{"dp_type": "Dataset", "free_text": "Till"}
[{"awards": "1914698 Hansen, Samantha", "bounds_geometry": ["POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))"], "date_created": "Wed, 24 Jan 2024 00:00:00 GMT", "description": "Recent investigations in polar environments have examined solid-Earth-ice-sheet feedbacks and have emphasized that glacial isostatic adjustment, tectonic, and geothermal forcings exert first-order control on the physical conditions at and below the ice-bed interface and must be taken into account when evaluating ice-sheet evolution. However, the solid-Earth structure beneath much of Antarctica is still poorly constrained given the sparse distribution of seismic stations across the continent and the generally low seismicity rate. One region of particular interest is the Wilkes Subglacial Basin (WSB) in East Antarctica. During the mid-Pliocene warm period, the WSB may have contributed 3-4 m to the estimated 20 m rise in sea-level, indicating that this region could also play an important role in future warming scenarios. However, the WSB may have experienced notable bedrock uplift since the Pliocene; therefore, past geologic inferences of instability may not serve as a simple analogue for the future.\r\n\r\nUsing records of ambient seismic noise recorded by both temporary and long-term seismic networks, along with a full-waveform tomographic inversion technique, we have developed improved images of the lithospheric structure beneath East Antarctica, including the WSB. Empirical Green\u2019s Functions with periods between 40 and 340 s have been extracted using a frequency-time normalization technique, and a finite-difference approach with a spherical grid has been employed to numerically model synthetic seismograms. Associated sensitivity kernels have also been constructed using a scattering integral method. Our results suggest the WSB is underlain by slow seismic velocities, with faster seismic structure beneath the adjacent Transantarctic Mountains and the Belgica Subglacial Highlands. This may indicate that the WSB is associated with a region of thinner lithosphere, possibly associated with prior continental rifting. The seismic heterogeneity highlighted in our model could have significant implications for understanding the geodynamic origin of WSB topography and its influence on ice-sheet behavior.\r\n\r\nThe model file and associated plotting scripts are provided.", "east": 180.0, "geometry": ["POINT(135 -77.5)"], "keywords": "Ambient Noise; Antarctica; East Antarctica; Geoscientificinformation; Seismic Tomography; Seismology", "locations": "Antarctica; East Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Hansen, Samantha; Emry, Erica", "project_titles": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)", "projects": [{"proj_uid": "p0010204", "repository": "USAP-DC", "title": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Full Waveform Ambient Noise Tomography for East Antarctica", "uid": "601763", "west": 90.0}, {"awards": "2013987 Zoet, Lucas", "bounds_geometry": null, "date_created": "Wed, 13 Dec 2023 00:00:00 GMT", "description": "This dataset contains AMS results and microstructure analysis from different depths within the sheared till.", "east": null, "geometry": null, "keywords": "Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Zoet, Lucas", "project_titles": "Collaborative Research: Freeze-on of Subglacial Sediments in Experiments and Theory", "projects": [{"proj_uid": "p0010434", "repository": "USAP-DC", "title": "Collaborative Research: Freeze-on of Subglacial Sediments in Experiments and Theory"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Ring shear bed deformation measurements", "uid": "601757", "west": null}, {"awards": "1643735 Li, Yun; 2021245 Li, Yun", "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 -61.8,180 -63.6,180 -65.4,180 -67.2,180 -69,180 -70.8,180 -72.6,180 -74.4,180 -76.2,180 -78,144 -78,108 -78,72 -78,36 -78,0 -78,-36 -78,-72 -78,-108 -78,-144 -78,-180 -78,-180 -76.2,-180 -74.4,-180 -72.6,-180 -70.8,-180 -69,-180 -67.2,-180 -65.4,-180 -63.6,-180 -61.8,-180 -60))"], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Coastal Antarctic polynyas are regions with concentrated phytoplankton blooms, and therefore have important implications for marine ecosystems and the associated carbon cycles. Seasonal water-column stratification, regulated by sea ice, can modulate the exposure of phytoplankton to light and nutrients, and is one of the most important factors that control the duration and strength of algal blooms. Polynyas differ greatly in their stratification, thus are not equally productive in terms of phytoplankton biomass, nor equally vulnerable to the changes in regional climate. To date, most studies have been focusing on individual polynyas, yet a systematic assessment of stratification patterns across polynyas is still lacking. Therefore, we examined the spatial and seasonal variability of stratification in circum-Antarctic coastal polynyas. Using \u003e105 in situ hydrographic casts combined from the World Ocean Database (1970-2021) and the Marine Mammals Exploring the Oceans Pole to Pole Consortium Database (2004-2017), we constructed stratification seasonal climatology using 0-100 m Simpson Energy. Our results showed that stratification magnitude varies by a factor of 6 and its onset time displays 1-2 months difference across all the polynyas. In the presence of warmer water at depths, polynyas tend to develop stronger stratification than others. The spatial variations of stratification are negatively related to sea ice retreat rate and polynya size, indicative of distinct dynamics resulted from the interaction of sea ice melting, advection and water-column mixing.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctic; Antarctica; Antarctic Coastal Polynyas; Polynya", "locations": "Antarctica; Antarctic; Antarctic Coastal Polynyas", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Li, Yun; Shunk, Nathan; Zhang, Weifeng", "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": -78.0, "title": "Monthly Stratification Climatology (1978-2021) in Antarctic Coastal Polynyas", "uid": "601628", "west": -180.0}, {"awards": "1744835 Wagner, Till", "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, 18 Jan 2022 00:00:00 GMT", "description": "Because of difficulties in adequately simulating their breakup, large Antarctic icebergs to date have either not been represented in models or represented but with no breakup scheme such that they consistently survive too long and travel too far compared with observations. Here, we introduce a representation of iceberg fracturing using a breakup scheme based on the \u201cfootloose mechanism.\u201d We optimize the parameters of this breakup scheme by forcing the iceberg model with an ocean state estimate and comparing the modeled iceberg trajectories and areas with the Antarctic Iceberg Tracking Database. We show that including large icebergs and a representation of their breakup substantially affects the iceberg meltwater distribution, with implications for the circulation and stratification of the Southern Ocean.\r\n\r\nThis data link includes the model developed for the study, including a link to the forcing fields needed to replicate the model results. ", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Footloose Mechanism; Iceberg Breakup; Iceberg Decay; Model; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "persons": "Wagner, Till", "project_titles": "Modeling Giant Icebergs and Their Decay", "projects": [{"proj_uid": "p0010290", "repository": "USAP-DC", "title": "Modeling Giant Icebergs and Their Decay"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Model of iceberg drift and decay including breakup", "uid": "601510", "west": -180.0}, {"awards": "1543325 Landolt, Scott; 1543377 Seefeldt, Mark", "bounds_geometry": ["POLYGON((166.918 -77.877,167.2997 -77.877,167.6814 -77.877,168.0631 -77.877,168.4448 -77.877,168.8265 -77.877,169.2082 -77.877,169.5899 -77.877,169.9716 -77.877,170.3533 -77.877,170.735 -77.877,170.735 -77.99,170.735 -78.103,170.735 -78.216,170.735 -78.329,170.735 -78.442,170.735 -78.555,170.735 -78.668,170.735 -78.781,170.735 -78.894,170.735 -79.007,170.3533 -79.007,169.9716 -79.007,169.5899 -79.007,169.2082 -79.007,168.8265 -79.007,168.4448 -79.007,168.0631 -79.007,167.6814 -79.007,167.2997 -79.007,166.918 -79.007,166.918 -78.894,166.918 -78.781,166.918 -78.668,166.918 -78.555,166.918 -78.442,166.918 -78.329,166.918 -78.216,166.918 -78.103,166.918 -77.99,166.918 -77.877))"], "date_created": "Tue, 04 May 2021 00:00:00 GMT", "description": "The