74.812,-107.38 -74.769,-107.38 -74.726,-107.38 -74.683,-107.38 -74.64))"], "date_created": "Thu, 27 Jan 2022 00:00:00 GMT", "description": "This dataset contains measurements from grain-size, x-ray fluorescence (XRF), and physical properties (including magnetic susceptibility, water content, and shear strength) analyses of five sediment cores collected offshore Thwaites Glacier during cruises NBP19-02 (cores KC04, KC08, and KC23) and NBP20-02 (cores KC33 and KC67). We estimate the cores, which are between 213.5 and 297.5 cm in length, reflect deposition during the last ~10 kyr, consistent with published constraints of deglaciation of this region. Data are organized in Microsoft Excel spreadsheets and core locations are provided in a PDF.", "east": -104.23, "geometry": ["POINT(-105.805 -74.855)"], "keywords": "Antarctica; Chemistry:sediment; Chemistry:Sediment; Glaciomarine Sediment; Grain Size; Magnetic Susceptibility; Marine Geoscience; Marine Sediments; NBP1902; NBP2002; Physical Properties; R/v Nathaniel B. Palmer; Sediment Core Data; Thwaites Glacier; Trace Elements; XRF", "locations": "Antarctica; Thwaites Glacier", "north": -74.64, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Lepp, Allison", "project_titles": "NSF-NERC: THwaites Offshore Research (THOR)", "projects": [{"proj_uid": "p0010062", "repository": "USAP-DC", "title": "NSF-NERC: THwaites Offshore Research (THOR)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.07, "title": "Physical and geochemical data from five sediment cores collected offshore Thwaites Glacier", "uid": "601514", "west": -107.38}, {"awards": "1744949 Campbell, Seth", "bounds_geometry": ["POLYGON((-127.5 -77,-127.4 -77,-127.3 -77,-127.2 -77,-127.1 -77,-127 -77,-126.9 -77,-126.8 -77,-126.7 -77,-126.6 -77,-126.5 -77,-126.5 -77.04,-126.5 -77.08,-126.5 -77.12,-126.5 -77.16,-126.5 -77.2,-126.5 -77.24,-126.5 -77.28,-126.5 -77.32,-126.5 -77.36,-126.5 -77.4,-126.6 -77.4,-126.7 -77.4,-126.8 -77.4,-126.9 -77.4,-127 -77.4,-127.1 -77.4,-127.2 -77.4,-127.3 -77.4,-127.4 -77.4,-127.5 -77.4,-127.5 -77.36,-127.5 -77.32,-127.5 -77.28,-127.5 -77.24,-127.5 -77.2,-127.5 -77.16,-127.5 -77.12,-127.5 -77.08,-127.5 -77.04,-127.5 -77))"], "date_created": "Wed, 08 Dec 2021 00:00:00 GMT", "description": "Here we deposited data sets from the 2018-2019 Mt. Waesche field season. Included are 5 MHz, 10 MHz, 100 MHz, and 350 MHz. Datasets are provided in SEG-Y format for the 100 and 350 MHz and H5 files for the 5 and 10 MHz.", "east": -126.5, "geometry": ["POINT(-127 -77.2)"], "keywords": "Antarctica; GPR; Mt. Waesche", "locations": "Antarctica; Mt. Waesche", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Braddock, Scott", "project_titles": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial", "projects": [{"proj_uid": "p0010272", "repository": "USAP-DC", "title": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.4, "title": "Mt. Waesche ground-penetrating radar data 2018-2019", "uid": "601490", "west": -127.5}, {"awards": "1246353 Anderson, John; 1745043 Simkins, Lauren; 1745055 Stearns, Leigh", "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))"], "date_created": "Wed, 10 Nov 2021 00:00:00 GMT", "description": "The dataset here allows exploration of the causes and significance of Antarctic grounding-line sinuosity by coupling observations of contemporary Antarctic grounding lines and paleo-grounding lines expressed as ice-marginal landforms on the Ross Sea continental shelf. Modern grounding lines are derived from the MEaSUREs Version 2 Differential Satellite Radar Interferometry dataset with spatial resolutions of 25-120 m spanning February 1992 to December 2014 (Rignot et al., 2016; Mouginot et al., 2017). The boundaries of individual grounding lines representative of individual glacial catchments (n=664) were delineated by the inflection points of the shear strain rate, \u03b5xy (c.f Van der Veen et al., 2011). Sinuosity was calculated as the ratio of the true length, orthogonal to ice-flow direction, of the grounding lines and the straight line length between end-points and in units of km/km. Raster data were extracted at 1-km points along each grounding line; the mean was calculated for each grounding line and merged in a table with sinuosity data. A dataset of 6,275 paleo-grounding lines expressed as ice-marginal landforms on the deglaciated western Ross Sea continental shelf are used in this study, originally published by Simkins et al., 2018. The ice-marginal landforms were mapped from multibeam echo sounder data that was collected onboard the RVIB Nathaniel B. Palmer (NBP) 15-02 cruise using a Kongsberg EM122 operating in dual swath mode at 12 kHz frequency with 30-60% swath overlap (Cruise DOI: 10.7284/901477). The resulting bathymetry data was gridded at 20-40 m with decimeter vertical elevation resolution depending on water depth and sea-state. Sinuosity is calculated as a ratio of true (mapped) landform length, measured in the across paleo-ice flow direction at the crest of the landform, to the straight line distance between the mapped landform endpoints and in units of km/km. \r\n\r\nTo compare modern and paleo-grounding lines, we use a consistent length scale by segmenting the grounding lines into 2-km sections for the two datasets (modern, n=12,966; paleo, n=5,832), even though this eliminates grounding lines that are less than 2-km long and thus results in 1 modern and 3,873 paleo-grounding lines removed. The full-length and 2-km segmented groundings lines are provided as shapefiles \"InSAR_groundinglines_full\" and \"InSAR_groundinglines_2km\", the paleo-grounding lines are provided as shapefiles \"RossSea_icemarginal_full\" and \"RossSea_icemarginal_2km\", and points marking modern grounding lines retreat from repeat InSAR surveys are provided as shapefile \"InSAR_retreat_points\", all stored together in a geodatabase named \"Antarctic_groundinglines.gbd\". Additional grounding line metrics, including length, sinuosity, bed roughness, and bed slope for modern and paleo-grounding lines, and height-above-buoyancy gradient, ice-flow velocity, presence of pinning points and ice shelves are provided for modern grounding lines. \r\n\r\nThe published dataset was compiled and analyzed in the article \"Controls on circum-Antarctic grounding-line sinuosity \" by Simkins, L.M., Stearns, L.A., and Riverman, K.L, which will be submitted to a peer-review journal in November 2021.\r\n\r\nReferences\r\nMouginot, J., B. Scheuchl, and E. Rignot. 2017. MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. \r\n\r\nRignot, E., J. Mouginot, and B. Scheuchl. 2016. MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry, Version 2. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. \r\n\r\nSimkins, L. M., Greenwood, S. L., \u0026 Anderson, J. B. (2018). Diagnosing ice sheet grounding line stability from landform morphology. The Cryosphere, 12(8), 2707-2726.\r\n\r\nVan der Veen, C. J., J. C. Plummer, \u0026 L. A. Stearns. (2011). Controls on the recent speed up of Jakobshavn Isbr\u00e6, West Greenland. Journal of Glaciology, 57(204), 770-782", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "locations": "Antarctica; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Simkins, Lauren; Stearns, Leigh; Riverman, Kiya", "project_titles": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations; Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum.", "projects": [{"proj_uid": "p0000395", "repository": "USAP-DC", "title": "Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum."}, {"proj_uid": "p0010269", "repository": "USAP-DC", "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Circum-Antarctic grounding-line sinuosity", "uid": "601484", "west": -180.0}, {"awards": "1738992 Pettit, Erin C", "bounds_geometry": ["POLYGON((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))"], "date_created": "Mon, 11 Oct 2021 00:00:00 GMT", "description": "This dataset includes GeoTiffs of two-year averages of ice flow velocity (including x- and y-components and flow speed) and longitudinal, transverse, and shear strain rates for the Thwaites Eastern Ice Shelf (TEIS) from 2001-2020. The grids were derived from feature tracking on MODIS, Landsat-7, and Landsat-8 imagery. Each pixel in a grid represents the median value of a stack of all available pixels for each time period. Data are gridded at a 500 m spatial resolution in a polar stereographic (EPSG:3031) projection. Speed units are m/day and strain rates are in units of /day. In addition, we provide videos of each variable (excluding x- and y-velocity components) placed alongside a MODIS image of the same extent and from around the same time to provide context. In addition to the variables noted above, we include videos for flow direction (in degrees from grid north in an EPSG:3031 projection) and a zoomed-in version of flow direction, which were calculated from the provided grids.", "east": -104.0, "geometry": ["POINT(-109 -75)"], "keywords": "Antarctica; Glaciology; Ice Shelf; Ice Velocity; Strain Rate; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": -74.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "persons": "Alley, Karen; Wild, Christian; Scambos, Ted; Muto, Atsu; Pettit, Erin; Truffer, Martin; Wallin, Bruce; Klinger, Marin", "project_titles": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment", "projects": [{"proj_uid": "p0010162", "repository": "USAP-DC", "title": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020", "uid": "601478", "west": -114.0}, {"awards": "2039432 Grapenthin, Ronni; 1917149 Grapenthin, Ronni; 1643952 Grapenthin, Ronni", "bounds_geometry": ["POLYGON((166 -77.1,166.39 -77.1,166.78 -77.1,167.17 -77.1,167.56 -77.1,167.95 -77.1,168.34 -77.1,168.73 -77.1,169.12 -77.1,169.51 -77.1,169.9 -77.1,169.9 -77.18,169.9 -77.26,169.9 -77.34,169.9 -77.42,169.9 -77.5,169.9 -77.58,169.9 -77.66,169.9 -77.74,169.9 -77.82,169.9 -77.9,169.51 -77.9,169.12 -77.9,168.73 -77.9,168.34 -77.9,167.95 -77.9,167.56 -77.9,167.17 -77.9,166.78 -77.9,166.39 -77.9,166 -77.9,166 -77.82,166 -77.74,166 -77.66,166 -77.58,166 -77.5,166 -77.42,166 -77.34,166 -77.26,166 -77.18,166 -77.1))"], "date_created": "Fri, 03 Sep 2021 00:00:00 GMT", "description": "We use NASA\u0027s Jet Propulsion Laboratory\u0027s (JPL) GipsyX software in PPP mode with ambiguity resolution \r\napplied to 24 hour segments of data to generate daily position solutions. We use JPL\u0027s orbit and\r\nclock products and International GNSS Service (IGS) antenna phase center models. Where available, \r\nwe use JPL\u0027s second order ionospheric corrections, otherwise we fall back on those provided by the \r\nIGS. To correct tropospheric delays, we use the GPT2 model as implemented in GipsyX. Ocean tidal \r\nloading corrections utilize the TPXO7.2 and ATLAS model, a combination of hydrodynamic model and \r\naltimetry data, with respect to Earth\u0027s Center of Mass implemented in SPOTL. We obtain position \r\nsolutions for each station day in a fiducial-free reference frame, which we then transform into \r\nthe 2014 International Reference Frame using JPL\u0027s transformation coefficients and generate\r\ntimeseries of position change relative to the first epoch, given in the *.series files which \r\nare ASCII files with the following columns:\r\n\r\ndecimal year\r\ndisplacement east (m)\r\ndisplacement north (m)\r\ndisplacement up (m) \r\nsigma east (m)\r\nsigma north (m)\r\nsigma up (m)\r\neast-north covariance\r\neast-up covariance\r\nnorth-up covariance\r\nYear (YYYY)\r\nMonth (MM)\r\nDay (DD)\r\nHour (hh)\r\nMinute (mm)\r\nSecond (ss)\r\nSolution path\r\n \r\nWe generate position time series relative to stable Antarctic plate by removing the plate velocities \r\nmodeled by Argus et al (2010). These are provided in the *.npy files that be readily read into \r\npython scripts:\r\n\r\npos_ts = np.load(\u0027test.npy\u0027).flatten()[0]\r\n\r\npos_ts[\u0027itrf\u0027] provides the ITRF data as above\r\npos_ts[\u0027plate\u0027] provides the data with Antarctic plate motion removed. ", "east": 169.9, "geometry": ["POINT(167.95 -77.5)"], "keywords": "Antarctica; GPS; Mount Erebus; Ross Island", "locations": "Mount Erebus; Ross Island; Ross Island; Antarctica", "north": -77.1, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Grapenthin, Ronni", "project_titles": "Collaborative Research: Multi-Parameter Geophysical Constraints on Volcano Dynamics of Mt. Erebus and Ross Island, Antarctica", "projects": [{"proj_uid": "p0010255", "repository": "USAP-DC", "title": "Collaborative Research: Multi-Parameter Geophysical Constraints on Volcano Dynamics of Mt. Erebus and Ross Island, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.9, "title": "Erebus GPS timeseries ", "uid": "601471", "west": 166.0}, {"awards": null, "bounds_geometry": ["POLYGON((-57.7 -64.2,-46.44 -64.2,-35.18 -64.2,-23.92 -64.2,-12.66 -64.2,-1.4 -64.2,9.86 -64.2,21.12 -64.2,32.38 -64.2,43.64 -64.2,54.9 -64.2,54.9 -65.99,54.9 -67.78,54.9 -69.57,54.9 -71.36,54.9 -73.15,54.9 -74.94,54.9 -76.73,54.9 -78.52,54.9 -80.31,54.9 -82.1,43.64 -82.1,32.38 -82.1,21.12 -82.1,9.86 -82.1,-1.4 -82.1,-12.66 -82.1,-23.92 -82.1,-35.18 -82.1,-46.44 -82.1,-57.7 -82.1,-57.7 -80.31,-57.7 -78.52,-57.7 -76.73,-57.7 -74.94,-57.7 -73.15,-57.7 -71.36,-57.7 -69.57,-57.7 -67.78,-57.7 -65.99,-57.7 -64.2))"], "date_created": "Fri, 16 Jul 2021 00:00:00 GMT", "description": "This dataset includes:\r\n1) rBC concentration and flux for 6 Antarctic ice core sites (JRI_2008, JRI_D98, NUS08_7, NUS07_7, B53, and B40). \r\n2) FLEXPART backward-model emission sensitivities for 4 Antarctic ice core sites (JRI, B40, B53, NUS07_7). \r\n3) FLEXPART forward-model deposition for simulated biomass burning emissions from New Zealand.\r\n4) Tie points to constrain flow model used to develop JRI_2008 chronology.", "east": 54.9, "geometry": ["POINT(-1.4 -73.15)"], "keywords": "Antarctica; Antarctic Peninsula; Biomass Burning; Black Carbon; Dronning Maud Land; East Antarctic Plateau; Ice Core", "locations": "East Antarctic Plateau; Antarctica; Dronning Maud Land; Antarctic Peninsula", "north": -64.2, "nsf_funding_programs": null, "persons": "McConnell, Joseph; Chellman, Nathan", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -82.1, "title": "Common-era black carbon deposition and atmospheric modeling for 6 Antarctic ice cores", "uid": "601464", "west": -57.7}, {"awards": "0944358 Dugger, Katie; 1543459 Dugger, Katie; 1935901 Dugger, Katie; 0439759 Ballard, Grant; 0944141 Ballard, Grant; 0944411 Ainley, David; 0440643 Ainley, David; 1543541 Ainley, David; 1543498 Ballard, Grant; 1935870 Ballard, Grant; 0439200 Dugger, Katie", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Wed, 12 May 2021 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": "Adelie Penguin; Antarctica; Biota; Demography; Mark-Recapture; Monitoring; Penguin; Ross Island", "locations": "Ross Island; Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "A Full Lifecycle Approach to Understanding Ad\u00e9lie Penguin Response to Changing Pack Ice Conditions in the Ross Sea.; COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels; COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change; Population Growth at the Southern Extreme: Effects of Early Life Conditions on Adelie penguin Individuals and Colonies", "projects": [{"proj_uid": "p0000068", "repository": "USAP-DC", "title": "COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change"}, {"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}, {"proj_uid": "p0010179", "repository": "USAP-DC", "title": "Population Growth at the Southern Extreme: Effects of Early Life Conditions on Adelie penguin Individuals and Colonies"}, {"proj_uid": "p0010177", "repository": "USAP-DC", "title": "A Full Lifecycle Approach to Understanding Ad\u00e9lie Penguin Response to Changing Pack Ice Conditions in the Ross Sea."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin resighting data 1997-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "601444", "west": 166.0}, {"awards": "1543498 Ballard, Grant; 1543541 Ainley, David; 1543459 Dugger, Katie; 0944141 Ballard, Grant; 0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 11 May 2021 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": "Adelie Penguin; Antarctica; Biota; Demography; Penguin; Ross Sea; Seabirds", "locations": "Ross Sea; Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Instrumentation and Support; Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "A Full Lifecycle Approach to Understanding Ad\u00e9lie Penguin Response to Changing Pack Ice Conditions in the Ross Sea.; COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change", "projects": [{"proj_uid": "p0000068", "repository": "USAP-DC", "title": "COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change"}, {"proj_uid": "p0010177", "repository": "USAP-DC", "title": "A Full Lifecycle Approach to Understanding Ad\u00e9lie Penguin Response to Changing Pack Ice Conditions in the Ross Sea."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin banding data 1994-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "601443", "west": 166.0}, {"awards": "1341663 O\u0027Brien, Kristin", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "The Southern Ocean has experienced stable, cold temperatures for over 10 million years, yet particular regions are currently undergoing rapid warming. To investigate the impacts of warming on cardiovascular oxygen transport, we compared the cardio-respiratory performance in an Antarctic notothenioid (Notothenia coriiceps) that was maintained at 0 or 5\u00b0C for 6.0-9.5 weeks. When compared at the fish\u0027s respective acclimation temperature, the oxygen consumption rate and cardiac output were significantly higher in 5\u00b0C-acclimated than 0\u00b0C-acclimated fish. The 2.7-fold elevation in cardiac output in 5\u00b0C-acclimated fish (17.4 vs. 6.5 ml min-1 kg-1) was predominantly due to a doubling of stroke volume, likely in response to increased cardiac preload, as measured by higher central venous pressure (0.15 vs. 0.08 kPa); tachycardia was minor (29.5 vs. 25.2 beats min-1). When fish were acutely warmed, oxygen consumption rate increased by similar amounts in 0\u00b0C- and 5\u00b0C-acclimated fish at equivalent test temperatures. In both acclimation groups, the increases in oxygen consumption rate during acute heating were supported by increased cardiac output achieved by elevating heart rate, while stroke volume changed relatively little. Cardiac output was similar between both acclimation groups until 12\u00b0C when cardiac output became significantly higher in 5\u00b0C-acclimated fish, driven largely by their higher stroke volume. Although cardiac arrhythmias developed at a similar temperature (~14.5\u00b0C) in both acclimation groups, the hearts of 5\u00b0C-acclimated fish continued to pump until significantly higher temperatures (CTmax for cardiac function 17.7 vs. 15.0\u00b0C for 0\u00b0C-acclimated fish). These results demonstrate that N. coriiceps is capable of increasing routine cardiac output during both acute and chronic warming, although the mechanisms are different (heart rate-dependent versus primarily stroke volume-dependent regulation, respectively). Cardiac performance was enhanced at higher temperatures following 5\u00b0C acclimation, suggesting cardiovascular function may not constrain the capacity of N. coriiceps to withstand a warming climate.", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctica; Antarctic Peninsula", "north": null, "nsf_funding_programs": null, "persons": "Joyce, William; Egginton, Stuart; Farrell, Anthony; Axelsson, Michael; Crockett, Elizabeth; O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Acclimation of cardiovascular function in Notothenia coriiceps", "uid": "601408", "west": null}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.6,-111 -83.2,-111 -83.8,-111 -84.4,-111 -85,-111 -85.6,-111 -86.2,-111 -86.8,-111 -87.4,-111 -88,-116.7 -88,-122.4 -88,-128.1 -88,-133.8 -88,-139.5 -88,-145.2 -88,-150.9 -88,-156.6 -88,-162.3 -88,-168 -88,-168 -87.4,-168 -86.8,-168 -86.2,-168 -85.6,-168 -85,-168 -84.4,-168 -83.8,-168 -83.2,-168 -82.6,-168 -82))"], "date_created": "Sat, 12 Dec 2020 00:00:00 GMT", "description": "The dataset includes initialization and output files of a numerical ice flow simulation of the Whillans and Mercer Ice Streams . The Ice Sheet System Model (ISSM) model was used to solve a 100-year transient stress balance solution of the region with ~10 kPA/yr friction increase downstream of the shear margin between the Whillans and Mercer ice streams. \r\n", "east": -111.0, "geometry": ["POINT(-139.5 -85)"], "keywords": "Antarctica; Glaciology; Ice Sheet Flow Model; Ice Shelf Dynamics; Mercer Ice Stream; Model Data; Snow/ice; Snow/Ice; Whillans Ice Stream", "locations": "Whillans Ice Stream; Mercer Ice Stream; Antarctica", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kaluzienski, Lynn", "project_titles": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "projects": [{"proj_uid": "p0010145", "repository": "USAP-DC", "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -88.0, "title": "Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "uid": "601404", "west": -168.0}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))"], "date_created": "Sat, 12 Dec 2020 00:00:00 GMT", "description": "The dataset includes GPS coordinates for crevasse/fracture locations picked from 350MHz and 400Mhz frequency GPR dataset in the Whillans/Mercer Shear Margin along the SALSA traverse route with associated kinematic outputs for each feature (shear strain rate, vorticity, dilatation). GPS coordinates are in the Antarctic Polar Stereographic projection (EPSG:3031). ", "east": -111.0, "geometry": ["POINT(-139.5 -84.5)"], "keywords": "Antarctica; Crevasses; Glaciology; GPR; GPS; Ice Sheet Flow Model; Ice Shelf Dynamics; Snow/ice; Snow/Ice; Whillans Ice Stream", "locations": "Whillans Ice Stream; Antarctica", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kaluzienski, Lynn", "project_titles": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "projects": [{"proj_uid": "p0010145", "repository": "USAP-DC", "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "2017 GPR Observations of the Whillans and Mercer Ice Streams", "uid": "601403", "west": -168.0}, {"awards": "0724929 Simms, Alexander", "bounds_geometry": ["POLYGON((-61.8 -61.3,-61.07 -61.3,-60.34 -61.3,-59.61 -61.3,-58.88 -61.3,-58.15 -61.3,-57.42 -61.3,-56.69 -61.3,-55.96 -61.3,-55.23 -61.3,-54.5 -61.3,-54.5 -61.55,-54.5 -61.8,-54.5 -62.05,-54.5 -62.3,-54.5 -62.55,-54.5 -62.8,-54.5 -63.05,-54.5 -63.3,-54.5 -63.55,-54.5 -63.8,-55.23 -63.8,-55.96 -63.8,-56.69 -63.8,-57.42 -63.8,-58.15 -63.8,-58.88 -63.8,-59.61 -63.8,-60.34 -63.8,-61.07 -63.8,-61.8 -63.8,-61.8 -63.55,-61.8 -63.3,-61.8 -63.05,-61.8 -62.8,-61.8 -62.55,-61.8 -62.3,-61.8 -62.05,-61.8 -61.8,-61.8 -61.55,-61.8 -61.3))"], "date_created": "Fri, 06 Nov 2020 00:00:00 GMT", "description": "", "east": -54.5, "geometry": ["POINT(-58.15 -62.55)"], "keywords": "Antarctica; Grain Size; Granulometry; Joinville Island; Livingston Island; LMG0412; Raised Beaches", "locations": "Antarctica; Livingston Island; Joinville Island", "north": -61.3, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Theilen, Brittany; Simms, Alexander", "project_titles": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "projects": [{"proj_uid": "p0010132", "repository": "USAP-DC", "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -63.8, "title": "Granulometry of Joinville and Livingston Island beaches", "uid": "601400", "west": -61.8}, {"awards": "1246148 Severinghaus, Jeffrey; 1245659 Petrenko, Vasilii; 1245821 Brook, Edward J.", "bounds_geometry": null, "date_created": "Mon, 02 Nov 2020 00:00:00 GMT", "description": "Ice core measurements of the concentration and stable isotopic composition of atmospheric nitrous oxide (N2O) 74,000-59,000 years ago constrain marine and terrestrial emissions. The data include two major Dansgaard-Oeschger (D-O) events and the N2O decrease during global cooling at the Marine Isotope Stage (MIS) 5a-4 transition. The N2O increase associated with D-O 19 (~73-71.5 ka) was driven by equal contributions from marine and terrestrial emissions. The N2O decrease during the transition into MIS 4 (~71.5-67.5 ka) was caused by gradual reductions of similar magnitude in both marine and terrestrial sources. A 50 ppb increase in N2O concentration at the end of MIS 4 was caused by gradual increases in marine and terrestrial emissions between ~64-61 ka, followed by an abrupt increase in marine emissions at the onset of D-O 16/17 (59.5 ka). This suggests that the importance of marine versus terrestrial emissions in controlling millennial-scale N2O fluctuations varied in time.", "east": null, "geometry": null, "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Gas Records; Ice Core Records; Marine Isotope Stage 4; MIS 4; Nitrous Oxide; Pleistocene; Taylor Dome Ice Core; Taylor Glacier", "locations": "Taylor Glacier; Taylor Glacier; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "persons": "Menking, James; Brook, Edward J.; Schilt, Adrian; Shackleton, Sarah; Dyonisius, Michael; Severinghaus, Jeffrey P.; Petrenko, Vasilii", "project_titles": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "projects": [{"proj_uid": "p0000283", "repository": "USAP-DC", "title": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": "N2O Concentration and Isotope Data for 74-59 ka from Taylor Glacier, Antarctica", "uid": "601398", "west": null}, {"awards": "1644187 Tulaczyk, Slawek", "bounds_geometry": ["POLYGON((161 -76.9,161.75 -76.9,162.5 -76.9,163.25 -76.9,164 -76.9,164.75 -76.9,165.5 -76.9,166.25 -76.9,167 -76.9,167.75 -76.9,168.5 -76.9,168.5 -77.04,168.5 -77.18,168.5 -77.32,168.5 -77.46,168.5 -77.6,168.5 -77.74,168.5 -77.88,168.5 -78.02,168.5 -78.16,168.5 -78.3,167.75 -78.3,167 -78.3,166.25 -78.3,165.5 -78.3,164.75 -78.3,164 -78.3,163.25 -78.3,162.5 -78.3,161.75 -78.3,161 -78.3,161 -78.16,161 -78.02,161 -77.88,161 -77.74,161 -77.6,161 -77.46,161 -77.32,161 -77.18,161 -77.04,161 -76.9))"], "date_created": "Sat, 12 Sep 2020 00:00:00 GMT", "description": " The ANTAEM survey was carried out in the period November 12th to 28th, 2018, with the SkyTEM 312 system. Twenty-one missions (flights) were conducted over 11 production days of helicopter service, resulting in a total of approximately ~3400 line km of data. The SkyTEM system records data from take-off until landing resulting in multiple lines converging to the landing pads in McMurdo and at Marble Point. The production without overlapping lines adds up to approximately 2900 line km. The flight speed was approximately 120 km/h at a target flight altitude of ~50 m (sensor height), but the actual sensor height varies depending on the terrain. The surveys were carried out with a Bell 212 helicopter, which carried the SkyTEM sensor as a sling load. The SkyTEM system was configured in a standard two-moment setup (low moment, LM and high moment, HM). Areas with extremely resistive dry and/or frozen sediment/bedrock, and glacier ice often produce EM-signals with amplitudes below the detection level of the system. Data from these low signal environments cannot be inverted into resistivity models. Data with strong induced polarization effects cannot be inverted for resistivity either. These data were discharged in this standard data delivery. \r\n The EM-data and inversion result (resistivity models) are delivered in the SkyTEM2018_dat.xyz and SkyTEM2018_inv.xyz files respectably. The RECORD number in the two files links data and model together. EM-data and data uncertainty for data entering inversion. Info stated in file Header: NAN value, Data unit, Coordinate system, Gate times. The SkyTEM system uses at High-Low moment data recording cycle, therefore only a subset of the total 40 time gates are preset for each moment. The standard lateral constraints inversion (LCI), delivered in the SkyTEM2018_inv.xyz file, was carried out with a smooth 30 layered resistivity model discretized to a depth of 500 m. A depth of investigation (DOI) was estimated for each resistivity model.