{"dp_type": "Dataset", "free_text": "Ice Flow"}
[{"awards": null, "bounds_geometry": null, "date_created": "Thu, 05 Sep 2024 00:00:00 GMT", "description": "The effects of soluble impurities on the flow of glaciers and ice sheets as well as the effects of ice flow on impurities migration are not well understood. This study investigates the effects of sulfuric acid (H2SO4) concentrations ranging from 10 to 25 ppm on the flow and fabric of polycrystalline ice under compression at temperatures of -3\u00b0C and -12\u00b0C. The results show that H2SO4-doped polycrystalline ice deforms significantly faster than high-purity polycrystalline ice, with the deformation rate being 1.5 to 3 times higher. At -12\u00b0C, the presence of H2SO4 within the grains induces the most ice softening, whereas at -3\u00b0C, H2SO4\u0027s softening effects are observed both within the grains and at grain boundaries. The migration of H2SO4 to grain boundaries during deformation leads to the formation of a liquid-like layer, with increased solubility at higher temperatures potentially homogenizing the impurities within the ice matrix. This homogenization at -3\u00b0C suggests that post-depositional processes near the bed of ice sheets could significantly alter sulfate records. At -12\u00b0C, where homogenization is absent, impurity-induced dislocation processes may heavily influence deformation and impurity migration. Additionally, the comparison of natural ice with lab-grown samples indicates that fabric development significantly impacts compressive strength and creep rates, with implications for the understanding of impurity-induced deformation processes in polar ice.", "east": null, "geometry": null, "keywords": "Antarctica; Cryosphere", "locations": "Antarctica", "north": null, "nsf_funding_programs": null, "persons": "Ogunmolasuyi, Ayobami", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": null, "title": "The Impacts of the Microstructural Location of H2SO4 on the Flow of Polycrystalline Ice", "uid": "601831", "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": "Siple Coast; Antarctica", "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": "1745043 Simkins, Lauren", "bounds_geometry": ["POINT(-100 -75)"], "date_created": "Thu, 11 Apr 2024 00:00:00 GMT", "description": "This dataset contains the elevation raster for Pine Island Bay and the raw elevation profiles used for each site. The transects are organized based on their orientation in relation to paleo-ice flow. They are spaced 500 meters apart, with elevation measurements extracted every 50 meters along each transect.", "east": -100.0, "geometry": ["POINT(-100 -75)"], "keywords": "Antarctica; Bed Roughness; Cryosphere; Geomorphology; Pine Island Bay", "locations": "Pine Island Bay; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Munevar Garcia, Santiago", "project_titles": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations", "projects": [{"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": -75.0, "title": "Elevation transects from Pine Island Bay", "uid": "601774", "west": -100.0}, {"awards": "1246353 Anderson, John; 1745055 Stearns, Leigh; 1745043 Simkins, Lauren", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "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": "Antarctica; Thwaites Glacier", "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": "0440670 Hulbe, Christina", "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 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))"], "date_created": "Fri, 19 Feb 2021 00:00:00 GMT", "description": "The surface of the Ross Ice Shelf (RIS) is textured by flow stripes, crevasses and other fea- tures related to ice flow and deformation. Here, moderate resolution optical satellite images are used to map and classify regions of the RIS characterized by different surface textures. Because the textures arise from ice deformation, the map is used to identify structural provinces with common deformation history. We classify four province types: regions associated with large outlet glaciers, shear zones, exten- sion downstream of obstacles and suture zones between provinces with different upstream sources. Adjacent provinces with contrasting histories are in some locations deforming at different rates, suggest- ing that our province map is also an ice fabric map. Structural provinces have more complicated shapes in the part of the ice shelf fed by West Antarctic ice streams than in the part fed by outlet glaciers from the Transantarctic Mountains. The map may be used to infer past variations in stress conditions and flow events that cannot be inferred from flow traces alone.", "east": 155.0, "geometry": ["POINT(-177.5 -81.5)"], "keywords": "Antarctica", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina; Ledoux, Christine; Forbes, Martin", "project_titles": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "projects": [{"proj_uid": "p0000096", "repository": "USAP-DC", "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "MOA-derived Structural Feature Map of the Ross Ice Shelf", "uid": "601432", "west": -150.0}, {"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 -82.6,-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": "Mercer Ice Stream; Antarctica; Whillans Ice