USAP-DC

{"dp_type": "Dataset", "free_text": "Wood"}

[{"awards": "1644128 Welten, Kees; 1644094 Caffee, Marc", "bounds_geometry": ["POINT(-112.05 -79.28)"], "date_created": "Sat, 20 May 2023 00:00:00 GMT", "description": "This dataset contains a continuous depth profile of 10Be measured in ice core samples from the WAIS Divide Core between 2850 and 3240 m depth.", "east": -112.05, "geometry": ["POINT(-112.05 -79.28)"], "keywords": "10Be; Antarctica; Beryllium; Cosmogenic Radionuclides; Ice Core Data; WAIS Divide", "locations": "WAIS Divide; Antarctica", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "persons": "Welten, Kees; Caffee, Marc; Woodruff, Thomas", "project_titles": "Synchronizing the WAIS Divide and Greenland Ice Cores from 30-65 ka BP using high-resolution 10Be measurements", "projects": [{"proj_uid": "p0010280", "repository": "USAP-DC", "title": "Synchronizing the WAIS Divide and Greenland Ice Cores from 30-65 ka BP using high-resolution 10Be measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "WAIS Divide Core 10Be data, 2850-3240 m", "uid": "601692", "west": -112.05}, {"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": "p0010269", "repository": "USAP-DC", "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations"}, {"proj_uid": "p0000395", "repository": "USAP-DC", "title": "Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Circum-Antarctic grounding-line sinuosity", "uid": "601484", "west": -180.0}, {"awards": "1745043 Simkins, Lauren; 1745055 Stearns, Leigh; 1246353 Anderson, John", "bounds_geometry": ["POLYGON((174 -75,174.4 -75,174.8 -75,175.2 -75,175.6 -75,176 -75,176.4 -75,176.8 -75,177.2 -75,177.6 -75,178 -75,178 -75.2,178 -75.4,178 -75.6,178 -75.8,178 -76,178 -76.2,178 -76.4,178 -76.6,178 -76.8,178 -77,177.6 -77,177.2 -77,176.8 -77,176.4 -77,176 -77,175.6 -77,175.2 -77,174.8 -77,174.4 -77,174 -77,174 -76.8,174 -76.6,174 -76.4,174 -76.2,174 -76,174 -75.8,174 -75.6,174 -75.4,174 -75.2,174 -75))"], "date_created": "Mon, 04 Oct 2021 00:00:00 GMT", "description": "Bathymetry from multibeam echo sounding data in Pennell Trough, Ross Sea, Antarctica 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 a 1\u00b0\u00d71\u00b0 beam width, swath angular coverage set to 62\u00b0\u00d762\u00b0, and 30-60% overlap between survey lines. All raw, ping-edited geophysical data collected on NBP15-02 can be accessed using the Marine Geoscience Data System (Cruise DOI: 10.7284/901477). The bathymetry dataset here is gridded at 20-m resolution with a water depth-dependent vertical resolution on the order of decimeters. Two shapefiles are provided for ice-marginal landforms and meltwater landforms observable in the bathymetry data. The purpose of collecting the bathymetry data on cruise NBP15-02 was to better understand the glacial history of the Ross Sea, and the dataset, inclusive of bathymetry data and shapefiles of glacial landforms, from Pennell Trough are used to understand impacts on subglacial channel morphology and organization during the deglaciation of the region following the Last Glacial Maximum. The published dataset was used and analyzed in the article \"Topographic controls on channelized meltwater in the subglacial environment\" by Simkins, L.M., Greenwood, S.L., Munevar Garcia, S., Eareckson, E.A., Anderson, J.B., and Prothro, L.O, which was published in Geophysical Research Letters in 2021 (DOI: 10.1029/2021GL094678).", "east": 178.0, "geometry": ["POINT(176 -76)"], "keywords": "Antarctica; Bathymetry; Elevation; Geomorphology; Glacial History; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; NBP1502; Pennell Trough; Ross Sea; R/v Nathaniel B. Palmer", "locations": "Ross Sea; Pennell Trough; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Greenwood, Sarah; Munevar Garcia, Santiago; Eareckson, Elizabeth; Anderson, John; Prothro, Lindsay; Simkins, Lauren", "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": "p0010269", "repository": "USAP-DC", "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations"}, {"proj_uid": "p0000395", "repository": "USAP-DC", "title": "Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "uid": "601474", "west": 174.0}, {"awards": "0839042 