\r\n", "east": 168.5, "geometry": ["POINT(164.75 -77.6)"], "keywords": "Antarctica; Dry Valleys; Hydrology; Ice Shelf; McMurdo; Permafrost", "locations": "Antarctica; McMurdo; Dry Valleys", "north": -76.9, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Tulaczyk, Slawek", "project_titles": "Collaborative Research: Antarctic Airborne ElectroMagnetics (ANTAEM) - Revealing Subsurface Water in Coastal Antarctica", "projects": [{"proj_uid": "p0010129", "repository": "USAP-DC", "title": "Collaborative Research: Antarctic Airborne ElectroMagnetics (ANTAEM) - Revealing Subsurface Water in Coastal Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "ANTAEM project airborne EM resistivity data from McMurdo Region", "uid": "601373", "west": 161.0}, {"awards": "0944021 Brook, Edward J.", "bounds_geometry": ["POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))"], "date_created": "Mon, 13 Jul 2020 00:00:00 GMT", "description": "Data archived here were used to create the Roosevelt Island Ice Core gas age and ice age time scales. Data include methane concentrations, nitrogen and oxygen isotope ratios of N2 and O2, total air content and the D/H ratio of the ice. Derived products included here include ice age and gas age time scales. ", "east": -161.0, "geometry": ["POINT(-162 -79.25)"], "keywords": "Antarctica; CO2; Ice Core; Roosevelt Island", "locations": "Roosevelt Island; Roosevelt Island; Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Brook, Edward J.; Lee, James", "project_titles": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "projects": [{"proj_uid": "p0000272", "repository": "USAP-DC", "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.5, "title": "Roosevelt Island Ice Core Time Scale and Associated Data", "uid": "601359", "west": -163.0}, {"awards": "1443482 Mak, John", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Thu, 09 Jul 2020 00:00:00 GMT", "description": "Data from measurement of CO mixing ratios and stable isotopes from the South Pole Ice Core for the first ca 10,000 years BP", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; CO; Delta 13C; Delta 18O; South Pole; SPICEcore", "locations": "Antarctica; South Pole", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Mak, John", "project_titles": "Collaborative Research: Using Stable Isotopes to Constrain the Atmospheric Carbon Monoxide Budget over the Last 20,000 Years", "projects": [{"proj_uid": "p0010117", "repository": "USAP-DC", "title": "Collaborative Research: Using Stable Isotopes to Constrain the Atmospheric Carbon Monoxide Budget over the Last 20,000 Years"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Carbon monoxide mixing ratios and stable isotopic values, SPICE", "uid": "601356", "west": -180.0}, {"awards": "1341658 Mukhopadhyay, Sujoy", "bounds_geometry": ["POLYGON((-116.46 -84.78,-116.452 -84.78,-116.444 -84.78,-116.436 -84.78,-116.428 -84.78,-116.42 -84.78,-116.412 -84.78,-116.404 -84.78,-116.396 -84.78,-116.388 -84.78,-116.38 -84.78,-116.38 -84.781,-116.38 -84.782,-116.38 -84.783,-116.38 -84.784,-116.38 -84.785,-116.38 -84.786,-116.38 -84.787,-116.38 -84.788,-116.38 -84.789,-116.38 -84.79,-116.388 -84.79,-116.396 -84.79,-116.404 -84.79,-116.412 -84.79,-116.42 -84.79,-116.428 -84.79,-116.436 -84.79,-116.444 -84.79,-116.452 -84.79,-116.46 -84.79,-116.46 -84.789,-116.46 -84.788,-116.46 -84.787,-116.46 -84.786,-116.46 -84.785,-116.46 -84.784,-116.46 -84.783,-116.46 -84.782,-116.46 -84.781,-116.46 -84.78))"], "date_created": "Sun, 28 Jun 2020 00:00:00 GMT", "description": "The data set consists of cosmogenic berrylium-10 and aluminum-26, along with neon-21, in a set of 4 rock-cores obtained from the Ohio Range, West Antarctica. The rock cores were obtained using the WInkie drill. The depth to the cores varies from 12 meters to 28 meters. The recovered rock cores analyzed for the cosmogenic isotopes varies from 22 cm long to 50 cm long. The data include the following formation: sample details, cosmogenic berrylium-10, aluminum-26 and upper bounds for cosmogenic 21 (since samples have nucleogenic 21) and the step heating data for neon. The data are in Mircrosoft excel format.", "east": -116.38, "geometry": ["POINT(-116.42 -84.785)"], "keywords": "Aluminum-26; Antarctica; Beryllium-10; Cosmogenic Dating; Cosmogenic Radionuclides; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Fluctuations; Ohio Range; Rocks", "locations": "Antarctica; Ohio Range", "north": -84.78, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Mukhopadhyay, Sujoy", "project_titles": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier", "projects": [{"proj_uid": "p0010113", "repository": "USAP-DC", "title": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.79, "title": "Ohio Range Subglacial rock core cosmogenic nuclide data", "uid": "601351", "west": -116.46}, {"awards": "1142167 Pettit, Erin", "bounds_geometry": ["POLYGON((-112.3 -79.2,-112.22 -79.2,-112.14 -79.2,-112.06 -79.2,-111.98 -79.2,-111.9 -79.2,-111.82 -79.2,-111.74 -79.2,-111.66 -79.2,-111.58 -79.2,-111.5 -79.2,-111.5 -79.23,-111.5 -79.26,-111.5 -79.29,-111.5 -79.32,-111.5 -79.35,-111.5 -79.38,-111.5 -79.41,-111.5 -79.44,-111.5 -79.47,-111.5 -79.5,-111.58 -79.5,-111.66 -79.5,-111.74 -79.5,-111.82 -79.5,-111.9 -79.5,-111.98 -79.5,-112.06 -79.5,-112.14 -79.5,-112.22 -79.5,-112.3 -79.5,-112.3 -79.47,-112.3 -79.44,-112.3 -79.41,-112.3 -79.38,-112.3 -79.35,-112.3 -79.32,-112.3 -79.29,-112.3 -79.26,-112.3 -79.23,-112.3 -79.2))"], "date_created": "Fri, 15 May 2020 00:00:00 GMT", "description": "We tested the ability of phase sensitive radar (ApRES) to detect vertical strain throughout the depth of an ice sheet 3400m thick. ", "east": -111.5, "geometry": ["POINT(-111.9 -79.35)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice Strain; Phase Sensitive Radar; Radar; Snow/ice; Snow/Ice; WAIS Divide", "locations": "Antarctica; WAIS Divide", "north": -79.2, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Pettit, Erin", "project_titles": "Collaborative Research: VeLveT Ice - eVoLution of Fabric and Texture in Ice at WAIS Divide, West Antarctica", "projects": [{"proj_uid": "p0010098", "repository": "USAP-DC", "title": "Collaborative Research: VeLveT Ice - eVoLution of Fabric and Texture in Ice at WAIS Divide, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "ApRES Vertical Strain Study", "uid": "601323", "west": -112.3}, {"awards": "1143981 Domack, Eugene", "bounds_geometry": ["POLYGON((-66.5 -61.5,-65.85 -61.5,-65.2 -61.5,-64.55 -61.5,-63.9 -61.5,-63.25 -61.5,-62.6 -61.5,-61.95 -61.5,-61.3 -61.5,-60.65 -61.5,-60 -61.5,-60 -61.87,-60 -62.24,-60 -62.61,-60 -62.98,-60 -63.35,-60 -63.72,-60 -64.09,-60 -64.46,-60 -64.83,-60 -65.2,-60.65 -65.2,-61.3 -65.2,-61.95 -65.2,-62.6 -65.2,-63.25 -65.2,-63.9 -65.2,-64.55 -65.2,-65.2 -65.2,-65.85 -65.2,-66.5 -65.2,-66.5 -64.83,-66.5 -64.46,-66.5 -64.09,-66.5 -63.72,-66.5 -63.35,-66.5 -62.98,-66.5 -62.61,-66.5 -62.24,-66.5 -61.87,-66.5 -61.5))"], "date_created": "Fri, 01 May 2020 00:00:00 GMT", "description": "This data set was acquired with a camera during Laurence M. Gould expedition LMG1311 conducted in 2013. These data files are of JPEG format and include Photograph images that have not been processed", "east": -60.0, "geometry": ["POINT(-63.25 -63.35)"], "keywords": "Antarctica; Antarctic Peninsula; Benthic Images; Camera; LARISSA; LMG1311; Marine Geoscience; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould", "locations": "Antarctica; Antarctic Peninsula", "north": -61.5, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Domack, Eugene Walter", "project_titles": "Continuation of the LARISSA Continuous GPS Network in View of Observed Dynamic Response to Antarctic Peninsula Ice Mass Balance and Required Geologic Constraints", "projects": [{"proj_uid": "p0000233", "repository": "USAP-DC", "title": "Continuation of the LARISSA Continuous GPS Network in View of Observed Dynamic Response to Antarctic Peninsula Ice Mass Balance and Required Geologic Constraints"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LARISSA", "south": -65.2, "title": "Processed Camera Images acquired during the Laurence M. Gould expedition LMG1311", "uid": "601311", "west": -66.5}, {"awards": "1543256 Shuster, David", "bounds_geometry": ["POLYGON((-66.80688 -67.420674,-66.732895 -67.420674,-66.65891 -67.420674,-66.584925 -67.420674,-66.51094 -67.420674,-66.436955 -67.420674,-66.36297 -67.420674,-66.288985 -67.420674,-66.215 -67.420674,-66.141015 -67.420674,-66.06703 -67.420674,-66.06703 -67.4542151,-66.06703 -67.4877562,-66.06703 -67.5212973,-66.06703 -67.5548384,-66.06703 -67.5883795,-66.06703 -67.6219206,-66.06703 -67.6554617,-66.06703 -67.6890028,-66.06703 -67.7225439,-66.06703 -67.756085,-66.141015 -67.756085,-66.215 -67.756085,-66.288985 -67.756085,-66.36297 -67.756085,-66.436955 -67.756085,-66.51094 -67.756085,-66.584925 -67.756085,-66.65891 -67.756085,-66.732895 -67.756085,-66.80688 -67.756085,-66.80688 -67.7225439,-66.80688 -67.6890028,-66.80688 -67.6554617,-66.80688 -67.6219206,-66.80688 -67.5883795,-66.80688 -67.5548384,-66.80688 -67.5212973,-66.80688 -67.4877562,-66.80688 -67.4542151,-66.80688 -67.420674))"], "date_created": "Thu, 27 Feb 2020 00:00:00 GMT", "description": "This dataset contains 80 detrital and 2 bedrock apatite (U-Th)/He thermochronometric ages from Bourgeois Fjord. Data was collected to constrain timing and patterns of topographic change at Bourgeois Fjord on Ma timescales. Analyses were conducted at the Berkeley Geochronology Center and presented in Microsoft Excel formats.", "east": -66.06703, "geometry": ["POINT(-66.436955 -67.5883795)"], "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctic Peninsula; Antarctica", "north": -67.420674, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Clinger, Anna", "project_titles": "Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry", "projects": [{"proj_uid": "p0000876", "repository": "USAP-DC", "title": "Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.756085, "title": "Detrital low-temperature thermochronometry from Bourgeois Fjord, AP", "uid": "601259", "west": -66.80688}, {"awards": "1443534 Bell, Robin", "bounds_geometry": ["POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,178.1 -86,176.2 -86,174.3 -86,172.4 -86,170.5 -86,168.6 -86,166.7 -86,164.8 -86,162.9 -86,161 -86,161 -85.1,161 -84.2,161 -83.3,161 -82.4,161 -81.5,161 -80.6,161 -79.7,161 -78.8,161 -77.9,161 -77,162.9 -77,164.8 -77,166.7 -77,168.6 -77,170.5 -77,172.4 -77,174.3 -77,176.2 -77,178.1 -77,-180 -77))"], "date_created": "Fri, 10 Jan 2020 00:00:00 GMT", "description": "This dataset was produced for the manuscript \\\"Multi-decadal basal melt rates and structure of the Ross Ice Shelf, Antarctica using airborne ice penetrating radar\\\" by Das et al., 2020 in Journal of Geophysical Research-Earth Surface. It has total ice thickness, thickness of the LMI layer, strain induced thickness change, basal melt rates and the error estimate for basal melt rates.", "east": 161.0, "geometry": ["POINT(-174.5 -81.5)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice-Shelf Basal Melting; Radar Echo Sounder; Radar Echo Sounding; Snow/ice; Snow/Ice", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Das, Indrani; Padman, Laurence; Bell, Robin; Fricker, Helen; Hulbe, Christina; Siddoway, Christine; Dhakal, Tejendra; Frearson, Nicholas; Mosbeux, Cyrille; Cordero, Isabel; Siegfried, Matt; Tinto, Kirsty", "project_titles": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)", "projects": [{"proj_uid": "p0010035", "repository": "USAP-DC", "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data", "uid": "601242", "west": -150.0}, {"awards": "1443464 Sowers, Todd", "bounds_geometry": ["POINT(0 -90)"], "date_created": "Wed, 11 Dec 2019 00:00:00 GMT", "description": "The overiding goal for our collaborative project is to provide the necessary data to construct an accurate gas age scale all along the SPICE core. Downcore measurements of CH4 and other species would help to constrain the ice age - gas age difference all along the core that is a prerequisite for the construction of the gas age vs depth profile that is the backbone for all atmospheric reconstructions. ", "east": 0.0, "geometry": ["POINT(0 -90)"], "keywords": "Antarctica; Atmospheric CH4; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Data; Methane; Methane Concentration; Snow/ice; Snow/Ice; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Sowers, Todd A.", "project_titles": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core", "projects": [{"proj_uid": "p0010005", "repository": "USAP-DC", "title": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "South Pole CH4 data for termination", "uid": "601230", "west": 0.0}, {"awards": "1443336 Osterberg, Erich", "bounds_geometry": ["POINT(-180 -90)"], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "The South Pole Ice Core (SPICEcore) was drilled in 2014-2016 to provide a detailed multi-proxy archive of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. Interpretation of these records requires an accurate depth-age relationship. Here, we present the SP19 timescale for the age of the ice of SPICEcore. SP19 is synchronized to the WD2014 chronology from the West Antarctic Ice Sheet Divide (WAIS Divide) ice core using stratigraphic matching of 251 volcanic events. These events indicate an age of 54,302 +/- 519 years BP (before the year 1950) at the bottom of SPICEcore. Annual layers identified in sodium and magnesium ions to 11,341 BP were used to interpolate between stratigraphic volcanic tie points, yielding an annually-resolved chronology through the Holocene. Estimated timescale uncertainty during the Holocene is less than 18 years relative to WD2014, with the exception of the interval between 1800 to 3100 BP when uncertainty estimates reach +/- 25 years due to widely spaced volcanic tie points. Prior to the Holocene, uncertainties remain within 124 years relative to WD2014. Results show an average Holocene accumulation rate of 7.4 cm/yr (water equivalent). The time variability of accumulation rate is consistent with expectations for steady-state ice flow through the modern spatial pattern of accumulation rate. Time variations in nitrate concentration, nitrate seasonal amplitude, and \u03b415N of N2 in turn are as expected for the accumulation-rate variations. The highly variable yet well-constrained Holocene accumulation history at the site can help improve scientific understanding of deposition-sensitive climate proxies such as \u03b415N of N2 and photolyzed chemical compounds.", "east": -180.0, "geometry": ["POINT(-180 -90)"], "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Winski, Dominic A.; Fudge, T. J.; Dunbar, Nelia; Buizert, Christo; Bay, Ryan; Souney, Joseph Jr.; Sigl, Michael; McConnell, Joseph; Fegyveresi, John; Cole-Dai, Jihong; Thundercloud, Zayta; Cox, Thomas S.; Kreutz, Karl; Epifanio, Jenna; Ortman, Nikolas; Brook, Edward J.; Beaudette, Ross; Sowers, Todd A.; Steig, Eric J.; Morris, Valerie; Kahle, Emma; Ferris, David G.; Aydin, Murat; Nicewonger, Melinda R.; Casey, Kimberly A.; Alley, Richard; Waddington, Edwin D.; Osterberg, Erich; Severinghaus, Jeffrey P.; Jones, Tyler R.; Iverson, Nels", "project_titles": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "uid": "601206", "west": -180.0}, {"awards": "1148982 Hansen, Samantha", "bounds_geometry": ["POLYGON((150 -72,152 -72,154 -72,156 -72,158 -72,160 -72,162 -72,164 -72,166 -72,168 -72,170 -72,170 -72.3,170 -72.6,170 -72.9,170 -73.2,170 -73.5,170 -73.8,170 -74.1,170 -74.4,170 -74.7,170 -75,168 -75,166 -75,164 -75,162 -75,160 -75,158 -75,156 -75,154 -75,152 -75,150 -75,150 -74.7,150 -74.4,150 -74.1,150 -73.8,150 -73.5,150 -73.2,150 -72.9,150 -72.6,150 -72.3,150 -72))"], "date_created": "Wed, 31 Jul 2019 00:00:00 GMT", "description": "The Transantarctic Mountains (TAMs) are the largest non-collisional mountain range on Earth. Their origin, as well as the origin of the Wilkes Subglacial Basin (WSB) along the inland side of the TAMs, have been widely debated, and a key constraint to distinguish between competing models is the underlying crustal structure. Previous investigations have examined this structure but have primarily focused on a small region of the central TAMs near Ross Island, providing little along-strike constraint. In this study, we use data from the new Transantarctic Mountains Northern Network and from five stations operated by the Korea Polar Research Institute to investigate the crustal structure beneath a previously unexplored portion of the TAMs. Using S-wave receiver functions and Rayleigh wave phase velocities, crustal thickness and average crustal shear velocity (\uf8e5Vs) are resolved within \u00b14 km and \u00b10.1 km/s, respectively. The crust thickens from ~20 km near the Ross Sea coast to ~46 km beneath the northern TAMs, which is somewhat thicker than that imaged in previous studies beneath the central TAMs. The crust thins to ~41 km beneath the WSB.\uf8e5Vs ranges from ~3.1-3.9 km/s, with slower velocities near the coast. Our findings are consistent with a flexural origin for the TAMs and WSB, where these features result from broad flexure of the East Antarctic lithosphere and uplift along its western edge due to thermal conduction from hotter mantle beneath West Antarctica. Locally thicker crust may explain the ~1 km of additional topography in the northern TAMs compared to the central TAMs.", "east": 170.0, "geometry": ["POINT(160 -73.5)"], "keywords": "Antarctica; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -72.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Hansen, Samantha", "project_titles": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin", "projects": [{"proj_uid": "p0000300", "repository": "USAP-DC", "title": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins", "uid": "601194", "west": 150.0}, {"awards": "1246407 Jenouvrier, Stephanie", "bounds_geometry": ["POLYGON((68.5 -48.5,68.725 -48.5,68.95 -48.5,69.175 -48.5,69.4 -48.5,69.625 -48.5,69.85 -48.5,70.075 -48.5,70.3 -48.5,70.525 -48.5,70.75 -48.5,70.75 -48.65,70.75 -48.8,70.75 -48.95,70.75 -49.1,70.75 -49.25,70.75 -49.4,70.75 -49.55,70.75 -49.7,70.75 -49.85,70.75 -50,70.525 -50,70.3 -50,70.075 -50,69.85 -50,69.625 -50,69.4 -50,69.175 -50,68.95 -50,68.725 -50,68.5 -50,68.5 -49.85,68.5 -49.7,68.5 -49.55,68.5 -49.4,68.5 -49.25,68.5 -49.1,68.5 -48.95,68.5 -48.8,68.5 -48.65,68.5 -48.5))"], "date_created": "Mon, 03 Dec 2018 00:00:00 GMT", "description": "1. Studies of the mechanisms underlying climate-induced population changes are critically needed to better understand and accurately predict population responses to climate change. Long-lived migratory species might be particularly vulnerable to climate change as they are constrained by different climate conditions and energetic requirements during the breeding and non-breeding seasons. Yet, most studies primarily focus on the breeding season of these species life cycle. Environmental conditions experienced in the non-breeding season may have downstream effects on the other stages of the annual life cycle. Not investigating such effects may potentially lead to erroneous inferences about population dynamics.\r\n2. Combining demographic and tracking data collected between 2006 and 2013 at Kerguelen Island on a long-lived migratory seabird, the Black-Browed Albatross (Thalassarche melanophris), we investigated the links between sea surface temperature during the non-breeding season and behavioural and phenological traits (at-sea behaviour and migratory schedules) while accounting for different responses between birds of different sex and reproductive status (previously failed or successful breeders). We then explored whether variation in the foraging behaviour and timing of spring migration influenced subsequent reproductive performance.\r\n3. Our results showed that foraging activity and migratory schedules varied by both sex and reproductive status suggesting different energetic requirements and constraints among individuals. Higher sea surface temperatures during late winter, assumed to reflect poor winter conditions, were associated with an earlier departure from the wintering grounds and an extended pre-breeding period. However, an earlier spring migration and an earlier return to Kerguelen grounds were associated with a lower breeding success.\r\n4. Our results highlighted that behaviour during some periods of the non-breeding season, particularly towards the end of the wintering period and the pre-breeding period, had a significant effect on the subsequent reproductive success. Therefore caution needs to be given to all stages of the annual cycle when predicting the influence of climate on population dynamics.", "east": 70.75, "geometry": ["POINT(69.625 -49.25)"], "keywords": "Albatross; Animal Behavior Observation; Antarctica; Biota; Birds; Black-Browed Albatross (thalassarche Melanophris); Field Investigations; Foraging; Kerguelen Island; Ocean Island/plateau; Ocean Island/Plateau; Southern Ocean", "locations": "Southern Ocean; Antarctica; Kerguelen Island", "north": -48.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Jenouvrier, Stephanie", "project_titles": "Linking Foraging Behaviors to Demography to understand Albatrosses Population Responses to Climate Change", "projects": [{"proj_uid": "p0010002", "repository": "USAP-DC", "title": "Linking Foraging Behaviors to Demography to understand Albatrosses Population Responses to Climate Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -50.0, "title": "Linking oceanographic conditions, migratory schedules and foraging behaviour during the non-breeding season to reproductive performance in a long-lived seabird", "uid": "601140", "west": 68.5}, {"awards": "0838947 Tulaczyk, Slawek", "bounds_geometry": ["POLYGON((-165.28 -84.24,-165.086 -84.24,-164.892 -84.24,-164.698 -84.24,-164.504 -84.24,-164.31 -84.24,-164.116 -84.24,-163.922 -84.24,-163.728 -84.24,-163.534 -84.24,-163.34 -84.24,-163.34 -84.252,-163.34 -84.264,-163.34 -84.276,-163.34 -84.288,-163.34 -84.3,-163.34 -84.312,-163.34 -84.324,-163.34 -84.336,-163.34 -84.348,-163.34 -84.36,-163.534 -84.36,-163.728 -84.36,-163.922 -84.36,-164.116 -84.36,-164.31 -84.36,-164.504 -84.36,-164.698 -84.36,-164.892 -84.36,-165.086 -84.36,-165.28 -84.36,-165.28 -84.348,-165.28 -84.336,-165.28 -84.324,-165.28 -84.312,-165.28 -84.3,-165.28 -84.288,-165.28 -84.276,-165.28 -84.264,-165.28 -84.252,-165.28 -84.24))"], "date_created": "Sun, 09 Sep 2018 00:00:00 GMT", "description": "This dataset contains ice-shelf basal melt rates and vertical strain rates for 11 sites near the Whillans Ice Stream grounding line. These rates were determined using Autonomous Phase-Sensitive Radar. Data processing is described in Begeman et al. 2018, JGR Oceans. These sites are concentrated within an embayment of the Ross Ice Shelf. These melt rates and strain rates were determined over periods ranging from 10 to 38 days in December 2014 to January 2015. ", "east": -163.34, "geometry": ["POINT(-164.31 -84.3)"], "keywords": "Antarctica; Flexure Zone; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Ice-Shelf Basal Melting; Ice-Shelf Strain Rate", "locations": "Antarctica", "north": -84.24, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Begeman, Carolyn", "project_titles": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "projects": [{"proj_uid": "p0000105", "repository": "USAP-DC", "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WISSARD", "south": -84.36, "title": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line", "uid": "601122", "west": -165.28}, {"awards": "0539578 Alley, Richard", "bounds_geometry": ["POINT(-112.085 -79.467)"], "date_created": "Thu, 01 Mar 2018 00:00:00 GMT", "description": "This dataset contains detailed grain and bubble properties data for a new hybrid analysis study relating bubble elongation to crystal orientations. All data are from a depth of 580 meters in a sample from the WAIS Divide ice core.", "east": -112.085, "geometry": ["POINT(-112.085 -79.467)"], "keywords": "Air Bubbles; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Strain; Physical Ice Properties; Snow/ice; Snow/Ice; Strain", "locations": "Antarctica", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fegyveresi, John; Alley, Richard", "project_titles": "Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core", "projects": [{"proj_uid": "p0000027", "repository": "USAP-DC", "title": "Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "WAIS Divide 580m Bubble and Grain Hybrid Data", "uid": "601087", "west": -112.085}, {"awards": "0943466 Hawley, Robert", "bounds_geometry": ["POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))"], "date_created": "Tue, 13 Feb 2018 00:00:00 GMT", "description": "A Borehole Optical Televiewer (OPTV) uses a conical mirror and scanning electronics to record a continuous 360-degree image of the borehole wall. An inclinometer and magnetometer allow the image to be \u0027unwrapped\u0027 and resented as a rectangular image, which shows the visible features of the wall oriented to magnetic north. This dataset includes both the raw bitmap (bmp) image data from the televiewer, as well as proprietary WellCad format (wcl) files. The WellCad format files contain the inclinometry, orientation, and temperature data in addition to the imagery data. Wellcad files can be viewed with a free wellcad file reader available from https://www.alt.lu/downloads.htm. This dataset includes OPTV logs from each of two seasons, November 2013 and 2014. The logs are of the 760 m deep hole drilled by the RICE project, a NZ-USA partnership.", "east": -161.0, "geometry": ["POINT(-162 -79.25)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Roosevelt Island; Snow/ice; Snow/Ice", "locations": "Roosevelt Island; Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "persons": "Hawley, Robert L.; Clemens-Sewall, David", "project_titles": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "projects": [{"proj_uid": "p0000272", "repository": "USAP-DC", "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.5, "title": "Roosevelt Island Borehole Optical Televiewer logs", "uid": "601086", "west": -163.0}, {"awards": "0943466 Hawley, Robert", "bounds_geometry": ["POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))"], "date_created": "Tue, 13 Feb 2018 00:00:00 GMT", "description": "These data are firn temperatures, measured by a meteorological station placed at Roosevelt Island. Thermistors were placed at multiple depths through the upper 20 meters of firn and measured through the course of roughly one year.", "east": -161.0, "geometry": ["POINT(-162 -79.25)"], "keywords": "Antarctica; Borehole; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Records; Ice Fabric; Optical Images; Roosevelt Island; Snow/ice; Snow/Ice; Temperature", "locations": "Roosevelt Island; Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "persons": "Hawley, Robert L.; Clemens-Sewall, David; Giese, Alexandra", "project_titles": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "projects": [{"proj_uid": "p0000272", "repository": "USAP-DC", "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.5, "title": "Roosevelt Island Borehole Firn temperatures", "uid": "601085", "west": -163.0}, {"awards": "0944307 Conway, Howard", "bounds_geometry": ["POLYGON((-162.83 -79.15,-162.637 -79.15,-162.444 -79.15,-162.251 -79.15,-162.058 -79.15,-161.865 -79.15,-161.672 -79.15,-161.479 -79.15,-161.286 -79.15,-161.093 -79.15,-160.9 -79.15,-160.9 -79.1885037,-160.9 -79.2270074,-160.9 -79.2655111,-160.9 -79.3040148,-160.9 -79.3425185,-160.9 -79.3810222,-160.9 -79.4195259,-160.9 -79.4580296,-160.9 -79.4965333,-160.9 -79.535037,-161.093 -79.535037,-161.286 -79.535037,-161.479 -79.535037,-161.672 -79.535037,-161.865 -79.535037,-162.058 -79.535037,-162.251 -79.535037,-162.444 -79.535037,-162.637 -79.535037,-162.83 -79.535037,-162.83 -79.4965333,-162.83 -79.4580296,-162.83 -79.4195259,-162.83 -79.3810222,-162.83 -79.3425185,-162.83 -79.3040148,-162.83 -79.2655111,-162.83 -79.2270074,-162.83 -79.1885037,-162.83 -79.15))"], "date_created": "Thu, 16 Nov 2017 00:00:00 GMT", "description": "Ground-based radar data include radar echograms and .mat files of internal stratigraphy. Also included are picks of ice thickness and surface elevation. \u003cbr\u003e GPS data include positions of 142 poles set in 2010 and resurveyed in 2012. Also given are velocity vectors for the poles. ", "east": -160.9, "geometry": ["POINT(-161.865 -79.3425185)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS Data; Ice Velocity; Navigation; Radar; Roosevelt Island; Ross Sea", "locations": "Roosevelt Island; Ross Sea; Antarctica", "north": -79.15, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "persons": "Conway, Howard", "project_titles": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "projects": [{"proj_uid": "p0000272", "repository": "USAP-DC", "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.535037, "title": "Roosevelt Island: Radar and GPS", "uid": "601070", "west": -162.83}, {"awards": "1246170 Hall, Brenda", "bounds_geometry": ["POLYGON((155.4 -79.8,155.54 -79.8,155.68 -79.8,155.82 -79.8,155.96 -79.8,156.1 -79.8,156.24 -79.8,156.38 -79.8,156.52 -79.8,156.66 -79.8,156.8 -79.8,156.8 -79.82,156.8 -79.84,156.8 -79.86,156.8 -79.88,156.8 -79.9,156.8 -79.92,156.8 -79.94,156.8 -79.96,156.8 -79.98,156.8 -80,156.66 -80,156.52 -80,156.38 -80,156.24 -80,156.1 -80,155.96 -80,155.82 -80,155.68 -80,155.54 -80,155.4 -80,155.4 -79.98,155.4 -79.96,155.4 -79.94,155.4 -79.92,155.4 -79.9,155.4 -79.88,155.4 -79.86,155.4 -79.84,155.4 -79.82,155.4 -79.8))"], "date_created": "Mon, 23 Oct 2017 00:00:00 GMT", "description": "Hatherton Glacier Radiocarbon Data", "east": 156.8, "geometry": ["POINT(156.1 -79.9)"], "keywords": "Antarctica; Geochronology; Hatherton Glacier; Radiocarbon; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "locations": "Hatherton Glacier; Transantarctic Mountains; Antarctica", "north": -79.8, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hall, Brenda", "project_titles": "Collaborative Research: Assessing the Antarctic Contribution to Sea-level Changes during the Last Deglaciation: Constraints from Darwin Glacier", "projects": [{"proj_uid": "p0000304", "repository": "USAP-DC", "title": "Collaborative Research: Assessing the Antarctic Contribution to Sea-level Changes during the Last Deglaciation: Constraints from Darwin Glacier"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Hatherton Glacier Radiocarbon Data", "uid": "601063", "west": 155.4}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": ["POLYGON((-113 -79,-112.8 -79,-112.6 -79,-112.4 -79,-112.2 -79,-112 -79,-111.8 -79,-111.6 -79,-111.4 -79,-111.2 -79,-111 -79,-111 -79.1,-111 -79.2,-111 -79.3,-111 -79.4,-111 -79.5,-111 -79.6,-111 -79.7,-111 -79.8,-111 -79.9,-111 -80,-111.2 -80,-111.4 -80,-111.6 -80,-111.8 -80,-112 -80,-112.2 -80,-112.4 -80,-112.6 -80,-112.8 -80,-113 -80,-113 -79.9,-113 -79.8,-113 -79.7,-113 -79.6,-113 -79.5,-113 -79.4,-113 -79.3,-113 -79.2,-113 -79.1,-113 -79))"], "date_created": "Fri, 18 Aug 2017 00:00:00 GMT", "description": "This data set contains measurements of d18Oatm (d18O of O2), d15N, dAr/N2, and dO2/N2 in gas bubbles from the WAIS Divide ice core. The time resolution is variable throughout the record but is ~100 years on average (from 65 ka to present). All measurements were made in the Noble Gas Isotope Laboratory at Scripps Institution of Oceanography (La Jolla, CA). The data set includes all replicate measurements as well as replicate-mean values and a calculation of measurement precision (pooled standard deviation). The second sheet of this data set includes fitted d18Oatm curves for the past 50 ka from both the WAIS Divide and Siple Dome Antarctic ice cores, both on the WD2014 timescale (Buizert et al., 2015). The second sheet also includes calculations of the time derivative of d18Oatm and d e LAND in both ice cores individual as well as in a composite record. Details of the entire data set and all relevant methods are provided in Seltzer et al., 2017.", "east": -111.0, "geometry": ["POINT(-112 -79.5)"], "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Gas; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; WAIS Divide Ice Core", "locations": "Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Seltzer, Alan; Severinghaus, Jeffrey P.", "project_titles": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "projects": [{"proj_uid": "p0000036", "repository": "USAP-DC", "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND", "uid": "601041", "west": -113.0}, {"awards": "1148982 Hansen, Samantha", "bounds_geometry": ["POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))"], "date_created": "Thu, 20 Apr 2017 00:00:00 GMT", "description": "Using data from the Transantarctic Mountains (TAMs) Northern Network, shear-wave splitting analysis has been employed to constrain azimuthal anisotropy beneath a portion of the northern TAMs. Splitting measurements were made for PKS, SKS, and SKKS phases with the eigenvalue method in SplitLab. The results show two distinct geographic regions of anisotropy: one behind the TAMs front and the other along the Ross Sea coastline. The anisotropic structure behind the TAMs front is best attributed to relict fabric associated with past tectonic episodes. Along the coastline, the anisotropy is interpreted to reflect mantle flow associated with rift-related decompression melting and Cenozoic extension.", "east": 165.120012, "geometry": ["POINT(159.223506 -74.6349495)"], "keywords": "Antarctica; Geology/Geophysics - Other; GPS; Sample/collection Description; Sample/Collection Description; Seismology; Shearwave Spitting; Solid Earth; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -73.032547, "nsf_funding_programs": null, "persons": "Hansen, Samantha", "project_titles": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin", "projects": [{"proj_uid": "p0000300", "repository": "USAP-DC", "title": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.237352, "title": "Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains", "uid": "601019", "west": 153.327}, {"awards": "1148982 Hansen, Samantha", "bounds_geometry": ["POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))"], "date_created": "Thu, 06 Apr 2017 00:00:00 GMT", "description": "Stretching ~3,500 km across Antarctica, with peak elevations up to 4,500 m, the Transantarctic Mountains (TAMs) are the largest non-compressional mountain range on Earth and represent a tectonic boundary between the East Antarctica (EA) craton and the West Antarctic Rift System. The origin and uplift mechanism associated with the TAMs is controversial, and multiple models have been proposed. Seismic investigations of the TAMs\u0027 subsurface structure can provide key constraints to help evaluate these models, but previous studies have been primarily focused only on the central TAMs near Ross Island. Using data from the new 15-station Transantarctic Mountain Northern Network as well as data from several smaller networks, this study investigates the upper mantle velocity structure beneath a previously unexplored portion of the northern TAMs through regional body wave tomography. Relative travel-times were calculated for 11,182 P-wave and 8,285 S-wave arrivals from 790 and 581 Mw \u2265 5.5 events, respectively, using multi-channel cross correlation, and these data were then inverted for models of the upper mantle seismic structure. Resulting P- and S-wave tomography images reveal two focused low velocity anomalies beneath Ross Island (RI; \u03b4VP \u2248 -2.0%; \u03b4VS \u2248 -1.5% to -4.0%) and Terra Nova Bay (TNB; \u03b4VP \u2248 -1.5% to -2.0%; \u03b4VS \u2248 -1.0% to -4.0%) that extend to depths of ~200 and ~150 km, respectively. The RI and TNB slow anomalies also extend ~50-100 km laterally beneath the TAMs front and sharply abut fast velocities beneath the EA craton (\u03b4VP \u2248 0.5% to 2%; \u03b4VS \u2248 1.5% to 4.0%). A low velocity region (\u03b4VP \u2248 -1.5%), centered at ~150 km depth beneath the Terror Rift (TR) and primarily constrained within the Victoria Land Basin, connects the RI and TNB anomalies. The focused low velocities are interpreted as regions of partial melt and buoyancy-driven upwelling, connected by a broad region of slow (presumably warm) upper mantle associated with Cenozoic extension along the TR. Dynamic topography estimates based on the imaged S-wave velocity perturbations are consistent with observed surface topography in the central and northern TAMs, thereby providing support for uplift models that advocate for thermal loading and a flexural origin for the mountain range.", "east": 165.120012, "geometry": ["POINT(159.223506 -74.6349495)"], "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -73.032547, "nsf_funding_programs": null, "persons": "Hansen, Samantha", "project_titles": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin", "projects": [{"proj_uid": "p0000300", "repository": "USAP-DC", "title": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.237352, "title": "Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography", "uid": "601017", "west": 153.327}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(-38.5 -76.2)"], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "This data set contains the results of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) performed on an archive of the GISP2 ice core containing the rapid climate warming of Dansgaard-Oeschger Event 21.", "east": -38.5, "geometry": ["POINT(-38.5 -76.2)"], "keywords": "Arctic; Geochemistry; GISP; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "locations": "Arctic", "north": -76.2, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Haines, Skylar; Mayewski, Paul A.; Kurbatov, Andrei V.", "project_titles": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "projects": [{"proj_uid": "p0000036", "repository": "USAP-DC", "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.2, "title": "Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event", "uid": "609635", "west": -38.5}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(-112.08 -79.47)"], "date_created": "Tue, 20 Oct 2015 00:00:00 GMT", "description": "This data set is a low-resolution set of measurements of d15N of N2 and d18O of O2, along with dO2/N and dAr/N2 supporting data, in the WAIS Divide 3405 m long ice core recovered in 2011. Data are distributed via FTP.", "east": -112.08, "geometry": ["POINT(-112.08 -79.47)"], "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.", "project_titles": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "projects": [{"proj_uid": "p0000036", "repository": "USAP-DC", "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core", "uid": "609660", "west": -112.08}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(-112.125 -79.463)"], "date_created": "Mon, 08 Jun 2015 00:00:00 GMT", "description": "This data set includes borehole temperature measurements performed in January 2008 and January 2009 at the West Antarctic Ice sheet divide from the 300 m hole WDC05A.", "east": -112.125, "geometry": ["POINT(-112.125 -79.463)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "locations": "Antarctica; WAIS Divide", "north": -79.463, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.; Orsi, Anais J.", "project_titles": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "projects": [{"proj_uid": "p0000036", "repository": "USAP-DC", "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.463, "title": "Borehole Temperature Measurement in WDC05A in January 2008 and January 2009", "uid": "609637", "west": -112.125}, {"awards": "1146399 Sidor, Christian", "bounds_geometry": ["POLYGON((162.41 -84.27,163.409 -84.27,164.408 -84.27,165.407 -84.27,166.406 -84.27,167.405 -84.27,168.404 -84.27,169.403 -84.27,170.402 -84.27,171.401 -84.27,172.4 -84.27,172.4 -84.353,172.4 -84.436,172.4 -84.519,172.4 -84.602,172.4 -84.685,172.4 -84.768,172.4 -84.851,172.4 -84.934,172.4 -85.017,172.4 -85.1,171.401 -85.1,170.402 -85.1,169.403 -85.1,168.404 -85.1,167.405 -85.1,166.406 -85.1,165.407 -85.1,164.408 -85.1,163.409 -85.1,162.41 -85.1,162.41 -85.017,162.41 -84.934,162.41 -84.851,162.41 -84.768,162.41 -84.685,162.41 -84.602,162.41 -84.519,162.41 -84.436,162.41 -84.353,162.41 -84.27))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "The PI requests support for preparation of a large collection of vertebrate fossils recently recovered from the Central Transantarctic Mountains (CTAM) of Antarctica. These fossils will be used to place early Mesozoic Antarctic dinosaurs and other vertebrates into a global evolutionary, biogeographic, and faunal context; assess the degree of endemism in Triassic vertebrate faunas of Antarctica; constrain temporal relationships of the Triassic Antarctic vertebrate faunas; and refine the stratigraphic context for the Triassic Antarctic vertebrate assemblages to establish a paleoenvironmental framework. The lower and middle Triassic fossils offer a rare window on life in terrestrial environments at high-latitudes immediately after the Permian mass extinction.\n\nThe PI will use their fossils to educate the public about the geologic, climatic, and biologic history of Antarctica by visiting local schools. They will create and publish at least two new videos to the Burke Museum blog that relate the graduate student\u0027s experience of fieldwork in Antarctica. They will also update the Antarctica section on the UWBM \u0027Explore Your World\u0027 website with images and findings from their field season.\n", "east": 172.4, "geometry": ["POINT(167.405 -84.685)"], "keywords": "Antarctica; Biota; Fossil; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains; Triassic", "locations": "Transantarctic Mountains; Antarctica", "north": -84.27, "nsf_funding_programs": null, "persons": "Sidor, Christian", "project_titles": "Preparation of Vertebrate Fossils from the Triassic of Antarctica", "projects": [{"proj_uid": "p0000418", "repository": "USAP-DC", "title": "Preparation of Vertebrate Fossils from the Triassic of Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.1, "title": "Preparation of Vertebrate Fossils from the Triassic of Antarctica", "uid": "600144", "west": 162.41}, {"awards": "1142156 Marschall, Horst", "bounds_geometry": ["POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth\u0027s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica.\n\nDronning Maud Land (DML) occupied a central location during the formation of supercontinents - large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth\u0027s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007-2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML.\n", "east": 4.18, "geometry": ["POINT(-1.13 -72.27)"], "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Dronning Maud Land; Geochemistry; Geochronology; Solid Earth", "locations": "Dronning Maud Land; Antarctica", "north": -71.93, "nsf_funding_programs": null, "persons": "Marschall, Horst", "project_titles": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica", "projects": [{"proj_uid": "p0000448", "repository": "USAP-DC", "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.61, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "uid": "600135", "west": -6.44}, {"awards": "1139739 Hansen, Samantha", "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))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: Numerous candidate models for the geologic processes that have shaped the Antarctic continent have been proposed. To discriminate between them, detailed images of the upper mantle structure are required; however, the only existing continental-scale images of seismic structure beneath Antarctica lack sufficient resolution to delineate important, diagnostic features. Using newly available data from various Antarctic seismic networks, the PI will employ the adaptively parameterized tomography method to develop a high-resolution, continental-scale seismic velocity model for all of Antarctica. The proposed tomography method combines regional seismic travel-time datasets in the context of a global model to create a composite continental-scale model of upper mantle structure. The proposed method allows for imaging of finer structure in areas with better seismic ray coverage while simultaneously limiting the resolution of features in regions with less coverage. This research will help advance understanding of important global processes, such as craton formation, mountain building, continental rifting and associated magmatism. Additionally, the proposed research will have important impacts on other fields of Antarctic science. Constraints provided by tomographic results can be used to develop thermal models of the lithosphere needed to characterize the history and dynamics of ice sheets. Also, further constraints on lithospheric structure are required by climate-ice models, which are focused on understanding the cooling history of the Antarctic continent.\n\nBroader impacts: The PI is a new faculty member at the University of Alabama after having been funded as a National Science Foundation Postdoctoral Fellow in Polar Regions Research. The graduate student supported by this project is new to polar research. Through the UA-Tuscaloosa Magnet School partnership program, the PI will educate K-12 students about the Antarctic environment and associated career opportunities through various online and hands-on activities. University of Alabama dedicates a significant percentage of its enrollment space to underrepresented groups.\n", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Geology/Geophysics - Other; Lithosphere; Seismic Tomography; Solid Earth", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": null, "persons": "Hansen, Samantha", "project_titles": "New Approach to Investigate the Seismic Velocity Structure beneath Antarctica", "projects": [{"proj_uid": "p0000354", "repository": "USAP-DC", "title": "New Approach to Investigate the Seismic Velocity Structure beneath Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "A New Approach to Investigate the Seismic Velocity Structure beneath Antarctica", "uid": "600132", "west": -180.0}, {"awards": "1043619 Hemming, Sidney", "bounds_geometry": ["POLYGON((-180 -63.997,-179.7982 -63.997,-179.5964 -63.997,-179.3946 -63.997,-179.1928 -63.997,-178.991 -63.997,-178.7892 -63.997,-178.5874 -63.997,-178.3856 -63.997,-178.1838 -63.997,-177.982 -63.997,-177.982 -66.3324,-177.982 -68.6678,-177.982 -71.0032,-177.982 -73.3386,-177.982 -75.674,-177.982 -78.0094,-177.982 -80.3448,-177.982 -82.6802,-177.982 -85.0156,-177.982 -87.351,-178.1838 -87.351,-178.3856 -87.351,-178.5874 -87.351,-178.7892 -87.351,-178.991 -87.351,-179.1928 -87.351,-179.3946 -87.351,-179.5964 -87.351,-179.7982 -87.351,180 -87.351,172.54273 -87.351,165.08546 -87.351,157.62819 -87.351,150.17092 -87.351,142.71365 -87.351,135.25638 -87.351,127.79911 -87.351,120.34184 -87.351,112.88457 -87.351,105.4273 -87.351,105.4273 -85.0156,105.4273 -82.6802,105.4273 -80.3448,105.4273 -78.0094,105.4273 -75.674,105.4273 -73.3386,105.4273 -71.0032,105.4273 -68.6678,105.4273 -66.3324,105.4273 -63.997,112.88457 -63.997,120.34184 -63.997,127.79911 -63.997,135.25638 -63.997,142.71365 -63.997,150.17092 -63.997,157.62819 -63.997,165.08546 -63.997,172.54273 -63.997,-180 -63.997))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars.\nBroader Impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields.", "east": 105.4273, "geometry": ["POINT(143.72265 -75.674)"], "keywords": "Antarctica; East Antarctica; Geochemistry; Ross Sea; Sample/collection Description; Sample/Collection Description; Solid Earth; Southern Ocean; West Antarctica", "locations": "West Antarctica; Southern Ocean; Ross Sea; Antarctica; East Antarctica", "north": -63.997, "nsf_funding_programs": null, "persons": "Hemming, Sidney R.", "project_titles": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "projects": [{"proj_uid": "p0000333", "repository": "USAP-DC", "title": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.351, "title": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "uid": "600124", "west": -177.982}, {"awards": "1043700 Harry, Dennis", "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))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.\n", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Andrill; Antarctica; Continental Rift; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "locations": "Antarctica; Ross Sea; Transantarctic Mountains", "north": -60.0, "nsf_funding_programs": null, "persons": "Harry, Dennis L.", "project_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "projects": [{"proj_uid": "p0000467", "repository": "USAP-DC", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -90.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "600128", "west": -180.0}, {"awards": "1039365 Rimmer, Susan", "bounds_geometry": null, "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming.\n", "east": null, "geometry": null, "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Solid Earth; Transantarctic Mountains", "locations": "Antarctica; Transantarctic Mountains", "north": null, "nsf_funding_programs": null, "persons": "Rimmer, Susan", "project_titles": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter", "projects": [{"proj_uid": "p0000507", "repository": "USAP-DC", "title": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "uid": "600121", "west": null}, {"awards": "0738975 Baker, Ian", "bounds_geometry": ["POINT(-148.82 -81.66)"], "date_created": "Mon, 26 Nov 2012 00:00:00 GMT", "description": "This data set characterizes the microstructure in ice cores, in particular the microstructural locations of impurities, grain orientations, and strain gradients. The fabric of polycrystalline ice is typically described using only the c-axis orientation, but this is insufficient for a full description of grain orientations in this hexagonal material. Thus, both the a-axis and c-axis are used in this data set showing pole figures for five depths of the Siple Dome (SDMA) core between 640 m and 790 m and misorientation angle distribution for the same grains.", "east": -148.82, "geometry": ["POINT(-148.82 -81.66)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core; South Pole; WAISCORES", "locations": "Siple Dome; South Pole; Antarctica", "north": -81.66, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Baker, Ian; Obbard, Rachel; Sieg, Katherine", "project_titles": "Advanced Microstructural Characterization of Polar Ice Cores", "projects": [{"proj_uid": "p0000178", "repository": "USAP-DC", "title": "Advanced Microstructural Characterization of Polar Ice Cores"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.66, "title": "Siple Dome A (SDMA) Grain Orientation 640 - 790 Meters", "uid": "609526", "west": -148.82}, {"awards": "0087521 Waddington, Edwin", "bounds_geometry": ["POINT(-148.82 -81.66)"], "date_created": "Sun, 15 Apr 2012 00:00:00 GMT", "description": "Researchers gathered data on annual snow layers at Siple Dome, Antarctica, using borehole optical stratigraphy. This data set contains annual layer depths and firn optical brightness. The brightness log is a record of reflectivity of the firn, and peaks in brightness are interpreted to be fine-grained high-density winter snow, as part of the wind slab depth-hoar couplet. \n\nData are available via FTP in ASCII text (.txt) format", "east": -148.82, "geometry": ["POINT(-148.82 -81.66)"], "keywords": "Antarctica; Borehole Optical Stratigraphy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Snow/ice; Snow/Ice", "locations": "Antarctica; Siple Dome", "north": -81.66, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hawley, Robert L.; Waddington, Edwin D.; Alley, Richard; Taylor, Kendrick C.", "project_titles": "Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales", "projects": [{"proj_uid": "p0000173", "repository": "USAP-DC", "title": "Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.66, "title": "Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy", "uid": "609515", "west": -148.82}, {"awards": "1043669 Yuan, Xiaojun", "bounds_geometry": ["POLYGON((70 -64,71 -64,72 -64,73 -64,74 -64,75 -64,76 -64,77 -64,78 -64,79 -64,80 -64,80 -64.6,80 -65.2,80 -65.8,80 -66.4,80 -67,80 -67.6,80 -68.2,80 -68.8,80 -69.4,80 -70,79 -70,78 -70,77 -70,76 -70,75 -70,74 -70,73 -70,72 -70,71 -70,70 -70,70 -69.4,70 -68.8,70 -68.2,70 -67.6,70 -67,70 -66.4,70 -65.8,70 -65.2,70 -64.6,70 -64))"], "date_created": "Sun, 01 Jan 2012 00:00:00 GMT", "description": "Processess governing the formation of Antarctic bottom water (AABW) in the Indian Ocean sector of the Southern Ocean remain poorly described. As with AABW formation in more well studied regions of the Antarctic continent, global climate impacts of the source regions of this dense, cold water that help drive the global ocean thermohaline circulation are uncertain. A combination of (annual) continental shelf and slope moorings, seasonal (summer) hydrographic surveys on board the Chinese icebreaker M/V Xuelong, together with synthesis of historic and satellite data will be used to better constrain shelf processes and the atmosphere-ocean-ice interactions in the Prydz Bay region. Despite the seeming remoteness of the study site, changes in the formation rate of AABW could potentially have impact on northern hemisphere climate via effects on the global heat budget and through sea-level rise in the coming decades. The project additionally seeks to promote international collaboration between Chinese and US researchers. The data collected will be broadly disseminated to the oceanographic community through the National Oceanography Data Center and Chinese Arctic and Antarctic Data Center.", "east": 80.0, "geometry": ["POINT(75 -67)"], "keywords": "Antarctica; CTD Data; Mooring; Oceans; Physical Oceanography; Prydz Bay; Southern Ocean", "locations": "Prydz Bay; Southern Ocean; Antarctica", "north": -64.0, "nsf_funding_programs": null, "persons": "Yuan, Xiaojun", "project_titles": "US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica", "projects": [{"proj_uid": "p0000439", "repository": "USAP-DC", "title": "US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica", "uid": "600126", "west": 70.0}, {"awards": "0440847 Raymond, Charles", "bounds_geometry": ["POLYGON((-115.457 -78.7489,-114.8241 -78.7489,-114.1912 -78.7489,-113.5583 -78.7489,-112.9254 -78.7489,-112.2925 -78.7489,-111.6596 -78.7489,-111.0267 -78.7489,-110.3938 -78.7489,-109.7609 -78.7489,-109.128 -78.7489,-109.128 -78.83802,-109.128 -78.92714,-109.128 -79.01626,-109.128 -79.10538,-109.128 -79.1945,-109.128 -79.28362,-109.128 -79.37274,-109.128 -79.46186,-109.128 -79.55098,-109.128 -79.6401,-109.7609 -79.6401,-110.3938 -79.6401,-111.0267 -79.6401,-111.6596 -79.6401,-112.2925 -79.6401,-112.9254 -79.6401,-113.5583 -79.6401,-114.1912 -79.6401,-114.8241 -79.6401,-115.457 -79.6401,-115.457 -79.55098,-115.457 -79.46186,-115.457 -79.37274,-115.457 -79.28362,-115.457 -79.1945,-115.457 -79.10538,-115.457 -79.01626,-115.457 -78.92714,-115.457 -78.83802,-115.457 -78.7489))"], "date_created": "Thu, 01 Sep 2011 00:00:00 GMT", "description": "This data set includes ice flow velocities and strain configurations, from GPS measurements on the West Antarctic Ice Sheet (WAIS) Divide. Ninety markers installed in the firn were measured during two consecutive field seasons running from 2005-2006 and 2006-2007. The markers were located in 150 by 60 km area, with smaller clusters of five markers located within about 10 km of each other. Consecutive GPS measurements were used to derive velocity for each marker. Strain configurations were estimated by differentiating a linear fit of the data at each marker cluster. \n\nData are available via FTP as ASCII text (.txt ) files in comma separated value format.", "east": -109.128, "geometry": ["POINT(-112.2925 -79.1945)"], "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ross-Amundsen Divide; Strain", "locations": "Ross-Amundsen Divide; Antarctica", "north": -78.7489, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Matsuoka, Kenichi; Power, Donovan; Rasmussen, Al", "project_titles": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods", "projects": [{"proj_uid": "p0000024", "repository": "USAP-DC", "title": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.6401, "title": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "uid": "609503", "west": -115.457}, {"awards": "0440847 Raymond, Charles", "bounds_geometry": ["POLYGON((-115.457 -78.7489,-114.8241 -78.7489,-114.1912 -78.7489,-113.5583 -78.7489,-112.9254 -78.7489,-112.2925 -78.7489,-111.6596 -78.7489,-111.0267 -78.7489,-110.3938 -78.7489,-109.7609 -78.7489,-109.128 -78.7489,-109.128 -78.83802,-109.128 -78.92714,-109.128 -79.01626,-109.128 -79.10538,-109.128 -79.1945,-109.128 -79.28362,-109.128 -79.37274,-109.128 -79.46186,-109.128 -79.55098,-109.128 -79.6401,-109.7609 -79.6401,-110.3938 -79.6401,-111.0267 -79.6401,-111.6596 -79.6401,-112.2925 -79.6401,-112.9254 -79.6401,-113.5583 -79.6401,-114.1912 -79.6401,-114.8241 -79.6401,-115.457 -79.6401,-115.457 -79.55098,-115.457 -79.46186,-115.457 -79.37274,-115.457 -79.28362,-115.457 -79.1945,-115.457 -79.10538,-115.457 -79.01626,-115.457 -78.92714,-115.457 -78.83802,-115.457 -78.7489))"], "date_created": "Tue, 30 Aug 2011 00:00:00 GMT", "description": "This dataset contains ground-based, co-polarized radar data collected using pulse-modulated 60 MHz and 179 MHz radar at 19 sites around a deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet (WAIS Divide). At each site, the radar data were collected at 12 orientations of the radar polarization plane for three radar pulse widths: 250 nsec, 500 nsec, and 1000 nsec. Useful signals were received from depths roughly between 200 m and 2000 m. Ice flow velocities and strain configurations were measured at most of these radar survey sites, and these ice motion data are also provided at NSIDC (GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica).\n\nData are available via FTP in MATLAB (.mat) format.", "east": -109.128, "geometry": ["POINT(-112.2925 -79.1945)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Ross-Amundsen Divide", "locations": "Antarctica; Ross-Amundsen Divide", "north": -78.7489, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji; Raymond, Charles", "project_titles": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods", "projects": [{"proj_uid": "p0000024", "repository": "USAP-DC", "title": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.6401, "title": "Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "uid": "609496", "west": -115.457}, {"awards": "0538674 Winebrenner, Dale", "bounds_geometry": ["POINT(73.17 -78.47)"], "date_created": "Mon, 15 Aug 2011 00:00:00 GMT", "description": "This data set provides a modeled radar attenuation rate profile, showing the predicted contributions from pure ice and impurities to radar attenuation at the Vostok 5G ice core site in Antarctica, as well as the total attenuation rate and its formal uncertainty. The model data are based on borehole temperature logs, concentrations of major soluble ions measured from melted ice core samples, and information about the electrical conductivity of ice. Attenuation rates and their spatial variability are important constraints for radar studies of ice sheets. Parameters include depth, total attenuation rate, and attenuation rate contribution from pure ice, acidity, and salinity.\n\nData are available via FTP as a text file (.txt) with columns in comma separated value format.", "east": 73.17, "geometry": ["POINT(73.17 -78.47)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Radar Attenuation Rate; Vostok Ice Core", "locations": "Antarctica; Lake Vostok", "north": -78.47, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S.", "project_titles": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data", "projects": [{"proj_uid": "p0000090", "repository": "USAP-DC", "title": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.47, "title": "Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "uid": "609501", "west": 73.17}, {"awards": "0538674 Winebrenner, Dale", "bounds_geometry": ["POLYGON((68.4 -75.7,69.61 -75.7,70.82 -75.7,72.03 -75.7,73.24 -75.7,74.45 -75.7,75.66 -75.7,76.87 -75.7,78.08 -75.7,79.29 -75.7,80.5 -75.7,80.5 -76.04,80.5 -76.38,80.5 -76.72,80.5 -77.06,80.5 -77.4,80.5 -77.74,80.5 -78.08,80.5 -78.42,80.5 -78.76,80.5 -79.1,79.29 -79.1,78.08 -79.1,76.87 -79.1,75.66 -79.1,74.45 -79.1,73.24 -79.1,72.03 -79.1,70.82 -79.1,69.61 -79.1,68.4 -79.1,68.4 -78.76,68.4 -78.42,68.4 -78.08,68.4 -77.74,68.4 -77.4,68.4 -77.06,68.4 -76.72,68.4 -76.38,68.4 -76.04,68.4 -75.7))"], "date_created": "Mon, 01 Aug 2011 00:00:00 GMT", "description": "This data set consists of inferred accumulation rates from three radar layers (26, 35 and 41 thousand years old) in the Vostok Subglacial Lake region. Accumulation rates were inferred using Local-Layer Approximation (LLA), which assumes that the strain-rate history of a particle traveling through the ice sheet can be approximated by the vertical strain-rate profile at the current position of the particle, which the researchers assume to be uniform. Parameters include location, in latitude and longitude, polar stereographic coordinates, and local grid X and Y coordinates, along with layer age, in thousands of years (ka), and inferred accumulation rate (cm/a). The data cover a 150 by 350 km area.\n\nData are available via FTP, as a text file (.txt) with columns in comma separated value format.", "east": 80.5, "geometry": ["POINT(74.45 -77.4)"], "keywords": "Accumulation Rate; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok", "locations": "Lake Vostok; Antarctica", "north": -75.7, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S.; Waddington, Edwin D.; Winebrenner, Dale", "project_titles": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data", "projects": [{"proj_uid": "p0000090", "repository": "USAP-DC", "title": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.1, "title": "Millennially Averaged Accumulation Rates for Lake Vostok", "uid": "609500", "west": 68.4}, {"awards": "0538015 Hulbe, Christina", "bounds_geometry": ["POLYGON((154.71 -82.78,154.79 -82.78,154.87 -82.78,154.95 -82.78,155.03 -82.78,155.11 -82.78,155.19 -82.78,155.27 -82.78,155.35 -82.78,155.43 -82.78,155.51 -82.78,155.51 -82.788,155.51 -82.796,155.51 -82.804,155.51 -82.812,155.51 -82.82,155.51 -82.828,155.51 -82.836,155.51 -82.844,155.51 -82.852,155.51 -82.86,155.43 -82.86,155.35 -82.86,155.27 -82.86,155.19 -82.86,155.11 -82.86,155.03 -82.86,154.95 -82.86,154.87 -82.86,154.79 -82.86,154.71 -82.86,154.71 -82.852,154.71 -82.844,154.71 -82.836,154.71 -82.828,154.71 -82.82,154.71 -82.812,154.71 -82.804,154.71 -82.796,154.71 -82.788,154.71 -82.78))"], "date_created": "Fri, 01 Jul 2011 00:00:00 GMT", "description": "This data set provides the results from a strain grid survey deployed across the Kamb Ice Stream grounding line on the West Antarctic Ice Sheet. The grid was deployed in 2006 and resurveyed in 2007 using a Global Positioning System (GPS). Parameters measured include latitude, longitude, and height of each survey mark in the strain grid, as well as northing, easting, elevations, and displacement of each point during the year between surveys.\n\nData are available via FTP in Microsoft Excel (.xls) format.", "east": 155.51, "geometry": ["POINT(155.11 -82.82)"], "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Grounding Line; Kamb Ice Stream; Strain", "locations": "Kamb Ice Stream; Antarctica", "north": -82.78, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina", "project_titles": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region", "projects": [{"proj_uid": "p0000019", "repository": "USAP-DC", "title": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -82.86, "title": "Grounding Line Strain Grid Surveys, Kamb Ice Stream, Antarctica", "uid": "609494", "west": 154.71}, {"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))"], "date_created": "Sat, 01 Jan 2011 00:00:00 GMT", "description": "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)"], "keywords": "Biota; Corals; Drake Passage; Geochronology; NBP0805; Oceans; Paleoclimate; Radiocarbon; Southern Ocean", "locations": "Drake Passage; Southern Ocean", "north": -54.5, "nsf_funding_programs": null, "persons": "Robinson, Laura", "project_titles": "LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals", "projects": [{"proj_uid": "p0000519", "repository": "USAP-DC", "title": "LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals"}], "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": "600111", "west": -70.5}, {"awards": "0944474 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))"], "date_created": "Sat, 01 Jan 2011 00:00:00 GMT", "description": "Polar oceans are the main sites of deep-water formation and are critical to the exchange of heat and carbon between the deep ocean and the atmosphere. This award \"Historic perspectives on climate and biogeography from deep-sea corals in the Drake Passage\" will address the following specific research questions: What was the radiocarbon content of the Southern Ocean during the last glacial maximum and during past rapid climate change events? and What are the major controls on the past and present distribution of cold-water corals within the Drake Passage and adjacent continental shelves? Testing these overall questions will allow the researchers to better understand how processes in the Southern Ocean are linked to climate change over millennia. This award is being funded by the Antarctic Earth Sciences Program of NSF\u0027s Office of Polar Programs, Antarctic Division. INTELLECTUAL MERIT: The skeletons of deep-sea corals are abundant in the Southern Ocean, and can be dated using U-series techniques making them a useful archive of oceanographic history. By pairing U-series and radiocarbon analyses the awardees can reconstruct the radiocarbon content of seawater in the past, allowing them to address the research questions raised above. Collection of living deep-sea corals along with environmental data will allow them to address the broader biogeography questions posed above as well. The awardees are uniquely qualified to answer these questions in their respective labs via cutting edge technologies, and they have shown promising results from a preliminary pilot cruise to the area in 2008. BROADER IMPACTS: Societal Relevance: The proposed paleoclimate research will make significant advances toward constraining the Southern Ocean\u0027s influence on global climate, specifically it should help set the bounds for the upper limits on how fast the ocean circulation might change in this region of the world, which is of high societal relevance in this era of changing climate. Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating undergraduate through post-doctoral students into research programs; ii) promotion of K-12 teaching and learning programs by providing information via a cruise website and in-school talks, iii) making the data collected available to the wider research community via data archives such as Seamounts Online and the Seamount Biogeographic Network and iv) reaching a larger public audience through such venues as interviews in the popular media.", "east": -35.0, "geometry": ["POINT(-52.75 -58)"], "keywords": "Biota; Corals; Cruise Report; Drake Passage; NBP1103; Oceans; Sample/collection Description; Sample/Collection Description; Southern Ocean", "locations": "Southern Ocean; Drake Passage", "north": -54.5, "nsf_funding_programs": null, "persons": "Robinson, Laura", "project_titles": "Collaborative Research: Historic Perspectives on Climate and Biogeography from Deep-sea Corals in the Drake Passage", "projects": [{"proj_uid": "p0000514", "repository": "USAP-DC", "title": "Collaborative Research: Historic Perspectives on Climate and Biogeography from Deep-sea Corals in the Drake Passage"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.5, "title": "Historic Perspectives on Climate and Biogeography from Deep-Sea Corals in the Drake Passage", "uid": "600114", "west": -70.5}, {"awards": "0424589 Gogineni, S. Prasad; 0538195 Marone, Chris; 0440523 Baker, Ian", "bounds_geometry": ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"], "date_created": "Wed, 14 Apr 2010 00:00:00 GMT", "description": "This data set includes the results of laboratory experiments examining the constitutive properties of subglacial till, under dynamic stressing. The data include the results of shear strain and stress experiments. Testing was carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, allowing both sliding and microstructural processes to be studied in detail. Till samples were collected from Matanuska, Alaska and from Caesar till at the Laurentide Ice Sheet. \n\nThe data are available via FTP in ASCII text format (.txt).", "east": 147.758889, "geometry": ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"], "keywords": "Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Shear Stress; Solid Earth; Strain", "locations": null, "north": 61.781667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Marone, Chris; Anandakrishnan, Sridhar", "project_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "projects": [{"proj_uid": "p0000554", "repository": "USAP-DC", "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": 40.067222, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "609460", "west": -147.753056}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin weighbridge data 1994-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600014", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Daily weather observations 1996-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600015", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin dive data 1999-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600013", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin banding data 1994-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600005", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin chick measurements 1996 - 2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600006", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": "Biota", "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin chick counts 1997-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600007", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin diet data 1996 - 2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600008", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin Geolocation Sensor data 2003-2007 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600009", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin satellite position data 2000-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600012", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": "Biota; Oceans", "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Leopard Seal counts 1997-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600010", "west": 166.0}, {"awards": "0439759 Ballard, Grant", "bounds_geometry": ["POINT(166 -77)"], "date_created": "Tue, 19 May 2009 00:00:00 GMT", "description": "This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. ", "east": 166.0, "geometry": ["POINT(166 -77)"], "keywords": null, "locations": null, "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Ballard, Grant", "project_titles": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "projects": [{"proj_uid": "p0000318", "repository": "USAP-DC", "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Adelie penguin resighting data 1997-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "uid": "600011", "west": 166.0}, {"awards": "0230276 Ward, Bess", "bounds_geometry": ["POLYGON((162 -77.2,162.16 -77.2,162.32 -77.2,162.48 -77.2,162.64 -77.2,162.8 -77.2,162.96 -77.2,163.12 -77.2,163.28 -77.2,163.44 -77.2,163.6 -77.2,163.6 -77.26,163.6 -77.32,163.6 -77.38,163.6 -77.44,163.6 -77.5,163.6 -77.56,163.6 -77.62,163.6 -77.68,163.6 -77.74,163.6 -77.8,163.44 -77.8,163.28 -77.8,163.12 -77.8,162.96 -77.8,162.8 -77.8,162.64 -77.8,162.48 -77.8,162.32 -77.8,162.16 -77.8,162 -77.8,162 -77.74,162 -77.68,162 -77.62,162 -77.56,162 -77.5,162 -77.44,162 -77.38,162 -77.32,162 -77.26,162 -77.2))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "Denitrification is the main process by which fixed nitrogen is lost from ecosystems and the regulation of this process may directly affect primary production and carbon cycling over short and long time scales. Previous investigations of the role of bioactive metals in regulating denitrification in bacteria from permanently ice-covered Lake Bonney in the Taylor Valley of East Antarctica indicated that denitrifying bacteria can be negatively affected by metals such as copper, iron, cadmium, lead, chromium, nickel, silver and zinc; and that there is a distinct difference in denitrifying activity between the east and west lobes of the lake. \n\nLow iron concentrations were found to exacerbate the potential toxicity of the other metals, while silver has the potential to specifically inhibit denitrification because of its ability to interfere with copper binding in redox proteins, such as nitrite reductase and nitrous oxide reductase. High silver concentrations might prevent the functioning of nitrous oxide reductase in the same way that simple copper limitation does, thereby causing the buildup of nitrous oxide and resulting in a nonfunctional nitrogen cycle. Other factors, such as oxygen concentration, are likely also to affect bacterial activity in Lake Bonney.\n\nThis project will investigate silver toxicity, general metal toxicity and oxygen concentration to determine their effect on denitrification in the lake by using a suite of \u0027sentinel\u0027 strains of denitrifying bacteria (isolated from the lake) incubated in Lake Bonney water and subjected to various treatments. The physiological responses of these strains to changes in metal and oxygen concentration will be quantified by flow cytometric detection of single cell molecular probes whose sensitivity and interpretation have been optimized for the sentinel strains. Understanding the relationships between metals and denitrification is expected to enhance our understanding of not only Lake Bonney\u0027s unusual nitrogen cycle, but more generally, of the potential role of metals in the regulation of microbial nitrogen transformations. The broader impacts of this work include not only a better understanding of regional biogeochemistry and global perspectives on these processes; but also the training of graduate students and a substantial outreach effort for school children.", "east": 163.6, "geometry": ["POINT(162.8 -77.5)"], "keywords": "Antarctica; Biota; CTD Data; Dry Valleys; Lake Bonney; Lake Vanda; Microbiology; Taylor Valley", "locations": "Antarctica; Lake Vanda; Lake Bonney; Dry Valleys; Taylor Valley", "north": -77.2, "nsf_funding_programs": null, "persons": "Ward, Bess", "project_titles": "Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?", "projects": [{"proj_uid": "p0000223", "repository": "USAP-DC", "title": "Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?", "uid": "600033", "west": 162.0}, {"awards": "0536526 Le Masurier, Wesley", "bounds_geometry": ["POLYGON((-136 -73,-133.4 -73,-130.8 -73,-128.2 -73,-125.6 -73,-123 -73,-120.4 -73,-117.8 -73,-115.2 -73,-112.6 -73,-110 -73,-110 -73.425,-110 -73.85,-110 -74.275,-110 -74.7,-110 -75.125,-110 -75.55,-110 -75.975,-110 -76.4,-110 -76.825,-110 -77.25,-112.6 -77.25,-115.2 -77.25,-117.8 -77.25,-120.4 -77.25,-123 -77.25,-125.6 -77.25,-128.2 -77.25,-130.8 -77.25,-133.4 -77.25,-136 -77.25,-136 -76.825,-136 -76.4,-136 -75.975,-136 -75.55,-136 -75.125,-136 -74.7,-136 -74.275,-136 -73.85,-136 -73.425,-136 -73))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project uses geochemical studies to determine the origin of volcanic rocks from Marie Byrd Land (MBL), Antarctica. Surprisingly, adjacent volcanoes in the MBL have dramatically different compositions, ranging from phonolite to trachyte to rhyolite. This diversity offers an opportunity to constrain the processes responsible for generating silica oversaturated and undersaturated magmas in a single geologic setting. Previous work suggests that the most obvious and simplest explanation--crustal contamination--is not a significant factor, and that polybaric fractional crystallization is the major cause. This study evaluates these factors through analyses and interpretation of trace and rare earth element abundances, as well as Sr and Nd isotopic ratios. The broader impacts include outreach programs to the Girl Scouts of America, and dissemination of results through publications and meetings.", "east": -110.0, "geometry": ["POINT(-123 -75.125)"], "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Intracontinental Magmatism; IntraContinental Magmatism; Marie Byrd Land; Solid Earth", "locations": "Antarctica; Marie Byrd Land", "north": -73.0, "nsf_funding_programs": null, "persons": "Le Masurier, Wesley", "project_titles": "Geochemistry and Petrologic Evolution of Felsic Volcanoes in Western Marie Byrd Land, Antarctica", "projects": [{"proj_uid": "p0000534", "repository": "USAP-DC", "title": "Geochemistry and Petrologic Evolution of Felsic Volcanoes in Western Marie Byrd Land, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.25, "title": "Geochemistry and Petrologic Evolution of Felsic Volcanoes in Western Marie Byrd Land, Antarctica", "uid": "600051", "west": -136.0}, {"awards": "0739693 Ashworth, Allan", "bounds_geometry": ["POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia. In terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica\u0027s ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise.", "east": 162.0, "geometry": ["POINT(161 -77.5)"], "keywords": "Antarctica; Geochronology; Geology/Geophysics - Other; GPS; Solid Earth", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": null, "persons": "Ashworth, Allan; Lewis, Adam", "project_titles": "Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "projects": [{"proj_uid": "p0000188", "repository": "USAP-DC", "title": "Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "uid": "600081", "west": 160.0}, {"awards": "0238281 Marsh, Adam", "bounds_geometry": ["POLYGON((163 -77,163.4 -77,163.8 -77,164.2 -77,164.6 -77,165 -77,165.4 -77,165.8 -77,166.2 -77,166.6 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.6 -78,166.2 -78,165.8 -78,165.4 -78,165 -78,164.6 -78,164.2 -78,163.8 -78,163.4 -78,163 -78,163 -77.9,163 -77.8,163 -77.7,163 -77.6,163 -77.5,163 -77.4,163 -77.3,163 -77.2,163 -77.1,163 -77))"], "date_created": "Tue, 01 Jan 2008 00:00:00 GMT", "description": "Although we envision the coastal margins of Antarctica as an extreme environment challenging to the existence of life, there are many marine invertebrates that are adapted to live and thrive under the sea ice. For two field seasons, the SCUBA diving activities of this project routinely involved photographing these animals in all the dive locations as a way to document what we observed as the dominant organisms at each site. Ice diving is very strenuous for humans, and often the constraints of managing the work on a dive, monitoring air reserves, tracking proximity to the dive hole, and the 50 minute exposure to subfreezing temperatures limits a divers ability to \"catalog\" observations that are not essential to the current dive plan. The photographs archived here have provided the project\u0027s dive team with the ability to \"debrief\" following a dive and more or less reenact the dive by moving through the photograph images. Studying these images often served as a visual trigger for divers to recall more specific observations and in many cases details in the photographs were captured without the photographer (A. Marsh) realizing that they were there (such as small, cryptic species hiding in a shadow until the strobe light fires for the photo, illuminating these secondary subjects). These photographs are intended to serve as a record of what organisms we encountered in the McMurdo Sound area in 2004 and 2005. All photographs were taken with a Nikon D-70 in a polycarbonate underwater housing using either a 18 mm (wide) or 60 mm (macro) lens.", "east": 167.0, "geometry": ["POINT(165 -77.5)"], "keywords": "Antarctica; Biota; McMurdo Sound; Oceans; Photo/video; Photo/Video; Southern Ocean", "locations": "McMurdo Sound; Southern Ocean; Antarctica", "north": -77.0, "nsf_funding_programs": null, "persons": "Marsh, Adam G.", "project_titles": "CAREER: Genomic Networks for Cold-Adaptation in Embryos of Polar Marine Invertebrates", "projects": [{"proj_uid": "p0000240", "repository": "USAP-DC", "title": "CAREER: Genomic Networks for Cold-Adaptation in Embryos of Polar Marine Invertebrates"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Marine Invertebrates of McMurdo Sound", "uid": "600034", "west": 163.0}, {"awards": "0230260 Bender, Michael", "bounds_geometry": ["POINT(106.8 -72.4667)"], "date_created": "Tue, 10 Jul 2007 00:00:00 GMT", "description": "This data set includes a time scale for the Vostok ice core, retrieved from Vostok Station on the East Antarctic Plateau. This chronology is derived by orbitally tuning to molecular oxygen to nitrogen (O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e) ratios in occluded air for depths deeper than 1550 m (greater than 112,000 years old), and by gas correlation to the Greenland Ice Sheet Project 2 (GISP2) chronology for the ice core section that is shallower than 1422 m (less than 102,000 years old). Because of poor gas preservation in air bubbles in shallower depths, investigators could only constrain the Vostok chronology for the section deeper than 1550 m by O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e. Thus for the shallower section of the core, they synchronized the Vostok delta oxygen-18 (\u0026delta;\u003csup\u003e18\u003c/sup\u003eO) and methane (CH\u003csub\u003e4\u003c/sub\u003e) measurements to those of the GISP2 to obtain the chronology (see Bender, et al. 2006). Note, CH\u003csub\u003e4\u003c/sub\u003e data are not included in this data set.\n\nInvestigators analyzed the O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e and the\u003cem\u003e\u003cstrong\u003e \u003c/strong\u003e\u003c/em\u003e\u0026delta;\u003csup\u003e18\u003c/sup\u003eO record ratios for approximately the past 115,000 to 400,000 years in the Vostok ice core. They combined new measurements for O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e and \u0026delta;\u003csup\u003e18\u003c/sup\u003eO with data from Bender (2002) and Petit, et al. (1999), respectively.\n\nData are in Microsoft Excel format and are available via FTP.", "east": 106.8, "geometry": ["POINT(106.8 -72.4667)"], "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Lake Vostok; Paleoclimate; Vostok; Vostok Ice Core", "locations": "Lake Vostok; Vostok; Antarctica", "north": -72.4667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Bender, Michael; Suwa, Makoto", "project_titles": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core", "projects": [{"proj_uid": "p0000257", "repository": "USAP-DC", "title": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.4667, "title": "Trapped Gas Composition and Chronology of the Vostok Ice Core", "uid": "609311", "west": 106.8}, {"awards": "9615502 Harrison, William", "bounds_geometry": ["POINT(-148.693 -81.595)", "POINT(-148.822 -81.655)"], "date_created": "Thu, 22 Feb 2007 00:00:00 GMT", "description": "At the Siple Dome area of Antarctica, much of the ice flow is vertical, which causes vertical ice deformation. To measure this phenomenon, the investigators used a method known as vertical strain rate. This project was a part of the West Antarctic Ice Sheet Cores (WAISCORES) project for deep ice coring in West Antarctica. WAISCORES is supported by the Office of Polar Programs (OPP), National Science Foundation (NSF).\n\nThis data set consists of a table of long-term average strain rates measured between 1999 and 2002 at Siple Dome, Antarctica. The measurements were taken in hot-water boreholes by bridge gauges. Data are available in tab-delimited ASCII text format or PDF via FTP.", "east": -148.693, "geometry": ["POINT(-148.693 -81.595)", "POINT(-148.822 -81.655)"], "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Strain; WAISCORES", "locations": "Siple Dome; Antarctica", "north": -81.595, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Harrison, William; Morack, James; Waddington, Edwin D.; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel", "project_titles": "Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome", "projects": [{"proj_uid": "p0000601", "repository": "USAP-DC", "title": "Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.655, "title": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "uid": "609214", "west": -148.822}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Lithospheric thicknesses in Antarctica from Sp receiver functions
|
2201129 |
2025-02-12 | Brown, Sarah; Fischer, Karen |
Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity |
This dataset contains the depths of negative velocity gradients that are potentially interpretable as the lithosphere-asthenosphere boundary (LAB) beneath Antarctica, derived from common conversion point stacking of Sp receiver functions. The dataset provides constraints on lithospheric thickness variations, particularly in West Antarctica, where a vertically localized LAB is observed at depths of 70–100 km. In East Antarctica, two zones of well-defined LAB depths are present in regions near the coast at depths of 75-110 km (~140˚E) and 90-130 km (~115˚E). Interpretation of these results and comparison with prior studies are provided in the associated journal article (see References). | ["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))"] | ["POINT(0 -89.999)"] | false | false |
Crustal thicknesses in Antarctica from Sp receiver functions
|
2201129 |
2025-02-12 | Brown, Sarah; Fischer, Karen |
Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity |
This dataset contains crustal thickness measurements at 99 individual broadband seismic stations across Antarctica derived from teleseismic Sp waves. Crustal thickness estimates were obtained by measuring the depth of the Sp phase associated with the crust-mantle boundary observed in single-station stacks of Sp receiver functions. The measurements offer new constraints on crustal structure in West and East Antarctica. Comparison with crustal thickness estimates from prior studies are provided in the associated journal article (see References). | ["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))"] | ["POINT(0 -89.999)"] | false | false |
Ice-penetrating radar data from the Thwaites Glacier grounding zone
|
1738989 |
2024-11-25 | Balco, Greg; Campbell, Seth; Goehring, Brent |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
Contains ice-penetrating radar data (10 and 400 MHz) from the Thwaites Glacier grounding zone. The main purpose of collecting these data was for safety assessment at a camp put-in; deep (10 MHz) radar data were also collected opportunistically. | ["POLYGON((-104.9429 -75.1543,-104.92228999999999 -75.1543,-104.90168 -75.1543,-104.88107 -75.1543,-104.86046 -75.1543,-104.83985 -75.1543,-104.81924 -75.1543,-104.79863 -75.1543,-104.77802 -75.1543,-104.75741000000001 -75.1543,-104.7368 -75.1543,-104.7368 -75.16263000000001,-104.7368 -75.17096000000001,-104.7368 -75.17929000000001,-104.7368 -75.18762000000001,-104.7368 -75.19595000000001,-104.7368 -75.20428,-104.7368 -75.21261,-104.7368 -75.22094,-104.7368 -75.22927,-104.7368 -75.2376,-104.75741000000001 -75.2376,-104.77802 -75.2376,-104.79863 -75.2376,-104.81924 -75.2376,-104.83985 -75.2376,-104.86046 -75.2376,-104.88107 -75.2376,-104.90168 -75.2376,-104.92228999999999 -75.2376,-104.9429 -75.2376,-104.9429 -75.22927,-104.9429 -75.22094,-104.9429 -75.21261,-104.9429 -75.20428,-104.9429 -75.19595000000001,-104.9429 -75.18762000000001,-104.9429 -75.17929000000001,-104.9429 -75.17096000000001,-104.9429 -75.16263000000001,-104.9429 -75.1543))"] | ["POINT(-104.83985 -75.19595000000001)"] | false | false |
Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif
|
1738989 |
2024-11-13 | Balco, Greg; Campbell, Seth; Goehring, Brent |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
Contains ice-penetrating radar data (10, 100, and 400 MHz) from the north side of the Mt. Murphy massif. Most of these data are closely spaced lines used for reconnaissance and site selection for a subglacial bedrock recovery drilling project very close to the ice margin at the north ridge of Kay Peak, a sub-peak of the massif. In addition, there are several longer exploratory lines that cross the embayment between the massif and the Crosson Ice Shelf, some of which may cross grounding lines. | ["POLYGON((-110.9665 -75.1967,-110.92041 -75.1967,-110.87432 -75.1967,-110.82822999999999 -75.1967,-110.78214 -75.1967,-110.73605 -75.1967,-110.68996 -75.1967,-110.64386999999999 -75.1967,-110.59778 -75.1967,-110.55169000000001 -75.1967,-110.5056 -75.1967,-110.5056 -75.20331,-110.5056 -75.20992000000001,-110.5056 -75.21653,-110.5056 -75.22314,-110.5056 -75.22975,-110.5056 -75.23636,-110.5056 -75.24297,-110.5056 -75.24958,-110.5056 -75.25619,-110.5056 -75.2628,-110.55169000000001 -75.2628,-110.59778 -75.2628,-110.64386999999999 -75.2628,-110.68996 -75.2628,-110.73605 -75.2628,-110.78214 -75.2628,-110.82822999999999 -75.2628,-110.87432 -75.2628,-110.92041 -75.2628,-110.9665 -75.2628,-110.9665 -75.25619,-110.9665 -75.24958,-110.9665 -75.24297,-110.9665 -75.23636,-110.9665 -75.22975,-110.9665 -75.22314,-110.9665 -75.21653,-110.9665 -75.20992000000001,-110.9665 -75.20331,-110.9665 -75.1967))"] | ["POINT(-110.73605 -75.22975)"] | false | false |
Law Dome firn air and ice core 14CO concentration
|
1643669 |
2024-10-24 | Petrenko, Vasilii |
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability |
This is a data set containing measurements of [14CO] in firn air and ice core samples from Law Dome DE08-OH site, Antarctica. The firn air and ice core samples were collected at Law Dome in December 2018 and January 2019. The [14CO] data represent atmospheric values (with the in situ cosmogenic and procedural components removed). [14CO] measurements were conducted as described in Hmiel et al., 2024 (https://doi.org/10.5194/tc-18-3363-2024). The in situ cosmogenic [14CO] contribution was calculated using parameters and model also described in Hmiel et al. (2024). As [14CO] measurements in ice cores are complex, use of the data in a publication requires contacting Vasilii Petrenko (vasilii.petrenko@rochester.edu) to ensure correct understanding of the data. Depending on nature of use of the data, co-authorship may be appropriate. | ["POLYGON((112 -66,112.2 -66,112.4 -66,112.6 -66,112.8 -66,113 -66,113.2 -66,113.4 -66,113.6 -66,113.8 -66,114 -66,114 -66.1,114 -66.2,114 -66.3,114 -66.4,114 -66.5,114 -66.6,114 -66.7,114 -66.8,114 -66.9,114 -67,113.8 -67,113.6 -67,113.4 -67,113.2 -67,113 -67,112.8 -67,112.6 -67,112.4 -67,112.2 -67,112 -67,112 -66.9,112 -66.8,112 -66.7,112 -66.6,112 -66.5,112 -66.4,112 -66.3,112 -66.2,112 -66.1,112 -66))"] | ["POINT(113 -66.5)"] | false | false |
Firn and Ice Density at Winkie Nunatak
|
2317097 |
2024-10-02 | Venturelli, Ryan |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
This data set contains an ice and firn density profile from Winkie Nunatak, West Antarctica. These data were collected when drilling a sub-ice access hole with an Eclipse drill in preparation for Winkie drill collection of subglacial bedrock. | ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"] | ["POINT(-99.769 -74.8635)"] | false | false |
Weddell seal dive behavior and rhythmicity from 2010-2012 in the Ross Sea
|
1853377 0838892 0838937 |
2024-09-20 | Shero, Michelle |
Collaborative Research: Physiological and Genetic Correlates of Reproductive Success in High- versus Low-Quality Weddell seals Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea |
Diel vertical migrations (DVM) have been well-documented across numerous taxa, with prey descend through the water column during daylight hours to avoid visual predators and feed at the surface at night. However, the ability of marine mammals such as Weddell seals (Leptonychotes weddellii) to follow prey to depths is likely constrained by limited breath-hold capacities and the physiological consequences of pushing aerobic thresholds. In particular, dives that exceed the aerobic dive limit require exponentially longer surface recuperation times to clear lactate byproducts from circulation. This is time that the animals then cannot spend foraging. In this study, we assess the circadian organization of the Weddell seal's dive efforts and when animals make their longest/deepest (most 'extreme') dives that far exceed aerobic thresholds. Sixty-two adult Weddell seals were instrumented with satellite linked relay loggers in the Ross Sea to collect behavioral information across the austral winter. Daily activities are likely to shift across the year in a highly-seasonal polar environment, and through this 'natural experiment' we test how free-ranging seals alter foraging behavior during Polar Day and Night (continuous light, LL and dark, DD, respectively) and varying light/dark (LD) cycling across the year. | ["POLYGON((-180 -72,-179.8 -72,-179.6 -72,-179.4 -72,-179.2 -72,-179 -72,-178.8 -72,-178.6 -72,-178.4 -72,-178.2 -72,-178 -72,-178 -72.7,-178 -73.4,-178 -74.1,-178 -74.8,-178 -75.5,-178 -76.2,-178 -76.9,-178 -77.6,-178 -78.3,-178 -79,-178.2 -79,-178.4 -79,-178.6 -79,-178.8 -79,-179 -79,-179.2 -79,-179.4 -79,-179.6 -79,-179.8 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.3,162 -77.6,162 -76.9,162 -76.2,162 -75.5,162 -74.8,162 -74.1,162 -73.4,162 -72.7,162 -72,163.8 -72,165.6 -72,167.4 -72,169.2 -72,171 -72,172.8 -72,174.6 -72,176.4 -72,178.2 -72,-180 -72))"] | ["POINT(172 -75.5)"] | false | false |
Tertiary creep rates of temperate ice containing greater than 0.7% liquid water
|
1643120 |
2024-09-16 | Iverson, Neal |
NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice |
Accurately modeling the deformation of temperate glacier ice, which is at its pressure-melting temperature and contains liquid water at grain boundaries, is essential for predicting ice sheet discharge to the ocean and associated sea-level rise. Central to such modeling is Glen’s flow law, in which strain rate depends on stress raised to a power of n=3-4. In sharp contrast to this nonlinearity, we find by conducting large-scale, shear-deformation experiments to tertiary creep that temperate ice is linear-viscous (n≈1.0) over common ranges of liquid water content and stress expected near glacier beds and in ice stream margins. This linearity is likely caused by diffusive pressure-melting and refreezing at grain boundaries and could help stabilize modeled responses of ice sheets to shrinkage-induced stress increases. | [] | [] | false | false |
Impulse HF radar data from Conway Ridge
|
0087144 |
2024-07-22 | Hoffman, Andrew; Conway, Howard; Christianson, Knut |
Glacial History of Ridge AB, West Antarctica |
Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\sim3000$ and $\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly. | ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"] | ["POINT(-140 -84.25)"] | false | false |
U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica
|
2042495 1644171 |
2024-07-01 | Edwards, Graham; Piccione, Gavin; Blackburn, Terrence; Tulaczyk, Slawek |
Collaborative Research: Reconstructing East Antarctica’s Past Response to Climate using Subglacial Precipitates U-Series Comminution Age Constraints on Taylor Valley Erosion |
This dataset contains uranium and thorium isotopic compositions (U-234, U-235, U-238, Th-230, Th-232) and major element compositions (Al, K, Na, Ca, Fe, Mn, reported as oxides) for silicate sediments from glaciogenic drifts associated with advances of Taylor Glacier in Taylor Valley, Antarctica. Isotopic measurements were obtained by ID-TIMS in the Keck Isotope Facility at UC Santa Cruz and elemental measurements were obtained by ICP-OES in the Plasma Analytical Laboratory. All measurements include fully propagated analytical and systematic (e.g. isotopic tracer) uncertainties. Chemical index of alteration was calculated from major element data. Prior to measurements, sediments were sieved to ≤125 μm grain sizes, separated into quartz-feldspar-rich and clay-rich aliquots by hydraulic settling, and subjected to sequential chemical extractions ("leaching") prior to silicate digestion. | ["POLYGON((161.9 -77.65,161.96 -77.65,162.02 -77.65,162.08 -77.65,162.14000000000001 -77.65,162.2 -77.65,162.26 -77.65,162.32 -77.65,162.38 -77.65,162.44 -77.65,162.5 -77.65,162.5 -77.66000000000001,162.5 -77.67,162.5 -77.68,162.5 -77.69,162.5 -77.7,162.5 -77.71000000000001,162.5 -77.72,162.5 -77.73,162.5 -77.74,162.5 -77.75,162.44 -77.75,162.38 -77.75,162.32 -77.75,162.26 -77.75,162.2 -77.75,162.14000000000001 -77.75,162.08 -77.75,162.02 -77.75,161.96 -77.75,161.9 -77.75,161.9 -77.74,161.9 -77.73,161.9 -77.72,161.9 -77.71000000000001,161.9 -77.7,161.9 -77.69,161.9 -77.68,161.9 -77.67,161.9 -77.66000000000001,161.9 -77.65))"] | ["POINT(162.2 -77.7)"] | false | false |
Multi-Site Brittle Ice Data and Measurements
|
2218402 |
2024-05-16 | Fegyveresi, John; Barnett, Samantha |
EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site. |
This data set includes all measurements and observations used in conjunction with NSF funded project 2218402 - "EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site". Data is directly related to the Masters Thesis of NAU graduate student Samantha Barnett | ["POLYGON((-148.812 -79.467,-143.7458 -79.467,-138.67960000000002 -79.467,-133.6134 -79.467,-128.5472 -79.467,-123.48100000000001 -79.467,-118.41480000000001 -79.467,-113.3486 -79.467,-108.28240000000001 -79.467,-103.21620000000001 -79.467,-98.15 -79.467,-98.15 -80.52029999999999,-98.15 -81.5736,-98.15 -82.6269,-98.15 -83.6802,-98.15 -84.73349999999999,-98.15 -85.7868,-98.15 -86.8401,-98.15 -87.8934,-98.15 -88.94669999999999,-98.15 -90,-103.2162 -90,-108.28240000000001 -90,-113.3486 -90,-118.41480000000001 -90,-123.48100000000001 -90,-128.5472 -90,-133.6134 -90,-138.6796 -90,-143.7458 -90,-148.812 -90,-148.812 -88.94669999999999,-148.812 -87.8934,-148.812 -86.8401,-148.812 -85.7868,-148.812 -84.73349999999999,-148.812 -83.6802,-148.812 -82.6269,-148.812 -81.5736,-148.812 -80.52029999999999,-148.812 -79.467))"] | ["POINT(-123.48100000000001 -84.73349999999999)"] | false | false |
Constraining the Radiocarbon Reservoir Age for the Southern Ocean Using Whale Bones Salvaged from Early 20th Century Whaling Stations
|
2200448 |
2024-05-10 | Divola, Claire; Simms, Alexander; Sremba, Angela; Baker, C. Scott; Friedlaender, Ari; Southon, John |
New constraints on 14C reservoirs around the Antarctic Peninsula and the Southern Ocean based on historically-harvested whale bones |
Radiocarbon dating is arguably the most common method for dating Quaternary deposits. However, accurate age assignments using radiocarbon dating are dependent on knowing the radiocarbon reservoir. For the coastal waters across Antarctica, the radiocarbon reservoirs show significant variation, ranging from 700 to 6,000 years depending on the material dated and the period in question. In this study, we examine the radiocarbon reservoir age for the shallow waters of the Southern Ocean using 23 whale bones salvaged from whaling stations operating on or near the Western Antarctic Peninsula between 1904 and 1916. The species origin of the bones had been identified previously as humpback, fin, or blue whales using sequences of mitochondrial (mt)DNA. We find an average reservoir age of 1050 +/- 135 years for these 23 whale bones, with a <100 year difference in the reservoir age value by species. A comparison between our results and other studies through the Holocene suggest that the Southern Ocean surface water radiocarbon reservoir age has not significantly changed for the last 14,000 years. Combining our new ages with existing data sets provides insight to the stability of the Southern Ocean marine radiocarbon reservoir age, enhancing our understanding of ocean ventilation and upwelling dynamics throughout the Holocene. | [] | [] | false | false |
Full Waveform Ambient Noise Tomography for East Antarctica
|
1914698 |
2024-01-24 | Hansen, Samantha; Emry, Erica |
Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes
Subglacial Basin (RESISSt) |
Recent investigations in polar environments have examined solid-Earth-ice-sheet feedbacks and have emphasized that glacial isostatic adjustment, tectonic, and geothermal forcings exert first-order control on the physical conditions at and below the ice-bed interface and must be taken into account when evaluating ice-sheet evolution. However, the solid-Earth structure beneath much of Antarctica is still poorly constrained given the sparse distribution of seismic stations across the continent and the generally low seismicity rate. One region of particular interest is the Wilkes Subglacial Basin (WSB) in East Antarctica. During the mid-Pliocene warm period, the WSB may have contributed 3-4 m to the estimated 20 m rise in sea-level, indicating that this region could also play an important role in future warming scenarios. However, the WSB may have experienced notable bedrock uplift since the Pliocene; therefore, past geologic inferences of instability may not serve as a simple analogue for the future. Using records of ambient seismic noise recorded by both temporary and long-term seismic networks, along with a full-waveform tomographic inversion technique, we have developed improved images of the lithospheric structure beneath East Antarctica, including the WSB. Empirical Green’s Functions with periods between 40 and 340 s have been extracted using a frequency-time normalization technique, and a finite-difference approach with a spherical grid has been employed to numerically model synthetic seismograms. Associated sensitivity kernels have also been constructed using a scattering integral method. Our results suggest the WSB is underlain by slow seismic velocities, with faster seismic structure beneath the adjacent Transantarctic Mountains and the Belgica Subglacial Highlands. This may indicate that the WSB is associated with a region of thinner lithosphere, possibly associated with prior continental rifting. The seismic heterogeneity highlighted in our model could have significant implications for understanding the geodynamic origin of WSB topography and its influence on ice-sheet behavior. The model file and associated plotting scripts are provided. | ["POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))"] | ["POINT(135 -77.5)"] | false | false |
Ocean CFC reconstructed data product
|
2023303 |
2023-10-31 | Cimoli, Laura; Purkey, Sarah; Gebbie, Jack |
Collaborative Research: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters? |
A global CFC Data product is derived used the Time-Corrected Method (TCM) in order to estimate CFCs and SF6 ocean concentration back to 1940. The Green's functions (GFs), describing the steady-state transport from the surface to the ocean interior, is solved, constrained by observations. From the GFs, we reconstruct global tracer concentrations (and associated uncertainties) in the ocean interior at annual resolution (1940–2021). The spatial resolution includes 50 neutral density levels that span the water column along World Ocean Circulation Experiment/Global Ocean Ship-Based Hydrographic Investigations Program lines. | ["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))"] | ["POINT(0 -89.999)"] | false | false |
d15N and d18O of air in the WAIS Divide ice core
|
0538657 |
2023-10-20 | Severinghaus, Jeffrey P. |
Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate |
Major gas components of air data set, containing d15N, d18O of O2, dO2/N2, and dAr/N2 from the WAIS Divide ice core at high resolution. These data are used to constrain surface temperature, biosphere oxygen cycling, and firn thickness through the past >60 kyr. | ["POINT(-112.05 -79.28)"] | ["POINT(-112.05 -79.28)"] | false | false |
Shear Wave Velocity of the Antarctic Upper Mantle from Full Waveform Inversion and Long Period Ambient Seismic Noise
|
1643798 1643873 |
2023-10-16 | Emry, Erica |
Collaborative Research: Imaging Seismic Heterogeneity within the Antarctic Mantle with Full Waveform Ambient Noise Tomography |
This dataset provides the shear wave velocity model resulting from a full-waveform inversion that was constrained using long-period empirical Green's functions extracted from ambient seismic noise. These results were presented by Emry and Hansen at the 2022 Fall Meeting of the American Geophysical Union. | ["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))"] | ["POINT(0 -89.999)"] | false | false |
In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers
|
1738989 |
2023-07-10 | Venturelli, Ryan; Goehring, Brent; Balco, Gregory |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
Included in this dataset are in situ carbon-14 concentrations for a series of bedrock cores recovered from the subglacial extension of Kay Peak, a grounding-line-proximal ridge of the volcanic edifice Mount Murphy (near Thwaites and Pope glaciers). Concentrations measured in these bedrock samples have been used in the associated publication to demonstrate that the Thwaites-Pope glacier system was thinner in the Holocene than it is today. | ["POINT(-110.96038 -75.21526)"] | ["POINT(-110.96038 -75.21526)"] | false | false |
Concentration and isotopic composition of atmospheric N2O over the last century
|
1643716 |
2023-05-22 | Ghosh, Sambit; Toyoda, Sakae ; Buizert, Christo ; Langenfelds, Ray L ; Yoshida, Naohiro ; Joong Kim, Seong; Ahn, Jinho ; Etheridge, David |
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability |
We have reconstructed the atmospheric N2O mole fraction and its isotopic composition by combining data from ice cores, firn air, and atmospheric samples. The mole fraction reconstruction extends back to 1000 CE using ice cores, firn air, and atmospheric sampling; and the isotopic reconstruction extends back to 1900 CE using only firn air data. We have incorporated both newly measured and previously published data. We present new data for the mole fraction, d15Nbulk, d18O, and d15NSP values from the Styx (East Antarctica) firn air, and mole fraction from the North Greenland Eemian Ice drilling Project (NEEM) firn air. We have used published records from the Styx and NEEM ice cores, direct atmospheric measurements from the NOAA global sampling network, and firn air data, giving a total of 11 sites for N2O mole fraction, 12 sites for d15Nbulk, 11 sites for d18O, and 8 sites for d15NSP values. | ["POLYGON((-180 -67,-144 -67,-108 -67,-72 -67,-36 -67,0 -67,36 -67,72 -67,108 -67,144 -67,180 -67,180 -69.3,180 -71.6,180 -73.9,180 -76.2,180 -78.5,180 -80.8,180 -83.1,180 -85.4,180 -87.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.7,-180 -85.4,-180 -83.1,-180 -80.8,-180 -78.5,-180 -76.2,-180 -73.9,-180 -71.6,-180 -69.3,-180 -67))"] | ["POINT(0 -89.999)"] | false | false |
Antarctic Subsea Cable Workshop Report
|
2130663 |
2023-05-18 | Andreasen, Julia; Roop, Heidi A; Pundsack, Jonathan W; Howe, Bruce; Jacobs, Gwen; Lassner, David; Yoshimi, Garrett; Timm, Kristin; Neff, Peter |
2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science |
Final report of the 2021 Antarctic Subsea Cable Workshop, held virtually June 29 - July 1. The National Science Foundation (NSF)-funded workshop addressed questions around the value and feasibility of deploying a new optical fiber submarine cable system that would supply high-speed internet connectivity to McMurdo Station to address the severe network bandwidth bottlenecks that currently constrain scientific research in Antarctica. | [] | [] | false | false |
200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica
|
2317097 |
2023-03-24 | Braddock, Scott |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
This data set contains unprocessed radar profiles collected with a GSSI 200 MHz Hyperstacking antenna near Winkie Nunatak, West Antarctica. This data was collected to estimate depth-to-bedrock along a subglacial ridge line at depths between 20 - 120 meters. | ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"] | ["POINT(-99.769 -74.8635)"] | false | false |
Radiocarbon Ages from Beaches on Joinville Island, Antarctic Peninsula
|
1644197 |
2022-12-19 | Simms, Alexander |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
This dataset consists of the location, elevation, and age of samples obtained from Joinville Island along the Antarctic Peninsula | [] | [] | false | false |
Ground-Penetrating Radar data from Livingston Island in the Antarctic Peninsula
|
1644197 |
2022-12-19 | Simms, Alexander |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
This dataset includes ground-penetrating radar (GPR) data collected on Livingston Island in the Antarctic Peninsula. | [] | [] | false | false |
Ground Penetrating Radar Profiles from Beaches on Joinville Island, Antarctic Peninsula
|
1644197 |
2022-12-19 | Simms, Alexander |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
This dataset provides the raw and processed ground-penetrating radar (GPR) data collected on Joinville Island in the Antarctic Peninsula. | [] | [] | false | false |
Walcott Glacier area radiocarbon data
|
1643248 |
2022-10-18 | Hall, Brenda |
Response of the Antarctic Ice Sheet to the last great global warming |
This dataset contains radiocarbon dates of subfossil algal mats associated with Ross Sea drift near Walcott and Howchin Glaciers, southern Royal Society Range. These dates constrain the age of Ross Sea drift in this region. | ["POLYGON((163.2 -78.1,163.26 -78.1,163.32 -78.1,163.38 -78.1,163.44 -78.1,163.5 -78.1,163.56 -78.1,163.62 -78.1,163.68 -78.1,163.74 -78.1,163.8 -78.1,163.8 -78.11999999999999,163.8 -78.14,163.8 -78.16,163.8 -78.17999999999999,163.8 -78.19999999999999,163.8 -78.22,163.8 -78.24,163.8 -78.25999999999999,163.8 -78.28,163.8 -78.3,163.74 -78.3,163.68 -78.3,163.62 -78.3,163.56 -78.3,163.5 -78.3,163.44 -78.3,163.38 -78.3,163.32 -78.3,163.26 -78.3,163.2 -78.3,163.2 -78.28,163.2 -78.25999999999999,163.2 -78.24,163.2 -78.22,163.2 -78.19999999999999,163.2 -78.17999999999999,163.2 -78.16,163.2 -78.14,163.2 -78.11999999999999,163.2 -78.1))"] | ["POINT(163.5 -78.19999999999999)"] | false | false |
Pyramid Trough Radiocarbon Data
|
1643248 |
2022-10-17 | Hall, Brenda |
Response of the Antarctic Ice Sheet to the last great global warming |
This dataset contains radiocarbon dates of subfossil algal mats associated with Ross Sea drift in Pyramid Trough. These dates constrain the age of Ross Sea drift in this region. The dataset also includes dates of modern algae. | ["POLYGON((163 -78.1,163.07 -78.1,163.14 -78.1,163.21 -78.1,163.28 -78.1,163.35 -78.1,163.42 -78.1,163.48999999999998 -78.1,163.56 -78.1,163.63 -78.1,163.7 -78.1,163.7 -78.13,163.7 -78.16,163.7 -78.19,163.7 -78.22,163.7 -78.25,163.7 -78.28,163.7 -78.31,163.7 -78.34,163.7 -78.37,163.7 -78.4,163.63 -78.4,163.56 -78.4,163.48999999999998 -78.4,163.42 -78.4,163.35 -78.4,163.28 -78.4,163.21 -78.4,163.14 -78.4,163.07 -78.4,163 -78.4,163 -78.37,163 -78.34,163 -78.31,163 -78.28,163 -78.25,163 -78.22,163 -78.19,163 -78.16,163 -78.13,163 -78.1))"] | ["POINT(163.35 -78.25)"] | false | false |
Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2
|
1643664 |
2022-08-16 | Severinghaus, Jeffrey P. |
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability |
This data set comprises measurements of noble and inert gases in the firn at the DE08-OH site sampled in 2018-2019 near the summit of Law Dome, Antarctica. The data show the expected gravitational enrichment of heavy isotopes with depth, somewhat attenuated by the high accumulation rate and a near-surface well-mixed zone (convective zone), and the "lock-in" horizon at 68 m depth. As seen at many other sites, the heavy isotope of oxygen 18O is depleted progressively with depth within the lock-in zone due to faster gas permeation of 16O16O relative to 18O16O from compressed air bubbles. | [] | [] | false | false |
Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy
|
1643664 |
2022-08-16 | Severinghaus, Jeffrey P. |
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability |
This data set consists of high-precision krypton and argon isotope measurements, along with 15N and 18O of O2. This data tests the hypothesis that the 2nd order parameter 86Krexcess (86Kr/82Kr - 40Ar/36Ar) serves as a proxy indicator of past storminess, via atmospheric pressure changes that cause barometric pumping in the firn and hence greater gravitational disequilibrium in the heavier Kr atom than in Ar. These measurements were made as part of the US-Australian Law Dome DE08-OH campaign in 2018-2019. Nitrogen and dioxygen isotopes were also measured. | [] | [] | false | false |
Specific growth rate measurements for 43 Southern Ocean diatoms
|
1543245 |
2022-06-27 | Bishop, Ian |
NSFGEO-NERC: Evolutionary Response of Southern Ocean Diatoms to Environmental Change |
This dataset includes records of the specific growth rates measured for 43 clonal diatom strains originally isolated during the research cruise NBP-1701 across the Pacific sector of the Southern Ocean during December 2016-January 2017. Strains were grown under continuous light (130 µmol m-2 s-1) at up to 8 temperatures that span all or most of each strain’s thermal niche width, from 0-12 degrees C, which encompasses each strain’s optimum temperature for growth. Strains have been molecularly identified to species via 18S Sanger sequencing. Data include the following information for each record: Internal lab strain reference ID, date collected, latitude, longitude, Southern Ocean region, species, tested temperature, replicate number and specific growth rate. Data are provided in comma-separated values (csv) format. | ["POLYGON((-179 -59,-167.7 -59,-156.4 -59,-145.1 -59,-133.8 -59,-122.5 -59,-111.19999999999999 -59,-99.89999999999999 -59,-88.6 -59,-77.3 -59,-66 -59,-66 -60.9,-66 -62.8,-66 -64.7,-66 -66.6,-66 -68.5,-66 -70.4,-66 -72.3,-66 -74.2,-66 -76.1,-66 -78,-77.3 -78,-88.6 -78,-99.9 -78,-111.2 -78,-122.5 -78,-133.8 -78,-145.10000000000002 -78,-156.4 -78,-167.7 -78,-179 -78,-179 -76.1,-179 -74.2,-179 -72.3,-179 -70.4,-179 -68.5,-179 -66.6,-179 -64.7,-179 -62.8,-179 -60.900000000000006,-179 -59))"] | ["POINT(-122.5 -68.5)"] | false | false |
Pine Island Bay Relative Sea-Level Data
|
1738989 |
2022-04-11 | Braddock, Scott; Hall, Brenda |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