Stream", "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": "1142167 Pettit, Erin", "bounds_geometry": ["POINT(-180 -90)"], "date_created": "Mon, 04 May 2020 00:00:00 GMT", "description": "Acoustic Televiewer measures borehole shape and tilt. These data were collected to study detailed borehole deformation with respect to ice properties to expand our understanding of the flow law for ice. ", "east": -180.0, "geometry": ["POINT(-180 -90)"], "keywords": "Acoustic Televiewer; Anisotropy; Antarctica; Borehole Logging; Deformation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Flow; Snow/ice; Snow/Ice; South Pole; SPICEcore", "locations": "Antarctica; South Pole", "north": -90.0, "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": "SPICEcore", "south": -90.0, "title": "South Pole (SPICEcore) Borehole Deformation", "uid": "601315", "west": -180.0}, {"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": "1443126 MacAyeal, Douglas", "bounds_geometry": ["POLYGON((166.02819 -77.887495,166.053634 -77.887495,166.079078 -77.887495,166.104522 -77.887495,166.129966 -77.887495,166.15541 -77.887495,166.180854 -77.887495,166.206298 -77.887495,166.231742 -77.887495,166.257186 -77.887495,166.28263 -77.887495,166.28263 -77.8926145,166.28263 -77.897734,166.28263 -77.9028535,166.28263 -77.907973,166.28263 -77.9130925,166.28263 -77.918212,166.28263 -77.9233315,166.28263 -77.928451,166.28263 -77.9335705,166.28263 -77.93869,166.257186 -77.93869,166.231742 -77.93869,166.206298 -77.93869,166.180854 -77.93869,166.15541 -77.93869,166.129966 -77.93869,166.104522 -77.93869,166.079078 -77.93869,166.053634 -77.93869,166.02819 -77.93869,166.02819 -77.9335705,166.02819 -77.928451,166.02819 -77.9233315,166.02819 -77.918212,166.02819 -77.9130925,166.02819 -77.907973,166.02819 -77.9028535,166.02819 -77.897734,166.02819 -77.8926145,166.02819 -77.887495))"], "date_created": "Tue, 24 Jul 2018 00:00:00 GMT", "description": "Over 2 Austral summer periods in 2015/6 and 2016/17, up to 12 geodetic GPS receivers were deployed on the McMurdo Ice Shelf to study its vertical deflection in response to moving meltwater loads. (5 GPS were deployed in 2015/16, 12 in 2016/17.) The GPS receivers and antennas were supplied by UNAVCO and were Trimble NetR9\u2019s and Zephyr Geodetic, respectively. The GPS receivers were stationary for the entire field seasons (were never moved). Following each field season, the GPS data were processed using MIT software called TRACK, which is part of the GAMIT package. The UNAVCO-run base station at McMurdo Station, approximately 16 km away from the field area, was used as part of the processing.", "east": 166.28263, "geometry": ["POINT(166.15541 -77.9130925)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ice Shelf; Ice-Shelf Flexure; Snow/ice; Snow/Ice; Surface Melt", "locations": "Antarctica", "north": -77.887495, "nsf_funding_programs": "Antarctic Glaciology", "persons": "MacAyeal, Douglas; Banwell, Alison", "project_titles": "Impact of Supraglacial Lakes on Ice-Shelf Stability", "projects": [{"proj_uid": "p0000138", "repository": "USAP-DC", "title": "Impact of Supraglacial Lakes on Ice-Shelf Stability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.93869, "title": "McMurdo Ice Shelf GPS survey of vertical motion", "uid": "601107", "west": 166.02819}, {"awards": "1542778 Alley, Richard", "bounds_geometry": ["POINT(-180 -90)"], "date_created": "Wed, 20 Sep 2017 00:00:00 GMT", "description": "Thin sections of the South Pole Ice Core, SPC14, were prepared from samples taken every ~20 meters starting at 100 meters depth. Samples from 140 meters to 1739 meters depth were analyzed to determine the c-axis fabric of the grains. The ice is generally fine-grained, with the samples at 100 and 120 meters depth too fine grained for successful analysis, but sufficient grain growth having occurred for analysis of all deeper samples.\r\r\nThe c-axis fabric was measured on the automated c-axis fabric analyzer located at Penn State University, designed and built by Larry Wilen. Raw data is in the form of multiple images of the ice thin section taken at defined angles under cross polarized light. The images are analyzed to determine position of the extinction minimum of each grain within the thin section, this being the orientation of the c-axis of that grain. During processing, the area of each analyzed grain is also measured.\r\r\nShallow samples show a fairly random distribution, although with a slight tendency for clustering of c-axes toward the vertical. With increasing depth, the c-axes rotate toward a vertical plane with a slight additional tendency of clustering toward the vertical within that plane. The core was not oriented during collection, so it is not possible to unambiguously tell how the vertical plane is related to ice flow, but physical understanding indicates that it is transverse to flow.", "east": -180.0, "geometry": ["POINT(-180 -90)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Voigt, Donald E.", "project_titles": "Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core", "projects": [{"proj_uid": "p0000141", "repository": "USAP-DC", "title": "Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "c-Axis Fabric of the South Pole Ice Core, SPC14", "uid": "601057", "west": -180.0}, {"awards": "0839059 Powell, Ross", "bounds_geometry": ["POLYGON((-168.7 -82.3,-168.69 -82.3,-168.68 -82.3,-168.67 -82.3,-168.66 -82.3,-168.65 -82.3,-168.64 -82.3,-168.63 -82.3,-168.62 -82.3,-168.61 -82.3,-168.6 -82.3,-168.6 -82.31,-168.6 -82.32,-168.6 -82.33,-168.6 -82.34,-168.6 -82.35,-168.6 -82.36,-168.6 -82.37,-168.6 -82.38,-168.6 -82.39,-168.6 -82.4,-168.61 -82.4,-168.62 -82.4,-168.63 -82.4,-168.64 -82.4,-168.65 -82.4,-168.66 -82.4,-168.67 -82.4,-168.68 -82.4,-168.69 -82.4,-168.7 -82.4,-168.7 -82.39,-168.7 -82.38,-168.7 -82.37,-168.7 -82.36,-168.7 -82.35,-168.7 -82.34,-168.7 -82.33,-168.7 -82.32,-168.7 -82.31,-168.7 -82.3))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF\u0027s Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling.\nThe latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations.\nSocietal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.", "east": -168.6, "geometry": ["POINT(-168.65 -82.35)"], "keywords": "Antarctica; Biota; Diatom; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Whillans; Paleoclimate; Ross Sea; Southern Ocean; Subglacial Lake; WISSARD", "locations": "Antarctica; Lake Whillans; Ross Sea; Southern Ocean", "north": -82.3, "nsf_funding_programs": null, "persons": "Powell, Ross", "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": null, "south": -82.4, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD)", "uid": "600154", "west": -168.7}, {"awards": "1142010 Talghader, Joseph", "bounds_geometry": ["POLYGON((-148.81 -79.42,-145.111 -79.42,-141.412 -79.42,-137.713 -79.42,-134.014 -79.42,-130.315 -79.42,-126.616 -79.42,-122.917 -79.42,-119.218 -79.42,-115.519 -79.42,-111.82 -79.42,-111.82 -79.643,-111.82 -79.866,-111.82 -80.089,-111.82 -80.312,-111.82 -80.535,-111.82 -80.758,-111.82 -80.981,-111.82 -81.204,-111.82 -81.427,-111.82 -81.65,-115.519 -81.65,-119.218 -81.65,-122.917 -81.65,-126.616 -81.65,-130.315 -81.65,-134.014 -81.65,-137.713 -81.65,-141.412 -81.65,-145.111 -81.65,-148.81 -81.65,-148.81 -81.427,-148.81 -81.204,-148.81 -80.981,-148.81 -80.758,-148.81 -80.535,-148.81 -80.312,-148.81 -80.089,-148.81 -79.866,-148.81 -79.643,-148.81 -79.42))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum.", "east": -111.82, "geometry": ["POINT(-130.315 -80.535)"], "keywords": "Antarctica; Ash Layer; Borehole Camera; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.42, "nsf_funding_programs": null, "persons": "Talghader, Joseph", "project_titles": "Optical Fabric and Fiber Logging of Glacial Ice", "projects": [{"proj_uid": "p0000339", "repository": "USAP-DC", "title": "Optical Fabric and Fiber Logging of Glacial Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Optical Fabric and Fiber Logging of Glacial Ice (1142010)", "uid": "600172", "west": -148.81}, {"awards": "0944248 MacAyeal, Douglas", "bounds_geometry": ["POLYGON((-63 -63,-62.2 -63,-61.4 -63,-60.6 -63,-59.8 -63,-59 -63,-58.2 -63,-57.4 -63,-56.6 -63,-55.8 -63,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-55 -65.4,-55 -65.8,-55 -66.2,-55 -66.6,-55 -67,-55.8 -67,-56.6 -67,-57.4 -67,-58.2 -67,-59 -67,-59.8 -67,-60.6 -67,-61.4 -67,-62.2 -67,-63 -67,-63 -66.6,-63 -66.2,-63 -65.8,-63 -65.4,-63 -65,-63 -64.6,-63 -64.2,-63 -63.8,-63 -63.4,-63 -63))"], "date_created": "Tue, 29 Apr 2014 00:00:00 GMT", "description": "This data set addresses why surface melt water lakes on ice shelves and ice sheets are notably influential in triggering ice-shelf break-up and modulating seasonal ice flow, and are thus principle avenues by which environmental change can be transmitted to the ice sheets of Antarctica and Greenland. A comparative analysis is performed of lake geometry and derived depth (using Landsat image reflectance) in two distinct regions, one a collapsing ice shelf and the other an ablation zone of a land terminating ice sheet, to better characterize the range of surface lake variability.", "east": -55.0, "geometry": ["POINT(-59 -65)"], "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Larsen B Ice Shelf; Sample/collection Description; Sample/Collection Description; Supraglacial Meltwater", "locations": "Antarctica; Larsen B Ice Shelf; Antarctic Peninsula", "north": -63.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "MacAyeal, Douglas", "project_titles": "Model Studies of Surface Water Behavior on Ice Shelves", "projects": [{"proj_uid": "p0000052", "repository": "USAP-DC", "title": "Model Studies of Surface Water Behavior on Ice Shelves"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Standing Water Depth on Larsen B Ice Shelf", "uid": "609584", "west": -63.0}, {"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": "0944475 Kaplan, Michael", "bounds_geometry": ["POLYGON((-180 -84.1,-176.97 -84.1,-173.94 -84.1,-170.91 -84.1,-167.88 -84.1,-164.85 -84.1,-161.82 -84.1,-158.79 -84.1,-155.76 -84.1,-152.73 -84.1,-149.7 -84.1,-149.7 -84.43,-149.7 -84.76,-149.7 -85.09,-149.7 -85.42,-149.7 -85.75,-149.7 -86.08,-149.7 -86.41,-149.7 -86.74,-149.7 -87.07,-149.7 -87.4,-152.73 -87.4,-155.76 -87.4,-158.79 -87.4,-161.82 -87.4,-164.85 -87.4,-167.88 -87.4,-170.91 -87.4,-173.94 -87.4,-176.97 -87.4,180 -87.4,178.12 -87.4,176.24 -87.4,174.36 -87.4,172.48 -87.4,170.6 -87.4,168.72 -87.4,166.84 -87.4,164.96 -87.4,163.08 -87.4,161.2 -87.4,161.2 -87.07,161.2 -86.74,161.2 -86.41,161.2 -86.08,161.2 -85.75,161.2 -85.42,161.2 -85.09,161.2 -84.76,161.2 -84.43,161.2 -84.1,163.08 -84.1,164.96 -84.1,166.84 -84.1,168.72 -84.1,170.6 -84.1,172.48 -84.1,174.36 -84.1,176.24 -84.1,178.12 -84.1,-180 -84.1))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica\u0027s inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed \u003c2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time.