{"dp_type": "Project", "free_text": "Ross Embayment"}
[{"awards": "1542756 Koutnik, Michelle", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.9,-175 -78.8,-175 -79.7,-175 -80.6,-175 -81.5,-175 -82.4,-175 -83.3,-175 -84.2,-175 -85.1,-175 -86,-175.5 -86,-176 -86,-176.5 -86,-177 -86,-177.5 -86,-178 -86,-178.5 -86,-179 -86,-179.5 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))", "dataset_titles": "Beardmore Glacier model in \u0027icepack\u0027", "datasets": [{"dataset_uid": "200339", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beardmore Glacier model in \u0027icepack\u0027", "url": "https://github.com/danshapero/beardmore"}], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "In this project we investigated glaciers that drain ice from the East Antarctic Ice Sheet through the Transantarctic Mountains into the present-day Ross Ice Shelf. The outlet glaciers that flow through the Transantarctic Mountains have thinned significantly over the past 15,000 years, especially as they retreated from Last Glacial Maximum highstands to their present-day grounding lines. At certain locations and for certain glaciers, rocks or bedrock have been sampled to provide constraints on the timing of when ice retreated from these locations. In the locations where geochronological data are available we can use these data as direct constraints on ice-flow models that simulate ice elevation change over time. The intellectual merit of this work is using ice-flow models to spatially and temporally extrapolate between these limited geochronological data points, which enables new understanding of glacier evolution. \r\n\r\nThe mountainous topography in this region is complex, and there are limited measurements of the topography beneath the ice of the Transantarctic outlet glaciers. Since the topography of the glacier bed is an important control on ice flow and is a necessary boundary condition in models we developed a new gridded bed product at Beardmore Glacier, the one location where sufficient data were available, and we compared this to continent-scale gridded bed products. We found that for this glacier, the BedMachine v1 product was reasonably similar to the Beardmore Glacier bed topography measurements; our limited evaluation suggests that the BedMachine product may be sufficient at other Transantarctic outlets where bed measurements are not available, but that other compilations of bed topography data that do not include information about ice flow directions do not provide reliable results. Using these data and available geochronological constraints we investigated Beardmore Glacier evolution since the Last Glacial Maximum using simplified (flowline) models of ice flow.\r\n\r\nIn addition to flowline modeling at Beardmore Glacier, we developed a flow-model setup using the open-source \u0027icepack\u0027 model that uses the shallow stream equations and resolves flow in both the x and y directions. The key value added over flowline (or parameterized flowband) models is that this can capture converging and diverging ice flow, variable side wall and bottom drag, and other geometric complexities. In these simulations we can evaluate the past accumulation, ice influx, and ice outflux to compare controls on deglaciation to data constraints on the chronology of deglaciation.\r\n\r\nWe also used a flowline model to investigate the Darwin-Hatherton Glacier System. Exposure ages and radiocarbon ages of glacial deposits at four locations alongside Hatherton and Darwin glaciers record several hundred meters of late Pleistocene to early Holocene thickening relative to present. Deglaciation was relatively complex at this site, and we also found that Byrd glacier likely contributed ice to the catchment of the Darwin-Hatherton glacier system during the last glacial maximum, and that subsequent convergent flow from Byrd and Mulock glaciers during deglaciation complicated the response of the Darwin-Hatherton system. These new insights can be used on their own to better understand local deglaciation, and can also be used to evaluate regional or continent-scale model calculations.\r\n\r\nSeparately, we investigated the general response of outlet glaciers to different sources of climate forcing. We found that outlet glaciers have a characteristically different response over time to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. Our models demonstrated that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. These insights contributed to our general understanding of how outlet glaciers may have evolved over time.\r\n\r\nOur new model investigations provide a framework that can be applied at other Transantarctic outlet glaciers where geochronological data are available. In particular, our \u0027icepack\u0027 setup is an archived and documented resource for the community. These tools are available for future investigations, including additional investigations at Beardmore Glacier and at other Transantarctic Mountain outlet glaciers. Scientific broader impacts include that this contributes to our understanding of the past behavior of East Antarctic ice, which provides an important constraint on the future evolution of Antarctica. Our team has engaged in public outreach and has engaged students in this research. Two graduate students led in aspects of this work, and have since gone on to research positions after their PhD.", "east": -175.0, "geometry": "POINT(170 -81.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS; Transantarctic Mountains; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Transantarctic Mountains", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Smith, Ben; Conway, Howard; Shapero, Daniel", "platforms": null, "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -86.0, "title": "Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers", "uid": "p0010398", "west": 155.0}, {"awards": "0944150 Hall, Brenda", "bounds_geometry": "POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Royal Society Range Headland Moraine Belt Radiocarbon Data; Salmon Valley Radiocarbon Data", "datasets": [{"dataset_uid": "601555", "doi": "10.15784/601555", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Royal Society Range Headland Moraine Belt Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601555"}, {"dataset_uid": "601556", "doi": "10.15784/601556", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Salmon Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601556"}, {"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth\u0027s climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. ", "east": 164.6, "geometry": "POINT(164.1 -77.85)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Amd/Us; AMD; USA/NSF; GLACIAL LANDFORMS; USAP-DC; Royal Society Range; GLACIER ELEVATION/ICE SHEET ELEVATION", "locations": "Royal Society Range", "north": -77.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.2, "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "uid": "p0010302", "west": 163.6}, {"awards": "9615281 Luyendyk, Bruce; 9615282 Siddoway, Christine", "bounds_geometry": "POLYGON((-170 -76,-166.5 -76,-163 -76,-159.5 -76,-156 -76,-152.5 -76,-149 -76,-145.5 -76,-142 -76,-138.5 -76,-135 -76,-135 -76.8,-135 -77.6,-135 -78.4,-135 -79.2,-135 -80,-135 -80.8,-135 -81.6,-135 -82.4,-135 -83.2,-135 -84,-138.5 -84,-142 -84,-145.5 -84,-149 -84,-152.5 -84,-156 -84,-159.5 -84,-163 -84,-166.5 -84,-170 -84,-170 -83.2,-170 -82.4,-170 -81.6,-170 -80.8,-170 -80,-170 -79.2,-170 -78.4,-170 -77.6,-170 -76.8,-170 -76))", "dataset_titles": "Bedrock sample data, Ford Ranges region (Marie Byrd Land); SOAR-WMB Airborne gravity data", "datasets": [{"dataset_uid": "601829", "doi": "10.15784/601829", "keywords": "Antarctica; Cryosphere; Gondwana; Marie Byrd Land; Migmatite", "people": "Siddoway, Christine", "repository": "USAP-DC", "science_program": null, "title": "Bedrock sample data, Ford Ranges region (Marie Byrd Land)", "url": "https://www.usap-dc.org/view/dataset/601829"}, {"dataset_uid": "601294", "doi": "10.15784/601294", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Ross Sea; Solid Earth", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WMB Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601294"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "This award supports a collaborative project that combines air and ground geological-geophysical investigations to understand the tectonic and geological development of the boundary between the Ross Sea Rift and the Marie Byrd Land (MBL) volcanic province. The project will determine the Cenozoic tectonic history of the region and whether Neogene structures that localized outlet glacier flow developed within the context of Cenozoic rifting on the eastern Ross Embayment margin, or within the volcanic province in MBL. The geological structure at the boundary between the Ross Embayment and western MBL may be a result of: 