dataset includes precipitation and associated observations at four sites across the northwest Ross Ice Shelf from December 2017 to November 2019. The general instruments at each site include precipitation gauge - installed inside a wind shield, anemometer, thermometer, sonic ranging sensor, optical particle detector, laser disdrometer, shortwave and longwave radiation sensors, and a field camera. The observations from each site include: precipitation (liquid water equivalent), temperature, wind speed, snow surface height, particle count, particle size and speed, upward/downward longwave radiation, upward/downward shortwave radiation, still image photos, and 5-second movies. The data are in comma-delimited text files, jpg photos, and mp4 movies. png plots of the quality-controlled observations are included for quick views of the data.", "east": 170.735, "geometry": ["POINT(168.8265 -78.442)"], "keywords": "Accumulation; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meteorology; Precipitation; Ross Ice Shelf; Snow; Snow/ice; Snow/Ice; Weatherstation; Weather Station Data", "locations": "Antarctica; Ross Ice Shelf", "north": -77.877, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "persons": "Seefeldt, Mark", "project_titles": "Collaborative Research: Implementing Low-power, Autonomous Observing Systems to Improve the Measurement and Understanding of Antarctic Precipitation", "projects": [{"proj_uid": "p0010173", "repository": "USAP-DC", "title": "Collaborative Research: Implementing Low-power, Autonomous Observing Systems to Improve the Measurement and Understanding of Antarctic Precipitation"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.007, "title": "Precipitation Observations for the Northwest Ross Ice Shelf - 2017-12 to 2019-11", "uid": "601441", "west": 166.918}, {"awards": "1644196 Cziko, Paul", "bounds_geometry": ["POINT(166.6645 -77.851)"], "date_created": "Tue, 29 Dec 2020 00:00:00 GMT", "description": "Long-term images taken by the camera from the McMurdo Oceanographic Observatory mooring in McMurdo Sound, Antarctica during its 2-year deployment (2017-2019). The mooring was situated at the seawater terminus of the McMurdo Station seawater intake jetty at 21 m deep, typically under thick sea ice cover. The automated 360\u00b0 pan-tilt-zoom (ptz) camera, inside of an air-filled self-cleaning dome, was programmed to move to 42 ptz \"waypoints\" every hour and take a still 1920x1080 JPG image for archiving. Lights, oriented in one direction only, illuminated a rock/rubble slope for much of each winter, when there was no natural illumination. The camera was situated on a concrete block, which elevated the camera about 1m off of the seabed. Motile and sessile benthic biota, including notothenioid fishes, anemones, pycnogonids, asteroids, soft-corals, sponges, and nudibranchs are commonly seen in the images. Some ptz waypoints survey the water column and underside of the sea ice, capturing also the presence of larval/juvenile fishes and other plankton/nekton in the water column. Maximum intervals between subsequent images from the same ptz waypoint were about 1 hour, though many waypoints were captured at somewhat higher frequency. Interval images, taken at 5-min intervals irrespective of camera orientation, were also captured. Images are occasionally obscured/impacted by the camera dome\u0027s wiper, darkness, low visibility, minor fouling of the camera dome, and out-of-focus lens elements. ", "east": 166.6645, "geometry": ["POINT(166.6645 -77.851)"], "keywords": "Antarctica; Benthic Ecology; Benthic Invertebrates; Biota; McMurdo Sound; Notothenioid; Notothenioid Fishes; Photo/video; Photo/Video; Rocky Reef Community; Soft-Bottom Community; Timelaps Images", "locations": "McMurdo Sound; Antarctica", "north": -77.851, "nsf_funding_programs": "Antarctic Instrumentation and Support", "persons": "Cziko, Paul", "project_titles": "Habitat Severity and Internal Ice in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010147", "repository": "USAP-DC", "title": "Habitat Severity and Internal Ice in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.851, "title": "Long-term underwater images from around a single mooring site in McMurdo Sound, Antarctica (2017-2019)", "uid": "601417", "west": 166.6645}, {"awards": "1724670 Williams, Trevor", "bounds_geometry": ["POLYGON((-70 -80,-65 -80,-60 -80,-55 -80,-50 -80,-45 -80,-40 -80,-35 -80,-30 -80,-25 -80,-20 -80,-20 -80.6,-20 -81.2,-20 -81.8,-20 -82.4,-20 -83,-20 -83.6,-20 -84.2,-20 -84.8,-20 -85.4,-20 -86,-25 -86,-30 -86,-35 -86,-40 -86,-45 -86,-50 -86,-55 -86,-60 -86,-65 -86,-70 -86,-70 -85.4,-70 -84.8,-70 -84.2,-70 -83.6,-70 -83,-70 -82.4,-70 -81.8,-70 -81.2,-70 -80.6,-70 -80))"], "date_created": "Mon, 05 Oct 2020 00:00:00 GMT", "description": "This dataset contains 40Ar/39Ar measurements on detrital mineral grains from till in modern moraines at the edges of the Institute, Foundation, Academy, Recovery, and the Slessor glaciers / ice streams.", "east": -20.0, "geometry": ["POINT(-45 -83)"], "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "locations": "Antarctica; Weddell Sea", "north": -80.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Williams, Trevor", "project_titles": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "projects": [{"proj_uid": "p0010128", "repository": "USAP-DC", "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "uid": "601377", "west": -70.0}, {"awards": "1724670 Williams, Trevor", "bounds_geometry": ["POLYGON((-50 -62,-49 -62,-48 -62,-47 -62,-46 -62,-45 -62,-44 -62,-43 -62,-42 -62,-41 -62,-40 -62,-40 -62.3,-40 -62.6,-40 -62.9,-40 -63.2,-40 -63.5,-40 -63.8,-40 -64.1,-40 -64.4,-40 -64.7,-40 -65,-41 -65,-42 -65,-43 -65,-44 -65,-45 -65,-46 -65,-47 -65,-48 -65,-49 -65,-50 -65,-50 -64.7,-50 -64.4,-50 -64.1,-50 -63.8,-50 -63.5,-50 -63.2,-50 -62.9,-50 -62.6,-50 -62.3,-50 -62))"], "date_created": "Mon, 05 Oct 2020 00:00:00 GMT", "description": "This dataset contains 40Ar/39Ar measurements on detrital mineral grains from ice-rafted detritus from sediment core PS1575-1 in the NW Weddell Sea. The depositional age of the sediments is approx. 0 to 300 ka. ", "east": -40.0, "geometry": ["POINT(-45 -63.5)"], "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "locations": "Weddell Sea; Antarctica", "north": -62.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Williams, Trevor", "project_titles": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "projects": [{"proj_uid": "p0010128", "repository": "USAP-DC", "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "uid": "601379", "west": -50.0}, {"awards": "1724670 Williams, Trevor", "bounds_geometry": ["POLYGON((-65 -74,-61 -74,-57 -74,-53 -74,-49 -74,-45 -74,-41 -74,-37 -74,-33 -74,-29 -74,-25 -74,-25 -74.6,-25 -75.2,-25 -75.8,-25 -76.4,-25 -77,-25 -77.6,-25 -78.2,-25 -78.8,-25 -79.4,-25 -80,-29 -80,-33 -80,-37 -80,-41 -80,-45 -80,-49 -80,-53 -80,-57 -80,-61 -80,-65 -80,-65 -79.4,-65 -78.8,-65 -78.2,-65 -77.6,-65 -77,-65 -76.4,-65 -75.8,-65 -75.2,-65 -74.6,-65 -74))"], "date_created": "Mon, 05 Oct 2020 00:00:00 GMT", "description": "This dataset contains 40Ar/39Ar measurements on detrital mineral grains from subglacial till and proximal glacimarine sediment from nine sediment cores along the front of the Filchner and Ronne Ice Shelves. ", "east": -25.0, "geometry": ["POINT(-45 -77)"], "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "locations": "Antarctica; Weddell Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Williams, Trevor", "project_titles": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "projects": [{"proj_uid": "p0010128", "repository": "USAP-DC", "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "uid": "601378", "west": -65.0}, {"awards": "1644209 Goldbogen, Jeremy; 1440435 Ducklow, Hugh", "bounds_geometry": ["POLYGON((-64.5 -63,-63.95 -63,-63.4 -63,-62.85 -63,-62.3 -63,-61.75 -63,-61.2 -63,-60.65 -63,-60.1 -63,-59.55 -63,-59 -63,-59 -63.22,-59 -63.44,-59 -63.66,-59 -63.88,-59 -64.1,-59 -64.32,-59 -64.54,-59 -64.76,-59 -64.98,-59 -65.2,-59.55 -65.2,-60.1 -65.2,-60.65 -65.2,-61.2 -65.2,-61.75 -65.2,-62.3 -65.2,-62.85 -65.2,-63.4 -65.2,-63.95 -65.2,-64.5 -65.2,-64.5 -64.98,-64.5 -64.76,-64.5 -64.54,-64.5 -64.32,-64.5 -64.1,-64.5 -63.88,-64.5 -63.66,-64.5 -63.44,-64.5 -63.22,-64.5 -63))"], "date_created": "Sun, 10 May 2020 00:00:00 GMT", "description": "This dataset contains UAV (drone) still images and video footage from whales in the Antarctic Peninsula region taken from LM Gould expedition (LMG1802) and small zodiacs. It also contains flight tracks as kml files.", "east": -59.0, "geometry": ["POINT(-61.75 -64.1)"], "keywords": "Aerial Imagery; Antarctica; Antarctic Peninsula; Biota; Camera; Humpback Whales; LMG1802; LTER; Minke Whales; Oceans; Palmer Station; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould; Species Size; UAV; Video Data; Whales", "locations": "Palmer Station; Antarctica; Antarctic Peninsula", "north": -63.