USAP-DC

{"dp_type": "Project", "free_text": "Ice Shelf Meltwater"}

[{"awards": "2434858 Washam, Peter", "bounds_geometry": "POLYGON((-0.2 -70.3,-0.16 -70.3,-0.12 -70.3,-0.08 -70.3,-0.04 -70.3,0 -70.3,0.04 -70.3,0.08 -70.3,0.12 -70.3,0.16 -70.3,0.2 -70.3,0.2 -70.31,0.2 -70.32,0.2 -70.33,0.2 -70.34,0.2 -70.35,0.2 -70.36,0.2 -70.37,0.2 -70.38000000000001,0.2 -70.39,0.2 -70.4,0.16 -70.4,0.12 -70.4,0.08 -70.4,0.04 -70.4,0 -70.4,-0.04 -70.4,-0.08 -70.4,-0.12 -70.4,-0.16 -70.4,-0.2 -70.4,-0.2 -70.39,-0.2 -70.38000000000001,-0.2 -70.37,-0.2 -70.36,-0.2 -70.35,-0.2 -70.34,-0.2 -70.33,-0.2 -70.32,-0.2 -70.31,-0.2 -70.3))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 10 Sep 2025 00:00:00 GMT", "description": "Ice shelves fringe most of Antarctica\u2019s coastline where the ice sheet detaches from the underlying bed and enters the ocean. These expansive floating bodies of ice provide an important bottleneck on seaward flow of ice from the Antarctic ice sheet and sea level rise through their resistive buttressing forces. The ocean melts ice shelves from below, which removes their mass and influences their buttressing capacity. Local regions of thin ice, referred to as channels and crevasses, form in the base of ice shelves from ocean-driven melting and strain-driven cracking. These features represent potential weak points in the ice that are particularly susceptible to increased melting if ocean temperatures rise, because of their high slope angles. Improving understanding of the processes that determine the rate of melting along ice bases of varying slopes has global societal and environmental implications, as it stands to reduce uncertainties in projected sea level rise. This project will study variable melting along sloping ice using a novel field data set collected in a channel etched into the base of Fimbul Ice Shelf, Antarctica in 2024. Results from this project will provide a baseline for how sloped bases of ice shelves melt, which can be used to improve parameterizations of this process in large-scale models responsible for sea level rise projections. This study focuses on ocean-driven melting along sloping sidewalls of local thin points in ice shelves, such as basal channels or basal crevasses. These features are particularly sensitive to oceanographic forcing, as they exhibit high slopes that can melt rapidly when exposed to warm ocean conditions. If this melting is strong enough, then it can erode features to the point that they become unstable, resulting in full-thickness fractures that promote iceberg calving and ice shelf destabilization. Notably, the upstream effect of ice shelf changes related to oceanographic forcing is a major source of uncertainty in projections of Antarctica\u2019s contribution to future global sea level rise, which could amount to 53 cm by 2100. The primary objective of this project is to make significant improvements to the understanding of how the ocean melts sloped ice shelf basal topography under various forcing. The secondary objective is to understand how ice topography then evolves over time from this ocean forcing. The principal study location is Fimbul Ice Shelf, Antarctica, where in situ data was collected with the Icefin underwater vehicle and other instrumentation in January 2024, as part of an international collaboration with the United Kingdom and Norway. Results from this study will be placed into the larger context of ice shelf melting around Antarctica by comparing with previous data collected with Icefin in various oceanographic settings. The goal of this effort is to better constrain the poorly understood coupled ice-ocean processes that control melting along variable slopes. The Icefin data will be analyzed alongside data from surface-based ice penetrating radar, remote sensing, long-term oceanographic mooring, and output from the Finite-Volume Community Ocean Model. This award reflects NSF\u0027\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027\u0027s intellectual merit and broader impacts review criteria.", "east": 0.2, "geometry": "POINT(0 -70.35)", "instruments": null, "is_usap_dc": true, "keywords": "OCEAN CURRENTS; Subglacial