Caffee, Marc; 0839137 Welten, Kees", "bounds_geometry": ["POLYGON((-113 -79.25,-112.8 -79.25,-112.6 -79.25,-112.4 -79.25,-112.2 -79.25,-112 -79.25,-111.8 -79.25,-111.6 -79.25,-111.4 -79.25,-111.2 -79.25,-111 -79.25,-111 -79.3,-111 -79.35,-111 -79.4,-111 -79.45,-111 -79.5,-111 -79.55,-111 -79.6,-111 -79.65,-111 -79.7,-111 -79.75,-111.2 -79.75,-111.4 -79.75,-111.6 -79.75,-111.8 -79.75,-112 -79.75,-112.2 -79.75,-112.4 -79.75,-112.6 -79.75,-112.8 -79.75,-113 -79.75,-113 -79.7,-113 -79.65,-113 -79.6,-113 -79.55,-113 -79.5,-113 -79.45,-113 -79.4,-113 -79.35,-113 -79.3,-113 -79.25))"], "date_created": "Tue, 27 Jul 2021 00:00:00 GMT", "description": "This is the second part of the 10Be data set for the WAIS Divide Core WDC06A ice core, from 1190.69 to 2453.25 m depth, produced by UC Berkeley\u0027s Space Sciences Laboratory and Purdue University\u0027s PRIME Laboratory. Each sample represents a continuous ice core section of ~3 m long (although they vary from 1.9 to 4.2 m). Experimental procedures for the extraction of 10Be from the ice samples and the measurement of 10Be by accelerator mass spectrometry (AMS) are described in Woodruff et al. (2013).", "east": -111.0, "geometry": ["POINT(-112 -79.5)"], "keywords": "Antarctica; West Antarctic Ice Sheet", "locations": "West Antarctic Ice Sheet; Antarctica", "north": -79.25, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "persons": "Welten, Kees; Nishiizumi, Kunihiko; Caffee, M. W.; Woodruff, T. E.", "project_titles": "Collaborative Research: Cosmogenic Radionuclides in the Deep WAIS Divide Core", "projects": [{"proj_uid": "p0000103", "repository": "USAP-DC", "title": "Collaborative Research: Cosmogenic Radionuclides in the Deep WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.75, "title": "Cosmogenic 10Be in WAIS Divide Ice core, 1190-2453 m", "uid": "601466", "west": -113.0}, {"awards": "1443347 Condron, Alan", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Tue, 08 Jun 2021 00:00:00 GMT", "description": "Meltwater and ice discharge from a retreating Antarctic Ice Sheet could have important impacts on future global climate. This dataset contains the results from multi-century (present\u20132250) climate simulations performed using a coupled numerical model integrated under future greenhouse-gas emission scenarios IPCC RCP4.5 and RCP8.5, with meltwater and ice discharge provided by a dynamic-thermodynamic ice sheet model. These results were published in Sadai et al., Science Advances, 2020, Vol. 6, eaaz1169\r\n\r\nPlease note that ALL the raw model data generated for this project is archived at Woods Hole Oceanographic Institution and the University of Massachusetts Amherst and freely available on request. ", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meltwater", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "persons": "Condron, Alan", "project_titles": "Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet", "projects": [{"proj_uid": "p0010007", "repository": "USAP-DC", "title": "Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming", "uid": "601449", "west": -180.0}, {"awards": "1443585 Polito, Michael; 1443424 McMahon, Kelton; 1826712 McMahon, Kelton; 1443386 Emslie, Steven", "bounds_geometry": ["POINT(-54.67855 -63.434067)"], "date_created": "Fri, 24 Jul 2020 00:00:00 GMT", "description": "This data set focuses on ornithogenic soils excavated from a test pit located in an active colony of Pygoscelis spp. penguins on Platter Island in the Danger Islands archipelago along the northeastern side of the Antarctic Peninsula in December 2015. It contains radiocarbon dates of recovered penguin tissues and the estimated age of ornithogenic soils by depth. It also contains measurements of carbon (\u03b413C) and nitrogen (\u03b415N) stable isotope values of Pygoscelis spp. penguins eggshell membrane and feather samples and Antarctic fur seal (Arctocephalus gazella) hair sample recovered from these ornithogenic soils. Accelerator Mass Spectrometry (AMS) was used to obtain radiocarbon dates at the Woods Hole National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Radiocarbon Dates were corrected for the marine carbon reservoir effect