1) Cenozoic extension on the eastern shoulder of the Ross Sea rift; 2) uplift and crustal extension related to Neogene mantle plume activity in western MBL; or a combination of the two. Faulting and volcanism, mountain uplift, and glacier downcutting appear to now be active in western MBL, where generally East-to-West-flowing outlet glaciers incise Paleozoic and Mesozoic bedrock, and deglaciated summits indicate a previous North-South glacial flow direction. This study requires data collection using SOAR (Support Office for Aerogeophysical Research, a facility supported by Office of Polar Programs which utilizes high precision differential GPS to support a laser altimeter, ice-penetrating radar, a towed proton magnetometer, and a Bell BGM-3 gravimeter). This survey requires data for 37,000 square kilometers using 5.3 kilometer line spacing with 15.6 kilometer tie lines, and 86,000 square kilometers using a grid of 10.6 by 10.6 kilometer spacing. Data will be acquired over several key features in the region including, among other, the eastern edge of the Ross Sea rift, over ice stream OEO, the transition from the Edward VII Peninsula plateau to the Ford Ranges, the continuation to the east of a gravity high known from previous reconnaissance mapping over the Fosdick Metamorphic Complex, an d the extent of the high-amplitude magnetic anomalies (volcanic centers?) detected southeast of the northern Ford Ranges by other investigators. SOAR products will include glaciology data useful for studying driving stresses, glacial flow and mass balance in the West Antarctic Ice Sheet (WAIS). The ground program is centered on the southern Ford Ranges. Geologic field mapping will focus on small scale brittle structures for regional kinematic interpretation, on glaciated surfaces and deposits, and on datable volcanic rocks for geochronologic control. The relative significance of fault and joint sets, the timing relationships between them, and the probable context of their formation will also be determined. Exposure ages will be determined for erosion surfaces and moraines. Interpretation of potential field data will be aided by on ground sampling for magnetic properties and density as well as ground based gravity measurements. Oriented samples will be taken for paleomagnetic studies. Combined airborne and ground investigations will obtain basic data for describing the geology and structure at the eastern boundary of the Ross Embayment both in outcrop and ice covered areas, and may be used to distinguish between Ross Sea rift- related structural activity from uplift and faulting on the perimeter of the MBL dome and volcanic province. Outcrop geology and structure will be extrapolated with the aerogeophysical data to infer the geology that resides beneath the WAIS. The new knowledge of Neogene tectonics in western MBL will contribute to a comprehensive model for the Cenozoic Ross rift and to understanding of the extent of plume activity in MBL. Both are important for determining the influence of Neogene tectonics on the ice streams and WAIS.", "east": -135.0, "geometry": "POINT(-152.5 -80)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e LGS", "is_usap_dc": true, "keywords": "GRAVITY; USAP-DC; Ross Sea; TECTONICS; Marie Byrd Land", "locations": "Ross Sea; Marie Byrd Land", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Luyendyk, Bruce P.; Siddoway, Christine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.0, "title": "Air-Ground Study of Tectonics at the Boundary Between the Eastern Ross Embayment and Western Marie Byrd Land, Antarctica: Basement Geology and Structure", "uid": "p0010096", "west": -170.0}, {"awards": "1443248 Hall, Brenda; 1443346 Stone, John", "bounds_geometry": "POLYGON((-174 -84.2,-172.4 -84.2,-170.8 -84.2,-169.2 -84.2,-167.6 -84.2,-166 -84.2,-164.4 -84.2,-162.8 -84.2,-161.2 -84.2,-159.6 -84.2,-158 -84.2,-158 -84.36,-158 -84.52,-158 -84.68,-158 -84.84,-158 -85,-158 -85.16,-158 -85.32,-158 -85.48,-158 -85.64,-158 -85.8,-159.6 -85.8,-161.2 -85.8,-162.8 -85.8,-164.4 -85.8,-166 -85.8,-167.6 -85.8,-169.2 -85.8,-170.8 -85.8,-172.4 -85.8,-174 -85.8,-174 -85.64,-174 -85.48,-174 -85.32,-174 -85.16,-174 -85,-174 -84.84,-174 -84.68,-174 -84.52,-174 -84.36,-174 -84.2))", "dataset_titles": "Cosmogenic nuclide data from glacial deposits along the Liv Glacier coast; Ice-D Antarctic Cosmogenic Nuclide database - site DUNCAN; Ice-D Antarctic Cosmogenic Nuclide database - site MAASON; Liv and Amundsen Glacier Radiocarbon Data", "datasets": [{"dataset_uid": "601226", "doi": "10.15784/601226", "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic; Cosmogenic Dating; Cosmogenic Radionuclides; Deglaciation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Liv Glacier; Rocks; Ross Ice Sheet; Surface Exposure Dates; Transantarctic Mountains", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Cosmogenic nuclide data from glacial deposits along the Liv Glacier coast", "url": "https://www.usap-dc.org/view/dataset/601226"}, {"dataset_uid": "601208", "doi": "10.15784/601208", "keywords": "Antarctica; Carbon; Glaciology; Holocene; Radiocarbon; Ross Embayment; Ross Sea; Transantarctic Mountains", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Liv and Amundsen Glacier Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601208"}, {"dataset_uid": "200088", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Ice-D Antarctic Cosmogenic Nuclide database - site DUNCAN", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200087", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Ice-D Antarctic Cosmogenic Nuclide database - site MAASON", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Thu, 05 Sep 2019 00:00:00 GMT", "description": "The response of the Antarctic Ice Sheet to future climatic changes is recognized as the greatest uncertainty in projections of future sea level. An understanding of past ice fluctuations affords insight into ice-sheet response to climate and sea-level change and thus is critical for improving sea-level predictions. This project will examine deglaciation of the southern Ross Sea over the past few thousand years to document oscillations in Antarctic ice volume during a period of relatively stable climate and sea level. We will help quantify changes in ice volume, improve understanding of the ice dynamics responsible, and examine the implications for future sea-level change. The project will train future scientists through participation of graduate students, as well as undergraduates who will develop research projects in our laboratories.\u003cbr/\u003e\u003cbr/\u003ePrevious research indicates rapid Ross Sea deglaciation as far south as Beardmore Glacier early in the Holocene epoch (which began approximately 11,700 years before present), followed by more gradual recession. However, deglaciation in the later half of the Holocene remains poorly constrained, with no chronological control on grounding-line migration between Beardmore and Scott Glaciers. Thus, we do not know if mid-Holocene recession drove the grounding line rapidly back to its present position at Scott Glacier, or if the ice sheet withdrew gradually in the absence of significant climate forcing or eustatic sea level change. The latter possibility raises concerns for future stability of the Ross Sea grounding line. To address this question, we will map and date glacial deposits on coastal mountains that constrain the thinning history of Liv and Amundsen Glaciers. By extending our chronology down to the level of floating ice at the mouths of these glaciers, we will date their thinning history from glacial maximum to present, as well as migration of the Ross Sea grounding line southwards along the Transantarctic Mountains. High-resolution dating will come from Beryllium-10 surface-exposure ages of erratics collected along elevation transects, as well as Carbon-14 dates of algae within shorelines from former ice-dammed ponds. Sites have been chosen specifically to allow close comparison of these two dating methods, which will afford constraints on Antarctic Beryllium-10 production rates.", "east": -158.0, "geometry": "POINT(-166 -85)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; NOT APPLICABLE; Antarctica; ICE SHEETS; USAP-DC", "locations": "Antarctica", "north": -84.2, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -85.8, "title": "Collaborative Research: High-resolution Reconstruction of Holocene Deglaciation in the Southern Ross Embayment", "uid": "p0010053", "west": -174.0}, {"awards": "1341585 Sorlien, Christopher", "bounds_geometry": "POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33))", "dataset_titles": "Ross Sea unconformities digital grids in depth and two-way time", "datasets": [{"dataset_uid": "601098", "doi": "10.15784/601098", "keywords": "Antarctica; Continental Margin; Geology/Geophysics - Other; Marine Geoscience; Miocene; Oligocene; Seismic Reflection", "people": "Sorlien, Christopher; Wilson, Douglas S.", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea unconformities digital grids in depth and two-way time", "url": "https://www.usap-dc.org/view/dataset/601098"}], "date_created": "Fri, 25 May 2018 00:00:00 GMT", "description": "Intellectual Merit:\u003cbr/\u003eThis project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.", "east": -171.0, "geometry": "POINT(177 -76)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.33, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sorlien, Christopher; Luyendyk, Bruce P.