This dataset includes radiocarbon dates and elevations of organic samples in raised beaches in the Edwards, Lindsey, and Schaefer Islands. It also includes a limited number of cosmogenic exposure-age data of bedrock from these islands. | ["POLYGON((-105 -73,-104.5 -73,-104 -73,-103.5 -73,-103 -73,-102.5 -73,-102 -73,-101.5 -73,-101 -73,-100.5 -73,-100 -73,-100 -73.1,-100 -73.2,-100 -73.3,-100 -73.4,-100 -73.5,-100 -73.6,-100 -73.7,-100 -73.8,-100 -73.9,-100 -74,-100.5 -74,-101 -74,-101.5 -74,-102 -74,-102.5 -74,-103 -74,-103.5 -74,-104 -74,-104.5 -74,-105 -74,-105 -73.9,-105 -73.8,-105 -73.7,-105 -73.6,-105 -73.5,-105 -73.4,-105 -73.3,-105 -73.2,-105 -73.1,-105 -73))"] | ["POINT(-102.5 -73.5)"] | false | false |
Electron Microprobe Analysis of feldspar separates from rock and sediment OSL samples from Joinville and Livingston Island Beaches
|
1644197 1643868 |
2022-03-11 | DeWitt, Regina |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
sediment and rock samples were collected on Joinville and Livingston Islands for OSL dating; feldspar separates were prepared; data set includes Electron microprobe analysis of selected feldspar extracts; includes bmp and tif with elemental maps plus elemental concentrations and Ca:Na:K ratios for feldspar analysis | ["POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))"] | ["POINT(-60 -63)"] | false | false |
Joinville and Livingston Islands - rock and sediment OSL ages
|
1644197 1643868 |
2022-03-11 | DeWitt, Regina |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
detailed results for rock and sediment OSL ages; De calculation; dose rate calculation, fading, signal measurement | ["POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))"] | ["POINT(-60 -63)"] | false | false |
OSL data - Joinville and Livingston Islands - Raw data
|
1644197 1643868 |
2022-03-11 | DeWitt, Regina |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
raw OSL data for rock and sediment samples collected on Joinville and Livingston Islands | ["POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))"] | ["POINT(-60 -63)"] | false | false |
Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy
|
1341464 |
2022-02-14 | Jones, Colin; Robinson, Rebecca; Brzezinski, Mark; Riesselman, Christina; Closset, Ivia; Kelly, Roger; Robinson, Rebecca |
Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump |
Tracking variations in the surface ocean supply and demand of nitrate, a key marine nutrient, can help constrain the contribution of biological production in driving past climate shifts. The nitrogen isotopic composition (as δ15N) of organic matter in marine sediments is a proxy for surface ocean nitrate supply and demand over time but it may be subject to alteration during sinking and burial. The isotopic composition of nitrogen contained in the shells, or frustules, of diatoms (δ15NDB) is protected and is therefore a potentially more robust tracer of nitrate use in the past. Here we show that δ15NDB in Southern Ocean community cultures does not depend on species composition. We found the εDB (= biomass δ15N - δ15NDB) of the community growouts was -4.8 ± 0.8‰, more than 10‰ different from previous monospecific growouts, but statistically indistinguishable from previous Southern Ocean and North Pacific surface ocean observations. The two community growouts, seeded with populations from 66° and 61°S, had distinct community compositions but indistinguishable εDB, suggesting species composition does not primarily set δ15NDB values in the Southern Ocean. Our results demonstrate that under nitrate-replete conditions, δ15NDB values of frustules sinking from the surface ocean robustly track surface ocean nitrate δ15N values and therefore nitrate supply and demand. | ["POLYGON((-170.4 -60.8,-170.36 -60.8,-170.32 -60.8,-170.28 -60.8,-170.24 -60.8,-170.2 -60.8,-170.16 -60.8,-170.12 -60.8,-170.08 -60.8,-170.04 -60.8,-170 -60.8,-170 -61.34,-170 -61.88,-170 -62.42,-170 -62.96,-170 -63.5,-170 -64.04,-170 -64.58,-170 -65.12,-170 -65.66,-170 -66.2,-170.04 -66.2,-170.08 -66.2,-170.12 -66.2,-170.16 -66.2,-170.2 -66.2,-170.24 -66.2,-170.28 -66.2,-170.32 -66.2,-170.36 -66.2,-170.4 -66.2,-170.4 -65.66,-170.4 -65.12,-170.4 -64.58,-170.4 -64.04,-170.4 -63.5,-170.4 -62.96,-170.4 -62.42,-170.4 -61.88,-170.4 -61.34,-170.4 -60.8))"] | ["POINT(-170.2 -63.5)"] | false | false |
Physical and geochemical data from five sediment cores collected offshore Thwaites Glacier
|
1738942 |
2022-01-27 | Lepp, Allison |
NSF-NERC: THwaites Offshore Research (THOR) |
This dataset contains measurements from grain-size, x-ray fluorescence (XRF), and physical properties (including magnetic susceptibility, water content, and shear strength) analyses of five sediment cores collected offshore Thwaites Glacier during cruises NBP19-02 (cores KC04, KC08, and KC23) and NBP20-02 (cores KC33 and KC67). We estimate the cores, which are between 213.5 and 297.5 cm in length, reflect deposition during the last ~10 kyr, consistent with published constraints of deglaciation of this region. Data are organized in Microsoft Excel spreadsheets and core locations are provided in a PDF. | ["POLYGON((-107.38 -74.64,-107.065 -74.64,-106.75 -74.64,-106.435 -74.64,-106.12 -74.64,-105.805 -74.64,-105.49 -74.64,-105.175 -74.64,-104.86 -74.64,-104.545 -74.64,-104.23 -74.64,-104.23 -74.683,-104.23 -74.726,-104.23 -74.769,-104.23 -74.812,-104.23 -74.855,-104.23 -74.898,-104.23 -74.941,-104.23 -74.984,-104.23 -75.027,-104.23 -75.07,-104.545 -75.07,-104.86 -75.07,-105.175 -75.07,-105.49 -75.07,-105.805 -75.07,-106.12 -75.07,-106.435 -75.07,-106.75 -75.07,-107.065 -75.07,-107.38 -75.07,-107.38 -75.027,-107.38 -74.984,-107.38 -74.941,-107.38 -74.898,-107.38 -74.855,-107.38 -74.812,-107.38 -74.769,-107.38 -74.726,-107.38 -74.683,-107.38 -74.64))"] | ["POINT(-105.805 -74.855)"] | false | false |
Mt. Waesche ground-penetrating radar data 2018-2019
|
1744949 |
2021-12-08 | Braddock, Scott |
Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial |
Here we deposited data sets from the 2018-2019 Mt. Waesche field season. Included are 5 MHz, 10 MHz, 100 MHz, and 350 MHz. Datasets are provided in SEG-Y format for the 100 and 350 MHz and H5 files for the 5 and 10 MHz. | ["POLYGON((-127.5 -77,-127.4 -77,-127.3 -77,-127.2 -77,-127.1 -77,-127 -77,-126.9 -77,-126.8 -77,-126.7 -77,-126.6 -77,-126.5 -77,-126.5 -77.04,-126.5 -77.08,-126.5 -77.12,-126.5 -77.16,-126.5 -77.2,-126.5 -77.24,-126.5 -77.28,-126.5 -77.32,-126.5 -77.36,-126.5 -77.4,-126.6 -77.4,-126.7 -77.4,-126.8 -77.4,-126.9 -77.4,-127 -77.4,-127.1 -77.4,-127.2 -77.4,-127.3 -77.4,-127.4 -77.4,-127.5 -77.4,-127.5 -77.36,-127.5 -77.32,-127.5 -77.28,-127.5 -77.24,-127.5 -77.2,-127.5 -77.16,-127.5 -77.12,-127.5 -77.08,-127.5 -77.04,-127.5 -77))"] | ["POINT(-127 -77.2)"] | false | false |
Circum-Antarctic grounding-line sinuosity
|
1246353 1745043 1745055 |
2021-11-10 | Simkins, Lauren; Stearns, Leigh; Riverman, Kiya |
Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum. Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations |
The dataset here allows exploration of the causes and significance of Antarctic grounding-line sinuosity by coupling observations of contemporary Antarctic grounding lines and paleo-grounding lines expressed as ice-marginal landforms on the Ross Sea continental shelf. Modern grounding lines are derived from the MEaSUREs Version 2 Differential Satellite Radar Interferometry dataset with spatial resolutions of 25-120 m spanning February 1992 to December 2014 (Rignot et al., 2016; Mouginot et al., 2017). The boundaries of individual grounding lines representative of individual glacial catchments (n=664) were delineated by the inflection points of the shear strain rate, εxy (c.f Van der Veen et al., 2011). Sinuosity was calculated as the ratio of the true length, orthogonal to ice-flow direction, of the grounding lines and the straight line length between end-points and in units of km/km. Raster data were extracted at 1-km points along each grounding line; the mean was calculated for each grounding line and merged in a table with sinuosity data. A dataset of 6,275 paleo-grounding lines expressed as ice-marginal landforms on the deglaciated western Ross Sea continental shelf are used in this study, originally published by Simkins et al., 2018. The ice-marginal landforms were mapped from multibeam echo sounder data that was collected onboard the RVIB Nathaniel B. Palmer (NBP) 15-02 cruise using a Kongsberg EM122 operating in dual swath mode at 12 kHz frequency with 30-60% swath overlap (Cruise DOI: 10.7284/901477). The resulting bathymetry data was gridded at 20-40 m with decimeter vertical elevation resolution depending on water depth and sea-state. Sinuosity is calculated as a ratio of true (mapped) landform length, measured in the across paleo-ice flow direction at the crest of the landform, to the straight line distance between the mapped landform endpoints and in units of km/km. To compare modern and paleo-grounding lines, we use a consistent length scale by segmenting the grounding lines into 2-km sections for the two datasets (modern, n=12,966; paleo, n=5,832), even though this eliminates grounding lines that are less than 2-km long and thus results in 1 modern and 3,873 paleo-grounding lines removed. The full-length and 2-km segmented groundings lines are provided as shapefiles "InSAR_groundinglines_full" and "InSAR_groundinglines_2km", the paleo-grounding lines are provided as shapefiles "RossSea_icemarginal_full" and "RossSea_icemarginal_2km", and points marking modern grounding lines retreat from repeat InSAR surveys are provided as shapefile "InSAR_retreat_points", all stored together in a geodatabase named "Antarctic_groundinglines.gbd". Additional grounding line metrics, including length, sinuosity, bed roughness, and bed slope for modern and paleo-grounding lines, and height-above-buoyancy gradient, ice-flow velocity, presence of pinning points and ice shelves are provided for modern grounding lines. The published dataset was compiled and analyzed in the article "Controls on circum-Antarctic grounding-line sinuosity " by Simkins, L.M., Stearns, L.A., and Riverman, K.L, which will be submitted to a peer-review journal in November 2021. References Mouginot, J., B. Scheuchl, and E. Rignot. 2017. MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. Rignot, E., J. Mouginot, and B. Scheuchl. 2016. MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry, Version 2. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. Simkins, L. M., Greenwood, S. L., & Anderson, J. B. (2018). Diagnosing ice sheet grounding line stability from landform morphology. The Cryosphere, 12(8), 2707-2726. Van der Veen, C. J., J. C. Plummer, & L. A. Stearns. (2011). Controls on the recent speed up of Jakobshavn Isbræ, West Greenland. Journal of Glaciology, 57(204), 770-782 | ["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))"] | ["POINT(0 -89.999)"] | false | false |
Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020
|
1738992 |
2021-10-11 | Alley, Karen; Wild, Christian; Scambos, Ted; Muto, Atsu; Pettit, Erin; Truffer, Martin; Wallin, Bruce; Klinger, Marin |
NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment |
This dataset includes GeoTiffs of two-year averages of ice flow velocity (including x- and y-components and flow speed) and longitudinal, transverse, and shear strain rates for the Thwaites Eastern Ice Shelf (TEIS) from 2001-2020. The grids were derived from feature tracking on MODIS, Landsat-7, and Landsat-8 imagery. Each pixel in a grid represents the median value of a stack of all available pixels for each time period. Data are gridded at a 500 m spatial resolution in a polar stereographic (EPSG:3031) projection. Speed units are m/day and strain rates are in units of /day. In addition, we provide videos of each variable (excluding x- and y-velocity components) placed alongside a MODIS image of the same extent and from around the same time to provide context. In addition to the variables noted above, we include videos for flow direction (in degrees from grid north in an EPSG:3031 projection) and a zoomed-in version of flow direction, which were calculated from the provided grids. | ["POLYGON((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))"] | ["POINT(-109 -75)"] | false | false |
Erebus GPS timeseries
|
2039432 1917149 1643952 |
2021-09-03 | Grapenthin, Ronni |
Collaborative Research: Multi-Parameter Geophysical Constraints on Volcano Dynamics of Mt. Erebus and Ross Island, Antarctica |
We use NASA's Jet Propulsion Laboratory's (JPL) GipsyX software in PPP mode with ambiguity resolution applied to 24 hour segments of data to generate daily position solutions. We use JPL's orbit and clock products and International GNSS Service (IGS) antenna phase center models. Where available, we use JPL's second order ionospheric corrections, otherwise we fall back on those provided by the IGS. To correct tropospheric delays, we use the GPT2 model as implemented in GipsyX. Ocean tidal loading corrections utilize the TPXO7.2 and ATLAS model, a combination of hydrodynamic model and altimetry data, with respect to Earth's Center of Mass implemented in SPOTL. We obtain position solutions for each station day in a fiducial-free reference frame, which we then transform into the 2014 International Reference Frame using JPL's transformation coefficients and generate timeseries of position change relative to the first epoch, given in the *.series files which are ASCII files with the following columns: decimal year displacement east (m) displacement north (m) displacement up (m) sigma east (m) sigma north (m) sigma up (m) east-north covariance east-up covariance north-up covariance Year (YYYY) Month (MM) Day (DD) Hour (hh) Minute (mm) Second (ss) Solution path We generate position time series relative to stable Antarctic plate by removing the plate velocities modeled by Argus et al (2010). These are provided in the *.npy files that be readily read into python scripts: pos_ts = np.load('test.npy').flatten()[0] pos_ts['itrf'] provides the ITRF data as above pos_ts['plate'] provides the data with Antarctic plate motion removed. | ["POLYGON((166 -77.1,166.39 -77.1,166.78 -77.1,167.17 -77.1,167.56 -77.1,167.95 -77.1,168.34 -77.1,168.73 -77.1,169.12 -77.1,169.51 -77.1,169.9 -77.1,169.9 -77.18,169.9 -77.26,169.9 -77.34,169.9 -77.42,169.9 -77.5,169.9 -77.58,169.9 -77.66,169.9 -77.74,169.9 -77.82,169.9 -77.9,169.51 -77.9,169.12 -77.9,168.73 -77.9,168.34 -77.9,167.95 -77.9,167.56 -77.9,167.17 -77.9,166.78 -77.9,166.39 -77.9,166 -77.9,166 -77.82,166 -77.74,166 -77.66,166 -77.58,166 -77.5,166 -77.42,166 -77.34,166 -77.26,166 -77.18,166 -77.1))"] | ["POINT(167.95 -77.5)"] | false | false |
Common-era black carbon deposition and atmospheric modeling for 6 Antarctic ice cores
|
None | 2021-07-16 | McConnell, Joseph; Chellman, Nathan | No project link provided | This dataset includes: 1) rBC concentration and flux for 6 Antarctic ice core sites (JRI_2008, JRI_D98, NUS08_7, NUS07_7, B53, and B40). 2) FLEXPART backward-model emission sensitivities for 4 Antarctic ice core sites (JRI, B40, B53, NUS07_7). 3) FLEXPART forward-model deposition for simulated biomass burning emissions from New Zealand. 4) Tie points to constrain flow model used to develop JRI_2008 chronology. | ["POLYGON((-57.7 -64.2,-46.44 -64.2,-35.18 -64.2,-23.92 -64.2,-12.66 -64.2,-1.4 -64.2,9.86 -64.2,21.12 -64.2,32.38 -64.2,43.64 -64.2,54.9 -64.2,54.9 -65.99,54.9 -67.78,54.9 -69.57,54.9 -71.36,54.9 -73.15,54.9 -74.94,54.9 -76.73,54.9 -78.52,54.9 -80.31,54.9 -82.1,43.64 -82.1,32.38 -82.1,21.12 -82.1,9.86 -82.1,-1.4 -82.1,-12.66 -82.1,-23.92 -82.1,-35.18 -82.1,-46.44 -82.1,-57.7 -82.1,-57.7 -80.31,-57.7 -78.52,-57.7 -76.73,-57.7 -74.94,-57.7 -73.15,-57.7 -71.36,-57.7 -69.57,-57.7 -67.78,-57.7 -65.99,-57.7 -64.2))"] | ["POINT(-1.4 -73.15)"] | false | false |
Adelie penguin resighting data 1997-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0944358 1543459 1935901 0439759 0944141 0944411 0440643 1543541 1543498 1935870 0439200 |
2021-05-12 | Ballard, Grant |
COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels Population Growth at the Southern Extreme: Effects of Early Life Conditions on Adelie penguin Individuals and Colonies A Full Lifecycle Approach to Understanding Adélie Penguin Response to Changing Pack Ice Conditions in the Ross Sea. |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin banding data 1994-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
1543498 1543541 1543459 0944141 0439759 |
2021-05-11 | Ballard, Grant |
COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change A Full Lifecycle Approach to Understanding Adélie Penguin Response to Changing Pack Ice Conditions in the Ross Sea. |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Acclimation of cardiovascular function in Notothenia coriiceps
|
1341663 |
2020-12-18 | Joyce, William; Egginton, Stuart; Farrell, Anthony; Axelsson, Michael; Crockett, Elizabeth; O'Brien, Kristin |
Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes |
The Southern Ocean has experienced stable, cold temperatures for over 10 million years, yet particular regions are currently undergoing rapid warming. To investigate the impacts of warming on cardiovascular oxygen transport, we compared the cardio-respiratory performance in an Antarctic notothenioid (Notothenia coriiceps) that was maintained at 0 or 5°C for 6.0-9.5 weeks. When compared at the fish's respective acclimation temperature, the oxygen consumption rate and cardiac output were significantly higher in 5°C-acclimated than 0°C-acclimated fish. The 2.7-fold elevation in cardiac output in 5°C-acclimated fish (17.4 vs. 6.5 ml min-1 kg-1) was predominantly due to a doubling of stroke volume, likely in response to increased cardiac preload, as measured by higher central venous pressure (0.15 vs. 0.08 kPa); tachycardia was minor (29.5 vs. 25.2 beats min-1). When fish were acutely warmed, oxygen consumption rate increased by similar amounts in 0°C- and 5°C-acclimated fish at equivalent test temperatures. In both acclimation groups, the increases in oxygen consumption rate during acute heating were supported by increased cardiac output achieved by elevating heart rate, while stroke volume changed relatively little. Cardiac output was similar between both acclimation groups until 12°C when cardiac output became significantly higher in 5°C-acclimated fish, driven largely by their higher stroke volume. Although cardiac arrhythmias developed at a similar temperature (~14.5°C) in both acclimation groups, the hearts of 5°C-acclimated fish continued to pump until significantly higher temperatures (CTmax for cardiac function 17.7 vs. 15.0°C for 0°C-acclimated fish). These results demonstrate that N. coriiceps is capable of increasing routine cardiac output during both acute and chronic warming, although the mechanisms are different (heart rate-dependent versus primarily stroke volume-dependent regulation, respectively). Cardiac performance was enhanced at higher temperatures following 5°C acclimation, suggesting cardiovascular function may not constrain the capacity of N. coriiceps to withstand a warming climate. | [] | [] | false | false |
Whillans and Mercer Shear Margin Ice Flow simulation in ISSM
|
1842021 |
2020-12-12 | Kaluzienski, Lynn |
RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence |
The dataset includes initialization and output files of a numerical ice flow simulation of the Whillans and Mercer Ice Streams . The Ice Sheet System Model (ISSM) model was used to solve a 100-year transient stress balance solution of the region with ~10 kPA/yr friction increase downstream of the shear margin between the Whillans and Mercer ice streams. | ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.6,-111 -83.2,-111 -83.8,-111 -84.4,-111 -85,-111 -85.6,-111 -86.2,-111 -86.8,-111 -87.4,-111 -88,-116.7 -88,-122.4 -88,-128.1 -88,-133.8 -88,-139.5 -88,-145.2 -88,-150.9 -88,-156.6 -88,-162.3 -88,-168 -88,-168 -87.4,-168 -86.8,-168 -86.2,-168 -85.6,-168 -85,-168 -84.4,-168 -83.8,-168 -83.2,-168 -82.6,-168 -82))"] | ["POINT(-139.5 -85)"] | false | false |
2017 GPR Observations of the Whillans and Mercer Ice Streams
|
1842021 |
2020-12-12 | Kaluzienski, Lynn |
RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence |
The dataset includes GPS coordinates for crevasse/fracture locations picked from 350MHz and 400Mhz frequency GPR dataset in the Whillans/Mercer Shear Margin along the SALSA traverse route with associated kinematic outputs for each feature (shear strain rate, vorticity, dilatation). GPS coordinates are in the Antarctic Polar Stereographic projection (EPSG:3031). | ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))"] | ["POINT(-139.5 -84.5)"] | false | false |
Granulometry of Joinville and Livingston Island beaches
|
0724929 |
2020-11-06 | Theilen, Brittany; Simms, Alexander |
Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches |
["POLYGON((-61.8 -61.3,-61.07 -61.3,-60.34 -61.3,-59.61 -61.3,-58.88 -61.3,-58.15 -61.3,-57.42 -61.3,-56.69 -61.3,-55.96 -61.3,-55.23 -61.3,-54.5 -61.3,-54.5 -61.55,-54.5 -61.8,-54.5 -62.05,-54.5 -62.3,-54.5 -62.55,-54.5 -62.8,-54.5 -63.05,-54.5 -63.3,-54.5 -63.55,-54.5 -63.8,-55.23 -63.8,-55.96 -63.8,-56.69 -63.8,-57.42 -63.8,-58.15 -63.8,-58.88 -63.8,-59.61 -63.8,-60.34 -63.8,-61.07 -63.8,-61.8 -63.8,-61.8 -63.55,-61.8 -63.3,-61.8 -63.05,-61.8 -62.8,-61.8 -62.55,-61.8 -62.3,-61.8 -62.05,-61.8 -61.8,-61.8 -61.55,-61.8 -61.3))"] | ["POINT(-58.15 -62.55)"] | false | false | |
N2O Concentration and Isotope Data for 74-59 ka from Taylor Glacier, Antarctica
|
1246148 1245659 1245821 |
2020-11-02 | Menking, James; Brook, Edward J.; Schilt, Adrian; Shackleton, Sarah; Dyonisius, Michael; Severinghaus, Jeffrey P.; Petrenko, Vasilii |
Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive |
Ice core measurements of the concentration and stable isotopic composition of atmospheric nitrous oxide (N2O) 74,000-59,000 years ago constrain marine and terrestrial emissions. The data include two major Dansgaard-Oeschger (D-O) events and the N2O decrease during global cooling at the Marine Isotope Stage (MIS) 5a-4 transition. The N2O increase associated with D-O 19 (~73-71.5 ka) was driven by equal contributions from marine and terrestrial emissions. The N2O decrease during the transition into MIS 4 (~71.5-67.5 ka) was caused by gradual reductions of similar magnitude in both marine and terrestrial sources. A 50 ppb increase in N2O concentration at the end of MIS 4 was caused by gradual increases in marine and terrestrial emissions between ~64-61 ka, followed by an abrupt increase in marine emissions at the onset of D-O 16/17 (59.5 ka). This suggests that the importance of marine versus terrestrial emissions in controlling millennial-scale N2O fluctuations varied in time. | [] | [] | false | false |
ANTAEM project airborne EM resistivity data from McMurdo Region
|
1644187 |
2020-09-12 | Tulaczyk, Slawek |
Collaborative Research: Antarctic Airborne ElectroMagnetics (ANTAEM) - Revealing Subsurface Water in Coastal Antarctica |
The ANTAEM survey was carried out in the period November 12th to 28th, 2018, with the SkyTEM 312 system. Twenty-one missions (flights) were conducted over 11 production days of helicopter service, resulting in a total of approximately ~3400 line km of data. The SkyTEM system records data from take-off until landing resulting in multiple lines converging to the landing pads in McMurdo and at Marble Point. The production without overlapping lines adds up to approximately 2900 line km. The flight speed was approximately 120 km/h at a target flight altitude of ~50 m (sensor height), but the actual sensor height varies depending on the terrain. The surveys were carried out with a Bell 212 helicopter, which carried the SkyTEM sensor as a sling load. The SkyTEM system was configured in a standard two-moment setup (low moment, LM and high moment, HM). Areas with extremely resistive dry and/or frozen sediment/bedrock, and glacier ice often produce EM-signals with amplitudes below the detection level of the system. Data from these low signal environments cannot be inverted into resistivity models. Data with strong induced polarization effects cannot be inverted for resistivity either. These data were discharged in this standard data delivery. The EM-data and inversion result (resistivity models) are delivered in the SkyTEM2018_dat.xyz and SkyTEM2018_inv.xyz files respectably. The RECORD number in the two files links data and model together. EM-data and data uncertainty for data entering inversion. Info stated in file Header: NAN value, Data unit, Coordinate system, Gate times. The SkyTEM system uses at High-Low moment data recording cycle, therefore only a subset of the total 40 time gates are preset for each moment. The standard lateral constraints inversion (LCI), delivered in the SkyTEM2018_inv.xyz file, was carried out with a smooth 30 layered resistivity model discretized to a depth of 500 m. A depth of investigation (DOI) was estimated for each resistivity model. | ["POLYGON((161 -76.9,161.75 -76.9,162.5 -76.9,163.25 -76.9,164 -76.9,164.75 -76.9,165.5 -76.9,166.25 -76.9,167 -76.9,167.75 -76.9,168.5 -76.9,168.5 -77.04,168.5 -77.18,168.5 -77.32,168.5 -77.46,168.5 -77.6,168.5 -77.74,168.5 -77.88,168.5 -78.02,168.5 -78.16,168.5 -78.3,167.75 -78.3,167 -78.3,166.25 -78.3,165.5 -78.3,164.75 -78.3,164 -78.3,163.25 -78.3,162.5 -78.3,161.75 -78.3,161 -78.3,161 -78.16,161 -78.02,161 -77.88,161 -77.74,161 -77.6,161 -77.46,161 -77.32,161 -77.18,161 -77.04,161 -76.9))"] | ["POINT(164.75 -77.6)"] | false | false |
Roosevelt Island Ice Core Time Scale and Associated Data
|
0944021 |
2020-07-13 | Brook, Edward J.; Lee, James |
Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island |
Data archived here were used to create the Roosevelt Island Ice Core gas age and ice age time scales. Data include methane concentrations, nitrogen and oxygen isotope ratios of N2 and O2, total air content and the D/H ratio of the ice. Derived products included here include ice age and gas age time scales. | ["POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))"] | ["POINT(-162 -79.25)"] | false | false |
Carbon monoxide mixing ratios and stable isotopic values, SPICE
|
1443482 |
2020-07-09 | Mak, John |
Collaborative Research: Using Stable Isotopes to Constrain the Atmospheric Carbon Monoxide Budget over the Last 20,000 Years |
Data from measurement of CO mixing ratios and stable isotopes from the South Pole Ice Core for the first ca 10,000 years BP | ["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))"] | ["POINT(0 -89.999)"] | false | false |
Ohio Range Subglacial rock core cosmogenic nuclide data
|
1341658 |
2020-06-28 | Mukhopadhyay, Sujoy |
Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier |
The data set consists of cosmogenic berrylium-10 and aluminum-26, along with neon-21, in a set of 4 rock-cores obtained from the Ohio Range, West Antarctica. The rock cores were obtained using the WInkie drill. The depth to the cores varies from 12 meters to 28 meters. The recovered rock cores analyzed for the cosmogenic isotopes varies from 22 cm long to 50 cm long. The data include the following formation: sample details, cosmogenic berrylium-10, aluminum-26 and upper bounds for cosmogenic 21 (since samples have nucleogenic 21) and the step heating data for neon. The data are in Mircrosoft excel format. | ["POLYGON((-116.46 -84.78,-116.452 -84.78,-116.444 -84.78,-116.436 -84.78,-116.428 -84.78,-116.42 -84.78,-116.412 -84.78,-116.404 -84.78,-116.396 -84.78,-116.388 -84.78,-116.38 -84.78,-116.38 -84.781,-116.38 -84.782,-116.38 -84.783,-116.38 -84.784,-116.38 -84.785,-116.38 -84.786,-116.38 -84.787,-116.38 -84.788,-116.38 -84.789,-116.38 -84.79,-116.388 -84.79,-116.396 -84.79,-116.404 -84.79,-116.412 -84.79,-116.42 -84.79,-116.428 -84.79,-116.436 -84.79,-116.444 -84.79,-116.452 -84.79,-116.46 -84.79,-116.46 -84.789,-116.46 -84.788,-116.46 -84.787,-116.46 -84.786,-116.46 -84.785,-116.46 -84.784,-116.46 -84.783,-116.46 -84.782,-116.46 -84.781,-116.46 -84.78))"] | ["POINT(-116.42 -84.785)"] | false | false |
ApRES Vertical Strain Study
|
1142167 |
2020-05-15 | Pettit, Erin |
Collaborative Research: VeLveT Ice - eVoLution of Fabric and Texture in Ice at WAIS Divide, West Antarctica |
We tested the ability of phase sensitive radar (ApRES) to detect vertical strain throughout the depth of an ice sheet 3400m thick. | ["POLYGON((-112.3 -79.2,-112.22 -79.2,-112.14 -79.2,-112.06 -79.2,-111.98 -79.2,-111.9 -79.2,-111.82 -79.2,-111.74 -79.2,-111.66 -79.2,-111.58 -79.2,-111.5 -79.2,-111.5 -79.23,-111.5 -79.26,-111.5 -79.29,-111.5 -79.32,-111.5 -79.35,-111.5 -79.38,-111.5 -79.41,-111.5 -79.44,-111.5 -79.47,-111.5 -79.5,-111.58 -79.5,-111.66 -79.5,-111.74 -79.5,-111.82 -79.5,-111.9 -79.5,-111.98 -79.5,-112.06 -79.5,-112.14 -79.5,-112.22 -79.5,-112.3 -79.5,-112.3 -79.47,-112.3 -79.44,-112.3 -79.41,-112.3 -79.38,-112.3 -79.35,-112.3 -79.32,-112.3 -79.29,-112.3 -79.26,-112.3 -79.23,-112.3 -79.2))"] | ["POINT(-111.9 -79.35)"] | false | false |