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Friedlaender, Ari; Dale, Julian; Nowacek, Douglas; Bierlich, KC", "project_titles": "LTER Palmer, Antarctica (PAL): Land-Shelf-Ocean Connectivity, Ecosystem Resilience and Transformation in a Sea-Ice Influenced Pelagic Ecosystem", "projects": [{"proj_uid": "p0000133", "repository": "USAP-DC", "title": "LTER Palmer, Antarctica (PAL): Land-Shelf-Ocean Connectivity, Ecosystem Resilience and Transformation in a Sea-Ice Influenced Pelagic Ecosystem"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LTER", "south": -65.2, "title": "UAV images and video of whales in the Antarctic Penisula during LMG1802", "uid": "601318", "west": -64.5}, {"awards": "0839059 Powell, Ross", "bounds_geometry": ["POLYGON((-180 -80,-174 -80,-168 -80,-162 -80,-156 -80,-150 -80,-144 -80,-138 -80,-132 -80,-126 -80,-120 -80,-120 -80.5,-120 -81,-120 -81.5,-120 -82,-120 -82.5,-120 -83,-120 -83.5,-120 -84,-120 -84.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -84.5,180 -84,180 -83.5,180 -83,180 -82.5,180 -82,180 -81.5,180 -81,180 -80.5,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,-180 -80))"], "date_created": "Fri, 17 Jan 2020 00:00:00 GMT", "description": "This data set includes counts of palynomorphs from subglacial and sub-ice shelf tills from beneath the West Antarctic Ice Sheet. In addition to counts the biostratigraphic ranges are presented on separate tabs. ", "east": -120.0, "geometry": ["POINT(-150 -82.5)"], "keywords": "Antarctica; Pollen; West Antarctica; WISSARD", "locations": "West Antarctica; Antarctica; West Antarctica", "north": -80.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Coenen, Jason; Baudoin, Patrick; Warny, Sophie; Askin, Rosemary; Scherer, Reed Paul; Casta\u00f1eda, Isla", "project_titles": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "projects": [{"proj_uid": "p0000105", "repository": "USAP-DC", "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WISSARD", "south": -85.0, "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set", "uid": "601245", "west": 180.0}, {"awards": "1246357 Bart, Philip", "bounds_geometry": ["POLYGON((-171 -75.8,-170.5 -75.8,-170 -75.8,-169.5 -75.8,-169 -75.8,-168.5 -75.8,-168 -75.8,-167.5 -75.8,-167 -75.8,-166.5 -75.8,-166 -75.8,-166 -75.99,-166 -76.18,-166 -76.37,-166 -76.56,-166 -76.75,-166 -76.94,-166 -77.13,-166 -77.32,-166 -77.51,-166 -77.7,-166.5 -77.7,-167 -77.7,-167.5 -77.7,-168 -77.7,-168.5 -77.7,-169 -77.7,-169.5 -77.7,-170 -77.7,-170.5 -77.7,-171 -77.7,-171 -77.51,-171 -77.32,-171 -77.13,-171 -76.94,-171 -76.75,-171 -76.56,-171 -76.37,-171 -76.18,-171 -75.99,-171 -75.8))"], "date_created": "Mon, 03 Jun 2019 00:00:00 GMT", "description": "Still and video benthic images collected during expedition NBP1502 in the Ross Sea using a YoYo camera system.", "east": -166.0, "geometry": ["POINT(-168.5 -76.75)"], "keywords": "Antarctica; Benthic; Benthic Images; Benthos; Bentic Fauna; Camera Tow; Marine Geoscience; Marine Sediments; NBP1502; Photo; Photo/video; Photo/Video; Ross Sea; R/v Nathaniel B. Palmer; Southern Ocean; Yoyo Camera", "locations": "Southern Ocean; Ross Sea; Antarctica", "north": -75.8, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Bart, Philip", "project_titles": "Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf", "projects": [{"proj_uid": "p0000877", "repository": "USAP-DC", "title": "Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.7, "title": "NBP1502 YoYo camera benthic images from Ross Sea", "uid": "601182", "west": -171.0}, {"awards": "0839031 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(161.71965 -77.76165)"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "This award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the \u0027clathrate hypothesis\u0027 that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (\u003e1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a \u0027horizontal ice core\u0027 would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica.", "east": 161.71965, "geometry": ["POINT(161.71965 -77.76165)"], "keywords": "Antarctica; Cosmogenic; Geochemistry; Ice Core Records; Paleoclimate; Radiocarbon; Taylor Glacier; Transantarctic Mountains", "locations": "Taylor Glacier; Antarctica; Transantarctic Mountains", "north": -77.76165, "nsf_funding_programs": null, "persons": "Severinghaus, Jeffrey P.", "project_titles": "Collaborative Research: A \"Horizontal Ice Core\" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica", "projects": [{"proj_uid": "p0000099", "repository": "USAP-DC", "title": "Collaborative Research: A \"Horizontal Ice Core\" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.76165, "title": "Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica", "uid": "600165", "west": 161.71965}, {"awards": "1245821 Brook, Edward J.", "bounds_geometry": ["POINT(162.167 -77.733)"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "This award supports a project to use the Taylor Glacier, Antarctica, ablation zone to collect ice samples for a range of paleoenvironmental studies. A record of carbon-14 of atmospheric methane (14CH4) will be obtained for the last deglaciation and the Early Holocene, together with a supporting record of CH4 stable isotopes. In-situ cosmogenic 14C content and partitioning of 14C between different species (14CH4, C-14 carbon monoxide (14CO) and C-14 carbon dioxide (14CO2)) will be determined with unprecedented precision in ice from the surface down to ~67 m. Further age-mapping of the ablating ice stratigraphy will take place using a combination of CH4, CO2, and delta 18O of oxygen gas and H2O stable isotopes. High precision, high-resolution records of CO2, delta 13C of CO2, nitrous oxide (N2O) and N2O isotopes will be obtained for the last deglaciation and intervals during the last glacial period. The potential of 14CO2 and Krypton-81 (81Kr) as absolute dating tools for glacial ice will be investigated. The intellectual merit of proposed work includes the fact that the response of natural methane sources to continuing global warming is uncertain, and available evidence is insufficient to rule out the possibility of catastrophic releases from large 14C-depleted reservoirs such as CH4 clathrates and permafrost. The proposed paleoatmospheric 14CH4 record will improve our understanding of the possible magnitude and timing of CH4 release from these reservoirs during a large climatic warming. A thorough understanding of in-situ cosmogenic 14C in glacial ice (production rates by different mechanisms and partitioning between species) is currently lacking. Such an understanding will likely enable the use of in-situ 14CO in ice at accumulation sites as a reliable, uncomplicated tracer of the past cosmic ray flux and possibly past solar activity, as well as the use of 14CO2 at both ice accumulation and ice ablation sites as an absolute dating tool. Significant gaps remain in our understanding of the natural carbon cycle, as well as in its responses to global climate change. The proposed high-resolution, high-precision records of delta 13C of CO2 would provide new information on carbon cycle changes both during times of rising CO2 in a warming climate and falling CO2 in a cooling climate. N2O is an important greenhouse gas that increased by ~30% during the last deglaciation. The causes of this increase are still largely uncertain, and the proposed high-precision record of N2O concentration and isotopes would provide further insights into N2O source changes in a warming world. The broader impacts of proposed work include an improvement in our understanding of the response of these greenhouse gas budgets to global warming and inform societally important model projections of future climate change. The continued age-mapping of Taylor Glacier ablation ice will add value to this high-quality, easily accessible archive of natural environmental variability. Establishing 14CO as a robust new tracer for past cosmic ray flux would inform paleoclimate studies and constitute a valuable contribution to the study of the societally important issue of climate change. The proposed work will contribute to the development of new laboratory and field analytical systems. The data from the study will be made available to the scientific community and the broad public through the NSIDC and NOAA Paleoclimatology data centers. 