and calibrated to calendar years before present (cal years BP) using a \u0394R of 750\u2009\u00b1\u200950 years and the MARINE13 calibration curve in Calib 7.04. The rbacon package ver. 2.3.9.1 in R was used to estimate age at depth of each soil level expressed as years relative to the common era (CE). Stable isotope analyses were conducted using an elemental analyzer coupled to a continuous flow stable isotope ratio mass spectrometer at Louisiana State University. The data set also includes associated data such as excavation date, location, site names, latitude/longitude, species, date of excavation, tissue used for radiocarbon dating, and carbon to nitrogen ratios. Details of the data set and all relevant methods are provided in Kalvakaalva et. al., 2020.", "east": -54.67855, "geometry": ["POINT(-54.67855 -63.434067)"], "keywords": "Antarctica; Antarctic Peninsula; Arctocephalus Gazella; Carbon; Holocene; Nitrogen; Paleoecology; Penguin; Pygoscelis Spp.; Stable Isotope Analysis; Weddell Sea", "locations": "Antarctic Peninsula; Weddell Sea; Antarctica", "north": -63.434067, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Kalvakaalva, Rohit; Clucas, Gemma; Herman, Rachael; Polito, Michael", "project_titles": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators", "projects": [{"proj_uid": "p0010047", "repository": "USAP-DC", "title": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -63.434067, "title": "Radiocarbon dating and stable isotope values of penguin and seal tissues recovered from ornithogenic soils on Platter Island, Danger Islands Archipelago, Antarctic Peninsula in December 2015.", "uid": "601364", "west": -54.67855}, {"awards": "1826712 McMahon, Kelton; 1443424 McMahon, Kelton; 1443585 Polito, Michael; 1443386 Emslie, Steven", "bounds_geometry": ["POLYGON((162 -72,162.9 -72,163.8 -72,164.7 -72,165.6 -72,166.5 -72,167.4 -72,168.3 -72,169.2 -72,170.1 -72,171 -72,171 -72.6,171 -73.2,171 -73.8,171 -74.4,171 -75,171 -75.6,171 -76.2,171 -76.8,171 -77.4,171 -78,170.1 -78,169.2 -78,168.3 -78,167.4 -78,166.5 -78,165.6 -78,164.7 -78,163.8 -78,162.9 -78,162 -78,162 -77.4,162 -76.8,162 -76.2,162 -75.6,162 -75,162 -74.4,162 -73.8,162 -73.2,162 -72.6,162 -72))"], "date_created": "Tue, 03 Mar 2020 00:00:00 GMT", "description": "This data set contains measurements of carbon (\u03b413C) and nitrogen (\u03b415N) stable isotope values of feather, skin, bone, and toenail samples of mummified Ad\u00e9lie penguin chick remains excavated from multiple sites around the Ross Sea region of Antarctica between 2004 and 2016, as well as the same measurements for modern Ad\u00e9lie chicks collected from the surface of Cape Hallett and Adelie Cove in January 2016. Stable isotope analyses were conducted using an elemental analyzer coupled to a continuous flow stable isotope ratio mass spectrometer. Where possible, accelerator Mass Spectrometry (AMS) radiocarbon dates on selected mummy tissues were completed at the Rafter Radiocarbon Laboratory, New Zealand (NZA), Beta Analytic, Inc. (Beta), the University of Georgia Center for Applied Isotope Studies (UGAMS), and Woods Hole National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. All dates were corrected for the marine carbon reservoir effect and calibrated to calendar years before present (cal years BP) using a \u0394R of 750\u2009\u00b1\u200950 years and the MARINE13 calibration curve in Calib 7.0 (2\u03c3 range). \r\nThe data set also includes excavation/collection site names and latitude/longitude, date of excavation/collection, tissue used for radiocarbon dating, and carbon to nitrogen ratios. Details of the data set and all relevant methods are provided in Kristan et. al., 2019.