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.67, "title": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea", "uid": "p0000271", "west": 165.0}, {"awards": "0944021 Brook, Edward J.; 0943466 Hawley, Robert; 0944307 Conway, Howard", "bounds_geometry": "POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))", "dataset_titles": "Roosevelt Island Borehole Firn temperatures; Roosevelt Island Borehole Optical Televiewer logs; Roosevelt Island Ice Core Time Scale and Associated Data; Roosevelt Island: Radar and GPS", "datasets": [{"dataset_uid": "601359", "doi": "10.15784/601359", "keywords": "Antarctica; CO2; Ice Core; Roosevelt Island", "people": "Lee, James; Brook, Edward J.", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Ice Core Time Scale and Associated Data", "url": "https://www.usap-dc.org/view/dataset/601359"}, {"dataset_uid": "601070", "doi": "10.15784/601070", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS Data; Ice Velocity; Navigation; Radar; Roosevelt Island; Ross Sea", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island: Radar and GPS", "url": "https://www.usap-dc.org/view/dataset/601070"}, {"dataset_uid": "601086", "doi": "10.15784/601086", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Roosevelt Island; Snow/ice; Snow/Ice", "people": "Clemens-Sewall, David; Hawley, Robert L.", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Optical Televiewer logs", "url": "https://www.usap-dc.org/view/dataset/601086"}, {"dataset_uid": "601085", "doi": "10.15784/601085", "keywords": "Antarctica; Borehole; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Records; Ice Fabric; Optical Images; Roosevelt Island; Snow/ice; Snow/Ice; Temperature", "people": "Hawley, Robert L.; Clemens-Sewall, David; Giese, Alexandra", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Firn temperatures", "url": "https://www.usap-dc.org/view/dataset/601085"}], "date_created": "Fri, 16 Feb 2018 00:00:00 GMT", "description": "This award supports a project to use the Roosevelt Island ice core as a glaciological dipstick for the eastern Ross Sea. Recent attention has focused on the eastern Ross Embayment, where there are no geological constraints on ice thickness changes, due to the lack of protruding rock \"dipsticks\" where the ice sheet can leave datable records of high stands. Recent work has shown how dated ice cores can be used as dipsticks to derive ice-thickness histories. Partners from New Zealand and Denmark will extract an ice core from Roosevelt Island during the 2010-2011 and 2011-12 austral summers. Their science objective is to contribute to understanding of climate variability over the past 40kyr. The science goal of this project is not the climate record, but rather the history of deglaciation in the Ross Sea. The new history from the eastern Ross Sea will be combined with the glacial histories from the central Ross Sea (Siple Dome and Byrd) and existing and emerging histories from geologic and marine records along the western Ross Sea margin and will allow investigators to establish an updated, self-consistent model of the configuration and thickness of ice in the Ross Embayment during the LGM, and the timing of deglaciation. Results from this work will provide ground truth for new-generation ice-sheet models that incorporate ice streams and fast-flow dynamics. Realistic ice-sheet models are needed not only for predicting the response to future possible environments, but also for investigating past behaviors of ice sheets. This research contributes to the primary goals of the West Antarctic Ice Sheet Initiative as well as the IPY focus on ice-sheet history and dynamics. It also contributes to understanding spatial and temporal patterns of climate change and climate dynamics over the past 40kyr, one of the primary goals of the International Partnerships in Ice Core Sciences (IPICS). The project will help to develop the next generation of scientists and will contribute to the education and training of two Ph.D. students. All participants will benefit from the international collaboration, which will expose them to different field and laboratory techniques and benefit future collaborative work. All participants are involved in scientific outreach and undergraduate education, and are committed to fostering diversity. Outreach will be accomplished through regularly scheduled community and K-12 outreach events, talks and popular writing by the PIs, as well as through University press offices.", "east": -161.0, "geometry": "POINT(-162 -79.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; Amd/Us; Deglaciation; USAP-DC; USA/NSF; NOT APPLICABLE; Ice Core; Not provided; Ross Sea Embayment", "locations": "Ross Sea Embayment", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Conway, Howard; Brook, Edward J.; Hawley, Robert L.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.5, "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "uid": "p0000272", "west": -163.0}, {"awards": "1245899 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Region Climate Model Output Plio-Pleistocene", "datasets": [{"dataset_uid": "601080", "doi": "10.15784/601080", "keywords": "Antarctica; Climate Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; McMurdo; Paleoclimate; Ross Sea", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Region Climate Model Output Plio-Pleistocene", "url": "https://www.usap-dc.org/view/dataset/601080"}], "date_created": "Tue, 16 Jan 2018 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eResults from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: West Antarctic Ice Sheet stability, Alpine Glaciation, and Climate Variability: a Terrestrial Perspective from Cosmogenic-nuclide Dating in McMurdo Sound", "uid": "p0000391", "west": 160.0}, {"awards": "1043572 Licht, Kathy; 1043619 Hemming, Sidney", "bounds_geometry": "POLYGON((-177.982 -63.997,-149.64107 -63.997,-121.30014 -63.997,-92.95921 -63.997,-64.61828 -63.997,-36.27735 -63.997,-7.93642 -63.997,20.40451 -63.997,48.74544 -63.997,77.08637 -63.997,105.4273 -63.997,105.4273 -66.3324,105.4273 -68.6678,105.4273 -71.0032,105.4273 -73.3386,105.4273 -75.674,105.4273 -78.0094,105.4273 -80.3448,105.4273 -82.6802,105.4273 -85.0156,105.4273 -87.351,77.08637 -87.351,48.74544 -87.351,20.40451 -87.351,-7.93642 -87.351,-36.27735 -87.351,-64.61828 -87.351,-92.95921 -87.351,-121.30014 -87.351,-149.64107 -87.351,-177.982 -87.351,-177.982 -85.0156,-177.982 -82.6802,-177.982 -80.3448,-177.982 -78.0094,-177.982 -75.674,-177.982 -73.3386,-177.982 -71.0032,-177.982 -68.6678,-177.982 -66.3324,-177.982 -63.997))", "dataset_titles": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "datasets": [{"dataset_uid": "600124", "doi": "10.15784/600124", "keywords": "Antarctica; East Antarctica; Geochemistry; Ross Sea; Sample/collection Description; Sample/Collection Description; Solid Earth; Southern Ocean; West Antarctica", "people": "Hemming, Sidney R.", "repository": "USAP-DC", "science_program": null, "title": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "url": "https://www.usap-dc.org/view/dataset/600124"}], "date_created": "Tue, 18 Feb 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe 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. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis 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(-36.27735 -75.674)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e PETROGRAPHIC MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS", "is_usap_dc": true, "keywords": "Not provided; FIELD SURVEYS", "locations": null, "north": -63.997, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Licht, Kathy; Hemming, Sidney R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.351, "title": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "uid": "p0000333", "west": -177.982}, {"awards": "0538033 Panter, Kurt", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 14 Sep 2011 00:00:00 GMT", "description": "This project studies glaciovolcanic deposits at Minna Bluff in the western Ross Embayment of Antarctica. Its goal is to determine the history of the Ross Ice Shelf, which is fed by the major ice sheets from both East and West Antarctica. Apart from determining how these ice sheets waxed and waned during a period of dynamic climate change, glaciovolcanic sequences may constrain ice sheet parameters that are critical to numerical models such as thickness, hydrology, and basal thermal regime. This three-year study would map, analyze, and determine the age of key units using 40Ar/39Ar dating. Pilot studies would also be conducted for 36Cl dating of glacial deposits and stable isotope evaluations of alteration. The project offers a complementary record of Ross Ice Shelf behavior to that sampled by ANDRILL. It also improves the general record of McMurdo area volcanostratigraphy, which is important to interpreting landforms, glacial deposits, and ancient ice found in the Dry Valleys.