\nBroader Impact: The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.", "east": -149.7, "geometry": ["POINT(-174.25 -85.75)"], "keywords": "Antarctica; Cosmogenic Dating; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains", "locations": "Antarctica; Transantarctic Mountains", "north": -84.1, "nsf_funding_programs": null, "persons": "Kaplan, Michael", "project_titles": "Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "projects": [{"proj_uid": "p0000459", "repository": "USAP-DC", "title": "Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.4, "title": "Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "uid": "600115", "west": 161.2}, {"awards": "9527571 Whillans, Ian; 0838843 Kurbatov, Andrei; 0229245 Hamilton, Gordon", "bounds_geometry": ["POLYGON((158.25 -76.66667,158.325 -76.66667,158.4 -76.66667,158.475 -76.66667,158.55 -76.66667,158.625 -76.66667,158.7 -76.66667,158.775 -76.66667,158.85 -76.66667,158.925 -76.66667,159 -76.66667,159 -76.683336,159 -76.700002,159 -76.716668,159 -76.733334,159 -76.75,159 -76.766666,159 -76.783332,159 -76.799998,159 -76.816664,159 -76.83333,158.925 -76.83333,158.85 -76.83333,158.775 -76.83333,158.7 -76.83333,158.625 -76.83333,158.55 -76.83333,158.475 -76.83333,158.4 -76.83333,158.325 -76.83333,158.25 -76.83333,158.25 -76.816664,158.25 -76.799998,158.25 -76.783332,158.25 -76.766666,158.25 -76.75,158.25 -76.733334,158.25 -76.716668,158.25 -76.700002,158.25 -76.683336,158.25 -76.66667))"], "date_created": "Tue, 20 Dec 2011 00:00:00 GMT", "description": "This data set includes includes high-precision GPS measurements of steel poles within the Allan Hills Main Ice Field, Near Western Ice Field, and extending to the eastern edge of the Middle Western Ice Field, in Antarctica. These data were collected between December 1997 and December 2010. The extended survey period allowed for vertical and horizontal velocities to be calculated with low associated error. Parameters include locations of poles in latitude and longitude, as well as elevation, ice velocity, and accumulation rates.\n\nData are available via FTP as ASCII text files in comma separated value (.csv) format. Raw data are also provided as Trimble raw data, compressed in .zip format, and supplementary information is provided in .csv format and portable document format (.pdf).", "east": 159.0, "geometry": ["POINT(158.625 -76.75)"], "keywords": "Allan Hills; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity", "locations": "Allan Hills; Antarctica", "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kurbatov, Andrei V.; Spikes, Vandy Blue; Hamilton, Gordon S.; Spaulding, Nicole", "project_titles": "GPS Measurements of Rock and Ice Motions in South Victoria Land", "projects": [{"proj_uid": "p0000523", "repository": "USAP-DC", "title": "GPS Measurements of Rock and Ice Motions in South Victoria Land"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.83333, "title": "GPS Ice Flow Measurements, Allan Hills, Antarctica", "uid": "609507", "west": 158.25}, {"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": "Ross-Amundsen Divide; Antarctica", "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": "0739372 Conway, Howard", "bounds_geometry": ["POLYGON((-123 -76,-120.65 -76,-118.3 -76,-115.95 -76,-113.6 -76,-111.25 -76,-108.9 -76,-106.55 -76,-104.2 -76,-101.85 -76,-99.5 -76,-99.5 -76.37,-99.5 -76.74,-99.5 -77.11,-99.5 -77.48,-99.5 -77.85,-99.5 -78.22,-99.5 -78.59,-99.5 -78.96,-99.5 -79.33,-99.5 -79.7,-101.85 -79.7,-104.2 -79.7,-106.55 -79.7,-108.9 -79.7,-111.25 -79.7,-113.6 -79.7,-115.95 -79.7,-118.3 -79.7,-120.65 -79.7,-123 -79.7,-123 -79.33,-123 -78.96,-123 -78.59,-123 -78.22,-123 -77.85,-123 -77.48,-123 -77.11,-123 -76.74,-123 -76.37,-123 -76))"], "date_created": "Sat, 01 May 2010 00:00:00 GMT", "description": "This data set contains past flow lines of Thwaites Glacier. The flow lines were identified using layer patterns tracked between parallel radar layers, from a radar profile of the Thwaites Glacier catchment. The radar data was run and processed by the University of Texas Institute for Geophysics. The flow lines were identified from distinct layer patterns tracked between parallel radar layers. \n\nData are available via FTP in ASCII text (.txt) format.", "east": -99.5, "geometry": ["POINT(-111.25 -77.85)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Flow Lines; Thwaites Glacier", "locations": "Antarctica; Thwaites Glacier", "north": -76.