\r\n", "east": 171.0, "geometry": ["POINT(166.5 -75)"], "keywords": "Abandoned Colonies; Antarctica; Holocene; Penguin; Ross Sea; Stable Isotope Analysis", "locations": "Antarctica; Ross Sea; Antarctica", "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Kristan, Allyson; Emslie, Steven; Patterson, William", "project_titles": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators", "projects": [{"proj_uid": "p0010047", "repository": "USAP-DC", "title": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Radioisotope dates and carbon (\u03b413C) and nitrogen (\u03b415N) stable isotope values from modern and mummified Ad\u00e9lie Penguin chick carcasses and tissue from the Ross Sea, Antarctica", "uid": "601263", "west": 162.0}, {"awards": "1142646 Twickler, Mark; 1142517 Aydin, Murat; 1141839 Steig, Eric", "bounds_geometry": ["POINT(90 -90)"], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "Qualitative assessment of ice-core quality versus depth for the South Pole ice core SPC14. The depths and core quality ratings presented here are from the field observations made at South Pole, Antarctica, during the course of the drilling of the ice core and also from the lab observations at the NSF-Ice Core Facility in Lakewood, Colorado. Depths are in meters. Core quality ratings were defined are as follows. Excellent: 0\u20131 breaks/no fractures; Very Good: 0\u20132 breaks/90% no fractures; Good: 0\u20133 breaks/50% no fractures; Fair: \u003e10 cm without fractures; Poor: \u003e10 cm without through fractures; Very Poor: \u003c10 cm without through fractures.", "east": 90.0, "geometry": ["POINT(90 -90)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "persons": "Souney, Joseph Jr.; Twickler, Mark; Fegyveresi, John; Casey, Kimberly A.; Aydin, Murat; Steig, Eric J.; Nunn, Richard; Hargreaves, Geoff; Fudge, T. J.; Nicewonger, Melinda R.; Kahle, Emma", "project_titles": "Collaborative Research: A 1500m Ice Core from South Pole", "projects": [{"proj_uid": "p0010060", "repository": "USAP-DC", "title": "Collaborative Research: A 1500m Ice Core from South Pole"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "uid": "601221", "west": 90.0}, {"awards": "1443386 Emslie, Steven; 1443424 McMahon, Kelton; 1443585 Polito, Michael; 1826712 McMahon, Kelton", "bounds_geometry": ["POLYGON((-59 -62,-58.9 -62,-58.8 -62,-58.7 -62,-58.6 -62,-58.5 -62,-58.4 -62,-58.3 -62,-58.2 -62,-58.1 -62,-58 -62,-58 -62.1,-58 -62.2,-58 -62.3,-58 -62.4,-58 -62.5,-58 -62.6,-58 -62.7,-58 -62.8,-58 -62.9,-58 -63,-58.1 -63,-58.2 -63,-58.3 -63,-58.4 -63,-58.5 -63,-58.6 -63,-58.7 -63,-58.8 -63,-58.9 -63,-59 -63,-59 -62.9,-59 -62.8,-59 -62.7,-59 -62.6,-59 -62.5,-59 -62.4,-59 -62.3,-59 -62.2,-59 -62.1,-59 -62))"], "date_created": "Tue, 24 Sep 2019 00:00:00 GMT", "description": "Radiocarbon dates from pygoscelid penguin tissues from ornithogenic soils and beach deposits at Stranger Point, King George (25 de Mayo) Island, Antarctic Peninsula. Uncorrected dates are in radiocarbon years before present (BP); calibrated dates were corrected for the marine carbon reservoir effect (delta R = 700 +/- 50 years) and calibrated with Calib 7.0.4 to provide 2\u03c3 ranges in calendar years BP. All dates except were completed at the Woods Hole National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility and are designated with OS numbers. Localities include ancient penguin breedings sites (mounds, M), active colonies (I9, B3), and a mid-Holocene marine beach deposit (Pingfo 1).", "east": -58.0, "geometry": ["POINT(-58.5 -62.5)"], "keywords": "Abandoned Colonies; Antarctica; Antarctic Peninsula; Beach Deposit; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Holocene; Penguin; Radiocarbon; Radiocarbon Dates; Snow/ice; Snow/Ice; Stranger Point", "locations": "Antarctic Peninsula; Stranger Point; Antarctica", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Emslie, Steven", "project_titles": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators", "projects": [{"proj_uid": "p0010047", "repository": "USAP-DC", "title": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -63.0, "title": "Radiocarbon dates from pygoscelid penguin tissues excavated at Stranger Point, King George Island, Antarctic Peninsula", "uid": "601212", "west": -59.0}, {"awards": "1643901 Zhang, Weifeng", "bounds_geometry": ["POLYGON((55 -62,65 -62,75 -62,85 -62,95 -62,105 -62,115 -62,125 -62,135 -62,145 -62,155 -62,155 -62.8,155 -63.6,155 -64.4,155 -65.2,155 -66,155 -66.8,155 -67.6,155 -68.4,155 -69.2,155 -70,145 -70,135 -70,125 -70,115 -70,105 -70,95 -70,85 -70,75 -70,65 -70,55 -70,55 -69.2,55 -68.4,55 -67.6,55 -66.8,55 -66,55 -65.2,55 -64.4,55 -63.6,55 -62.8,55 -62))"], "date_created": "Tue, 10 Sep 2019 00:00:00 GMT", "description": "The emperor penguin, an iconic species threatened by projected sea-ice loss in Antarctica, has long been considered to forage at the fast ice edge, presumably relying on large/yearly-persistent polynyas as their main foraging habitat during the breeding season. Using newly developed fine-scale sea-icescape data and historical penguin tracking data, this study for the first time suggests the importance of less-recognized small openings, including cracks, flaw leads and ephemeral short-term polynyas, as foraging habitats for emperor penguins. The tracking data retrieved from 47 emperor penguins in two different colonies in East Antarctica suggest that those penguins spent 23% of their time in ephemeral polynyas and did not use the large/yearly-persistent, well-studied polynyas, even they occur much more regularly with predictable locations. These findings challenge our previous understanding of emperor penguin breeding habitats, highlighting the need for incorporating fine-scale seascape features when assessing the population persistence in a rapidly changing polar environment.", "east": 155.0, "geometry": ["POINT(105 -66)"], "keywords": "Animal Behavior Observation; Antarctica; Biota; East Antarctica; GPS; Oceans; Penguin; Southern Ocean", "locations": "East Antarctica; Southern Ocean; Antarctica", "north": -62.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Labrousse, Sara; Fraser, Alexander; Tamura, Takeshi; Pinaud, David; Wienecke, Barbara; Kirkwood, Roger; Ropert-Coudert, Yan; Resinger, Ryan; Jonsen, Ian; Porter-Smith, Rick; Barbraud, Christophe; Bost, Charles-Andr\u00e9; Ji, Rubao; Jenouvrier, Stephanie; Sumner, Michael", "project_titles": "Collaborative Research: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability", "projects": [{"proj_uid": "p0010044", "repository": "USAP-DC", "title": "Collaborative Research: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Dynamic fine-scale sea-icescape shapes adult emperor penguin foraging habitat in East Antarctica", "uid": "601209", "west": 55.0}, {"awards": "1543031 Ivany, Linda", "bounds_geometry": ["POLYGON((-57 -64,-56.9 -64,-56.8 -64,-56.7 -64,-56.6 -64,-56.5 -64,-56.4 -64,-56.3 -64,-56.2 -64,-56.1 -64,-56 -64,-56 -64.05,-56 -64.1,-56 -64.15,-56 -64.2,-56 -64.25,-56 -64.3,-56 -64.35,-56 -64.4,-56 -64.45,-56 -64.5,-56.1 -64.5,-56.2 -64.5,-56.3 -64.5,-56.4 -64.5,-56.5 -64.5,-56.6 -64.5,-56.7 -64.5,-56.8 -64.5,-56.9 -64.5,-57 -64.5,-57 -64.45,-57 -64.4,-57 -64.35,-57 -64.3,-57 -64.25,-57 -64.2,-57 -64.15,-57 -64.1,-57 -64.05,-57 -64))"], "date_created": "Mon, 22 Apr 2019 00:00:00 GMT", "description": "Serially-sampled high-resolution organic carbon isotope data from middle Eocene (~42 Ma) driftwood preserved within the La Meseta Formation, Seymour Island, Antarctica.", "east": -56.0, "geometry": ["POINT(-56.5 -64.25)"], "keywords": "Antarctica; Carbon Isotopes; Driftwood; Eocene; Geochemistry; Geochronology; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Organic Carbon Isotopes; Seasonality; Seymour Island; Wood", "locations": "Seymour Island; La Meseta Formation; Antarctica", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Judd, Emily", "project_titles": "Seasonality, Summer Cooling, and Calibrating the Approach of the Icehouse in Late Eocene Antarctica", "projects": [{"proj_uid": "p0010025", "repository": "USAP-DC", "title": "Seasonality, Summer Cooling, and Calibrating the Approach of the Icehouse in Late Eocene Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.5, "title": "Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour Island, Antarctica", "uid": "601173", "west": -57.0}, {"awards": "1341485 Woods, H. Arthur", "bounds_geometry": ["POINT(166.666 -77.8499966)"], "date_created": "Sun, 06 Jan 2019 00:00:00 GMT", "description": "Data used in Lane, SJ, CM Shishido, AL Moran, BW Tobalske, CP Arango, HA Woods (2017) Upper limits to body size imposed by respiratory-structural trade-offs in Antarctic pycnogonids. Proceedings of the Royal Society B 284, No. 1865, p. 20171779, DOI: 10.1098/rspb.2017.1779. File includes data on species identification, body mass, leg