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include improving society\u0027s understanding of global climate change, sea level rise, and graduate and undergraduate student education. Outreach efforts include educational programs for public schools and community groups, exhibits for a local science museum, and a project website.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Panter, Kurt", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Proposal: Late Cenozoic Volcanism and Glaciation at Minna Bluff, Antarctica: Implications for Antarctic Cryosphere History", "uid": "p0000252", "west": null}, {"awards": "0636818 Stone, John", "bounds_geometry": "POLYGON((-157 -85,-156 -85,-155 -85,-154 -85,-153 -85,-152 -85,-151 -85,-150 -85,-149 -85,-148 -85,-147 -85,-147 -85.3,-147 -85.6,-147 -85.9,-147 -86.2,-147 -86.5,-147 -86.8,-147 -87.1,-147 -87.4,-147 -87.7,-147 -88,-148 -88,-149 -88,-150 -88,-151 -88,-152 -88,-153 -88,-154 -88,-155 -88,-156 -88,-157 -88,-157 -87.7,-157 -87.4,-157 -87.1,-157 -86.8,-157 -86.5,-157 -86.2,-157 -85.9,-157 -85.6,-157 -85.3,-157 -85))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Aug 2011 00:00:00 GMT", "description": "Hall/0636687\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate late Pleistocene and Holocene changes in Scott Glacier, a key outlet glacier that flows directly into the Ross Sea just west of the present-day West Antarctic Ice Sheet (WAIS) grounding line. The overarching goals are to understand changes in WAIS configuration in the Ross Sea sector at and since the last glacial maximum (LGM) and to determine whether Holocene retreat observed in the Ross Embayment has ended or if it is still ongoing. To address these goals, moraine and drift sequences associated with Scott Glacier will be mapped and dated and ice thickness, surface velocity and surface mass balance will be measured to constrain an ice-flow model of the glacier. This model will be used to help interpret the dated geologic sequences. The intellectual merit of the project relates to gaining a better understanding of the West Antarctic Ice Sheet and how changing activity of fast-flowing outlet glaciers and ice streams exerts strong control on the mass balance of the ice sheet. Previous work suggests that grounding-line retreat in the Ross Sea continued into the late Holocene and left open the possibility of ongoing deglaciation as part of a long-term trend. Results from Reedy Glacier, an outlet glacier just behind the grounding line, suggest that retreat may have slowed substantially over the past 2000 years and perhaps even stopped. By coupling the work on Scott Glacier with recent data from Reedy Glacier, the grounding-line position will be bracketed and it should be possible to establish whether the retreat has truly ended or if it is ongoing. The broader impacts of the work relate to the societal relevance of an improved understanding of the West Antarctic ice sheet to establish how it will respond to current and possible future environmental changes. The work addresses this key goal of the West Antarctic Ice Sheet Initiative, as well as the International Polar Year focus on ice sheet history and dynamics. The work will develop future scientists through the education and training of one undergraduate and two Ph.D. students, interaction with K-12 students through classroom visits, web-based \u0027expedition\u0027 journals, letters from the field, and discussions with teachers. Results from this project will be posted with previous exposure dating results from Antarctica, on the University of Washington Cosmogenic Nuclide Lab website, which also provides information about chemical procedures and calculation methods to other scientists working with cosmogenic nuclides.", "east": -147.0, "geometry": "POINT(-152 -86.5)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -85.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John; Conway, Howard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -88.0, "title": "Collaborative Research:Grounding-line Retreat in the Southern Ross Sea - Constraints from Scott Glacier", "uid": "p0000149", "west": -157.0}, {"awards": "0003619 Dalziel, Ian", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG9810", "datasets": [{"dataset_uid": "002678", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9810", "url": "https://www.rvdata.us/search/cruise/LMG9810"}, {"dataset_uid": "002092", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG9810"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program to initiate a Global Positioning System (GPS) network to measure crustal motions in the bedrock surrounding and underlying the West Antarctic Ice Sheet (WAIS). Evaluation of the role of both tectonic and ice-induced crustal motions of the WAIS bedrock is a critical goal for understanding past, present, and future dynamics of WAIS and its potential role in future global change scenarios, as well as improving our understanding of the role of Antarctica in global plate motions. The extent of active tectonism in West Antarctica is largely speculative, as few data exist that constrain its geographic distribution, directions, or rates of deformation. Active tectonism and the influence of bedrock on the WAIS have been highlighted recently by geophysical data indicating active subglacial volcanism and control of ice streaming by the presence of sedimentary basins. The influence of bedrock crustal motion on the WAIS and its future dynamics is a fundamental issue. Existing GPS projects are located only on the fringe of the ice sheet and do not address the regional picture. It is important that baseline GPS measurements on the bedrock around and within the WAIS be started so that a basis is established for detecting change.\u003cbr/\u003e\u003cbr/\u003eTo measure crustal motions, this project will build a West Antarctica GPS Network (WAGN) of at least 15 GPS sites across the interior of West Antarctica (approximately the size of the contiguous United States from the Rocky Mountains to the Pacific coast) over a two-year period beginning in the Antarctic field season 2001-2002. The planned network is designed using the Multi-modal Occupation Strategy (MOST), in which a small number of independent GPS \"roving\" receivers make differential measurements against a network of continuous GPS stations for comparatively short periods at each site. This experimental strategy, successfully implemented by a number of projects in California, S America, the SW Pacific and Central Asia, minimizes logistical requirements, an essential element of application of GPS geodesy in the scattered and remote outcrops of the WAIS bedrock.\u003cbr/\u003e\u003cbr/\u003eThe WAGN program will be integrated with the GPS network that has been established linking the Antarctic Peninsula with South America through the Scotia arc (Scotia Arc GPS Project (SCARP)). It will also interface with stations currently measuring motion across the Ross Embayment, and with the continent-wide GIANT program of the Working Group on Geodesy and Geographic Information Systems of the Scientific Committee on Antarctic Research (SCAR). The GPS network will be based on permanent monuments set in solid rock outcrops that will have near-zero set-up error for roving GPS occupations, and that can be directly converted to a continuous GPS site when future technology makes autonomous operation and satellite data linkage throughout West Antarctica both reliable and economical. The planned network both depends on and complements the existing and planned continuous networks. It is presently not practical, for reasons of cost and logistics, to accomplish the measurements proposed herein with either a network of continuous stations or traditional campaigns.