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Conway, Howard; Fudge, T. J.; Catania, Ginny", "project_titles": "Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica", "projects": [{"proj_uid": "p0000143", "repository": "USAP-DC", "title": "Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.7, "title": "Ice Flow History of the Thwaites Glacier, West Antarctica", "uid": "609463", "west": -123.0}, {"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": "Antarctica; Siple Dome", "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}, {"awards": "9527373 Dunbar, Nelia", "bounds_geometry": ["POLYGON((158.55 -75.86,158.562 -75.86,158.574 -75.86,158.586 -75.86,158.598 -75.86,158.61 -75.86,158.622 -75.86,158.634 -75.86,158.646 -75.86,158.658 -75.86,158.67 -75.86,158.67 -75.864,158.67 -75.868,158.67 -75.872,158.67 -75.876,158.67 -75.88,158.67 -75.884,158.67 -75.888,158.67 -75.892,158.67 -75.896,158.67 -75.9,158.658 -75.9,158.646 -75.9,158.634 -75.9,158.622 -75.9,158.61 -75.9,158.598 -75.9,158.586 -75.9,158.574 -75.9,158.562 -75.9,158.55 -75.9,158.55 -75.896,158.55 -75.892,158.55 -75.888,158.55 -75.884,158.55 -75.88,158.55 -75.876,158.55 -75.872,158.55 -75.868,158.55 -75.864,158.55 -75.86))"], "date_created": "Tue, 18 Feb 2003 00:00:00 GMT", "description": "This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Brimstone Peak (75.888S 158.55E) in East Antarctica. Tephra samples were collected between 15 November 1996 and 15 January 1997.\n\nThe Antarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date.\n\nData include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography.Data are provided as Excel 97 data files, JPG map files, and GIF-formatted BSE images. Data are available via ftp.", "east": 158.67, "geometry": ["POINT(158.61 -75.88)"], "keywords": "Antarctica; Blue Ice; Brimstone Peak; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Petrography; Tephra", "locations": "Brimstone Peak; Antarctica", "north": -75.86, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Dunbar, Nelia", "project_titles": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region", "projects": [{"proj_uid": "p0000065", "repository": "USAP-DC", "title": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.9, "title": "Blue Ice Tephra II - Brimstone Peak", "uid": "609114", "west": 158.55}, {"awards": "9527373 Dunbar, Nelia", "bounds_geometry": ["POINT(-159.51 -77.12)"], "date_created": "Sat, 01 Feb 2003 00:00:00 GMT", "description": "This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Mt. DeWitt, Antarctica (77.12 deg S, 159.51 deg E). Tephra samples were collected between 15 November 1996 and 15 January 1997.\n\nData include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography. Data are provided as an Excel 97 data file, (this file is also divided into various text files) and TIF images. Data are available via ftp.\n\nAntarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date.", "east": -159.51, "geometry": ["POINT(-159.51 -77.12)"], "keywords": "Antarctica; Blue Ice; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mount Dewitt; Petrography; Tephra", "locations": "Antarctica; Mount Dewitt", "north": -77.12, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Dunbar, Nelia", "project_titles": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region", "projects": [{"proj_uid": "p0000065", "repository": "USAP-DC", "title": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.12, "title": "Blue Ice Tephra II - Mt. DeWitt", "uid": "609115", "west": -159.51}]
X
X
Help on the Results MapX
This window can be dragged by its header, and can be resized from the bottom right corner.
Clicking the Layers button - the blue square in the top left of the Results Map - will display a list of map layers you can add or remove
from the currently displayed map view.
The Results Map and the Results Table
- The Results Map displays the centroids of the geographic bounds of all the results returned by the search.
- Results that are displayed in the current map view will be highlighted in blue and brought to the top of the Results Table.
- As the map is panned or zoomed, the highlighted rows in the table will update.
- If you click on a centroid on the map, it will turn yellow and display a popup with details for that project/dataset - including a link to the landing page. The bounds for the project(s)/dataset(s) selected will be displayed in red. The selected result(s) will be highlighted in red and brought to the top of the table.
- The default table sorting order is: Selected, Visible, Date (descending), but this can be changed by clicking on column headers in the table.
- Selecting Show on Map for an individual row will both display the geographic bounds for that result on a mini map, and also display the bounds and highlight the centroid on the Results Map.
- Clicking the 'Show boundaries' checkbox at the top of the Results Map will display all the bounds for the filtered results.
Defining a search area on the Results Map
- If you click on the Rectangle or Polygon icons in the top right of the Results Map, you can define a search area which will be added to any other search criteria already selected.
- After you have drawn a polygon, you can edit it using the Edit Geometry dropdown in the search form at the top.
- Clicking Clear in the map will clear any drawn polygon.
- Clicking Search in the map, or Search on the form will have the same effect.
- The returned results will be any projects/datasets with bounds that intersect the polygon.
- Use the Exclude project/datasets checkbox to exclude any projects/datasets that cover the whole Antarctic region.
Viewing map layers on the Results Map
To sort the table of search results, click the header of the column you wish to search by. To sort by multiple columns, hold down the shift key whilst selecting the sort columns in order.
Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
The Impacts of the Microstructural Location of H2SO4 on the Flow of Polycrystalline Ice
|
None | 2024-09-05 | Ogunmolasuyi, Ayobami | No project link provided | The effects of soluble impurities on the flow of glaciers and ice sheets as well as the effects of ice flow on impurities migration are not well understood. This study investigates the effects of sulfuric acid (H2SO4) concentrations ranging from 10 to 25 ppm on the flow and fabric of polycrystalline ice under compression at temperatures of -3°C and -12°C. The results show that H2SO4-doped polycrystalline ice deforms significantly faster than high-purity polycrystalline ice, with the deformation rate being 1.5 to 3 times higher. At -12°C, the presence of H2SO4 within the grains induces the most ice softening, whereas at -3°C, H2SO4's softening effects are observed both within the grains and at grain boundaries. The migration of H2SO4 to grain boundaries during deformation leads to the formation of a liquid-like layer, with increased solubility at higher temperatures potentially homogenizing the impurities within the ice matrix. This homogenization at -3°C suggests that post-depositional processes near the bed of ice sheets could significantly alter sulfate records. At -12°C, where homogenization is absent, impurity-induced dislocation processes may heavily influence deformation and impurity migration. Additionally, the comparison of natural ice with lab-grown samples indicates that fabric development significantly impacts compressive strength and creep rates, with implications for the understanding of impurity-induced deformation processes in polar ice. | [] | [] | 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 |
Elevation transects from Pine Island Bay
|
1745043 |
2024-04-11 | Munevar Garcia, Santiago |
Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations |
This dataset contains the elevation raster for Pine Island Bay and the raw elevation profiles used for each site. The transects are organized based on their orientation in relation to paleo-ice flow. They are spaced 500 meters apart, with elevation measurements extracted every 50 meters along each transect. | ["POINT(-100 -75)"] | ["POINT(-100 -75)"] | false | false |
Circum-Antarctic grounding-line sinuosity
|
1246353 1745055 1745043 |
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 |
MOA-derived Structural Feature Map of the Ross Ice Shelf
|
0440670 |
2021-02-19 | Hulbe, Christina; Ledoux, Christine; Forbes, Martin |
Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams |
The surface of the Ross Ice Shelf (RIS) is textured by flow stripes, crevasses and other fea- tures related to ice flow and deformation. Here, moderate resolution optical satellite images are used to map and classify regions of the RIS characterized by different surface textures. Because the textures arise from ice deformation, the map is used to identify structural provinces with common deformation history. We classify four province types: regions associated with large outlet glaciers, shear zones, exten- sion downstream of obstacles and suture zones between provinces with different upstream sources. Adjacent provinces with contrasting histories are in some locations deforming at different rates, suggest- ing that our province map is also an ice fabric map. Structural provinces have more complicated shapes in the part of the ice shelf fed by West Antarctic ice streams than in the part fed by outlet glaciers from the Transantarctic Mountains. The map may be used to infer past variations in stress conditions and flow events that cannot be inferred from flow traces alone. | ["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 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))"] | ["POINT(-177.5 -81.5)"] | 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 |
South Pole (SPICEcore) Borehole Deformation
|
1142167 |
2020-05-04 | Pettit, Erin |
Collaborative Research: VeLveT Ice - eVoLution of Fabric and Texture in Ice at WAIS Divide, West Antarctica |
Acoustic Televiewer measures borehole shape and tilt. These data were collected to study detailed borehole deformation with respect to ice properties to expand our understanding of the flow law for ice. | ["POINT(-180 -90)"] | ["POINT(-180 -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 |
McMurdo Ice Shelf GPS survey of vertical motion
|
1443126 |
2018-07-24 | MacAyeal, Douglas; Banwell, Alison |
Impact of Supraglacial Lakes on Ice-Shelf Stability |
Over 2 Austral summer periods in 2015/6 and 2016/17, up to 12 geodetic GPS receivers were deployed on the McMurdo Ice Shelf to study its vertical deflection in response to moving meltwater loads. (5 GPS were deployed in 2015/16, 12 in 2016/17.) The GPS receivers and antennas were supplied by UNAVCO and were Trimble NetR9’s and Zephyr Geodetic, respectively. The GPS receivers were stationary for the entire field seasons (were never moved). Following each field season, the GPS data were processed using MIT software called TRACK, which is part of the GAMIT package. The UNAVCO-run base station at McMurdo Station, approximately 16 km away from the field area, was used as part of the processing. | ["POLYGON((166.02819 -77.887495,166.053634 -77.887495,166.079078 -77.887495,166.104522 -77.887495,166.129966 -77.887495,166.15541 -77.887495,166.180854 -77.887495,166.206298 -77.887495,166.231742 -77.887495,166.257186 -77.887495,166.28263 -77.887495,166.28263 -77.8926145,166.28263 -77.897734,166.28263 -77.9028535,166.28263 -77.907973,166.28263 -77.9130925,166.28263 -77.918212,166.28263 -77.9233315,166.28263 -77.928451,166.28263 -77.9335705,166.28263 -77.93869,166.257186 -77.93869,166.231742 -77.93869,166.206298 -77.93869,166.180854 -77.93869,166.15541 -77.93869,166.129966 -77.93869,166.104522 -77.93869,166.079078 -77.93869,166.053634 -77.93869,166.02819 -77.93869,166.02819 -77.9335705,166.02819 -77.928451,166.02819 -77.9233315,166.02819 -77.918212,166.02819 -77.9130925,166.02819 -77.907973,166.02819 -77.9028535,166.02819 -77.897734,166.02819 -77.8926145,166.02819 -77.887495))"] | ["POINT(166.15541 -77.9130925)"] | false | false |