dimensions, oxygen gradients across the cuticle, and metabolic rate. ", "east": 166.666, "geometry": ["POINT(166.666 -77.8499966)"], "keywords": "Antarctica; Biota; Body Size; Cuticle; Metabolic Rate; Oxygen; Polar Gigantism; Respiration; Size Limits; Southern Ocean; Temperature", "locations": "Southern Ocean; Antarctica", "north": -77.8499966, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Lane, Steven J.; Moran, Amy; Shishido, Caitlin; Woods, H. Arthur", "project_titles": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida", "projects": [{"proj_uid": "p0000007", "repository": "USAP-DC", "title": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8499966, "title": "Size scaling of oxygen physiology and metabolic rate of Antarctic sea spiders", "uid": "601150", "west": 166.666}, {"awards": "1341485 Woods, H. Arthur", "bounds_geometry": ["POINT(166.666 -77.8499966)"], "date_created": "Sun, 06 Jan 2019 00:00:00 GMT", "description": "Data used in Lane, SJ, BW Tobalske, AL Moran, CM Shishido, HA Woods (2018) Costs of epibionts on Antarctic sea spiders. Marine Biology 165, 137 https://doi.org/10.1007/s00227-018-3389-9. Data sets include (1) measurements of drag on individual sea spiders with or without epibiotic barnacles and other fouling; (2) data on locomotion by fouled and unfouled sea spiders; (3) functional diffusion coefficients of oxygen through fouled and unfouled cuticle; and (4) levels of oxygen at the cuticle surface of fouled and unfouled individuals.", "east": 166.666, "geometry": ["POINT(166.666 -77.8499966)"], "keywords": "Antarctica; Barnacles; Biota; Cuticle; Epibionts; Fouling; Grooming; Locomotion; Oxygen; Respiration", "locations": "Antarctica", "north": -77.8499966, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Lane, Steven J.; Tobalske, Bret; Moran, Amy; Shishido, Caitlin; Woods, H. Arthur", "project_titles": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida", "projects": [{"proj_uid": "p0000007", "repository": "USAP-DC", "title": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8499966, "title": "Physiological, biomechanical, and locomotory data on Antarctic sea spiders fouled and unfouled with epibionts", "uid": "601149", "west": 166.666}, {"awards": "1341485 Woods, H. Arthur", "bounds_geometry": ["POLYGON((163.85 -77.6,164.134 -77.6,164.418 -77.6,164.702 -77.6,164.986 -77.6,165.27 -77.6,165.554 -77.6,165.838 -77.6,166.122 -77.6,166.406 -77.6,166.69 -77.6,166.69 -77.624,166.69 -77.648,166.69 -77.672,166.69 -77.696,166.69 -77.72,166.69 -77.744,166.69 -77.768,166.69 -77.792,166.69 -77.816,166.69 -77.84,166.406 -77.84,166.122 -77.84,165.838 -77.84,165.554 -77.84,165.27 -77.84,164.986 -77.84,164.702 -77.84,164.418 -77.84,164.134 -77.84,163.85 -77.84,163.85 -77.816,163.85 -77.792,163.85 -77.768,163.85 -77.744,163.85 -77.72,163.85 -77.696,163.85 -77.672,163.85 -77.648,163.85 -77.624,163.85 -77.6))"], "date_created": "Sat, 22 Dec 2018 00:00:00 GMT", "description": "Raw data from Lane, SJ, AL Moran, CM Shishido, BW Tobalske, HA Woods (2018) Cuticular gas exchange by Antarctic sea spiders. Journal of Experimental Biology. jeb.177568 doi: 10.1242/jeb.177568.\r\n\r\nThe file contains data on pore morphology, cuticle thickness, oxygen gradients across the cuticle, and estimated resistances of the cuticle to oxygen flux. Most of the sea spiders were collected near McMurdo Station, with a few extras collected at New Harbor, Antarctica.", "east": 166.69, "geometry": ["POINT(165.27 -77.72)"], "keywords": "Antarctica; Benthos; Biota; Body Size; Cuticle; Mcmurdo Sound; Microelectrodes; Microscope; Microscopy; Oxygen; Pore; Respiration; Sea Spider; Southern Ocean", "locations": "Mcmurdo Sound; Southern Ocean; Antarctica", "north": -77.6, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Woods, H. Arthur; Arthur Woods, H.", "project_titles": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida", "projects": [{"proj_uid": "p0000007", "repository": "USAP-DC", "title": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.84, "title": "Cuticle morphology and oxygen gradients of Antarctic sea spiders", "uid": "601145", "west": 163.85}, {"awards": "1341476 Moran, Amy; 1341485 