1 graduate student each will be trained at UR, OSU and SIO, and the work will contribute to the training of a postdoc at OSU. 3 UR undergraduates will be involved in fieldwork and research. The work will support a new, junior UR faculty member, Petrenko. All PIs have a strong history of and commitment to scientific outreach in the forms of media interviews, participation in filming of field projects, as well as speaking to schools and the public about their research, and will continue these activities as part of the proposed work. This award has field work in Antarctica.", "east": 162.167, "geometry": ["POINT(162.167 -77.733)"], "keywords": "Antarctica; Atmosphere; Geochemistry; Ice Core Records; Isotope; Paleoclimate; Taylor Glacier; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica; Taylor Glacier", "north": -77.733, "nsf_funding_programs": null, "persons": "Brook, Edward J.", "project_titles": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "projects": [{"proj_uid": "p0000283", "repository": "USAP-DC", "title": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.733, "title": "The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "uid": "600163", "west": 162.167}, {"awards": "0839107 Powell, Ross", "bounds_geometry": ["POLYGON((-163.7 -84,-163.68 -84,-163.66 -84,-163.64 -84,-163.62 -84,-163.6 -84,-163.58 -84,-163.56 -84,-163.54 -84,-163.52 -84,-163.5 -84,-163.5 -84.05,-163.5 -84.1,-163.5 -84.15,-163.5 -84.2,-163.5 -84.25,-163.5 -84.3,-163.5 -84.35,-163.5 -84.4,-163.5 -84.45,-163.5 -84.5,-163.52 -84.5,-163.54 -84.5,-163.56 -84.5,-163.58 -84.5,-163.6 -84.5,-163.62 -84.5,-163.64 -84.5,-163.66 -84.5,-163.68 -84.5,-163.7 -84.5,-163.7 -84.45,-163.7 -84.4,-163.7 -84.35,-163.7 -84.3,-163.7 -84.25,-163.7 -84.2,-163.7 -84.15,-163.7 -84.1,-163.7 -84.05,-163.7 -84))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "The RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative 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 RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main variables listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding zone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf cavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice-shelf cavity. Unique tools to be deployed include a multisensor Sub-Ice ROVer (Remotely Operated Vehicle) and long-term, sub-ice oceanographic moorings.\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. The RAGES project represents a significant advance in polar technology by incorporating the use of complex new instrumentation like the Sub-Ice ROVer and subglacial ocean/lake mooring systems. 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": -163.5, "geometry": ["POINT(-163.6 -84.25)"], "keywords": "Antarctica; Glaciology; Oceans; Southern Ocean; WISSARD", "locations": "Southern Ocean; Antarctica", "north": -84.0, "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": -84.5, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)", "uid": "600155", "west": -163.7}, {"awards": "1142156 Marschall, Horst", "bounds_geometry": ["POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth\u0027s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica.\n\nDronning Maud Land (DML) occupied a central location during the formation of supercontinents - large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth\u0027s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007-2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML.\n", "east": 4.18, "geometry": ["POINT(-1.13 -72.27)"], "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Dronning Maud Land; Geochemistry; Geochronology; Solid Earth", "locations": "Dronning Maud Land; Antarctica", "north": -71.93, "nsf_funding_programs": null, "persons": "Marschall, Horst", "project_titles": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica", "projects": [{"proj_uid": "p0000448", "repository": "USAP-DC", "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.61, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "uid": "600135", "west": -6.44}, {"awards": "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": "0739783 Junge, Karen", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation. This research program has two main objectives. The first is to investigate metabolic activities and gene expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (\u003c54C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern if psychrophilic processes of leucine incorporation into proteins, shown to occur to -196C, amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. We will examine extracellular and intracellular processes of psychrophilic activity above and below the eutectic by (i) determining the temperature range of metabolic activities such as DNA synthesis, carbon utilization, respiration and ATP generation using radioactive tracer technology, including a control at liquid helium temperature (-268.9C), (ii) analyzing gene expression in ice using whole genome and microarray analyses and iii) examining the role of exopolymeric substances (EPS) and ice micro-physics for the observed activity using an in-situ microscopy technique. Results of the proposed research can be expected to aid in the determination of cellular and genetic strategies that allow cells to maintain activity at extremely low temperatures within an icy matrix and/or to resume activity again when more growth-permissive conditions are encountered. The research is an interdisciplinary collaboration involving three different institutions with participants in Oceanography, Genomics, and Geophysical Sciences. The proposed activity will support the beginning professional career of a female researcher and will serve as the basis for several undergraduate student laboratory projects.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Biota; Microbiology; Oceans; Sea Ice; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "Junge, Karen", "project_titles": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "projects": [{"proj_uid": "p0000673", "repository": "USAP-DC", "title": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "uid": "600083", "west": -180.0}, {"awards": "0424589 Gogineni, S. Prasad; 0538195 Marone, Chris; 0440523 Baker, Ian", "bounds_geometry": ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"], "date_created": "Wed, 14 Apr 2010 00:00:00 GMT", "description": "This data set includes the results of laboratory experiments examining the constitutive properties of subglacial till, under dynamic stressing. The data include the results of shear strain and stress experiments. Testing was carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, allowing both sliding and microstructural processes to be studied in detail. Till samples were collected from Matanuska, Alaska and from Caesar till at the Laurentide Ice Sheet. \n\nThe data are available via FTP in ASCII text format (.txt).", "east": 147.758889, "geometry": ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"], "keywords": "Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Shear Stress; Solid Earth; Strain", "locations": null, "north": 61.781667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Marone, Chris; Anandakrishnan, Sridhar", "project_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "projects": [{"proj_uid": "p0000554", "repository": "USAP-DC", "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": 40.067222, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "609460", "west": -147.753056}, {"awards": "0649609 Horning, Markus", "bounds_geometry": ["POLYGON((165.975 -77.54,166.0631 -77.54,166.1512 -77.54,166.2393 -77.54,166.3274 -77.54,166.4155 -77.54,166.5036 -77.54,166.5917 -77.54,166.6798 -77.54,166.7679 -77.54,166.856 -77.54,166.856 -77.5709,166.856 -77.6018,166.856 -77.6327,166.856 -77.6636,166.856 -77.6945,166.856 -77.7254,166.856 -77.7563,166.856 -77.7872,166.856 -77.8181,166.856 -77.849,166.7679 -77.849,166.6798 -77.849,166.5917 -77.849,166.5036 -77.849,166.4155 -77.849,166.3274 -77.849,166.2393 -77.849,166.1512 -77.849,166.0631 -77.849,165.975 -77.849,165.975 -77.8181,165.975 -77.7872,165.975 -77.7563,165.975 -77.7254,165.975 -77.6945,165.975 -77.6636,165.975 -77.6327,165.975 -77.6018,165.975 -77.5709,165.975 -77.54))"], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "The primary objectives of this research are to investigate the proximate effects of aging on diving capability in the Weddell Seal and to describe mechanisms by which aging may influence foraging ecology, through physiology and behavior. This model pinniped species has been the focus of three decades of research