Processed Camera Images acquired during the Laurence M. Gould expedition LMG1311
|
1143981 |
2020-05-01 | Domack, Eugene Walter |
Continuation of the LARISSA Continuous GPS Network in View of Observed Dynamic Response to Antarctic Peninsula Ice Mass Balance and Required Geologic Constraints |
This data set was acquired with a camera during Laurence M. Gould expedition LMG1311 conducted in 2013. These data files are of JPEG format and include Photograph images that have not been processed | ["POLYGON((-66.5 -61.5,-65.85 -61.5,-65.2 -61.5,-64.55 -61.5,-63.9 -61.5,-63.25 -61.5,-62.6 -61.5,-61.95 -61.5,-61.3 -61.5,-60.65 -61.5,-60 -61.5,-60 -61.87,-60 -62.24,-60 -62.61,-60 -62.98,-60 -63.35,-60 -63.72,-60 -64.09,-60 -64.46,-60 -64.83,-60 -65.2,-60.65 -65.2,-61.3 -65.2,-61.95 -65.2,-62.6 -65.2,-63.25 -65.2,-63.9 -65.2,-64.55 -65.2,-65.2 -65.2,-65.85 -65.2,-66.5 -65.2,-66.5 -64.83,-66.5 -64.46,-66.5 -64.09,-66.5 -63.72,-66.5 -63.35,-66.5 -62.98,-66.5 -62.61,-66.5 -62.24,-66.5 -61.87,-66.5 -61.5))"] | ["POINT(-63.25 -63.35)"] | false | false |
Detrital low-temperature thermochronometry from Bourgeois Fjord, AP
|
1543256 |
2020-02-27 | Clinger, Anna |
Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry |
This dataset contains 80 detrital and 2 bedrock apatite (U-Th)/He thermochronometric ages from Bourgeois Fjord. Data was collected to constrain timing and patterns of topographic change at Bourgeois Fjord on Ma timescales. Analyses were conducted at the Berkeley Geochronology Center and presented in Microsoft Excel formats. | ["POLYGON((-66.80688 -67.420674,-66.732895 -67.420674,-66.65891 -67.420674,-66.584925 -67.420674,-66.51094 -67.420674,-66.436955 -67.420674,-66.36297 -67.420674,-66.288985 -67.420674,-66.215 -67.420674,-66.141015 -67.420674,-66.06703 -67.420674,-66.06703 -67.4542151,-66.06703 -67.4877562,-66.06703 -67.5212973,-66.06703 -67.5548384,-66.06703 -67.5883795,-66.06703 -67.6219206,-66.06703 -67.6554617,-66.06703 -67.6890028,-66.06703 -67.7225439,-66.06703 -67.756085,-66.141015 -67.756085,-66.215 -67.756085,-66.288985 -67.756085,-66.36297 -67.756085,-66.436955 -67.756085,-66.51094 -67.756085,-66.584925 -67.756085,-66.65891 -67.756085,-66.732895 -67.756085,-66.80688 -67.756085,-66.80688 -67.7225439,-66.80688 -67.6890028,-66.80688 -67.6554617,-66.80688 -67.6219206,-66.80688 -67.5883795,-66.80688 -67.5548384,-66.80688 -67.5212973,-66.80688 -67.4877562,-66.80688 -67.4542151,-66.80688 -67.420674))"] | ["POINT(-66.436955 -67.5883795)"] | false | false |
Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data
|
1443534 |
2020-01-10 | Das, Indrani; Padman, Laurence; Bell, Robin; Fricker, Helen; Hulbe, Christina; Siddoway, Christine; Dhakal, Tejendra; Frearson, Nicholas; Mosbeux, Cyrille; Cordero, Isabel; Siegfried, Matt; Tinto, Kirsty |
Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE) |
This dataset was produced for the manuscript \"Multi-decadal basal melt rates and structure of the Ross Ice Shelf, Antarctica using airborne ice penetrating radar\" by Das et al., 2020 in Journal of Geophysical Research-Earth Surface. It has total ice thickness, thickness of the LMI layer, strain induced thickness change, basal melt rates and the error estimate for basal melt rates. | ["POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,178.1 -86,176.2 -86,174.3 -86,172.4 -86,170.5 -86,168.6 -86,166.7 -86,164.8 -86,162.9 -86,161 -86,161 -85.1,161 -84.2,161 -83.3,161 -82.4,161 -81.5,161 -80.6,161 -79.7,161 -78.8,161 -77.9,161 -77,162.9 -77,164.8 -77,166.7 -77,168.6 -77,170.5 -77,172.4 -77,174.3 -77,176.2 -77,178.1 -77,-180 -77))"] | ["POINT(-174.5 -81.5)"] | false | false |
South Pole CH4 data for termination
|
1443464 |
2019-12-11 | Sowers, Todd A. |
Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core |
The overiding goal for our collaborative project is to provide the necessary data to construct an accurate gas age scale all along the SPICE core. Downcore measurements of CH4 and other species would help to constrain the ice age - gas age difference all along the core that is a prerequisite for the construction of the gas age vs depth profile that is the backbone for all atmospheric reconstructions. | ["POINT(0 -90)"] | ["POINT(0 -90)"] | false | false |
The South Pole Ice Core (SPICEcore) chronology and supporting data
|
1443336 |
2019-08-29 | Winski, Dominic A.; Fudge, T. J.; Dunbar, Nelia; Buizert, Christo; Bay, Ryan; Souney, Joseph Jr.; Sigl, Michael; McConnell, Joseph; Fegyveresi, John; Cole-Dai, Jihong; Thundercloud, Zayta; Cox, Thomas S.; Kreutz, Karl; Epifanio, Jenna; Ortman, Nikolas; Brook, Edward J.; Beaudette, Ross; Sowers, Todd A.; Steig, Eric J.; Morris, Valerie; Kahle, Emma; Ferris, David G.; Aydin, Murat; Nicewonger, Melinda R.; Casey, Kimberly A.; Alley, Richard; Waddington, Edwin D.; Osterberg, Erich; Severinghaus, Jeffrey P.; Jones, Tyler R.; Iverson, Nels |
Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements |
The South Pole Ice Core (SPICEcore) was drilled in 2014-2016 to provide a detailed multi-proxy archive of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. Interpretation of these records requires an accurate depth-age relationship. Here, we present the SP19 timescale for the age of the ice of SPICEcore. SP19 is synchronized to the WD2014 chronology from the West Antarctic Ice Sheet Divide (WAIS Divide) ice core using stratigraphic matching of 251 volcanic events. These events indicate an age of 54,302 +/- 519 years BP (before the year 1950) at the bottom of SPICEcore. Annual layers identified in sodium and magnesium ions to 11,341 BP were used to interpolate between stratigraphic volcanic tie points, yielding an annually-resolved chronology through the Holocene. Estimated timescale uncertainty during the Holocene is less than 18 years relative to WD2014, with the exception of the interval between 1800 to 3100 BP when uncertainty estimates reach +/- 25 years due to widely spaced volcanic tie points. Prior to the Holocene, uncertainties remain within 124 years relative to WD2014. Results show an average Holocene accumulation rate of 7.4 cm/yr (water equivalent). The time variability of accumulation rate is consistent with expectations for steady-state ice flow through the modern spatial pattern of accumulation rate. Time variations in nitrate concentration, nitrate seasonal amplitude, and δ15N of N2 in turn are as expected for the accumulation-rate variations. The highly variable yet well-constrained Holocene accumulation history at the site can help improve scientific understanding of deposition-sensitive climate proxies such as δ15N of N2 and photolyzed chemical compounds. | ["POINT(-180 -90)"] | ["POINT(-180 -90)"] | false | false |
Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins
|
1148982 |
2019-07-31 | Hansen, Samantha |
CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin |
The Transantarctic Mountains (TAMs) are the largest non-collisional mountain range on Earth. Their origin, as well as the origin of the Wilkes Subglacial Basin (WSB) along the inland side of the TAMs, have been widely debated, and a key constraint to distinguish between competing models is the underlying crustal structure. Previous investigations have examined this structure but have primarily focused on a small region of the central TAMs near Ross Island, providing little along-strike constraint. In this study, we use data from the new Transantarctic Mountains Northern Network and from five stations operated by the Korea Polar Research Institute to investigate the crustal structure beneath a previously unexplored portion of the TAMs. Using S-wave receiver functions and Rayleigh wave phase velocities, crustal thickness and average crustal shear velocity (Vs) are resolved within ±4 km and ±0.1 km/s, respectively. The crust thickens from ~20 km near the Ross Sea coast to ~46 km beneath the northern TAMs, which is somewhat thicker than that imaged in previous studies beneath the central TAMs. The crust thins to ~41 km beneath the WSB.Vs ranges from ~3.1-3.9 km/s, with slower velocities near the coast. Our findings are consistent with a flexural origin for the TAMs and WSB, where these features result from broad flexure of the East Antarctic lithosphere and uplift along its western edge due to thermal conduction from hotter mantle beneath West Antarctica. Locally thicker crust may explain the ~1 km of additional topography in the northern TAMs compared to the central TAMs. | ["POLYGON((150 -72,152 -72,154 -72,156 -72,158 -72,160 -72,162 -72,164 -72,166 -72,168 -72,170 -72,170 -72.3,170 -72.6,170 -72.9,170 -73.2,170 -73.5,170 -73.8,170 -74.1,170 -74.4,170 -74.7,170 -75,168 -75,166 -75,164 -75,162 -75,160 -75,158 -75,156 -75,154 -75,152 -75,150 -75,150 -74.7,150 -74.4,150 -74.1,150 -73.8,150 -73.5,150 -73.2,150 -72.9,150 -72.6,150 -72.3,150 -72))"] | ["POINT(160 -73.5)"] | false | false |
Linking oceanographic conditions, migratory schedules and foraging behaviour during the non-breeding season to reproductive performance in a long-lived seabird
|
1246407 |
2018-12-03 | Jenouvrier, Stephanie |
Linking Foraging Behaviors to Demography to understand Albatrosses Population Responses to Climate Change |
1. Studies of the mechanisms underlying climate-induced population changes are critically needed to better understand and accurately predict population responses to climate change. Long-lived migratory species might be particularly vulnerable to climate change as they are constrained by different climate conditions and energetic requirements during the breeding and non-breeding seasons. Yet, most studies primarily focus on the breeding season of these species life cycle. Environmental conditions experienced in the non-breeding season may have downstream effects on the other stages of the annual life cycle. Not investigating such effects may potentially lead to erroneous inferences about population dynamics. 2. Combining demographic and tracking data collected between 2006 and 2013 at Kerguelen Island on a long-lived migratory seabird, the Black-Browed Albatross (Thalassarche melanophris), we investigated the links between sea surface temperature during the non-breeding season and behavioural and phenological traits (at-sea behaviour and migratory schedules) while accounting for different responses between birds of different sex and reproductive status (previously failed or successful breeders). We then explored whether variation in the foraging behaviour and timing of spring migration influenced subsequent reproductive performance. 3. Our results showed that foraging activity and migratory schedules varied by both sex and reproductive status suggesting different energetic requirements and constraints among individuals. Higher sea surface temperatures during late winter, assumed to reflect poor winter conditions, were associated with an earlier departure from the wintering grounds and an extended pre-breeding period. However, an earlier spring migration and an earlier return to Kerguelen grounds were associated with a lower breeding success. 4. Our results highlighted that behaviour during some periods of the non-breeding season, particularly towards the end of the wintering period and the pre-breeding period, had a significant effect on the subsequent reproductive success. Therefore caution needs to be given to all stages of the annual cycle when predicting the influence of climate on population dynamics. | ["POLYGON((68.5 -48.5,68.725 -48.5,68.95 -48.5,69.175 -48.5,69.4 -48.5,69.625 -48.5,69.85 -48.5,70.075 -48.5,70.3 -48.5,70.525 -48.5,70.75 -48.5,70.75 -48.65,70.75 -48.8,70.75 -48.95,70.75 -49.1,70.75 -49.25,70.75 -49.4,70.75 -49.55,70.75 -49.7,70.75 -49.85,70.75 -50,70.525 -50,70.3 -50,70.075 -50,69.85 -50,69.625 -50,69.4 -50,69.175 -50,68.95 -50,68.725 -50,68.5 -50,68.5 -49.85,68.5 -49.7,68.5 -49.55,68.5 -49.4,68.5 -49.25,68.5 -49.1,68.5 -48.95,68.5 -48.8,68.5 -48.65,68.5 -48.5))"] | ["POINT(69.625 -49.25)"] | false | false |
Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line
|
0838947 |
2018-09-09 | Begeman, Carolyn |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
This dataset contains ice-shelf basal melt rates and vertical strain rates for 11 sites near the Whillans Ice Stream grounding line. These rates were determined using Autonomous Phase-Sensitive Radar. Data processing is described in Begeman et al. 2018, JGR Oceans. These sites are concentrated within an embayment of the Ross Ice Shelf. These melt rates and strain rates were determined over periods ranging from 10 to 38 days in December 2014 to January 2015. | ["POLYGON((-165.28 -84.24,-165.086 -84.24,-164.892 -84.24,-164.698 -84.24,-164.504 -84.24,-164.31 -84.24,-164.116 -84.24,-163.922 -84.24,-163.728 -84.24,-163.534 -84.24,-163.34 -84.24,-163.34 -84.252,-163.34 -84.264,-163.34 -84.276,-163.34 -84.288,-163.34 -84.3,-163.34 -84.312,-163.34 -84.324,-163.34 -84.336,-163.34 -84.348,-163.34 -84.36,-163.534 -84.36,-163.728 -84.36,-163.922 -84.36,-164.116 -84.36,-164.31 -84.36,-164.504 -84.36,-164.698 -84.36,-164.892 -84.36,-165.086 -84.36,-165.28 -84.36,-165.28 -84.348,-165.28 -84.336,-165.28 -84.324,-165.28 -84.312,-165.28 -84.3,-165.28 -84.288,-165.28 -84.276,-165.28 -84.264,-165.28 -84.252,-165.28 -84.24))"] | ["POINT(-164.31 -84.3)"] | false | false |
WAIS Divide 580m Bubble and Grain Hybrid Data
|
0539578 |
2018-03-01 | Fegyveresi, John; Alley, Richard |
Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core |
This dataset contains detailed grain and bubble properties data for a new hybrid analysis study relating bubble elongation to crystal orientations. All data are from a depth of 580 meters in a sample from the WAIS Divide ice core. | ["POINT(-112.085 -79.467)"] | ["POINT(-112.085 -79.467)"] | false | false |
Roosevelt Island Borehole Optical Televiewer logs
|
0943466 |
2018-02-13 | Hawley, Robert L.; Clemens-Sewall, David |
Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island |
A Borehole Optical Televiewer (OPTV) uses a conical mirror and scanning electronics to record a continuous 360-degree image of the borehole wall. An inclinometer and magnetometer allow the image to be 'unwrapped' and resented as a rectangular image, which shows the visible features of the wall oriented to magnetic north. This dataset includes both the raw bitmap (bmp) image data from the televiewer, as well as proprietary WellCad format (wcl) files. The WellCad format files contain the inclinometry, orientation, and temperature data in addition to the imagery data. Wellcad files can be viewed with a free wellcad file reader available from https://www.alt.lu/downloads.htm. This dataset includes OPTV logs from each of two seasons, November 2013 and 2014. The logs are of the 760 m deep hole drilled by the RICE project, a NZ-USA partnership. | ["POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))"] | ["POINT(-162 -79.25)"] | false | false |
Roosevelt Island Borehole Firn temperatures
|
0943466 |
2018-02-13 | Hawley, Robert L.; Clemens-Sewall, David; Giese, Alexandra |
Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island |
These data are firn temperatures, measured by a meteorological station placed at Roosevelt Island. Thermistors were placed at multiple depths through the upper 20 meters of firn and measured through the course of roughly one year. | ["POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))"] | ["POINT(-162 -79.25)"] | false | false |
Roosevelt Island: Radar and GPS
|
0944307 |
2017-11-16 | Conway, Howard |
Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island |
Ground-based radar data include radar echograms and .mat files of internal stratigraphy. Also included are picks of ice thickness and surface elevation. <br> GPS data include positions of 142 poles set in 2010 and resurveyed in 2012. Also given are velocity vectors for the poles. | ["POLYGON((-162.83 -79.15,-162.637 -79.15,-162.444 -79.15,-162.251 -79.15,-162.058 -79.15,-161.865 -79.15,-161.672 -79.15,-161.479 -79.15,-161.286 -79.15,-161.093 -79.15,-160.9 -79.15,-160.9 -79.1885037,-160.9 -79.2270074,-160.9 -79.2655111,-160.9 -79.3040148,-160.9 -79.3425185,-160.9 -79.3810222,-160.9 -79.4195259,-160.9 -79.4580296,-160.9 -79.4965333,-160.9 -79.535037,-161.093 -79.535037,-161.286 -79.535037,-161.479 -79.535037,-161.672 -79.535037,-161.865 -79.535037,-162.058 -79.535037,-162.251 -79.535037,-162.444 -79.535037,-162.637 -79.535037,-162.83 -79.535037,-162.83 -79.4965333,-162.83 -79.4580296,-162.83 -79.4195259,-162.83 -79.3810222,-162.83 -79.3425185,-162.83 -79.3040148,-162.83 -79.2655111,-162.83 -79.2270074,-162.83 -79.1885037,-162.83 -79.15))"] | ["POINT(-161.865 -79.3425185)"] | false | false |
Hatherton Glacier Radiocarbon Data
|
1246170 |
2017-10-23 | Hall, Brenda |
Collaborative Research: Assessing the Antarctic Contribution to Sea-level Changes during the Last Deglaciation: Constraints from Darwin Glacier |
Hatherton Glacier Radiocarbon Data | ["POLYGON((155.4 -79.8,155.54 -79.8,155.68 -79.8,155.82 -79.8,155.96 -79.8,156.1 -79.8,156.24 -79.8,156.38 -79.8,156.52 -79.8,156.66 -79.8,156.8 -79.8,156.8 -79.82,156.8 -79.84,156.8 -79.86,156.8 -79.88,156.8 -79.9,156.8 -79.92,156.8 -79.94,156.8 -79.96,156.8 -79.98,156.8 -80,156.66 -80,156.52 -80,156.38 -80,156.24 -80,156.1 -80,155.96 -80,155.82 -80,155.68 -80,155.54 -80,155.4 -80,155.4 -79.98,155.4 -79.96,155.4 -79.94,155.4 -79.92,155.4 -79.9,155.4 -79.88,155.4 -79.86,155.4 -79.84,155.4 -79.82,155.4 -79.8))"] | ["POINT(156.1 -79.9)"] | false | false |
WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND
|
0538657 |
2017-08-18 | Seltzer, Alan; Severinghaus, Jeffrey P. |
Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate |
This data set contains measurements of d18Oatm (d18O of O2), d15N, dAr/N2, and dO2/N2 in gas bubbles from the WAIS Divide ice core. The time resolution is variable throughout the record but is ~100 years on average (from 65 ka to present). All measurements were made in the Noble Gas Isotope Laboratory at Scripps Institution of Oceanography (La Jolla, CA). The data set includes all replicate measurements as well as replicate-mean values and a calculation of measurement precision (pooled standard deviation). The second sheet of this data set includes fitted d18Oatm curves for the past 50 ka from both the WAIS Divide and Siple Dome Antarctic ice cores, both on the WD2014 timescale (Buizert et al., 2015). The second sheet also includes calculations of the time derivative of d18Oatm and d e LAND in both ice cores individual as well as in a composite record. Details of the entire data set and all relevant methods are provided in Seltzer et al., 2017. | ["POLYGON((-113 -79,-112.8 -79,-112.6 -79,-112.4 -79,-112.2 -79,-112 -79,-111.8 -79,-111.6 -79,-111.4 -79,-111.2 -79,-111 -79,-111 -79.1,-111 -79.2,-111 -79.3,-111 -79.4,-111 -79.5,-111 -79.6,-111 -79.7,-111 -79.8,-111 -79.9,-111 -80,-111.2 -80,-111.4 -80,-111.6 -80,-111.8 -80,-112 -80,-112.2 -80,-112.4 -80,-112.6 -80,-112.8 -80,-113 -80,-113 -79.9,-113 -79.8,-113 -79.7,-113 -79.6,-113 -79.5,-113 -79.4,-113 -79.3,-113 -79.2,-113 -79.1,-113 -79))"] | ["POINT(-112 -79.5)"] | false | false |
Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains
|
1148982 |
2017-04-20 | Hansen, Samantha |
CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin |
Using data from the Transantarctic Mountains (TAMs) Northern Network, shear-wave splitting analysis has been employed to constrain azimuthal anisotropy beneath a portion of the northern TAMs. Splitting measurements were made for PKS, SKS, and SKKS phases with the eigenvalue method in SplitLab. The results show two distinct geographic regions of anisotropy: one behind the TAMs front and the other along the Ross Sea coastline. The anisotropic structure behind the TAMs front is best attributed to relict fabric associated with past tectonic episodes. Along the coastline, the anisotropy is interpreted to reflect mantle flow associated with rift-related decompression melting and Cenozoic extension. | ["POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))"] | ["POINT(159.223506 -74.6349495)"] | false | false |
Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography
|
1148982 |
2017-04-06 | Hansen, Samantha |
CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin |
Stretching ~3,500 km across Antarctica, with peak elevations up to 4,500 m, the Transantarctic Mountains (TAMs) are the largest non-compressional mountain range on Earth and represent a tectonic boundary between the East Antarctica (EA) craton and the West Antarctic Rift System. The origin and uplift mechanism associated with the TAMs is controversial, and multiple models have been proposed. Seismic investigations of the TAMs' subsurface structure can provide key constraints to help evaluate these models, but previous studies have been primarily focused only on the central TAMs near Ross Island. Using data from the new 15-station Transantarctic Mountain Northern Network as well as data from several smaller networks, this study investigates the upper mantle velocity structure beneath a previously unexplored portion of the northern TAMs through regional body wave tomography. Relative travel-times were calculated for 11,182 P-wave and 8,285 S-wave arrivals from 790 and 581 Mw ≥ 5.5 events, respectively, using multi-channel cross correlation, and these data were then inverted for models of the upper mantle seismic structure. Resulting P- and S-wave tomography images reveal two focused low velocity anomalies beneath Ross Island (RI; δVP ≈ -2.0%; δVS ≈ -1.5% to -4.0%) and Terra Nova Bay (TNB; δVP ≈ -1.5% to -2.0%; δVS ≈ -1.0% to -4.0%) that extend to depths of ~200 and ~150 km, respectively. The RI and TNB slow anomalies also extend ~50-100 km laterally beneath the TAMs front and sharply abut fast velocities beneath the EA craton (δVP ≈ 0.5% to 2%; δVS ≈ 1.5% to 4.0%). A low velocity region (δVP ≈ -1.5%), centered at ~150 km depth beneath the Terror Rift (TR) and primarily constrained within the Victoria Land Basin, connects the RI and TNB anomalies. The focused low velocities are interpreted as regions of partial melt and buoyancy-driven upwelling, connected by a broad region of slow (presumably warm) upper mantle associated with Cenozoic extension along the TR. Dynamic topography estimates based on the imaged S-wave velocity perturbations are consistent with observed surface topography in the central and northern TAMs, thereby providing support for uplift models that advocate for thermal loading and a flexural origin for the mountain range. | ["POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))"] | ["POINT(159.223506 -74.6349495)"] | false | false |
Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event
|
0538657 |
2015-10-27 | Haines, Skylar; Mayewski, Paul A.; Kurbatov, Andrei V. |
Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate |
This data set contains the results of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) performed on an archive of the GISP2 ice core containing the rapid climate warming of Dansgaard-Oeschger Event 21. | ["POINT(-38.5 -76.2)"] | ["POINT(-38.5 -76.2)"] | false | false |
Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core
|
0538657 |
2015-10-20 | Severinghaus, Jeffrey P. |
Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate |
This data set is a low-resolution set of measurements of d15N of N2 and d18O of O2, along with dO2/N and dAr/N2 supporting data, in the WAIS Divide 3405 m long ice core recovered in 2011. Data are distributed via FTP. | ["POINT(-112.08 -79.47)"] | ["POINT(-112.08 -79.47)"] | false | false |
Borehole Temperature Measurement in WDC05A in January 2008 and January 2009
|
0538657 |
2015-06-08 | Severinghaus, Jeffrey P.; Orsi, Anais J. |
Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate |
This data set includes borehole temperature measurements performed in January 2008 and January 2009 at the West Antarctic Ice sheet divide from the 300 m hole WDC05A. | ["POINT(-112.125 -79.463)"] | ["POINT(-112.125 -79.463)"] | false | false |
Preparation of Vertebrate Fossils from the Triassic of Antarctica
|
1146399 |
2015-01-01 | Sidor, Christian |
Preparation of Vertebrate Fossils from the Triassic of Antarctica |
The PI requests support for preparation of a large collection of vertebrate fossils recently recovered from the Central Transantarctic Mountains (CTAM) of Antarctica. These fossils will be used to place early Mesozoic Antarctic dinosaurs and other vertebrates into a global evolutionary, biogeographic, and faunal context; assess the degree of endemism in Triassic vertebrate faunas of Antarctica; constrain temporal relationships of the Triassic Antarctic vertebrate faunas; and refine the stratigraphic context for the Triassic Antarctic vertebrate assemblages to establish a paleoenvironmental framework. The lower and middle Triassic fossils offer a rare window on life in terrestrial environments at high-latitudes immediately after the Permian mass extinction. The PI will use their fossils to educate the public about the geologic, climatic, and biologic history of Antarctica by visiting local schools. They will create and publish at least two new videos to the Burke Museum blog that relate the graduate student's experience of fieldwork in Antarctica. They will also update the Antarctica section on the UWBM 'Explore Your World' website with images and findings from their field season. | ["POLYGON((162.41 -84.27,163.409 -84.27,164.408 -84.27,165.407 -84.27,166.406 -84.27,167.405 -84.27,168.404 -84.27,169.403 -84.27,170.402 -84.27,171.401 -84.27,172.4 -84.27,172.4 -84.353,172.4 -84.436,172.4 -84.519,172.4 -84.602,172.4 -84.685,172.4 -84.768,172.4 -84.851,172.4 -84.934,172.4 -85.017,172.4 -85.1,171.401 -85.1,170.402 -85.1,169.403 -85.1,168.404 -85.1,167.405 -85.1,166.406 -85.1,165.407 -85.1,164.408 -85.1,163.409 -85.1,162.41 -85.1,162.41 -85.017,162.41 -84.934,162.41 -84.851,162.41 -84.768,162.41 -84.685,162.41 -84.602,162.41 -84.519,162.41 -84.436,162.41 -84.353,162.41 -84.27))"] | ["POINT(167.405 -84.685)"] | false | false |
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica
|
1142156 |
2015-01-01 | Marschall, Horst |
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica |
Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth's crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica. Dronning Maud Land (DML) occupied a central location during the formation of supercontinents - large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth's history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007-2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML. | ["POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))"] | ["POINT(-1.13 -72.27)"] | false | false |
A New Approach to Investigate the Seismic Velocity Structure beneath Antarctica
|
1139739 |
2014-01-01 | Hansen, Samantha |
New Approach to Investigate the Seismic Velocity Structure beneath Antarctica |
Intellectual Merit: Numerous candidate models for the geologic processes that have shaped the Antarctic continent have been proposed. To discriminate between them, detailed images of the upper mantle structure are required; however, the only existing continental-scale images of seismic structure beneath Antarctica lack sufficient resolution to delineate important, diagnostic features. Using newly available data from various Antarctic seismic networks, the PI will employ the adaptively parameterized tomography method to develop a high-resolution, continental-scale seismic velocity model for all of Antarctica. The proposed tomography method combines regional seismic travel-time datasets in the context of a global model to create a composite continental-scale model of upper mantle structure. The proposed method allows for imaging of finer structure in areas with better seismic ray coverage while simultaneously limiting the resolution of features in regions with less coverage. This research will help advance understanding of important global processes, such as craton formation, mountain building, continental rifting and associated magmatism. Additionally, the proposed research will have important impacts on other fields of Antarctic science. Constraints provided by tomographic results can be used to develop thermal models of the lithosphere needed to characterize the history and dynamics of ice sheets. Also, further constraints on lithospheric structure are required by climate-ice models, which are focused on understanding the cooling history of the Antarctic continent. Broader impacts: The PI is a new faculty member at the University of Alabama after having been funded as a National Science Foundation Postdoctoral Fellow in Polar Regions Research. The graduate student supported by this project is new to polar research. Through the UA-Tuscaloosa Magnet School partnership program, the PI will educate K-12 students about the Antarctic environment and associated career opportunities through various online and hands-on activities. University of Alabama dedicates a significant percentage of its enrollment space to underrepresented groups. | ["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))"] | ["POINT(0 -89.999)"] | false | false |