Woods, H. Arthur", "bounds_geometry": ["POINT(166.67 -77.85)"], "date_created": "Fri, 07 Dec 2018 00:00:00 GMT", "description": "This dataset contains morphometric (mass, surface area, cuticle thickness, cuticle morphometrics) and physiological (oxygen consumption) data for Antarctic pycnognonids collected in McMurdo Sound, Antarctica .", "east": 166.67, "geometry": ["POINT(166.67 -77.85)"], "keywords": "Antarctica; Biomechanics; Biota; Cold Adaptation; Mcmurdo Sound; Metabolism; Oceans; Oxygen; Pycnogonida; Southern Ocean", "locations": "Mcmurdo Sound; Antarctica; Southern Ocean", "north": -77.85, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Moran, Amy; Woods, H. Arthur; Tobalske, Bret", "project_titles": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida", "projects": [{"proj_uid": "p0000007", "repository": "USAP-DC", "title": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.85, "title": "Physiological and biochemical measurements on Pycnogonida from McMurdo Sound", "uid": "601142", "west": 166.67}, {"awards": "0842639 Soreghan, Gerilyn", "bounds_geometry": ["POLYGON((-163.12865 -77.41693,-163.06062 -77.41693,-162.99259 -77.41693,-162.92456 -77.41693,-162.85653 -77.41693,-162.7885 -77.41693,-162.72047 -77.41693,-162.65244 -77.41693,-162.58441 -77.41693,-162.51638 -77.41693,-162.44835 -77.41693,-162.44835 -77.445495,-162.44835 -77.47406,-162.44835 -77.502625,-162.44835 -77.53119,-162.44835 -77.559755,-162.44835 -77.58832,-162.44835 -77.616885,-162.44835 -77.64545,-162.44835 -77.674015,-162.44835 -77.70258,-162.51638 -77.70258,-162.58441 -77.70258,-162.65244 -77.70258,-162.72047 -77.70258,-162.7885 -77.70258,-162.85653 -77.70258,-162.92456 -77.70258,-162.99259 -77.70258,-163.06062 -77.70258,-163.12865 -77.70258,-163.12865 -77.674015,-163.12865 -77.64545,-163.12865 -77.616885,-163.12865 -77.58832,-163.12865 -77.559755,-163.12865 -77.53119,-163.12865 -77.502625,-163.12865 -77.47406,-163.12865 -77.445495,-163.12865 -77.41693))"], "date_created": "Sat, 01 Jan 2011 00:00:00 GMT", "description": "The proposed research seeks to test the hypothesis that chemical and physical weathering in proximal alluvial systems will show systematic and measurable variations between glacial and nonglacial systems. To accomplish this, the investigation will attempt to quantify the natural variation of chemical and physical weathering in granitoid-sourced proximal alluvial sediments in end-member glacial and nonglacial systems, when other, \u0027non-climatic\u0027 factors (e.g. provenance, drainage basin area and relief, sample grain size, sediment facies) are controlled. If chemical weathering in the proposed hot-humid, hot-arid, hot semi-arid nonglacial systems and the cool-wet, cold semi-arid, and cold-arid glacial systems show systematic variations, then chemical indices may be used to help differentiate paleoclimatic conditions. Continued reliance on students provides a broader impact of this proposed research and firmly grounds this effort in its educational mission.", "east": -162.44835, "geometry": ["POINT(-162.7885 -77.559755)"], "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Chemistry:rock; Chemistry:Rock; Chemistry:sediment; Chemistry:Sediment; Critical Zone; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet", "locations": "Antarctica", "north": -77.41693, "nsf_funding_programs": null, "persons": "Soreghan, Gerilyn; Elwood Madden, Megan", "project_titles": "Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record", "projects": [{"proj_uid": "p0000518", "repository": "USAP-DC", "title": "Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.70258, "title": "Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record", "uid": "600110", "west": -163.12865}, {"awards": "0338008 Wemple, Beverley", "bounds_geometry": ["POLYGON((-71.77 43.96,-71.766 43.96,-71.762 43.96,-71.758 43.96,-71.754 43.96,-71.75 43.96,-71.746 43.96,-71.742 43.96,-71.738 43.96,-71.734 43.96,-71.73 43.96,-71.73 43.955,-71.73 43.95,-71.73 43.945,-71.73 43.94,-71.73 43.935,-71.73 43.93,-71.73 43.925,-71.73 43.92,-71.73 43.915,-71.73 43.91,-71.734 43.91,-71.738 43.91,-71.742 43.91,-71.746 43.91,-71.75 43.91,-71.754 43.91,-71.758 43.91,-71.762 