c-Axis Fabric of the South Pole Ice Core, SPC14
|
1542778 |
2017-09-20 | Voigt, Donald E. |
Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core |
Thin sections of the South Pole Ice Core, SPC14, were prepared from samples taken every ~20 meters starting at 100 meters depth. Samples from 140 meters to 1739 meters depth were analyzed to determine the c-axis fabric of the grains. The ice is generally fine-grained, with the samples at 100 and 120 meters depth too fine grained for successful analysis, but sufficient grain growth having occurred for analysis of all deeper samples. The c-axis fabric was measured on the automated c-axis fabric analyzer located at Penn State University, designed and built by Larry Wilen. Raw data is in the form of multiple images of the ice thin section taken at defined angles under cross polarized light. The images are analyzed to determine position of the extinction minimum of each grain within the thin section, this being the orientation of the c-axis of that grain. During processing, the area of each analyzed grain is also measured. Shallow samples show a fairly random distribution, although with a slight tendency for clustering of c-axes toward the vertical. With increasing depth, the c-axes rotate toward a vertical plane with a slight additional tendency of clustering toward the vertical within that plane. The core was not oriented during collection, so it is not possible to unambiguously tell how the vertical plane is related to ice flow, but physical understanding indicates that it is transverse to flow. | ["POINT(-180 -90)"] | ["POINT(-180 -90)"] | false | false |
Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD)
|
0839059 |
2016-01-01 | Powell, Ross |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars. | ["POLYGON((-168.7 -82.3,-168.69 -82.3,-168.68 -82.3,-168.67 -82.3,-168.66 -82.3,-168.65 -82.3,-168.64 -82.3,-168.63 -82.3,-168.62 -82.3,-168.61 -82.3,-168.6 -82.3,-168.6 -82.31,-168.6 -82.32,-168.6 -82.33,-168.6 -82.34,-168.6 -82.35,-168.6 -82.36,-168.6 -82.37,-168.6 -82.38,-168.6 -82.39,-168.6 -82.4,-168.61 -82.4,-168.62 -82.4,-168.63 -82.4,-168.64 -82.4,-168.65 -82.4,-168.66 -82.4,-168.67 -82.4,-168.68 -82.4,-168.69 -82.4,-168.7 -82.4,-168.7 -82.39,-168.7 -82.38,-168.7 -82.37,-168.7 -82.36,-168.7 -82.35,-168.7 -82.34,-168.7 -82.33,-168.7 -82.32,-168.7 -82.31,-168.7 -82.3))"] | ["POINT(-168.65 -82.35)"] | false | false |
Optical Fabric and Fiber Logging of Glacial Ice (1142010)
|
1142010 |
2015-01-01 | Talghader, Joseph |
Optical Fabric and Fiber Logging of Glacial Ice |
This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum. | ["POLYGON((-148.81 -79.42,-145.111 -79.42,-141.412 -79.42,-137.713 -79.42,-134.014 -79.42,-130.315 -79.42,-126.616 -79.42,-122.917 -79.42,-119.218 -79.42,-115.519 -79.42,-111.82 -79.42,-111.82 -79.643,-111.82 -79.866,-111.82 -80.089,-111.82 -80.312,-111.82 -80.535,-111.82 -80.758,-111.82 -80.981,-111.82 -81.204,-111.82 -81.427,-111.82 -81.65,-115.519 -81.65,-119.218 -81.65,-122.917 -81.65,-126.616 -81.65,-130.315 -81.65,-134.014 -81.65,-137.713 -81.65,-141.412 -81.65,-145.111 -81.65,-148.81 -81.65,-148.81 -81.427,-148.81 -81.204,-148.81 -80.981,-148.81 -80.758,-148.81 -80.535,-148.81 -80.312,-148.81 -80.089,-148.81 -79.866,-148.81 -79.643,-148.81 -79.42))"] | ["POINT(-130.315 -80.535)"] | false | false |
Standing Water Depth on Larsen B Ice Shelf
|
0944248 |
2014-04-29 | MacAyeal, Douglas |
Model Studies of Surface Water Behavior on Ice Shelves |
This data set addresses why surface melt water lakes on ice shelves and ice sheets are notably influential in triggering ice-shelf break-up and modulating seasonal ice flow, and are thus principle avenues by which environmental change can be transmitted to the ice sheets of Antarctica and Greenland. A comparative analysis is performed of lake geometry and derived depth (using Landsat image reflectance) in two distinct regions, one a collapsing ice shelf and the other an ablation zone of a land terminating ice sheet, to better characterize the range of surface lake variability. | ["POLYGON((-63 -63,-62.2 -63,-61.4 -63,-60.6 -63,-59.8 -63,-59 -63,-58.2 -63,-57.4 -63,-56.6 -63,-55.8 -63,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-55 -65.4,-55 -65.8,-55 -66.2,-55 -66.6,-55 -67,-55.8 -67,-56.6 -67,-57.4 -67,-58.2 -67,-59 -67,-59.8 -67,-60.6 -67,-61.4 -67,-62.2 -67,-63 -67,-63 -66.6,-63 -66.2,-63 -65.8,-63 -65.4,-63 -65,-63 -64.6,-63 -64.2,-63 -63.8,-63 -63.4,-63 -63))"] | ["POINT(-59 -65)"] | 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 |
Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines
|
0944475 |
2014-01-01 | Kaplan, Michael |
Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines |
Intellectual Merit: The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica's inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed <2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time. Broader Impact: The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences. | ["POLYGON((-180 -84.1,-176.97 -84.1,-173.94 -84.1,-170.91 -84.1,-167.88 -84.1,-164.85 -84.1,-161.82 -84.1,-158.79 -84.1,-155.76 -84.1,-152.73 -84.1,-149.7 -84.1,-149.7 -84.43,-149.7 -84.76,-149.7 -85.09,-149.7 -85.42,-149.7 -85.75,-149.7 -86.08,-149.7 -86.41,-149.7 -86.74,-149.7 -87.07,-149.7 -87.4,-152.73 -87.4,-155.76 -87.4,-158.79 -87.4,-161.82 -87.4,-164.85 -87.4,-167.88 -87.4,-170.91 -87.4,-173.94 -87.4,-176.97 -87.4,180 -87.4,178.12 -87.4,176.24 -87.4,174.36 -87.4,172.48 -87.4,170.6 -87.4,168.72 -87.4,166.84 -87.4,164.96 -87.4,163.08 -87.4,161.2 -87.4,161.2 -87.07,161.2 -86.74,161.2 -86.41,161.2 -86.08,161.2 -85.75,161.2 -85.42,161.2 -85.09,161.2 -84.76,161.2 -84.43,161.2 -84.1,163.08 -84.1,164.96 -84.1,166.84 -84.1,168.72 -84.1,170.6 -84.1,172.48 -84.1,174.36 -84.1,176.24 -84.1,178.12 -84.1,-180 -84.1))"] | ["POINT(-174.25 -85.75)"] | false | false |
GPS Ice Flow Measurements, Allan Hills, Antarctica
|
9527571 0838843 0229245 |
2011-12-20 | Kurbatov, Andrei V.; Spikes, Vandy Blue; Hamilton, Gordon S.; Spaulding, Nicole |
GPS Measurements of Rock and Ice Motions in South Victoria Land |
This data set includes includes high-precision GPS measurements of steel poles within the Allan Hills Main Ice Field, Near Western Ice Field, and extending to the eastern edge of the Middle Western Ice Field, in Antarctica. These data were collected between December 1997 and December 2010. The extended survey period allowed for vertical and horizontal velocities to be calculated with low associated error. Parameters include locations of poles in latitude and longitude, as well as elevation, ice velocity, and accumulation rates. Data are available via FTP as ASCII text files in comma separated value (.csv) format. Raw data are also provided as Trimble raw data, compressed in .zip format, and supplementary information is provided in .csv format and portable document format (.pdf). | ["POLYGON((158.25 -76.66667,158.325 -76.66667,158.4 -76.66667,158.475 -76.66667,158.55 -76.66667,158.625 -76.66667,158.7 -76.66667,158.775 -76.66667,158.85 -76.66667,158.925 -76.66667,159 -76.66667,159 -76.683336,159 -76.700002,159 -76.716668,159 -76.733334,159 -76.75,159 -76.766666,159 -76.783332,159 -76.799998,159 -76.816664,159 -76.83333,158.925 -76.83333,158.85 -76.83333,158.775 -76.83333,158.7 -76.83333,158.625 -76.83333,158.55 -76.83333,158.475 -76.83333,158.4 -76.83333,158.325 -76.83333,158.25 -76.83333,158.25 -76.816664,158.25 -76.799998,158.25 -76.783332,158.25 -76.766666,158.25 -76.75,158.25 -76.733334,158.25 -76.716668,158.25 -76.700002,158.25 -76.683336,158.25 -76.66667))"] | ["POINT(158.625 -76.75)"] | 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 |
Ice Flow History of the Thwaites Glacier, West Antarctica
|
0739372 |
2010-05-01 | Conway, Howard; Fudge, T. J.; Catania, Ginny |
Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica |
This data set contains past flow lines of Thwaites Glacier. The flow lines were identified using layer patterns tracked between parallel radar layers, from a radar profile of the Thwaites Glacier catchment. The radar data was run and processed by the University of Texas Institute for Geophysics. The flow lines were identified from distinct layer patterns tracked between parallel radar layers. Data are available via FTP in ASCII text (.txt) format. | ["POLYGON((-123 -76,-120.65 -76,-118.3 -76,-115.95 -76,-113.6 -76,-111.25 -76,-108.9 -76,-106.55 -76,-104.2 -76,-101.85 -76,-99.5 -76,-99.5 -76.37,-99.5 -76.74,-99.5 -77.11,-99.5 -77.48,-99.5 -77.85,-99.5 -78.22,-99.5 -78.59,-99.5 -78.96,-99.5 -79.33,-99.5 -79.7,-101.85 -79.7,-104.2 -79.7,-106.55 -79.7,-108.9 -79.7,-111.25 -79.7,-113.6 -79.7,-115.95 -79.7,-118.3 -79.7,-120.65 -79.7,-123 -79.7,-123 -79.33,-123 -78.96,-123 -78.59,-123 -78.22,-123 -77.85,-123 -77.48,-123 -77.11,-123 -76.74,-123 -76.37,-123 -76))"] | ["POINT(-111.25 -77.85)"] | 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 |
Blue Ice Tephra II - Brimstone Peak
|
9527373 |
2003-02-18 | Dunbar, Nelia |
Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region |
This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Brimstone Peak (75.888S 158.55E) in East Antarctica. Tephra samples were collected between 15 November 1996 and 15 January 1997. The Antarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date. Data include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography.Data are provided as Excel 97 data files, JPG map files, and GIF-formatted BSE images. Data are available via ftp. | ["POLYGON((158.55 -75.86,158.562 -75.86,158.574 -75.86,158.586 -75.86,158.598 -75.86,158.61 -75.86,158.622 -75.86,158.634 -75.86,158.646 -75.86,158.658 -75.86,158.67 -75.86,158.67 -75.864,158.67 -75.868,158.67 -75.872,158.67 -75.876,158.67 -75.88,158.67 -75.884,158.67 -75.888,158.67 -75.892,158.67 -75.896,158.67 -75.9,158.658 -75.9,158.646 -75.9,158.634 -75.9,158.622 -75.9,158.61 -75.9,158.598 -75.9,158.586 -75.9,158.574 -75.9,158.562 -75.9,158.55 -75.9,158.55 -75.896,158.55 -75.892,158.55 -75.888,158.55 -75.884,158.55 -75.88,158.55 -75.876,158.55 -75.872,158.55 -75.868,158.55 -75.864,158.55 -75.86))"] | ["POINT(158.61 -75.88)"] | false | false |
Blue Ice Tephra II - Mt. DeWitt
|
9527373 |
2003-02-01 | Dunbar, Nelia |
Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region |
This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Mt. DeWitt, Antarctica (77.12 deg S, 159.51 deg E). Tephra samples were collected between 15 November 1996 and 15 January 1997. Data include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography. Data are provided as an Excel 97 data file, (this file is also divided into various text files) and TIF images. Data are available via ftp. Antarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date. | ["POINT(-159.51 -77.12)"] | ["POINT(-159.51 -77.12)"] | false | false |