\u003cbr/\u003e\u003cbr/\u003eThe proposed WAGN will complement existing GPS projects by filling a major gap in coverage among several discrete crustal blocks that make up West Antarctica, a critical area of potential bedrock movements. If crustal motions are relatively slow, meaningful results will only begin to emerge within the five-year maximum period of time for an individual funded project. Hence this proposal is only to initiate the network and test precision and velocities at the most critical sites. Once built, however, the network will yield increasingly meaningful results with the passage of time. Indeed, the slower the rates turn out to be, the more important an early start to measuring. It is anticipated that the results of this project will initiate an iterative process that will gradually resolve into an understanding of the contributions from plate rotations and viscoelastic and elastic motions resulting from deglaciation and ice mass changes. Velocities obtained from initial reoccupation of the most critical sites will dictate the timing of a follow-up proposal for reoccupation of the entire network when detectable motions have occurred.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Dalziel, Ian W.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: A GPS Network to Determine Crustal Motions in the Bedrock of the West Antarctic Ice Sheet: Phase I - Installation", "uid": "p0000859", "west": null}, {"awards": "0440959 Cande, Steven", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0701", "datasets": [{"dataset_uid": "002644", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0701", "url": "https://www.rvdata.us/search/cruise/NBP0701"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This work will perform a marine geophysical survey of sea floor spreading off Cape Adare, Antarctica. Magnetic, gravity, swath bathymetry and multi-channel seismic data will be acquired from the southern end of the Adare Basin to the northern parts of the Northern Basin and Central Trough in the Ross Embayment. Previous surveys documented 170 km of regional extension between forty-three and twenty-six million years ago, which resulted in some seafloor spreading in the Adare Basin. However, the relationship of Adare Basin spreading to the overall extension and the southward continental basins of the Ross Embayment has not been established. This relationship is critical to understanding the tectonic evolution of East and West Antarctica and linking Pacific plate motions to the rest of the world. The study will also offer unique insight into rifting processes by studying the transition of rifting between oceanic and continental lithosphere. In terms of broader impacts, this project will support two graduate students and field research experience for undergraduates. The project also involves cooperation between scientists from the US, Australia, New Zealand and Japan.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Cande, Steven", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: The Connection Between Mid-Cenozoic Seafloor Spreading and the Western Ross Sea Embayment", "uid": "p0000835", "west": null}, {"awards": "8919147 Elliot, David", "bounds_geometry": null, "dataset_titles": "Ice Thickness and Surface Elevation, Southeastern Ross Embayment, West Antarctica", "datasets": [{"dataset_uid": "609099", "doi": "10.7265/N5WW7FKC", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ross Embayment; West Antarctica", "people": "Behrendt, J. C.; Finn, C. A.; Blankenship, Donald D.; Morse, David L.; Bell, Robin; Peters, M. E.; Kempf, Scott D.; Hodge, S. M.; Brozena, J. M.; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Ice Thickness and Surface Elevation, Southeastern Ross Embayment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609099"}], "date_created": "Wed, 17 Mar 2004 00:00:00 GMT", "description": "This award will support a combined airborne radar and aeromagnetic survey of two 220 x 330 km regions between the Transantarctica Mountains and Marie Byrd Land during the 1990-91 and 1991-92 field seasons. These efforts will address significant problems identified in the Ross Transect Zone (RTZ) by the National Academy of Sciences (1986) report \"Antarctic Solid Earth Sciences Research,\" and by the report to NSF \"A Plan for a United States Program to Study the Structure and Evolution of the Antarctic Lithosphere (SEAL).\" The surveys will be flown using the NSF/TUD radar and an areomagnetics system mounted in a light aircraft. The grid spacing will be 5 km and navigation will be by radiopositioning. In addition to maps of subglacial topography and magnetic intensity, attempts will be made to reconstruct the position of subglacial diffractors in three dimensions. This reconstruction should give new information about the distribution of escarpments and therefore the tectonic relationships within the region, especially when combined with the magnetic results. These experiments will be conducted by the Byrd Polar Research Center of the Ohio State University and the Water Resources and Geological Divisions of the U.S. Geological Survey.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Subglacial Topography; SOAR; Airborne Laser Altimeters; Ross Embayment; West Antarctica; Ice Stream; Surface Morphology; Airborne Laser Altimetry; Aerogeophysics; Ice Sheet Thickness; Airborne Radar Sounding; Ice Thickness; West Antarctic Ice Sheet; Ice Surface Elevation; Casertz", "locations": "Ross Embayment; West Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Elliot, David; Bell, Robin; Blankenship, Donald D.; Brozena, J. M.; Finn, C. A.; Hodge, S. M.; Kempf, Scott D.; Behrendt, J. C.; Morse, David L.; Peters, M. E.; Studinger, Michael S.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Corridor Aerogeophysics of the Southeastern Ross Transect Zone (CASERTZ), Antarctica", "uid": "p0000056", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||||||
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Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers
|
1542756 |
2022-12-12 | Koutnik, Michelle; Smith, Ben; Conway, Howard; Shapero, Daniel |
|
In this project we investigated glaciers that drain ice from the East Antarctic Ice Sheet through the Transantarctic Mountains into the present-day Ross Ice Shelf. The outlet glaciers that flow through the Transantarctic Mountains have thinned significantly over the past 15,000 years, especially as they retreated from Last Glacial Maximum highstands to their present-day grounding lines. At certain locations and for certain glaciers, rocks or bedrock have been sampled to provide constraints on the timing of when ice retreated from these locations. In the locations where geochronological data are available we can use these data as direct constraints on ice-flow models that simulate ice elevation change over time. The intellectual merit of this work is using ice-flow models to spatially and temporally extrapolate between these limited geochronological data points, which enables new understanding of glacier evolution. The mountainous topography in this region is complex, and there are limited measurements of the topography beneath the ice of the Transantarctic outlet glaciers. Since the topography of the glacier bed is an important control on ice flow and is a necessary boundary condition in models we developed a new gridded bed product at Beardmore Glacier, the one location where sufficient data were available, and we compared this to continent-scale gridded bed products. We found that for this glacier, the BedMachine v1 product was reasonably similar to the Beardmore Glacier bed topography measurements; our limited evaluation suggests that the BedMachine product may be sufficient at other Transantarctic outlets where bed measurements are not available, but that other compilations of bed topography data that do not include information about ice flow directions do not provide reliable results. Using these data and available geochronological constraints we investigated Beardmore Glacier evolution since the Last Glacial Maximum using simplified (flowline) models of ice flow. In addition to flowline modeling at Beardmore Glacier, we developed a flow-model setup using the open-source 'icepack' model that uses the shallow stream equations and resolves flow in both the x and y directions. The key value added over flowline (or parameterized flowband) models is that this can capture converging and diverging ice flow, variable side wall and bottom drag, and other geometric complexities. In these simulations we can evaluate the past accumulation, ice influx, and ice outflux to compare controls on deglaciation to data constraints on the chronology of deglaciation. We also used a flowline model to investigate the Darwin-Hatherton Glacier System. Exposure ages and radiocarbon ages of glacial deposits at four locations alongside Hatherton and Darwin glaciers record several hundred meters of late Pleistocene to early Holocene thickening relative to present. Deglaciation was relatively complex at this site, and we also found that Byrd glacier likely contributed ice to the catchment of the Darwin-Hatherton glacier system during the last glacial maximum, and that subsequent convergent flow from Byrd and Mulock glaciers during deglaciation complicated the response of the Darwin-Hatherton system. These new insights can be