43.91,-71.766 43.91,-71.77 43.91,-71.77 43.915,-71.77 43.92,-71.77 43.925,-71.77 43.93,-71.77 43.935,-71.77 43.94,-71.77 43.945,-71.77 43.95,-71.77 43.955,-71.77 43.96))"], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "This data set contains snow depth, Snow Water Equivalent (SWE), and forest cover characteristics for sites at the Hubbard Brook Experimental Forest in northern New Hampshire. Measurements were made at 26 sampling sites on 4 March and 1 April 2009.The data were collected as part of a collaborative research project on isotopic exchange in snow. The project aims to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is important to Antarctic ice core interpretation. Data are in Microsoft Excel (.xls) format. The data set also includes maps showing site locations in Joint Photography Experts Group (.jpg) format.", "east": -71.73, "geometry": ["POINT(-71.75 43.935)"], "keywords": "Snow/ice; Snow/Ice", "locations": null, "north": 43.96, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Wemple, Beverley C.", "project_titles": "Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow and Firn", "projects": [{"proj_uid": "p0000132", "repository": "USAP-DC", "title": "Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow and Firn"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": 43.91, "title": "Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "uid": "609441", "west": -71.77}, {"awards": "0739693 Ashworth, Allan", "bounds_geometry": ["POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia. In terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica\u0027s ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise.", "east": 162.0, "geometry": ["POINT(161 -77.5)"], "keywords": "Antarctica; Geochronology; Geology/Geophysics - Other; GPS; Solid Earth", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": null, "persons": "Ashworth, Allan; Lewis, Adam", "project_titles": "Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "projects": [{"proj_uid": "p0000188", "repository": "USAP-DC", "title": "Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "uid": "600081", "west": 160.0}, {"awards": null, "bounds_geometry": null, "date_created": "Thu, 15 Jun 2006 00:00:00 GMT", "description": "CUB shear velocity model is created from a large data set of the surface wave fundamental model phase and group velocity measurements. Phase velocities in period range between 40 an 150 s are generously donated by Harvard University and Utrecht University. These phase velocity data sets are described by Ekstr\u00f6m et al. (1997) and Trampert and Woodhouse (1995). The group velocity measurements at periods between 16 and 200s are performed at the Center for Imaging the Earth\u0027s Interior in the University of Colorado at Boulder. The group velocities are measured with the frequency-time analysis (Levshin et al., 1989) in which for every waveform a human analyst defines the frequency range of measurements and separate the signal form a variety of noise sources (e.g., overtones, fundamental modes of different types, other earthquakes, multipaths, scattered arrivals). We used broadband waveforms following earthquakes occurred from 1997 to present and recorded at stations from both global networks (GDSN, GSN, GEOSCOPE) as well as temporary regional arrays. At present, the group velocity dataset is composed of about 200000 paths.\n\nData coverage is generally better for Rayleigh waves than for Love waves, is better at intermediate periods than at very short or very long periods, and is better in the northern than in the southern hemisphere. This heterogeneous data coverage is imposed by the distribution of seismic stations and earthquakes. Data coverage optimizes in Eurasia and is currently worst across Africa, the central Pacific, parts of the Indian Ocean, and Antarctica.", "east": null, "geometry": null, "keywords": null, "locations": null, "north": null, "nsf_funding_programs": null, "persons": "Ritzwoller, Michael", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": null, "title": "Upper Mantle Shear Velocity Model", "uid": "600004", "west": null}]

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