Observations; Ocean Circulation Model; Observation Data; GLACIERS/ICE SHEETS; East Antarctica; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; Ice Shelf; SALINITY/DENSITY; Ice Shelf Meltwater; Antarctica; Subglacial Topography; OCEAN TEMPERATURE; Dronning Maud Land; WATER MASSES; Glacier-Ocean Boundary Layer; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY", "locations": "Dronning Maud Land; Antarctica; East Antarctica", "north": -70.3, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Washam, Peter; Schmidt, Britney", "platforms": null, "repositories": null, "science_programs": null, "south": -70.4, "title": "SLOPES: The role of basal slopes in ice shelf melting", "uid": "p0010540", "west": -0.2}, {"awards": "0540915 Scambos, Ted", "bounds_geometry": "POLYGON((-57.9857 -48.444,-55.95557 -48.444,-53.92544 -48.444,-51.89531 -48.444,-49.86518 -48.444,-47.83505 -48.444,-45.80492 -48.444,-43.77479 -48.444,-41.74466 -48.444,-39.71453 -48.444,-37.6844 -48.444,-37.6844 -50.12802,-37.6844 -51.81204,-37.6844 -53.49606,-37.6844 -55.18008,-37.6844 -56.8641,-37.6844 -58.54812,-37.6844 -60.23214,-37.6844 -61.91616,-37.6844 -63.60018,-37.6844 -65.2842,-39.71453 -65.2842,-41.74466 -65.2842,-43.77479 -65.2842,-45.80492 -65.2842,-47.83505 -65.2842,-49.86518 -65.2842,-51.89531 -65.2842,-53.92544 -65.2842,-55.95557 -65.2842,-57.9857 -65.2842,-57.9857 -63.60018,-57.9857 -61.91616,-57.9857 -60.23214,-57.9857 -58.54812,-57.9857 -56.8641,-57.9857 -55.18008,-57.9857 -53.49606,-57.9857 -51.81204,-57.9857 -50.12802,-57.9857 -48.444))", "dataset_titles": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.; Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007; MODIS Mosaic of Antarctica (MOA)", "datasets": [{"dataset_uid": "000190", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "MODIS Mosaic of Antarctica (MOA)", "url": "http://nsidc.org/data/nsidc-0280.html"}, {"dataset_uid": "609466", "doi": "10.7265/N5N014GW", "keywords": "Ablation; Atmosphere; Glaciology; GPS; Meteorology; Oceans; Photo/video; Photo/Video; Sea Ice; Southern Ocean; Temperature", "people": "Bauer, Rob; Scambos, Ted; Thom, Jonathan; Yermolin, Yevgeny; Bohlander, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007", "url": "https://www.usap-dc.org/view/dataset/609466"}, {"dataset_uid": "000189", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.", "url": "http://nsidc.org/MMS/atlas/cryosphere_atlas_north.html"}], "date_created": "Thu, 16 Aug 2007 00:00:00 GMT", "description": "This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.", "east": -37.6844, "geometry": "POINT(-47.83505 -56.8641)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SNOW DENSITY CUTTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Air Temperature; Weddell Sea; Edge-Wasting; Ice Shelf Meltwater; TERRA; Antarctic; GPS; Iceberg; Ice Breakup; South Atlantic Ocean; AQUA; Tabular; Photo; Not provided; Icetrek; HELICOPTER; Antarctica", "locations": "Antarctic; Weddell Sea; Antarctica; South Atlantic Ocean", "north": -48.444, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Bohlander, Jennifer; Bauer, Rob; Yermolin, Yevgeny; Thom, Jonathan", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e AQUA; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e TERRA; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -65.2842, "title": "Investigating Iceberg Evolution During Drift and Break-Up: A Proxy for Climate-Related Changes in Antarctic Ice Shelves", "uid": "p0000003", "west": -57.9857}, {"awards": "0233303 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.\u003cbr/\u003eThis award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.\u003cbr/\u003eA better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Ice Sheet; Basal Melting; Ice Shelf Meltwater; Not provided; Oceanography; Ice Velocity; Glaciology; Sea Level Rise; Ice Sheet Stability; Mass; Ross Ice Sheet; Numerical Model; Basal Freezing; Ice Cavity Circulations; George VI Ice Shelf; Outflow", "locations": "Ross Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Melting and Calving of Antarctic Ice Shelves", "uid": "p0000730", "west": null}]

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