used on their own to better understand local deglaciation, and can also be used to evaluate regional or continent-scale model calculations. Separately, we investigated the general response of outlet glaciers to different sources of climate forcing. We found that outlet glaciers have a characteristically different response over time to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. Our models demonstrated that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. These insights contributed to our general understanding of how outlet glaciers may have evolved over time. Our new model investigations provide a framework that can be applied at other Transantarctic outlet glaciers where geochronological data are available. In particular, our 'icepack' setup is an archived and documented resource for the community. These tools are available for future investigations, including additional investigations at Beardmore Glacier and at other Transantarctic Mountain outlet glaciers. Scientific broader impacts include that this contributes to our understanding of the past behavior of East Antarctic ice, which provides an important constraint on the future evolution of Antarctica. Our team has engaged in public outreach and has engaged students in this research. Two graduate students led in aspects of this work, and have since gone on to research positions after their PhD. | POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.9,-175 -78.8,-175 -79.7,-175 -80.6,-175 -81.5,-175 -82.4,-175 -83.3,-175 -84.2,-175 -85.1,-175 -86,-175.5 -86,-176 -86,-176.5 -86,-177 -86,-177.5 -86,-178 -86,-178.5 -86,-179 -86,-179.5 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77)) | POINT(170 -81.5) | false | false | |||||||||
Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles
|
0944150 |
2022-03-03 | Hall, Brenda; Denton, George |
|
This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth's climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. | POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5)) | POINT(164.1 -77.85) | false | false | |||||||||
Air-Ground Study of Tectonics at the Boundary Between the Eastern Ross Embayment and Western Marie Byrd Land, Antarctica: Basement Geology and Structure
|
9615281 9615282 |
2020-04-24 | Luyendyk, Bruce P.; Siddoway, Christine |
|
This award supports a collaborative project that combines air and ground geological-geophysical investigations to understand the tectonic and geological development of the boundary between the Ross Sea Rift and the Marie Byrd Land (MBL) volcanic province. The project will determine the Cenozoic tectonic history of the region and whether Neogene structures that localized outlet glacier flow developed within the context of Cenozoic rifting on the eastern Ross Embayment margin, or within the volcanic province in MBL. The geological structure at the boundary between the Ross Embayment and western MBL may be a result of: 1) Cenozoic extension on the eastern shoulder of the Ross Sea rift; 2) uplift and crustal extension related to Neogene mantle plume activity in western MBL; or a combination of the two. Faulting and volcanism, mountain uplift, and glacier downcutting appear to now be active in western MBL, where generally East-to-West-flowing outlet glaciers incise Paleozoic and Mesozoic bedrock, and deglaciated summits indicate a previous North-South glacial flow direction. This study requires data collection using SOAR (Support Office for Aerogeophysical Research, a facility supported by Office of Polar Programs which utilizes high precision differential GPS to support a laser altimeter, ice-penetrating radar, a towed proton magnetometer, and a Bell BGM-3 gravimeter). This survey requires data for 37,000 square kilometers using 5.3 kilometer line spacing with 15.6 kilometer tie lines, and 86,000 square kilometers using a grid of 10.6 by 10.6 kilometer spacing. Data will be acquired over several key features in the region including, among other, the eastern edge of the Ross Sea rift, over ice stream OEO, the transition from the Edward VII Peninsula plateau to the Ford Ranges, the continuation to the east of a gravity high known from previous reconnaissance mapping over the Fosdick Metamorphic Complex, an d the extent of the high-amplitude magnetic anomalies (volcanic centers?) detected southeast of the northern Ford Ranges by other investigators. SOAR products will include glaciology data useful for studying driving stresses, glacial flow and mass balance in the West Antarctic Ice Sheet (WAIS). The ground program is centered on the southern Ford Ranges. Geologic field mapping will focus on small scale brittle structures for regional kinematic interpretation, on glaciated surfaces and deposits, and on datable volcanic rocks for geochronologic control. The relative significance of fault and joint sets, the timing relationships between them, and the probable context of their formation will also be determined. Exposure ages will be determined for erosion surfaces and moraines. Interpretation of potential field data will be aided by on ground sampling for magnetic properties and density as well as ground based gravity measurements. Oriented samples will be taken for paleomagnetic studies. Combined airborne and ground investigations will obtain basic data for describing the geology and structure at the eastern boundary of the Ross Embayment both in outcrop and ice covered areas, and may be used to distinguish between Ross Sea rift- related structural activity from uplift and faulting on the perimeter of the MBL dome and volcanic province. Outcrop geology and structure will be extrapolated with the aerogeophysical data to infer the geology that resides beneath the WAIS. The new knowledge of Neogene tectonics in western MBL will contribute to a comprehensive model for the Cenozoic Ross rift and to understanding of the extent of plume activity in MBL. Both are important for determining the influence of Neogene tectonics on the ice streams and WAIS. | POLYGON((-170 -76,-166.5 -76,-163 -76,-159.5 -76,-156 -76,-152.5 -76,-149 -76,-145.5 -76,-142 -76,-138.5 -76,-135 -76,-135 -76.8,-135 -77.6,-135 -78.4,-135 -79.2,-135 -80,-135 -80.8,-135 -81.6,-135 -82.4,-135 -83.2,-135 -84,-138.5 -84,-142 -84,-145.5 -84,-149 -84,-152.5 -84,-156 -84,-159.5 -84,-163 -84,-166.5 -84,-170 -84,-170 -83.2,-170 -82.4,-170 -81.6,-170 -80.8,-170 -80,-170 -79.2,-170 -78.4,-170 -77.6,-170 -76.8,-170 -76)) | POINT(-152.5 -80) | false | false | |||||||||
Collaborative Research: High-resolution Reconstruction of Holocene Deglaciation in the Southern Ross Embayment
|
1443248 1443346 |
2019-09-05 | Hall, Brenda; Stone, John | The response of the Antarctic Ice Sheet to future climatic changes is recognized as the greatest uncertainty in projections of future sea level. An understanding of past ice fluctuations affords insight into ice-sheet response to climate and sea-level change and thus is critical for improving sea-level predictions. This project will examine deglaciation of the southern Ross Sea over the past few thousand years to document oscillations in Antarctic ice volume during a period of relatively stable climate and sea level. We will help quantify changes in ice volume, improve understanding of the ice dynamics responsible, and examine the implications for future sea-level change. The project will train future scientists through participation of graduate students, as well as undergraduates who will develop research projects in our laboratories.<br/><br/>Previous research indicates rapid Ross Sea deglaciation as far south as Beardmore Glacier early in the Holocene epoch (which began approximately 11,700 years before present), followed by more gradual recession. However, deglaciation in the later half of the Holocene remains poorly constrained, with no chronological control on grounding-line migration between Beardmore and Scott Glaciers. Thus, we do not know if mid-Holocene recession drove the grounding line rapidly back to its present position at Scott Glacier, or if the ice sheet withdrew gradually in the absence of significant climate forcing or eustatic sea level change. The latter possibility raises concerns for future stability of the Ross Sea grounding line. To address this question, we will map and date glacial deposits on coastal mountains that constrain the thinning history of Liv and Amundsen Glaciers. By extending our chronology down to the level of floating ice at the mouths of these glaciers, we will date their thinning history from glacial maximum to present, as well as migration of the Ross Sea grounding line southwards along the Transantarctic Mountains. High-resolution dating will come from Beryllium-10 surface-exposure ages of erratics collected along elevation transects, as well as Carbon-14 dates of algae within shorelines from former ice-dammed ponds. Sites have been chosen specifically to allow close comparison of these two dating methods, which will afford constraints on Antarctic Beryllium-10 production rates. | POLYGON((-174 -84.2,-172.4 -84.2,-170.8 -84.2,-169.2 -84.2,-167.6 -84.2,-166 -84.2,-164.4 -84.2,-162.8 -84.2,-161.2 -84.2,-159.6 -84.2,-158 -84.2,-158 -84.36,-158 -84.52,-158 -84.68,-158 -84.84,-158 -85,-158 -85.16,-158 -85.32,-158 -85.48,-158 -85.64,-158 -85.8,-159.6 -85.8,-161.2 -85.8,-162.8 -85.8,-164.4 -85.8,-166 -85.8,-167.6 -85.8,-169.2 -85.8,-170.8 -85.8,-172.4 -85.8,-174 -85.8,-174 -85.64,-174 -85.48,-174 -85.32,-174 -85.16,-174 -85,-174 -84.84,-174 -84.68,-174 -84.52,-174 -84.36,-174 -84.2)) | POINT(-166 -85) | false | false | ||||||||||
Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea
|
1341585 |
2018-05-25 | Sorlien, Christopher; Luyendyk, Bruce P. |
|
Intellectual Merit:<br/>This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances.<br/><br/>Broader impacts: <br/>The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy. | POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33)) | POINT(177 -76) | false | false | |||||||||
Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island
|
0944021 0943466 0944307 |
2018-02-16 | Conway, Howard; Brook, Edward J.; Hawley, Robert L. | This award supports a project to use the Roosevelt Island ice core as a glaciological dipstick for the eastern Ross Sea. Recent attention has focused on the eastern Ross Embayment, where there are no geological constraints on ice thickness changes, due to the lack of protruding rock "dipsticks" where the ice sheet can leave datable records of high stands. Recent work has shown how dated ice cores can be used as dipsticks to derive ice-thickness histories. Partners from New Zealand and Denmark will extract an ice core from Roosevelt Island during the 2010-2011 and 2011-12 austral summers. Their science objective is to contribute to understanding of climate variability over the past 40kyr. The science goal of this project is not the climate record, but rather the history of deglaciation in the Ross Sea. The new history from the eastern Ross Sea will be combined with the glacial histories from the central Ross Sea (Siple Dome and Byrd) and existing and emerging histories from geologic and marine records along the western Ross Sea margin and will allow investigators to establish an updated, self-consistent model of the configuration and thickness of ice in the Ross Embayment during the LGM, and the timing of deglaciation. Results from this work will provide ground truth for new-generation ice-sheet models that incorporate ice streams and fast-flow dynamics. Realistic ice-sheet models are needed not only for predicting the response to future possible environments, but also for investigating past behaviors of ice sheets. This research contributes to the primary goals of the West Antarctic Ice Sheet Initiative as well as the IPY focus on ice-sheet history and dynamics. It also contributes to understanding spatial and temporal patterns of climate change and climate dynamics over the past 40kyr, one of the primary goals of the International Partnerships in Ice Core Sciences (IPICS). The project will help to develop the next generation of scientists and will contribute to the education and training of two Ph.D. students. All participants will benefit from the international collaboration, which will expose them to different field and laboratory techniques and benefit future collaborative work. All participants are involved in scientific outreach and undergraduate education, and are committed to fostering diversity. Outreach will be accomplished through regularly scheduled community and K-12 outreach events, talks and popular writing by the PIs, as well as through University press offices. | POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79)) | POINT(-162 -79.25) | false | false | ||||||||||
Collaborative Research: West Antarctic Ice Sheet stability, Alpine Glaciation, and Climate Variability: a Terrestrial Perspective from Cosmogenic-nuclide Dating in McMurdo Sound
|
1245899 |
2018-01-16 | Kowalewski, Douglas |
|
Intellectual Merit: <br/>The PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica.<br/><br/>Broader impacts: <br/>Results from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University. | POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70)) | POINT(-160 -77.5) | false | false | |||||||||
Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains
|
1043572 1043619 |
2014-02-18 | Licht, Kathy; Hemming, Sidney R. |
|
Intellectual Merit: <br/>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. <br/><br/>Broader impacts: <br/>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((-177.982 -63.997,-149.64107 -63.997,-121.30014 -63.997,-92.95921 -63.997,-64.61828 -63.997,-36.27735 -63.997,-7.93642 -63.997,20.40451 -63.997,48.74544 -63.997,77.08637 -63.997,105.4273 -63.997,105.4273 -66.3324,105.4273 -68.6678,105.4273 -71.0032,105.4273 -73.3386,105.4273 -75.674,105.4273 -78.0094,105.4273 -80.3448,105.4273 -82.6802,105.4273 -85.0156,105.4273 -87.351,77.08637 -87.351,48.74544 -87.351,20.40451 -87.351,-7.93642 -87.351,-36.27735 -87.351,-64.61828 -87.351,-92.95921 -87.351,-121.30014 -87.351,-149.64107 -87.351,-177.982 -87.351,-177.982 -85.0156,-177.982 -82.6802,-177.982 -80.3448,-177.982 -78.0094,-177.982 -75.674,-177.982 -73.3386,-177.982 -71.0032,-177.982 -68.6678,-177.982 -66.3324,-177.982 -63.997)) | POINT(-36.27735 -75.674) | false | false | |||||||||
Collaborative Proposal: Late Cenozoic Volcanism and Glaciation at Minna Bluff, Antarctica: Implications for Antarctic Cryosphere History
|
0538033 |
2011-09-14 | Panter, Kurt | No dataset link provided | This project studies glaciovolcanic deposits at Minna Bluff in the western Ross Embayment of Antarctica. Its goal is to determine the history of the Ross Ice Shelf, which is fed by the major ice sheets from both East and West Antarctica. Apart from determining how these ice sheets waxed and waned during a period of dynamic climate change, glaciovolcanic sequences may constrain ice sheet parameters that are critical to numerical models such as thickness, hydrology, and basal thermal regime. This three-year study would map, analyze, and determine the age of key units using 40Ar/39Ar dating. Pilot studies would also be conducted for 36Cl dating of glacial deposits and stable isotope evaluations of alteration. The project offers a complementary record of Ross Ice Shelf behavior to that sampled by ANDRILL. It also improves the general record of McMurdo area volcanostratigraphy, which is important to interpreting landforms, glacial deposits, and ancient ice found in the Dry Valleys.<br/><br/>The broader impacts of this project include improving society's understanding of global climate change, sea level rise, and graduate and undergraduate student education. Outreach efforts include educational programs for public schools and community groups, exhibits for a local science museum, and a project website. | None | None | false | false | |||||||||
Collaborative Research:Grounding-line Retreat in the Southern Ross Sea - Constraints from Scott Glacier
|
0636818 |
2011-08-05 | Stone, John; Conway, Howard | No dataset link provided | Hall/0636687<br/><br/>This award supports a project to investigate late Pleistocene and Holocene changes in Scott Glacier, a key outlet glacier that flows directly into the Ross Sea just west of the present-day West Antarctic Ice Sheet (WAIS) grounding line. The overarching goals are to understand changes in WAIS configuration in the Ross Sea sector at and since the last glacial maximum (LGM) and to determine whether Holocene retreat observed in the Ross Embayment has ended or if it is still ongoing. To address these goals, moraine and drift sequences associated with Scott Glacier will be mapped and dated and ice thickness, surface velocity and surface mass balance will be measured to constrain an ice-flow model of the glacier. This model will be used to help interpret the dated geologic sequences. The intellectual merit of the project relates to gaining a better understanding of the West Antarctic Ice Sheet and how changing activity of fast-flowing outlet glaciers and ice streams exerts strong control on the mass balance of the ice sheet. Previous work suggests that grounding-line retreat in the Ross Sea continued into the late Holocene and left open the possibility of ongoing deglaciation as part of a long-term trend. Results from Reedy Glacier, an outlet glacier just behind the grounding line, suggest that retreat may have slowed substantially over the past 2000 years and perhaps even stopped. By coupling the work on Scott Glacier with recent data from Reedy Glacier, the grounding-line position will be bracketed and it should be possible to establish whether the retreat has truly ended or if it is ongoing. The broader impacts of the work relate to the societal relevance of an improved understanding of the West Antarctic ice sheet to establish how it will respond to current and possible future environmental changes. The work addresses this key goal of the West Antarctic Ice Sheet Initiative, as well as the International Polar Year focus on ice sheet history and dynamics. The work will develop future scientists through the education and training of one undergraduate and two Ph.D. students, interaction with K-12 students through classroom visits, web-based 'expedition' journals, letters from the field, and discussions with teachers. Results from this project will be posted with previous exposure dating results from Antarctica, on the University of Washington Cosmogenic Nuclide Lab website, which also provides information about chemical procedures and calculation methods to other scientists working with cosmogenic nuclides. | POLYGON((-157 -85,-156 -85,-155 -85,-154 -85,-153 -85,-152 -85,-151 -85,-150 -85,-149 -85,-148 -85,-147 -85,-147 -85.3,-147 -85.6,-147 -85.9,-147 -86.2,-147 -86.5,-147 -86.8,-147 -87.1,-147 -87.4,-147 -87.7,-147 -88,-148 -88,-149 -88,-150 -88,-151 -88,-152 -88,-153 -88,-154 -88,-155 -88,-156 -88,-157 -88,-157 -87.7,-157 -87.4,-157 -87.1,-157 -86.8,-157 -86.5,-157 -86.2,-157 -85.9,-157 -85.6,-157 -85.3,-157 -85)) | POINT(-152 -86.5) | false | false | |||||||||