in McMurdo Sound, Antarctica. Compared to the knowledge of pinniped diving physiology and ecology during early development and young adulthood, little is known about individuals nearing the upper limit of their normal reproductive age range. Evolutionary aging theories predict that elderly diving seals should exhibit senescence. This should be exacerbated by surges in the generation of oxygen free radicals via hypoxia-reoxygenation during breath-hold diving and hunting, which are implicated in age-related damage to cellular mitochondria. Surprisingly, limited observations of non-threatened pinniped populations indicate that senescence does not occur to a level where reproductive output is affected. The ability of pinnipeds to avoid apparent senescence raises two major questions: what specific physiological and morphological changes occur with advancing age in pinnipeds; and what subtle adjustments are made by these animals to cope with such changes? This investigation will focus on specific, functional physiological and behavioral changes relating to dive capability with advancing age. Data will be compared between Weddell seals in the peak, and near the end, of their reproductive age range. The investigators will quantify age-related changes in general health and body condition, combined with fine scale assessments of external and internal ability to do work in the form of diving. Specifically, patterns of muscle morphology, oxidant status and oxygen storage with age will be examined. The effects of age on skeletal muscular function and exercise performance will also be examined. The investigators hypothesize that senescence does occur in Weddell seals at the level of small-scale, proximate physiological effects and performance, but that behavioral plasticity allows for a given degree of compensation. Broader impacts include the training of students and outreach activities including interviews and articles written for the popular media. This study should also establish diving seals as a novel model for the study of cardiovascular and muscular physiology of aging and develop a foundation for similar research on other species. Advancement of the understanding of aging by medical science has been impressive in recent years but basic mammalian aging is an area of study the still requires considerable effort. The development of new models for the study of aging has tremendous potential benefits to society at large.", "east": 166.856, "geometry": ["POINT(166.4155 -77.6945)"], "keywords": "Antarctica; Biota; McMurdo; Oceans; Seals; Southern Ocean", "locations": "Antarctica; Southern Ocean; McMurdo", "north": -77.54, "nsf_funding_programs": null, "persons": "Horning, Markus", "project_titles": "Collaborative Research: Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment", "projects": [{"proj_uid": "p0000487", "repository": "USAP-DC", "title": "Collaborative Research: Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.849, "title": "Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment", "uid": "600071", "west": 165.975}, {"awards": "0538195 Marone, Chris", "bounds_geometry": null, "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.", "east": null, "geometry": null, "keywords": "Antarctica; Glacial Till; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lab Experiment; Marine Sediments; Physical Properties; Solid Earth", "locations": "Antarctica", "north": null, "nsf_funding_programs": null, "persons": "Marone, Chris; Anandakrishnan, Sridhar", "project_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "projects": [{"proj_uid": "p0000554", "repository": "USAP-DC", "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "600054", "west": null}, {"awards": "0636629 Kurz, Mark", "bounds_geometry": ["POLYGON((160.7 -77.8,161.06 -77.8,161.42 -77.8,161.78 -77.8,162.14 -77.8,162.5 -77.8,162.86 -77.8,163.22 -77.8,163.58 -77.8,163.94 -77.8,164.3 -77.8,164.3 -77.86,164.3 -77.92,164.3 -77.98,164.3 -78.04,164.3 -78.1,164.3 -78.16,164.3 -78.22,164.3 -78.28,164.3 -78.34,164.3 -78.4,163.94 -78.4,163.58 -78.4,163.22 -78.4,162.86 -78.4,162.5 -78.4,162.14 -78.4,161.78 -78.4,161.42 -78.4,161.06 -78.4,160.7 -78.4,160.7 -78.34,160.7 -78.28,160.7 -78.22,160.7 -78.16,160.7 -78.1,160.7 -78.04,160.7 -77.98,160.7 -77.92,160.7 -77.86,160.7 -77.8))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change.", "east": 164.3, "geometry": ["POINT(162.5 -78.1)"], "keywords": "Antarctica; Cosmogenic Radionuclides; Dry Valleys; Geology/Geophysics - Other; Glaciology; LIDAR; Navigation; Sample/collection Description; Sample/Collection Description", "locations": "Antarctica; Dry Valleys", "north": -77.8, "nsf_funding_programs": null, "persons": "Soule, S. Adam; Kurz, Mark D.", "project_titles": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "projects": [{"proj_uid": "p0000559", "repository": "USAP-DC", "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.4, "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "uid": "600066", "west": 160.7}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Full Waveform Ambient Noise Tomography for East Antarctica
|
1914698 |
2024-01-24 | Hansen, Samantha; Emry, Erica |
Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes
Subglacial Basin (RESISSt) |
Recent investigations in polar environments have examined solid-Earth-ice-sheet feedbacks and have emphasized that glacial isostatic adjustment, tectonic, and geothermal forcings exert first-order control on the physical conditions at and below the ice-bed interface and must be taken into account when evaluating ice-sheet evolution. However, the solid-Earth structure beneath much of Antarctica is still poorly constrained given the sparse distribution of seismic stations across the continent and the generally low seismicity rate. One region of particular interest is the Wilkes Subglacial Basin (WSB) in East Antarctica. During the mid-Pliocene warm period, the WSB may have contributed 3-4 m to the estimated 20 m rise in sea-level, indicating that this region could also play an important role in future warming scenarios. However, the WSB may have experienced notable bedrock uplift since the Pliocene; therefore, past geologic inferences of instability may not serve as a simple analogue for the future. Using records of ambient seismic noise recorded by both temporary and long-term seismic networks, along with a full-waveform tomographic inversion technique, we have developed improved images of the lithospheric structure beneath East Antarctica, including the WSB. Empirical Green’s Functions with periods between 40 and 340 s have been extracted using a frequency-time normalization technique, and a finite-difference approach with a spherical grid has been employed to numerically model synthetic seismograms. Associated sensitivity kernels have also been constructed using a scattering integral method. Our results suggest the WSB is underlain by slow seismic velocities, with faster seismic structure beneath the adjacent Transantarctic Mountains and the Belgica Subglacial Highlands. This may indicate that the WSB is associated with a region of thinner lithosphere, possibly associated with prior continental rifting. The seismic heterogeneity highlighted in our model could have significant implications for understanding the geodynamic origin of WSB topography and its influence on ice-sheet behavior. The model file and associated plotting scripts are provided. | ["POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))"] | ["POINT(135 -77.5)"] | false | false |
Ring shear bed deformation measurements
|
2013987 |
2023-12-13 | Zoet, Lucas |
Collaborative Research: Freeze-on of Subglacial Sediments in Experiments and Theory |
This dataset contains AMS results and microstructure analysis from different depths within the sheared till. | [] | [] | false | false |
Monthly Stratification Climatology (1978-2021) in Antarctic Coastal Polynyas
|
1643735 2021245 |
2022-12-12 | Li, Yun; Shunk, Nathan; Zhang, Weifeng |
Collaborative Research: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability |
Coastal Antarctic polynyas are regions with concentrated phytoplankton blooms, and therefore have important implications for marine ecosystems and the associated carbon cycles. Seasonal water-column stratification, regulated by sea ice, can modulate the exposure of phytoplankton to light and nutrients, and is one of the most important factors that control the duration and strength of algal blooms. Polynyas differ greatly in their stratification, thus are not equally productive in terms of phytoplankton biomass, nor equally vulnerable to the changes in regional climate. To date, most studies have been focusing on individual polynyas, yet a systematic assessment of stratification patterns across polynyas is still lacking. Therefore, we examined the spatial and seasonal variability of stratification in circum-Antarctic coastal polynyas. Using >105 in situ hydrographic casts combined from the World Ocean Database (1970-2021) and the Marine Mammals Exploring the Oceans Pole to Pole Consortium Database (2004-2017), we constructed stratification seasonal climatology using 0-100 m Simpson Energy. Our results showed that stratification magnitude varies by a factor of 6 and its onset time displays 1-2 months difference across all the polynyas. In the presence of warmer water at depths, polynyas tend to develop stronger stratification than others. The spatial variations of stratification are negatively related to sea ice retreat rate and polynya size, indicative of distinct dynamics resulted from the interaction of sea ice melting, advection and water-column mixing. | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -61.8,180 -63.6,180 -65.4,180 -67.2,180 -69,180 -70.8,180 -72.6,180 -74.4,180 -76.2,180 -78,144 -78,108 -78,72 -78,36 -78,0 -78,-36 -78,-72 -78,-108 -78,-144 -78,-180 -78,-180 -76.2,-180 -74.4,-180 -72.6,-180 -70.8,-180 -69,-180 -67.2,-180 -65.4,-180 -63.6,-180 -61.8,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |
Model of iceberg drift and decay including breakup
|
1744835 |
2022-01-18 | Wagner, Till |
Modeling Giant Icebergs and Their Decay |
Because of difficulties in adequately simulating their breakup, large Antarctic icebergs to date have either not been represented in models or represented but with no breakup scheme such that they consistently survive too long and travel too far compared with observations. Here, we introduce a representation of iceberg fracturing using a breakup scheme based on the “footloose mechanism.” We optimize the parameters of this breakup scheme by forcing the iceberg model with an ocean state estimate and comparing the modeled iceberg trajectories and areas with the Antarctic Iceberg Tracking Database. We show that including large icebergs and a representation of their breakup substantially affects the iceberg meltwater distribution, with implications for the circulation and stratification of the Southern Ocean. This data link includes the model developed for the study, including a link to the forcing fields needed to replicate the model results. | ["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 |
Precipitation Observations for the Northwest Ross Ice Shelf - 2017-12 to 2019-11
|
1543325 1543377 |
2021-05-04 | Seefeldt, Mark |
Collaborative Research: Implementing Low-power, Autonomous Observing Systems to Improve the Measurement and Understanding of Antarctic Precipitation |
The dataset includes precipitation and associated observations at four sites across the northwest Ross Ice Shelf from December 2017 to November 2019. The general instruments at each site include precipitation gauge - installed inside a wind shield, anemometer, thermometer, sonic ranging sensor, optical particle detector, laser disdrometer, shortwave and longwave radiation sensors, and a field camera. The observations from each site include: precipitation (liquid water equivalent), temperature, wind speed, snow surface height, particle count, particle size and speed, upward/downward longwave radiation, upward/downward shortwave radiation, still image photos, and 5-second movies. The data are in comma-delimited text files, jpg photos, and mp4 movies. png plots of the quality-controlled observations are included for quick views of the data. | ["POLYGON((166.918 -77.877,167.2997 -77.877,167.6814 -77.877,168.0631 -77.877,168.4448 -77.877,168.8265 -77.877,169.2082 -77.877,169.5899 -77.877,169.9716 -77.877,170.3533 -77.877,170.735 -77.877,170.735 -77.99,170.735 -78.103,170.735 -78.216,170.735 -78.329,170.735 -78.442,170.735 -78.555,170.735 -78.668,170.735 -78.781,170.735 -78.894,170.735 -79.007,170.3533 -79.007,169.9716 -79.007,169.5899 -79.007,169.2082 -79.007,168.8265 -79.007,168.4448 -79.007,168.0631 -79.007,167.6814 -79.007,167.2997 -79.007,166.918 -79.007,166.918 -78.894,166.918 -78.781,166.918 -78.668,166.918 -78.555,166.918 -78.442,166.918 -78.329,166.918 -78.216,166.918 -78.103,166.918 -77.99,166.918 -77.877))"] | ["POINT(168.8265 -78.442)"] | false | false |
Long-term underwater images from around a single mooring site in McMurdo Sound, Antarctica (2017-2019)
|
1644196 |
2020-12-29 | Cziko, Paul |
Habitat Severity and Internal Ice in Antarctic Notothenioid Fishes |
Long-term images taken by the camera from the McMurdo Oceanographic Observatory mooring in McMurdo Sound, Antarctica during its 2-year deployment (2017-2019). The mooring was situated at the seawater terminus of the McMurdo Station seawater intake jetty at 21 m deep, typically under thick sea ice cover. The automated 360° pan-tilt-zoom (ptz) camera, inside of an air-filled self-cleaning dome, was programmed to move to 42 ptz "waypoints" every hour and take a still 1920x1080 JPG image for archiving. Lights, oriented in one direction only, illuminated a rock/rubble slope for much of each winter, when there was no natural illumination. The camera was situated on a concrete block, which elevated the camera about 1m off of the seabed. Motile and sessile benthic biota, including notothenioid fishes, anemones, pycnogonids, asteroids, soft-corals, sponges, and nudibranchs are commonly seen in the images. Some ptz waypoints survey the water column and underside of the sea ice, capturing also the presence of larval/juvenile fishes and other plankton/nekton in the water column. Maximum intervals between subsequent images from the same ptz waypoint were about 1 hour, though many waypoints were captured at somewhat higher frequency. Interval images, taken at 5-min intervals irrespective of camera orientation, were also captured. Images are occasionally obscured/impacted by the camera dome's wiper, darkness, low visibility, minor fouling of the camera dome, and out-of-focus lens elements. | ["POINT(166.6645 -77.851)"] | ["POINT(166.6645 -77.851)"] | false | false |
Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment
|
1724670 |
2020-10-05 | Williams, Trevor |
Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance |
This dataset contains 40Ar/39Ar measurements on detrital mineral grains from till in modern moraines at the edges of the Institute, Foundation, Academy, Recovery, and the Slessor glaciers / ice streams. | ["POLYGON((-70 -80,-65 -80,-60 -80,-55 -80,-50 -80,-45 -80,-40 -80,-35 -80,-30 -80,-25 -80,-20 -80,-20 -80.6,-20 -81.2,-20 -81.8,-20 -82.4,-20 -83,-20 -83.6,-20 -84.2,-20 -84.8,-20 -85.4,-20 -86,-25 -86,-30 -86,-35 -86,-40 -86,-45 -86,-50 -86,-55 -86,-60 -86,-65 -86,-70 -86,-70 -85.4,-70 -84.8,-70 -84.2,-70 -83.6,-70 -83,-70 -82.4,-70 -81.8,-70 -81.2,-70 -80.6,-70 -80))"] | ["POINT(-45 -83)"] | false | false |
Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment
|
1724670 |
2020-10-05 | Williams, Trevor |
Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance |
This dataset contains 40Ar/39Ar measurements on detrital mineral grains from ice-rafted detritus from sediment core PS1575-1 in the NW Weddell Sea. The depositional age of the sediments is approx. 0 to 300 ka. | ["POLYGON((-50 -62,-49 -62,-48 -62,-47 -62,-46 -62,-45 -62,-44 -62,-43 -62,-42 -62,-41 -62,-40 -62,-40 -62.3,-40 -62.6,-40 -62.9,-40 -63.2,-40 -63.5,-40 -63.8,-40 -64.1,-40 -64.4,-40 -64.7,-40 -65,-41 -65,-42 -65,-43 -65,-44 -65,-45 -65,-46 -65,-47 -65,-48 -65,-49 -65,-50 -65,-50 -64.7,-50 -64.4,-50 -64.1,-50 -63.8,-50 -63.5,-50 -63.2,-50 -62.9,-50 -62.6,-50 -62.3,-50 -62))"] | ["POINT(-45 -63.5)"] | false | false |
Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment
|
1724670 |
2020-10-05 | Williams, Trevor |
Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance |
This dataset contains 40Ar/39Ar measurements on detrital mineral grains from subglacial till and proximal glacimarine sediment from nine sediment cores along the front of the Filchner and Ronne Ice Shelves. | ["POLYGON((-65 -74,-61 -74,-57 -74,-53 -74,-49 -74,-45 -74,-41 -74,-37 -74,-33 -74,-29 -74,-25 -74,-25 -74.6,-25 -75.2,-25 -75.8,-25 -76.4,-25 -77,-25 -77.6,-25 -78.2,-25 -78.8,-25 -79.4,-25 -80,-29 -80,-33 -80,-37 -80,-41 -80,-45 -80,-49 -80,-53 -80,-57 -80,-61 -80,-65 -80,-65 -79.4,-65 -78.8,-65 -78.2,-65 -77.6,-65 -77,-65 -76.4,-65 -75.8,-65 -75.2,-65 -74.6,-65 -74))"] | ["POINT(-45 -77)"] | false | false |
UAV images and video of whales in the Antarctic Penisula during LMG1802
|
1644209 1440435 |
