{"dp_type": "Dataset", "free_text": "Communication"}
[{"awards": "2130663 Neff, Peter", "bounds_geometry": null, "date_created": "Thu, 18 May 2023 00:00:00 GMT", "description": "Final report of the 2021 Antarctic Subsea Cable Workshop, held virtually June 29 - July 1. The National Science Foundation (NSF)-funded workshop addressed questions around the value and feasibility of deploying a new optical fiber submarine cable system that would supply high-speed internet connectivity to McMurdo Station to address the severe network bandwidth bottlenecks that currently constrain scientific research in Antarctica.", "east": null, "geometry": null, "keywords": "Antarctica; Communication; Internet; Report", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Polar Cyberinfrastructure", "persons": "Andreasen, Julia; Roop, Heidi A; Pundsack, Jonathan W; Howe, Bruce; Jacobs, Gwen; Lassner, David; Yoshimi, Garrett; Timm, Kristin; Neff, Peter", "project_titles": "2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science", "projects": [{"proj_uid": "p0010389", "repository": "USAP-DC", "title": "2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Antarctic Subsea Cable Workshop Report", "uid": "601691", "west": null}, {"awards": "1142162 Stone, John", "bounds_geometry": ["POLYGON((-104.14 -81.07,-102.24 -81.07,-100.34 -81.07,-98.44 -81.07,-96.54 -81.07,-94.64 -81.07,-92.74 -81.07,-90.84 -81.07,-88.94 -81.07,-87.04 -81.07,-85.14 -81.07,-85.14 -81.207,-85.14 -81.344,-85.14 -81.481,-85.14 -81.618,-85.14 -81.755,-85.14 -81.892,-85.14 -82.029,-85.14 -82.166,-85.14 -82.303,-85.14 -82.44,-87.04 -82.44,-88.94 -82.44,-90.84 -82.44,-92.74 -82.44,-94.64 -82.44,-96.54 -82.44,-98.44 -82.44,-100.34 -82.44,-102.24 -82.44,-104.14 -82.44,-104.14 -82.303,-104.14 -82.166,-104.14 -82.029,-104.14 -81.892,-104.14 -81.755,-104.14 -81.618,-104.14 -81.481,-104.14 -81.344,-104.14 -81.207,-104.14 -81.07))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "This award supports a reconnaissance geological and radar-sounding study of promising sites in West Antarctica for a future project to measure cosmogenic nuclides in subglacial bedrock. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain the highest possible surface detail. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public.", "east": -85.14, "geometry": ["POINT(-94.64 -81.755)"], "keywords": "Antarctica; Be-10; Chemistry:rock; Chemistry:Rock; Cosmogenic Dating; Glaciology; Nunataks; Sample/collection Description; Sample/Collection Description; Solid Earth; Whitmore Mountains", "locations": "Whitmore Mountains; Antarctica", "north": -81.07, "nsf_funding_programs": null, "persons": "Stone, John", "project_titles": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "projects": [{"proj_uid": "p0000335", "repository": "USAP-DC", "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -82.44, "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "uid": "600162", "west": -104.14}, {"awards": "1142010 Talghader, Joseph", "bounds_geometry": ["POLYGON((-148.81 -79.42,-145.111 -79.42,-141.412 -79.42,-137.713 -79.42,-134.014 -79.42,-130.315 -79.42,-126.616 -79.42,-122.917 -79.42,-119.218 -79.42,-115.519 -79.42,-111.82 -79.42,-111.82 -79.643,-111.82 -79.866,-111.82 -80.089,-111.82 -80.312,-111.82 -80.535,-111.82 -80.758,-111.82 -80.981,-111.82 -81.204,-111.82 -81.427,-111.82 -81.65,-115.519 -81.65,-119.218 -81.65,-122.917 -81.65,-126.616 -81.65,-130.315 -81.65,-134.014 -81.65,-137.713 -81.65,-141.412 -81.65,-145.111 -81.65,-148.81 -81.65,-148.81 -81.427,-148.81 -81.204,-148.81 -80.981,-148.81 -80.758,-148.81 -80.535,-148.81 -80.312,-148.81 -80.089,-148.81 -79.866,-148.81 -79.643,-148.81 -79.42))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum.", "east": -111.82, "geometry": ["POINT(-130.315 -80.535)"], "keywords": "Antarctica; Ash Layer; Borehole