Collaborative Research: A GPS Network to Determine Crustal Motions in the Bedrock of the West Antarctic Ice Sheet: Phase I - Installation
|
0003619 |
2010-05-04 | Dalziel, Ian W. |
|
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program to initiate a Global Positioning System (GPS) network to measure crustal motions in the bedrock surrounding and underlying the West Antarctic Ice Sheet (WAIS). Evaluation of the role of both tectonic and ice-induced crustal motions of the WAIS bedrock is a critical goal for understanding past, present, and future dynamics of WAIS and its potential role in future global change scenarios, as well as improving our understanding of the role of Antarctica in global plate motions. The extent of active tectonism in West Antarctica is largely speculative, as few data exist that constrain its geographic distribution, directions, or rates of deformation. Active tectonism and the influence of bedrock on the WAIS have been highlighted recently by geophysical data indicating active subglacial volcanism and control of ice streaming by the presence of sedimentary basins. The influence of bedrock crustal motion on the WAIS and its future dynamics is a fundamental issue. Existing GPS projects are located only on the fringe of the ice sheet and do not address the regional picture. It is important that baseline GPS measurements on the bedrock around and within the WAIS be started so that a basis is established for detecting change.<br/><br/>To measure crustal motions, this project will build a West Antarctica GPS Network (WAGN) of at least 15 GPS sites across the interior of West Antarctica (approximately the size of the contiguous United States from the Rocky Mountains to the Pacific coast) over a two-year period beginning in the Antarctic field season 2001-2002. The planned network is designed using the Multi-modal Occupation Strategy (MOST), in which a small number of independent GPS "roving" receivers make differential measurements against a network of continuous GPS stations for comparatively short periods at each site. This experimental strategy, successfully implemented by a number of projects in California, S America, the SW Pacific and Central Asia, minimizes logistical requirements, an essential element of application of GPS geodesy in the scattered and remote outcrops of the WAIS bedrock.<br/><br/>The WAGN program will be integrated with the GPS network that has been established linking the Antarctic Peninsula with South America through the Scotia arc (Scotia Arc GPS Project (SCARP)). It will also interface with stations currently measuring motion across the Ross Embayment, and with the continent-wide GIANT program of the Working Group on Geodesy and Geographic Information Systems of the Scientific Committee on Antarctic Research (SCAR). The GPS network will be based on permanent monuments set in solid rock outcrops that will have near-zero set-up error for roving GPS occupations, and that can be directly converted to a continuous GPS site when future technology makes autonomous operation and satellite data linkage throughout West Antarctica both reliable and economical. The planned network both depends on and complements the existing and planned continuous networks. It is presently not practical, for reasons of cost and logistics, to accomplish the measurements proposed herein with either a network of continuous stations or traditional campaigns.<br/><br/>The proposed WAGN will complement existing GPS projects by filling a major gap in coverage among several discrete crustal blocks that make up West Antarctica, a critical area of potential bedrock movements. If crustal motions are relatively slow, meaningful results will only begin to emerge within the five-year maximum period of time for an individual funded project. Hence this proposal is only to initiate the network and test precision and velocities at the most critical sites. Once built, however, the network will yield increasingly meaningful results with the passage of time. Indeed, the slower the rates turn out to be, the more important an early start to measuring. It is anticipated that the results of this project will initiate an iterative process that will gradually resolve into an understanding of the contributions from plate rotations and viscoelastic and elastic motions resulting from deglaciation and ice mass changes. Velocities obtained from initial reoccupation of the most critical sites will dictate the timing of a follow-up proposal for reoccupation of the entire network when detectable motions have occurred. | None | None | false | false | |||||||||
Collaborative Research: The Connection Between Mid-Cenozoic Seafloor Spreading and the Western Ross Sea Embayment
|
0440959 |
2010-05-04 | Cande, Steven |
|
This work will perform a marine geophysical survey of sea floor spreading off Cape Adare, Antarctica. Magnetic, gravity, swath bathymetry and multi-channel seismic data will be acquired from the southern end of the Adare Basin to the northern parts of the Northern Basin and Central Trough in the Ross Embayment. Previous surveys documented 170 km of regional extension between forty-three and twenty-six million years ago, which resulted in some seafloor spreading in the Adare Basin. However, the relationship of Adare Basin spreading to the overall extension and the southward continental basins of the Ross Embayment has not been established. This relationship is critical to understanding the tectonic evolution of East and West Antarctica and linking Pacific plate motions to the rest of the world. The study will also offer unique insight into rifting processes by studying the transition of rifting between oceanic and continental lithosphere. In terms of broader impacts, this project will support two graduate students and field research experience for undergraduates. The project also involves cooperation between scientists from the US, Australia, New Zealand and Japan. | None | None | false | false | |||||||||
Corridor Aerogeophysics of the Southeastern Ross Transect Zone (CASERTZ), Antarctica
|
8919147 |
2004-03-17 | Elliot, David; Bell, Robin; Blankenship, Donald D.; Brozena, J. M.; Finn, C. A.; Hodge, S. M.; Kempf, Scott D.; Behrendt, J. C.; Morse, David L.; Peters, M. E.; Studinger, Michael S. |
|
This award will support a combined airborne radar and aeromagnetic survey of two 220 x 330 km regions between the Transantarctica Mountains and Marie Byrd Land during the 1990-91 and 1991-92 field seasons. These efforts will address significant problems identified in the Ross Transect Zone (RTZ) by the National Academy of Sciences (1986) report "Antarctic Solid Earth Sciences Research," and by the report to NSF "A Plan for a United States Program to Study the Structure and Evolution of the Antarctic Lithosphere (SEAL)." The surveys will be flown using the NSF/TUD radar and an areomagnetics system mounted in a light aircraft. The grid spacing will be 5 km and navigation will be by radiopositioning. In addition to maps of subglacial topography and magnetic intensity, attempts will be made to reconstruct the position of subglacial diffractors in three dimensions. This reconstruction should give new information about the distribution of escarpments and therefore the tectonic relationships within the region, especially when combined with the magnetic results. These experiments will be conducted by the Byrd Polar Research Center of the Ohio State University and the Water Resources and Geological Divisions of the U.S. Geological Survey. | None | None | false | false |