2020-05-10 | Friedlaender, Ari; Dale, Julian; Nowacek, Douglas; Bierlich, KC |
LTER Palmer, Antarctica (PAL): Land-Shelf-Ocean Connectivity, Ecosystem Resilience and Transformation in a Sea-Ice Influenced Pelagic Ecosystem |
This dataset contains UAV (drone) still images and video footage from whales in the Antarctic Peninsula region taken from LM Gould expedition (LMG1802) and small zodiacs. It also contains flight tracks as kml files. | ["POLYGON((-64.5 -63,-63.95 -63,-63.4 -63,-62.85 -63,-62.3 -63,-61.75 -63,-61.2 -63,-60.65 -63,-60.1 -63,-59.55 -63,-59 -63,-59 -63.22,-59 -63.44,-59 -63.66,-59 -63.88,-59 -64.1,-59 -64.32,-59 -64.54,-59 -64.76,-59 -64.98,-59 -65.2,-59.55 -65.2,-60.1 -65.2,-60.65 -65.2,-61.2 -65.2,-61.75 -65.2,-62.3 -65.2,-62.85 -65.2,-63.4 -65.2,-63.95 -65.2,-64.5 -65.2,-64.5 -64.98,-64.5 -64.76,-64.5 -64.54,-64.5 -64.32,-64.5 -64.1,-64.5 -63.88,-64.5 -63.66,-64.5 -63.44,-64.5 -63.22,-64.5 -63))"] | ["POINT(-61.75 -64.1)"] | false | false |
Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set
|
0839059 |
2020-01-17 | Coenen, Jason; Baudoin, Patrick; Warny, Sophie; Askin, Rosemary; Scherer, Reed Paul; Castañeda, Isla |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
This data set includes counts of palynomorphs from subglacial and sub-ice shelf tills from beneath the West Antarctic Ice Sheet. In addition to counts the biostratigraphic ranges are presented on separate tabs. | ["POLYGON((-180 -80,-174 -80,-168 -80,-162 -80,-156 -80,-150 -80,-144 -80,-138 -80,-132 -80,-126 -80,-120 -80,-120 -80.5,-120 -81,-120 -81.5,-120 -82,-120 -82.5,-120 -83,-120 -83.5,-120 -84,-120 -84.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -85,180 -84.5,180 -84,180 -83.5,180 -83,180 -82.5,180 -82,180 -81.5,180 -81,180 -80.5,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,180 -80,-180 -80))"] | ["POINT(-150 -82.5)"] | false | false |
NBP1502 YoYo camera benthic images from Ross Sea
|
1246357 |
2019-06-03 | Bart, Philip |
Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf |
Still and video benthic images collected during expedition NBP1502 in the Ross Sea using a YoYo camera system. | ["POLYGON((-171 -75.8,-170.5 -75.8,-170 -75.8,-169.5 -75.8,-169 -75.8,-168.5 -75.8,-168 -75.8,-167.5 -75.8,-167 -75.8,-166.5 -75.8,-166 -75.8,-166 -75.99,-166 -76.18,-166 -76.37,-166 -76.56,-166 -76.75,-166 -76.94,-166 -77.13,-166 -77.32,-166 -77.51,-166 -77.7,-166.5 -77.7,-167 -77.7,-167.5 -77.7,-168 -77.7,-168.5 -77.7,-169 -77.7,-169.5 -77.7,-170 -77.7,-170.5 -77.7,-171 -77.7,-171 -77.51,-171 -77.32,-171 -77.13,-171 -76.94,-171 -76.75,-171 -76.56,-171 -76.37,-171 -76.18,-171 -75.99,-171 -75.8))"] | ["POINT(-168.5 -76.75)"] | false | false |
Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica
|
0839031 |
2016-01-01 | Severinghaus, Jeffrey P. |
Collaborative Research: A "Horizontal Ice Core" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica |
This award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the 'clathrate hypothesis' that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (>1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a 'horizontal ice core' would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica. | ["POINT(161.71965 -77.76165)"] | ["POINT(161.71965 -77.76165)"] | false | false |
The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive
|
1245821 |
2016-01-01 | Brook, Edward J. |
Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive |
This award supports a project to use the Taylor Glacier, Antarctica, ablation zone to collect ice samples for a range of paleoenvironmental studies. A record of carbon-14 of atmospheric methane (14CH4) will be obtained for the last deglaciation and the Early Holocene, together with a supporting record of CH4 stable isotopes. In-situ cosmogenic 14C content and partitioning of 14C between different species (14CH4, C-14 carbon monoxide (14CO) and C-14 carbon dioxide (14CO2)) will be determined with unprecedented precision in ice from the surface down to ~67 m. Further age-mapping of the ablating ice stratigraphy will take place using a combination of CH4, CO2, and delta 18O of oxygen gas and H2O stable isotopes. High precision, high-resolution records of CO2, delta 13C of CO2, nitrous oxide (N2O) and N2O isotopes will be obtained for the last deglaciation and intervals during the last glacial period. The potential of 14CO2 and Krypton-81 (81Kr) as absolute dating tools for glacial ice will be investigated. The intellectual merit of proposed work includes the fact that the response of natural methane sources to continuing global warming is uncertain, and available evidence is insufficient to rule out the possibility of catastrophic releases from large 14C-depleted reservoirs such as CH4 clathrates and permafrost. The proposed paleoatmospheric 14CH4 record will improve our understanding of the possible magnitude and timing of CH4 release from these reservoirs during a large climatic warming. A thorough understanding of in-situ cosmogenic 14C in glacial ice (production rates by different mechanisms and partitioning between species) is currently lacking. Such an understanding will likely enable the use of in-situ 14CO in ice at accumulation sites as a reliable, uncomplicated tracer of the past cosmic ray flux and possibly past solar activity, as well as the use of 14CO2 at both ice accumulation and ice ablation sites as an absolute dating tool. Significant gaps remain in our understanding of the natural carbon cycle, as well as in its responses to global climate change. The proposed high-resolution, high-precision records of delta 13C of CO2 would provide new information on carbon cycle changes both during times of rising CO2 in a warming climate and falling CO2 in a cooling climate. N2O is an important greenhouse gas that increased by ~30% during the last deglaciation. The causes of this increase are still largely uncertain, and the proposed high-precision record of N2O concentration and isotopes would provide further insights into N2O source changes in a warming world. The broader impacts of proposed work include an improvement in our understanding of the response of these greenhouse gas budgets to global warming and inform societally important model projections of future climate change. The continued age-mapping of Taylor Glacier ablation ice will add value to this high-quality, easily accessible archive of natural environmental variability. Establishing 14CO as a robust new tracer for past cosmic ray flux would inform paleoclimate studies and constitute a valuable contribution to the study of the societally important issue of climate change. The proposed work will contribute to the development of new laboratory and field analytical systems. The data from the study will be made available to the scientific community and the broad public through the NSIDC and NOAA Paleoclimatology data centers. 1 graduate student each will be trained at UR, OSU and SIO, and the work will contribute to the training of a postdoc at OSU. 3 UR undergraduates will be involved in fieldwork and research. The work will support a new, junior UR faculty member, Petrenko. All PIs have a strong history of and commitment to scientific outreach in the forms of media interviews, participation in filming of field projects, as well as speaking to schools and the public about their research, and will continue these activities as part of the proposed work. This award has field work in Antarctica. | ["POINT(162.167 -77.733)"] | ["POINT(162.167 -77.733)"] | false | false |
Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)
|
0839107 |
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 RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative 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 RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main variables listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding zone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf cavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice-shelf cavity. Unique tools to be deployed include a multisensor Sub-Ice ROVer (Remotely Operated Vehicle) and long-term, sub-ice oceanographic moorings. 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. The RAGES project represents a significant advance in polar technology by incorporating the use of complex new instrumentation like the Sub-Ice ROVer and subglacial ocean/lake mooring systems. 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((-163.7 -84,-163.68 -84,-163.66 -84,-163.64 -84,-163.62 -84,-163.6 -84,-163.58 -84,-163.56 -84,-163.54 -84,-163.52 -84,-163.5 -84,-163.5 -84.05,-163.5 -84.1,-163.5 -84.15,-163.5 -84.2,-163.5 -84.25,-163.5 -84.3,-163.5 -84.35,-163.5 -84.4,-163.5 -84.45,-163.5 -84.5,-163.52 -84.5,-163.54 -84.5,-163.56 -84.5,-163.58 -84.5,-163.6 -84.5,-163.62 -84.5,-163.64 -84.5,-163.66 -84.5,-163.68 -84.5,-163.7 -84.5,-163.7 -84.45,-163.7 -84.4,-163.7 -84.35,-163.7 -84.3,-163.7 -84.25,-163.7 -84.2,-163.7 -84.15,-163.7 -84.1,-163.7 -84.05,-163.7 -84))"] | ["POINT(-163.6 -84.25)"] | false | false |