Camera; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.42, "nsf_funding_programs": null, "persons": "Talghader, Joseph", "project_titles": "Optical Fabric and Fiber Logging of Glacial Ice", "projects": [{"proj_uid": "p0000339", "repository": "USAP-DC", "title": "Optical Fabric and Fiber Logging of Glacial Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Optical Fabric and Fiber Logging of Glacial Ice (1142010)", "uid": "600172", "west": -148.81}, {"awards": "0440636 Fahnestock, Mark", "bounds_geometry": null, "date_created": "Thu, 25 Sep 2008 00:00:00 GMT", "description": "Flow features on the surface of the Ross Ice Shelf, West Antarctica, record two episodes of ice stream stagnation and reactivation within the last 1,000 years. We document these events using maps of streaklines emerging from individual ice streams made using visible band imagery, together with numerical models of ice shelf flow. Forward model experiments demonstrate that only a limited set of discharge scenarios could have produced the current streakline configuration. According to our analysis, Whillans Ice Stream ceased rapid flow about 850 calendar years ago and restarted about 400 years later and MacAyeal Ice Stream either stopped or slowed significantly between 800 and 700 years ago, restarting about 150 years later. Until now, ice-stream scenarios emphasized runaway retreat or stagnation on millennial time scales. Here, we identify a new scenario: century-scale stagnation and reactivation cycles, as well as lateral communication with adjacent ice streams through thickness changes on lightly grounded ice plains. This introduces uncertainty into predictions for future sea-level withdrawls by the West Antarctic Ice Sheet, which are based in part on recent slowing of Whillans Ice Stream and the stagnant condition of Kamb Ice Stream. This paper documents the evidence for delimiting the source regions (provenance) of ice now in the shelf; for bracketing the possible discharge scenarios that could have produced the patterns captured in the shelf, and shows that it is difficult to reproduce these patterns with a model without stopping and restarting individual streams. The modeling facilitated by Co-PI Hulbe\u2019s system has allowed us to cover a range of possible scenarios, and in the process to learn about other aspects of the behavior of this system. The flow variability recorded in the ice shelf provides an important reference history against which current changes can be put in context.", "east": null, "geometry": null, "keywords": null, "locations": null, "north": null, "nsf_funding_programs": null, "persons": "Fahnestock, Mark", "project_titles": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "projects": [{"proj_uid": "p0000096", "repository": "USAP-DC", "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "uid": "600024", "west": null}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Antarctic Subsea Cable Workshop Report
|
2130663 |
2023-05-18 | Andreasen, Julia; Roop, Heidi A; Pundsack, Jonathan W; Howe, Bruce; Jacobs, Gwen; Lassner, David; Yoshimi, Garrett; Timm, Kristin; Neff, Peter |
2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science |
Final report of the 2021 Antarctic Subsea Cable Workshop, held virtually June 29 - July 1. The National Science Foundation (NSF)-funded workshop addressed questions around the value and feasibility of deploying a new optical fiber submarine cable system that would supply high-speed internet connectivity to McMurdo Station to address the severe network bandwidth bottlenecks that currently constrain scientific research in Antarctica. | [] | [] | false | false |
Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling
|
1142162 |
2016-01-01 | Stone, John |
Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling |
This award supports a reconnaissance geological and radar-sounding study of promising sites in West Antarctica for a future project to measure cosmogenic nuclides in subglacial bedrock. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain the highest possible surface detail. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public. | ["POLYGON((-104.14 -81.07,-102.24 -81.07,-100.34 -81.07,-98.44 -81.07,-96.54 -81.07,-94.64 -81.07,-92.74 -81.07,-90.84 -81.07,-88.94 -81.07,-87.04 -81.07,-85.14 -81.07,-85.14 -81.207,-85.14 -81.344,-85.14 -81.481,-85.14 -81.618,-85.14 -81.755,-85.14 -81.892,-85.14 -82.029,-85.14 -82.166,-85.14 -82.303,-85.14 -82.44,-87.04 -82.44,-88.94 -82.44,-90.84 -82.44,-92.74 -82.44,-94.64 -82.44,-96.54 -82.44,-98.44 -82.44,-100.34 -82.44,-102.24 -82.44,-104.14 -82.44,-104.14 -82.303,-104.14 -82.166,-104.14 -82.029,-104.14 -81.892,-104.14 -81.755,-104.14 -81.618,-104.14 -81.481,-104.14 -81.344,-104.14 -81.207,-104.14 -81.07))"] | ["POINT(-94.64 -81.755)"] | false | false |
Optical Fabric and Fiber Logging of Glacial Ice (1142010)
|
1142010 |
2015-01-01 | Talghader, Joseph |
Optical Fabric and Fiber Logging of Glacial Ice |
This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum. | ["POLYGON((-148.81 -79.42,-145.111 -79.42,-141.412 -79.42,-137.713 -79.42,-134.014 -79.42,-130.315 -79.42,-126.616 -79.42,-122.917 -79.42,-119.218 -79.42,-115.519 -79.42,-111.82 -79.42,-111.82 -79.643,-111.82 -79.866,-111.82 -80.089,-111.82 -80.312,-111.82 -80.535,-111.82 -80.758,-111.82 -80.981,-111.82 -81.204,-111.82 -81.427,-111.82 -81.65,-115.519 -81.65,-119.218 -81.65,-122.917 -81.65,-126.616 -81.65,-130.315 -81.65,-134.014 -81.65,-137.713 -81.65,-141.412 -81.65,-145.111 -81.65,-148.81 -81.65,-148.81 -81.427,-148.81 -81.204,-148.81 -80.981,-148.81 -80.758,-148.81 -80.535,-148.81 -80.312,-148.81 -80.089,-148.81 -79.866,-148.81 -79.643,-148.81 -79.42))"] | ["POINT(-130.315 -80.535)"] | false | false |
Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams
|
0440636 |
2008-09-25 | Fahnestock, Mark |
Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams |
Flow features on the surface of the Ross Ice Shelf, West Antarctica, record two episodes of ice stream stagnation and reactivation within the last 1,000 years. We document these events using maps of streaklines emerging from individual ice streams made using visible band imagery, together with numerical models of ice shelf flow. Forward model experiments demonstrate that only a limited set of discharge scenarios could have produced the current streakline configuration. According to our analysis, Whillans Ice Stream ceased rapid flow about 850 calendar years ago and restarted about 400 years later and MacAyeal Ice Stream either stopped or slowed significantly between 800 and 700 years ago, restarting about 150 years later. Until now, ice-stream scenarios emphasized runaway retreat or stagnation on millennial time scales. Here, we identify a new scenario: century-scale stagnation and reactivation cycles, as well as lateral communication with adjacent ice streams through thickness changes on lightly grounded ice plains. This introduces uncertainty into predictions for future sea-level withdrawls by the West Antarctic Ice Sheet, which are based in part on recent slowing of Whillans Ice Stream and the stagnant condition of Kamb Ice Stream. This paper documents the evidence for delimiting the source regions (provenance) of ice now in the shelf; for bracketing the possible discharge scenarios that could have produced the patterns captured in the shelf, and shows that it is difficult to reproduce these patterns with a model without stopping and restarting individual streams. The modeling facilitated by Co-PI Hulbe’s system has allowed us to cover a range of possible scenarios, and in the process to learn about other aspects of the behavior of this system. The flow variability recorded in the ice shelf provides an important reference history against which current changes can be put in context. | [] | [] | false | false |