East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains
|
1043619 |
2014-01-01 | Hemming, Sidney R. |
Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains |
Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars. Broader Impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields. | ["POLYGON((-180 -63.997,-179.7982 -63.997,-179.5964 -63.997,-179.3946 -63.997,-179.1928 -63.997,-178.991 -63.997,-178.7892 -63.997,-178.5874 -63.997,-178.3856 -63.997,-178.1838 -63.997,-177.982 -63.997,-177.982 -66.3324,-177.982 -68.6678,-177.982 -71.0032,-177.982 -73.3386,-177.982 -75.674,-177.982 -78.0094,-177.982 -80.3448,-177.982 -82.6802,-177.982 -85.0156,-177.982 -87.351,-178.1838 -87.351,-178.3856 -87.351,-178.5874 -87.351,-178.7892 -87.351,-178.991 -87.351,-179.1928 -87.351,-179.3946 -87.351,-179.5964 -87.351,-179.7982 -87.351,180 -87.351,172.54273 -87.351,165.08546 -87.351,157.62819 -87.351,150.17092 -87.351,142.71365 -87.351,135.25638 -87.351,127.79911 -87.351,120.34184 -87.351,112.88457 -87.351,105.4273 -87.351,105.4273 -85.0156,105.4273 -82.6802,105.4273 -80.3448,105.4273 -78.0094,105.4273 -75.674,105.4273 -73.3386,105.4273 -71.0032,105.4273 -68.6678,105.4273 -66.3324,105.4273 -63.997,112.88457 -63.997,120.34184 -63.997,127.79911 -63.997,135.25638 -63.997,142.71365 -63.997,150.17092 -63.997,157.62819 -63.997,165.08546 -63.997,172.54273 -63.997,-180 -63.997))"] | ["POINT(143.72265 -75.674)"] | false | false |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History
|
1043700 |
2014-01-01 | Harry, Dennis L. |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History |
Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs. | ["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))"] | ["POINT(0 -89.999)"] | false | false |
The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter
|
1039365 |
2013-01-01 | Rimmer, Susan |
Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter |
This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming. | [] | [] | false | false |
Siple Dome A (SDMA) Grain Orientation 640 - 790 Meters
|
0738975 |
2012-11-26 | Baker, Ian; Obbard, Rachel; Sieg, Katherine |
Advanced Microstructural Characterization of Polar Ice Cores |
This data set characterizes the microstructure in ice cores, in particular the microstructural locations of impurities, grain orientations, and strain gradients. The fabric of polycrystalline ice is typically described using only the c-axis orientation, but this is insufficient for a full description of grain orientations in this hexagonal material. Thus, both the a-axis and c-axis are used in this data set showing pole figures for five depths of the Siple Dome (SDMA) core between 640 m and 790 m and misorientation angle distribution for the same grains. | ["POINT(-148.82 -81.66)"] | ["POINT(-148.82 -81.66)"] | false | false |
Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy
|
0087521 |
2012-04-15 | Hawley, Robert L.; Waddington, Edwin D.; Alley, Richard; Taylor, Kendrick C. |
Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales |
Researchers gathered data on annual snow layers at Siple Dome, Antarctica, using borehole optical stratigraphy. This data set contains annual layer depths and firn optical brightness. The brightness log is a record of reflectivity of the firn, and peaks in brightness are interpreted to be fine-grained high-density winter snow, as part of the wind slab depth-hoar couplet. Data are available via FTP in ASCII text (.txt) format | ["POINT(-148.82 -81.66)"] | ["POINT(-148.82 -81.66)"] | false | false |
US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica
|
1043669 |
2012-01-01 | Yuan, Xiaojun |
US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica |
Processess governing the formation of Antarctic bottom water (AABW) in the Indian Ocean sector of the Southern Ocean remain poorly described. As with AABW formation in more well studied regions of the Antarctic continent, global climate impacts of the source regions of this dense, cold water that help drive the global ocean thermohaline circulation are uncertain. A combination of (annual) continental shelf and slope moorings, seasonal (summer) hydrographic surveys on board the Chinese icebreaker M/V Xuelong, together with synthesis of historic and satellite data will be used to better constrain shelf processes and the atmosphere-ocean-ice interactions in the Prydz Bay region. Despite the seeming remoteness of the study site, changes in the formation rate of AABW could potentially have impact on northern hemisphere climate via effects on the global heat budget and through sea-level rise in the coming decades. The project additionally seeks to promote international collaboration between Chinese and US researchers. The data collected will be broadly disseminated to the oceanographic community through the National Oceanography Data Center and Chinese Arctic and Antarctic Data Center. | ["POLYGON((70 -64,71 -64,72 -64,73 -64,74 -64,75 -64,76 -64,77 -64,78 -64,79 -64,80 -64,80 -64.6,80 -65.2,80 -65.8,80 -66.4,80 -67,80 -67.6,80 -68.2,80 -68.8,80 -69.4,80 -70,79 -70,78 -70,77 -70,76 -70,75 -70,74 -70,73 -70,72 -70,71 -70,70 -70,70 -69.4,70 -68.8,70 -68.2,70 -67.6,70 -67,70 -66.4,70 -65.8,70 -65.2,70 -64.6,70 -64))"] | ["POINT(75 -67)"] | false | false |
GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica
|
0440847 |
2011-09-01 | Matsuoka, Kenichi; Power, Donovan; Rasmussen, Al |
Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods |
This data set includes ice flow velocities and strain configurations, from GPS measurements on the West Antarctic Ice Sheet (WAIS) Divide. Ninety markers installed in the firn were measured during two consecutive field seasons running from 2005-2006 and 2006-2007. The markers were located in 150 by 60 km area, with smaller clusters of five markers located within about 10 km of each other. Consecutive GPS measurements were used to derive velocity for each marker. Strain configurations were estimated by differentiating a linear fit of the data at each marker cluster. Data are available via FTP as ASCII text (.txt ) files in comma separated value format. | ["POLYGON((-115.457 -78.7489,-114.8241 -78.7489,-114.1912 -78.7489,-113.5583 -78.7489,-112.9254 -78.7489,-112.2925 -78.7489,-111.6596 -78.7489,-111.0267 -78.7489,-110.3938 -78.7489,-109.7609 -78.7489,-109.128 -78.7489,-109.128 -78.83802,-109.128 -78.92714,-109.128 -79.01626,-109.128 -79.10538,-109.128 -79.1945,-109.128 -79.28362,-109.128 -79.37274,-109.128 -79.46186,-109.128 -79.55098,-109.128 -79.6401,-109.7609 -79.6401,-110.3938 -79.6401,-111.0267 -79.6401,-111.6596 -79.6401,-112.2925 -79.6401,-112.9254 -79.6401,-113.5583 -79.6401,-114.1912 -79.6401,-114.8241 -79.6401,-115.457 -79.6401,-115.457 -79.55098,-115.457 -79.46186,-115.457 -79.37274,-115.457 -79.28362,-115.457 -79.1945,-115.457 -79.10538,-115.457 -79.01626,-115.457 -78.92714,-115.457 -78.83802,-115.457 -78.7489))"] | ["POINT(-112.2925 -79.1945)"] | false | false |
Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica
|
0440847 |
2011-08-30 | Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji; Raymond, Charles |
Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods |
This dataset contains ground-based, co-polarized radar data collected using pulse-modulated 60 MHz and 179 MHz radar at 19 sites around a deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet (WAIS Divide). At each site, the radar data were collected at 12 orientations of the radar polarization plane for three radar pulse widths: 250 nsec, 500 nsec, and 1000 nsec. Useful signals were received from depths roughly between 200 m and 2000 m. Ice flow velocities and strain configurations were measured at most of these radar survey sites, and these ice motion data are also provided at NSIDC (GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica). Data are available via FTP in MATLAB (.mat) format. | ["POLYGON((-115.457 -78.7489,-114.8241 -78.7489,-114.1912 -78.7489,-113.5583 -78.7489,-112.9254 -78.7489,-112.2925 -78.7489,-111.6596 -78.7489,-111.0267 -78.7489,-110.3938 -78.7489,-109.7609 -78.7489,-109.128 -78.7489,-109.128 -78.83802,-109.128 -78.92714,-109.128 -79.01626,-109.128 -79.10538,-109.128 -79.1945,-109.128 -79.28362,-109.128 -79.37274,-109.128 -79.46186,-109.128 -79.55098,-109.128 -79.6401,-109.7609 -79.6401,-110.3938 -79.6401,-111.0267 -79.6401,-111.6596 -79.6401,-112.2925 -79.6401,-112.9254 -79.6401,-113.5583 -79.6401,-114.1912 -79.6401,-114.8241 -79.6401,-115.457 -79.6401,-115.457 -79.55098,-115.457 -79.46186,-115.457 -79.37274,-115.457 -79.28362,-115.457 -79.1945,-115.457 -79.10538,-115.457 -79.01626,-115.457 -78.92714,-115.457 -78.83802,-115.457 -78.7489))"] | ["POINT(-112.2925 -79.1945)"] | false | false |
Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica
|
0538674 |
2011-08-15 | Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S. |
Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data |
This data set provides a modeled radar attenuation rate profile, showing the predicted contributions from pure ice and impurities to radar attenuation at the Vostok 5G ice core site in Antarctica, as well as the total attenuation rate and its formal uncertainty. The model data are based on borehole temperature logs, concentrations of major soluble ions measured from melted ice core samples, and information about the electrical conductivity of ice. Attenuation rates and their spatial variability are important constraints for radar studies of ice sheets. Parameters include depth, total attenuation rate, and attenuation rate contribution from pure ice, acidity, and salinity. Data are available via FTP as a text file (.txt) with columns in comma separated value format. | ["POINT(73.17 -78.47)"] | ["POINT(73.17 -78.47)"] | false | false |
Millennially Averaged Accumulation Rates for Lake Vostok
|
0538674 |
2011-08-01 | Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S.; Waddington, Edwin D.; Winebrenner, Dale |
Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data |
This data set consists of inferred accumulation rates from three radar layers (26, 35 and 41 thousand years old) in the Vostok Subglacial Lake region. Accumulation rates were inferred using Local-Layer Approximation (LLA), which assumes that the strain-rate history of a particle traveling through the ice sheet can be approximated by the vertical strain-rate profile at the current position of the particle, which the researchers assume to be uniform. Parameters include location, in latitude and longitude, polar stereographic coordinates, and local grid X and Y coordinates, along with layer age, in thousands of years (ka), and inferred accumulation rate (cm/a). The data cover a 150 by 350 km area. Data are available via FTP, as a text file (.txt) with columns in comma separated value format. | ["POLYGON((68.4 -75.7,69.61 -75.7,70.82 -75.7,72.03 -75.7,73.24 -75.7,74.45 -75.7,75.66 -75.7,76.87 -75.7,78.08 -75.7,79.29 -75.7,80.5 -75.7,80.5 -76.04,80.5 -76.38,80.5 -76.72,80.5 -77.06,80.5 -77.4,80.5 -77.74,80.5 -78.08,80.5 -78.42,80.5 -78.76,80.5 -79.1,79.29 -79.1,78.08 -79.1,76.87 -79.1,75.66 -79.1,74.45 -79.1,73.24 -79.1,72.03 -79.1,70.82 -79.1,69.61 -79.1,68.4 -79.1,68.4 -78.76,68.4 -78.42,68.4 -78.08,68.4 -77.74,68.4 -77.4,68.4 -77.06,68.4 -76.72,68.4 -76.38,68.4 -76.04,68.4 -75.7))"] | ["POINT(74.45 -77.4)"] | false | false |
Grounding Line Strain Grid Surveys, Kamb Ice Stream, Antarctica
|
0538015 |
2011-07-01 | Hulbe, Christina |
Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region |
This data set provides the results from a strain grid survey deployed across the Kamb Ice Stream grounding line on the West Antarctic Ice Sheet. The grid was deployed in 2006 and resurveyed in 2007 using a Global Positioning System (GPS). Parameters measured include latitude, longitude, and height of each survey mark in the strain grid, as well as northing, easting, elevations, and displacement of each point during the year between surveys. Data are available via FTP in Microsoft Excel (.xls) format. | ["POLYGON((154.71 -82.78,154.79 -82.78,154.87 -82.78,154.95 -82.78,155.03 -82.78,155.11 -82.78,155.19 -82.78,155.27 -82.78,155.35 -82.78,155.43 -82.78,155.51 -82.78,155.51 -82.788,155.51 -82.796,155.51 -82.804,155.51 -82.812,155.51 -82.82,155.51 -82.828,155.51 -82.836,155.51 -82.844,155.51 -82.852,155.51 -82.86,155.43 -82.86,155.35 -82.86,155.27 -82.86,155.19 -82.86,155.11 -82.86,155.03 -82.86,154.95 -82.86,154.87 -82.86,154.79 -82.86,154.71 -82.86,154.71 -82.852,154.71 -82.844,154.71 -82.836,154.71 -82.828,154.71 -82.82,154.71 -82.812,154.71 -82.804,154.71 -82.796,154.71 -82.788,154.71 -82.78))"] | ["POINT(155.11 -82.82)"] | false | false |
LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals
|
0902957 |
2011-01-01 | Robinson, Laura |
LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals |
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's 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's 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. | ["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))"] | ["POINT(-52.75 -58)"] | false | false |
Historic Perspectives on Climate and Biogeography from Deep-Sea Corals in the Drake Passage
|
0944474 |
2011-01-01 | Robinson, Laura |
Collaborative Research: Historic Perspectives on Climate and Biogeography from Deep-sea Corals in the Drake Passage |
Polar oceans are the main sites of deep-water formation and are critical to the exchange of heat and carbon between the deep ocean and the atmosphere. This award "Historic perspectives on climate and biogeography from deep-sea corals in the Drake Passage" will address the following specific research questions: What was the radiocarbon content of the Southern Ocean during the last glacial maximum and during past rapid climate change events? and What are the major controls on the past and present distribution of cold-water corals within the Drake Passage and adjacent continental shelves? Testing these overall questions will allow the researchers to better understand how processes in the Southern Ocean are linked to climate change over millennia. This award is being funded by the Antarctic Earth Sciences Program of NSF's Office of Polar Programs, Antarctic Division. INTELLECTUAL MERIT: The skeletons of deep-sea corals are abundant in the Southern Ocean, and can be dated using U-series techniques making them a useful archive of oceanographic history. By pairing U-series and radiocarbon analyses the awardees can reconstruct the radiocarbon content of seawater in the past, allowing them to address the research questions raised above. Collection of living deep-sea corals along with environmental data will allow them to address the broader biogeography questions posed above as well. The awardees are uniquely qualified to answer these questions in their respective labs via cutting edge technologies, and they have shown promising results from a preliminary pilot cruise to the area in 2008. BROADER IMPACTS: Societal Relevance: The proposed paleoclimate research will make significant advances toward constraining the Southern Ocean's influence on global climate, specifically it should help set the bounds for the upper limits on how fast the ocean circulation might change in this region of the world, which is of high societal relevance in this era of changing climate. Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating undergraduate through post-doctoral students into research programs; ii) promotion of K-12 teaching and learning programs by providing information via a cruise website and in-school talks, iii) making the data collected available to the wider research community via data archives such as Seamounts Online and the Seamount Biogeographic Network and iv) reaching a larger public audience through such venues as interviews in the popular media. | ["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))"] | ["POINT(-52.75 -58)"] | false | false |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till
|
0424589 0538195 0440523 |
2010-04-14 | Marone, Chris; Anandakrishnan, Sridhar |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till |
This data set includes the results of laboratory experiments examining the constitutive properties of subglacial till, under dynamic stressing. The data include the results of shear strain and stress experiments. Testing was carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, allowing both sliding and microstructural processes to be studied in detail. Till samples were collected from Matanuska, Alaska and from Caesar till at the Laurentide Ice Sheet. The data are available via FTP in ASCII text format (.txt). | ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"] | ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"] | false | false |
Adelie penguin weighbridge data 1994-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Daily weather observations 1996-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin dive data 1999-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin banding data 1994-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin chick measurements 1996 - 2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin chick counts 1997-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin diet data 1996 - 2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin Geolocation Sensor data 2003-2007 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin satellite position data 2000-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Leopard Seal counts 1997-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
Adelie penguin resighting data 1997-2009 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science
|
0439759 |
2009-05-19 | Ballard, Grant |
COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels |
This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. | ["POINT(166 -77)"] | ["POINT(166 -77)"] | false | false |
What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?
|
0230276 |
2009-01-01 | Ward, Bess |
Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica? |
Denitrification is the main process by which fixed nitrogen is lost from ecosystems and the regulation of this process may directly affect primary production and carbon cycling over short and long time scales. Previous investigations of the role of bioactive metals in regulating denitrification in bacteria from permanently ice-covered Lake Bonney in the Taylor Valley of East Antarctica indicated that denitrifying bacteria can be negatively affected by metals such as copper, iron, cadmium, lead, chromium, nickel, silver and zinc; and that there is a distinct difference in denitrifying activity between the east and west lobes of the lake. Low iron concentrations were found to exacerbate the potential toxicity of the other metals, while silver has the potential to specifically inhibit denitrification because of its ability to interfere with copper binding in redox proteins, such as nitrite reductase and nitrous oxide reductase. High silver concentrations might prevent the functioning of nitrous oxide reductase in the same way that simple copper limitation does, thereby causing the buildup of nitrous oxide and resulting in a nonfunctional nitrogen cycle. Other factors, such as oxygen concentration, are likely also to affect bacterial activity in Lake Bonney. This project will investigate silver toxicity, general metal toxicity and oxygen concentration to determine their effect on denitrification in the lake by using a suite of 'sentinel' strains of denitrifying bacteria (isolated from the lake) incubated in Lake Bonney water and subjected to various treatments. The physiological responses of these strains to changes in metal and oxygen concentration will be quantified by flow cytometric detection of single cell molecular probes whose sensitivity and interpretation have been optimized for the sentinel strains. Understanding the relationships between metals and denitrification is expected to enhance our understanding of not only Lake Bonney's unusual nitrogen cycle, but more generally, of the potential role of metals in the regulation of microbial nitrogen transformations. The broader impacts of this work include not only a better understanding of regional biogeochemistry and global perspectives on these processes; but also the training of graduate students and a substantial outreach effort for school children. | ["POLYGON((162 -77.2,162.16 -77.2,162.32 -77.2,162.48 -77.2,162.64 -77.2,162.8 -77.2,162.96 -77.2,163.12 -77.2,163.28 -77.2,163.44 -77.2,163.6 -77.2,163.6 -77.26,163.6 -77.32,163.6 -77.38,163.6 -77.44,163.6 -77.5,163.6 -77.56,163.6 -77.62,163.6 -77.68,163.6 -77.74,163.6 -77.8,163.44 -77.8,163.28 -77.8,163.12 -77.8,162.96 -77.8,162.8 -77.8,162.64 -77.8,162.48 -77.8,162.32 -77.8,162.16 -77.8,162 -77.8,162 -77.74,162 -77.68,162 -77.62,162 -77.56,162 -77.5,162 -77.44,162 -77.38,162 -77.32,162 -77.26,162 -77.2))"] | ["POINT(162.8 -77.5)"] | false | false |
Geochemistry and Petrologic Evolution of Felsic Volcanoes in Western Marie Byrd Land, Antarctica
|
0536526 |
2009-01-01 | Le Masurier, Wesley |
Geochemistry and Petrologic Evolution of Felsic Volcanoes in Western Marie Byrd Land, Antarctica |
This project uses geochemical studies to determine the origin of volcanic rocks from Marie Byrd Land (MBL), Antarctica. Surprisingly, adjacent volcanoes in the MBL have dramatically different compositions, ranging from phonolite to trachyte to rhyolite. This diversity offers an opportunity to constrain the processes responsible for generating silica oversaturated and undersaturated magmas in a single geologic setting. Previous work suggests that the most obvious and simplest explanation--crustal contamination--is not a significant factor, and that polybaric fractional crystallization is the major cause. This study evaluates these factors through analyses and interpretation of trace and rare earth element abundances, as well as Sr and Nd isotopic ratios. The broader impacts include outreach programs to the Girl Scouts of America, and dissemination of results through publications and meetings. | ["POLYGON((-136 -73,-133.4 -73,-130.8 -73,-128.2 -73,-125.6 -73,-123 -73,-120.4 -73,-117.8 -73,-115.2 -73,-112.6 -73,-110 -73,-110 -73.425,-110 -73.85,-110 -74.275,-110 -74.7,-110 -75.125,-110 -75.55,-110 -75.975,-110 -76.4,-110 -76.825,-110 -77.25,-112.6 -77.25,-115.2 -77.25,-117.8 -77.25,-120.4 -77.25,-123 -77.25,-125.6 -77.25,-128.2 -77.25,-130.8 -77.25,-133.4 -77.25,-136 -77.25,-136 -76.825,-136 -76.4,-136 -75.975,-136 -75.55,-136 -75.125,-136 -74.7,-136 -74.275,-136 -73.85,-136 -73.425,-136 -73))"] | ["POINT(-123 -75.125)"] | false | false |
Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains
|
0739693 |
2009-01-01 | Ashworth, Allan; Lewis, Adam |
Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains |
This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia. In terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica's ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise. | ["POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))"] | ["POINT(161 -77.5)"] | false | false |
Marine Invertebrates of McMurdo Sound
|
0238281 |
2008-01-01 | Marsh, Adam G. |
CAREER: Genomic Networks for Cold-Adaptation in Embryos of Polar Marine Invertebrates |
Although we envision the coastal margins of Antarctica as an extreme environment challenging to the existence of life, there are many marine invertebrates that are adapted to live and thrive under the sea ice. For two field seasons, the SCUBA diving activities of this project routinely involved photographing these animals in all the dive locations as a way to document what we observed as the dominant organisms at each site. Ice diving is very strenuous for humans, and often the constraints of managing the work on a dive, monitoring air reserves, tracking proximity to the dive hole, and the 50 minute exposure to subfreezing temperatures limits a divers ability to "catalog" observations that are not essential to the current dive plan. The photographs archived here have provided the project's dive team with the ability to "debrief" following a dive and more or less reenact the dive by moving through the photograph images. Studying these images often served as a visual trigger for divers to recall more specific observations and in many cases details in the photographs were captured without the photographer (A. Marsh) realizing that they were there (such as small, cryptic species hiding in a shadow until the strobe light fires for the photo, illuminating these secondary subjects). These photographs are intended to serve as a record of what organisms we encountered in the McMurdo Sound area in 2004 and 2005. All photographs were taken with a Nikon D-70 in a polycarbonate underwater housing using either a 18 mm (wide) or 60 mm (macro) lens. | ["POLYGON((163 -77,163.4 -77,163.8 -77,164.2 -77,164.6 -77,165 -77,165.4 -77,165.8 -77,166.2 -77,166.6 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.6 -78,166.2 -78,165.8 -78,165.4 -78,165 -78,164.6 -78,164.2 -78,163.8 -78,163.4 -78,163 -78,163 -77.9,163 -77.8,163 -77.7,163 -77.6,163 -77.5,163 -77.4,163 -77.3,163 -77.2,163 -77.1,163 -77))"] | ["POINT(165 -77.5)"] | false | false |
Trapped Gas Composition and Chronology of the Vostok Ice Core
|
0230260 |
2007-07-10 | Bender, Michael; Suwa, Makoto |
Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core |
This data set includes a time scale for the Vostok ice core, retrieved from Vostok Station on the East Antarctic Plateau. This chronology is derived by orbitally tuning to molecular oxygen to nitrogen (O<sub>2</sub>/N<sub>2</sub>) ratios in occluded air for depths deeper than 1550 m (greater than 112,000 years old), and by gas correlation to the Greenland Ice Sheet Project 2 (GISP2) chronology for the ice core section that is shallower than 1422 m (less than 102,000 years old). Because of poor gas preservation in air bubbles in shallower depths, investigators could only constrain the Vostok chronology for the section deeper than 1550 m by O<sub>2</sub>/N<sub>2</sub>. Thus for the shallower section of the core, they synchronized the Vostok delta oxygen-18 (δ<sup>18</sup>O) and methane (CH<sub>4</sub>) measurements to those of the GISP2 to obtain the chronology (see Bender, et al. 2006). Note, CH<sub>4</sub> data are not included in this data set. Investigators analyzed the O<sub>2</sub>/N<sub>2</sub> and the<em><strong> </strong></em>δ<sup>18</sup>O record ratios for approximately the past 115,000 to 400,000 years in the Vostok ice core. They combined new measurements for O<sub>2</sub>/N<sub>2</sub> and δ<sup>18</sup>O with data from Bender (2002) and Petit, et al. (1999), respectively. Data are in Microsoft Excel format and are available via FTP. | ["POINT(106.8 -72.4667)"] | ["POINT(106.8 -72.4667)"] | false | false |
Vertical Strain at Siple Dome, Antarctica, 1999-2002
|
9615502 |
2007-02-22 | Harrison, William; Morack, James; Waddington, Edwin D.; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel |
Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome |
At the Siple Dome area of Antarctica, much of the ice flow is vertical, which causes vertical ice deformation. To measure this phenomenon, the investigators used a method known as vertical strain rate. This project was a part of the West Antarctic Ice Sheet Cores (WAISCORES) project for deep ice coring in West Antarctica. WAISCORES is supported by the Office of Polar Programs (OPP), National Science Foundation (NSF). This data set consists of a table of long-term average strain rates measured between 1999 and 2002 at Siple Dome, Antarctica. The measurements were taken in hot-water boreholes by bridge gauges. Data are available in tab-delimited ASCII text format or PDF via FTP. | ["POINT(-148.693 -81.595)", "POINT(-148.822 -81.655)"] | ["POINT(-148.693 -81.595)", "POINT(-148.822 -81.655)"] | false | false |