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica
|
1142156 |
2015-01-01 | Marschall, Horst |
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica |
Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth's crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica. Dronning Maud Land (DML) occupied a central location during the formation of supercontinents - large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth's history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007-2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML. | ["POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))"] | ["POINT(-1.13 -72.27)"] | false | false |
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 |
Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice
|
0739783 |
2013-01-01 | Junge, Karen |
Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice |
The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation. This research program has two main objectives. The first is to investigate metabolic activities and gene expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (<54C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern if psychrophilic processes of leucine incorporation into proteins, shown to occur to -196C, amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. We will examine extracellular and intracellular processes of psychrophilic activity above and below the eutectic by (i) determining the temperature range of metabolic activities such as DNA synthesis, carbon utilization, respiration and ATP generation using radioactive tracer technology, including a control at liquid helium temperature (-268.9C), (ii) analyzing gene expression in ice using whole genome and microarray analyses and iii) examining the role of exopolymeric substances (EPS) and ice micro-physics for the observed activity using an in-situ microscopy technique. Results of the proposed research can be expected to aid in the determination of cellular and genetic strategies that allow cells to maintain activity at extremely low temperatures within an icy matrix and/or to resume activity again when more growth-permissive conditions are encountered. The research is an interdisciplinary collaboration involving three different institutions with participants in Oceanography, Genomics, and Geophysical Sciences. The proposed activity will support the beginning professional career of a female researcher and will serve as the basis for several undergraduate student laboratory projects. | ["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 |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till
|
0424589 0538195 0440523 |
2010-04-14 | Marone, Chris; Anandakrishnan, Sridhar |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till |
This data set includes the results of laboratory experiments examining the constitutive properties of subglacial till, under dynamic stressing. The data include the results of shear strain and stress experiments. Testing was carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, allowing both sliding and microstructural processes to be studied in detail. Till samples were collected from Matanuska, Alaska and from Caesar till at the Laurentide Ice Sheet. The data are available via FTP in ASCII text format (.txt). | ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"] | ["POINT(-83.006944 40.067222)", "POINT(147.758889 61.779444)", "POINT(-147.753056 61.781667)"] | false | false |
Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment
|
0649609 |
2010-01-01 | Horning, Markus |
Collaborative Research: Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment |
The primary objectives of this research are to investigate the proximate effects of aging on diving capability in the Weddell Seal and to describe mechanisms by which aging may influence foraging ecology, through physiology and behavior. This model pinniped species has been the focus of three decades of research in McMurdo Sound, Antarctica. Compared to the knowledge of pinniped diving physiology and ecology during early development and young adulthood, little is known about individuals nearing the upper limit of their normal reproductive age range. Evolutionary aging theories predict that elderly diving seals should exhibit senescence. This should be exacerbated by surges in the generation of oxygen free radicals via hypoxia-reoxygenation during breath-hold diving and hunting, which are implicated in age-related damage to cellular mitochondria. Surprisingly, limited observations of non-threatened pinniped populations indicate that senescence does not occur to a level where reproductive output is affected. The ability of pinnipeds to avoid apparent senescence raises two major questions: what specific physiological and morphological changes occur with advancing age in pinnipeds; and what subtle adjustments are made by these animals to cope with such changes? This investigation will focus on specific, functional physiological and behavioral changes relating to dive capability with advancing age. Data will be compared between Weddell seals in the peak, and near the end, of their reproductive age range. The investigators will quantify age-related changes in general health and body condition, combined with fine scale assessments of external and internal ability to do work in the form of diving. Specifically, patterns of muscle morphology, oxidant status and oxygen storage with age will be examined. The effects of age on skeletal muscular function and exercise performance will also be examined. The investigators hypothesize that senescence does occur in Weddell seals at the level of small-scale, proximate physiological effects and performance, but that behavioral plasticity allows for a given degree of compensation. Broader impacts include the training of students and outreach activities including interviews and articles written for the popular media. This study should also establish diving seals as a novel model for the study of cardiovascular and muscular physiology of aging and develop a foundation for similar research on other species. Advancement of the understanding of aging by medical science has been impressive in recent years but basic mammalian aging is an area of study the still requires considerable effort. The development of new models for the study of aging has tremendous potential benefits to society at large. | ["POLYGON((165.975 -77.54,166.0631 -77.54,166.1512 -77.54,166.2393 -77.54,166.3274 -77.54,166.4155 -77.54,166.5036 -77.54,166.5917 -77.54,166.6798 -77.54,166.7679 -77.54,166.856 -77.54,166.856 -77.5709,166.856 -77.6018,166.856 -77.6327,166.856 -77.6636,166.856 -77.6945,166.856 -77.7254,166.856 -77.7563,166.856 -77.7872,166.856 -77.8181,166.856 -77.849,166.7679 -77.849,166.6798 -77.849,166.5917 -77.849,166.5036 -77.849,166.4155 -77.849,166.3274 -77.849,166.2393 -77.849,166.1512 -77.849,166.0631 -77.849,165.975 -77.849,165.975 -77.8181,165.975 -77.7872,165.975 -77.7563,165.975 -77.7254,165.975 -77.6945,165.975 -77.6636,165.975 -77.6327,165.975 -77.6018,165.975 -77.5709,165.975 -77.54))"] | ["POINT(166.4155 -77.6945)"] | false | false |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till
|
0538195 |
2009-01-01 | Marone, Chris; Anandakrishnan, Sridhar |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till |
This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard. | [] | [] | false | false |
Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills
|
0636629 |
2009-01-01 | Soule, S. Adam; Kurz, Mark D. |
Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills |
This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change. | ["POLYGON((160.7 -77.8,161.06 -77.8,161.42 -77.8,161.78 -77.8,162.14 -77.8,162.5 -77.8,162.86 -77.8,163.22 -77.8,163.58 -77.8,163.94 -77.8,164.3 -77.8,164.3 -77.86,164.3 -77.92,164.3 -77.98,164.3 -78.04,164.3 -78.1,164.3 -78.16,164.3 -78.22,164.3 -78.28,164.3 -78.34,164.3 -78.4,163.94 -78.4,163.58 -78.4,163.22 -78.4,162.86 -78.4,162.5 -78.4,162.14 -78.4,161.78 -78.4,161.42 -78.4,161.06 -78.4,160.7 -78.4,160.7 -78.34,160.7 -78.28,160.7 -78.22,160.7 -78.16,160.7 -78.1,160.7 -78.04,160.7 -77.98,160.7 -77.92,160.7 -77.86,160.7 -77.8))"] | ["POINT(162.5 -78.1)"] | false | false |