Measuring the location and width of the Antarctic grounding zone using CryoSat-2
We present the results of mapping the limit of the tidal flexure (point F) and hydrostatic equilibrium (point H) of the grounding zone of Antarctic ice shelves from CryoSat-2 standard and swath elevation data. Overall we were able to map 31 % of the grounding zone of the Antarctic floating ice shelv...
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ftcopernicus:oai:publications.copernicus.org:tc79535 2023-05-15T13:22:12+02:00 Measuring the location and width of the Antarctic grounding zone using CryoSat-2 Dawson, Geoffrey J. Bamber, Jonathan L. 2020-06-25 application/pdf https://doi.org/10.5194/tc-14-2071-2020 https://tc.copernicus.org/articles/14/2071/2020/ eng eng doi:10.5194/tc-14-2071-2020 https://tc.copernicus.org/articles/14/2071/2020/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-14-2071-2020 2020-07-20T16:22:03Z We present the results of mapping the limit of the tidal flexure (point F) and hydrostatic equilibrium (point H) of the grounding zone of Antarctic ice shelves from CryoSat-2 standard and swath elevation data. Overall we were able to map 31 % of the grounding zone of the Antarctic floating ice shelves and outlet glaciers. We obtain near-complete coverage of the Filchner–Ronne Ice Shelf. Here we manage to map areas of Support Force Glacier and the Doake Ice Rumples, which have previously only been mapped using break-in-slope methods. Over the Ross Ice Shelf, Dronning Maud Land and the Antarctic Peninsula, we obtained partial coverage, and we could not map a continuous grounding zone for the Amery Ice Shelf and the Amundsen Sea sector. Tidal amplitude and distance south (i.e. across-track spacing) are controlling factors in the quality of the coverage and performance of the approach. The location of the point F agrees well with previous observations that used differential satellite radar interferometry (DInSAR) and ICESat-1, with an average landward bias of 0.1 and 0.6 km and standard deviation of 1.1 and 1.5 km for DInSAR and ICESat measurements, respectively. We also compared the results directly with DInSAR interferograms from the Sentinel-1 satellites, acquired over the Evans Ice Stream and the Carlson Inlet (Ronne Ice Shelf), and found good agreement with the mapped points F and H. We also present the results of the spatial distribution of the grounding zone width (the distance between points F and H) and used a simple elastic beam model, along with ice thickness calculations, to calculate an effective Young modulus of ice of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>E</mi><mo>=</mo><mn mathvariant="normal">1.4</mn><mo>±</mo><mn mathvariant="normal">0.9</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="65pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="cbc2b6e2e322ef8e65d7777d688818c5"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-14-2071-2020-ie00001.svg" width="65pt" height="10pt" src="tc-14-2071-2020-ie00001.png"/></svg:svg> GPa. Text Amery Ice Shelf Amundsen Sea Antarc* Antarctic Antarctic Peninsula Dronning Maud Land Evans Ice Stream Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ice Shelves Ronne Ice Shelf Ross Ice Shelf Support Force Glacier Copernicus Publications: E-Journals Antarctic The Antarctic Antarctic Peninsula Dronning Maud Land Amundsen Sea Ross Ice Shelf Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Amery Ice Shelf ENVELOPE(71.000,71.000,-69.750,-69.750) Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) The Sentinel ENVELOPE(73.317,73.317,-52.983,-52.983) Evans Ice Stream ENVELOPE(-78.000,-78.000,-76.000,-76.000) Doake Ice Rumples ENVELOPE(-67.000,-67.000,-79.750,-79.750) Support Force Glacier ENVELOPE(-47.500,-47.500,-83.083,-83.083) Carlson Inlet ENVELOPE(-80.000,-80.000,-77.833,-77.833) The Cryosphere 14 6 2071 2086 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We present the results of mapping the limit of the tidal flexure (point F) and hydrostatic equilibrium (point H) of the grounding zone of Antarctic ice shelves from CryoSat-2 standard and swath elevation data. Overall we were able to map 31 % of the grounding zone of the Antarctic floating ice shelves and outlet glaciers. We obtain near-complete coverage of the Filchner–Ronne Ice Shelf. Here we manage to map areas of Support Force Glacier and the Doake Ice Rumples, which have previously only been mapped using break-in-slope methods. Over the Ross Ice Shelf, Dronning Maud Land and the Antarctic Peninsula, we obtained partial coverage, and we could not map a continuous grounding zone for the Amery Ice Shelf and the Amundsen Sea sector. Tidal amplitude and distance south (i.e. across-track spacing) are controlling factors in the quality of the coverage and performance of the approach. The location of the point F agrees well with previous observations that used differential satellite radar interferometry (DInSAR) and ICESat-1, with an average landward bias of 0.1 and 0.6 km and standard deviation of 1.1 and 1.5 km for DInSAR and ICESat measurements, respectively. We also compared the results directly with DInSAR interferograms from the Sentinel-1 satellites, acquired over the Evans Ice Stream and the Carlson Inlet (Ronne Ice Shelf), and found good agreement with the mapped points F and H. We also present the results of the spatial distribution of the grounding zone width (the distance between points F and H) and used a simple elastic beam model, along with ice thickness calculations, to calculate an effective Young modulus of ice of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>E</mi><mo>=</mo><mn mathvariant="normal">1.4</mn><mo>±</mo><mn mathvariant="normal">0.9</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="65pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="cbc2b6e2e322ef8e65d7777d688818c5"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-14-2071-2020-ie00001.svg" width="65pt" height="10pt" src="tc-14-2071-2020-ie00001.png"/></svg:svg> GPa. |
format |
Text |
author |
Dawson, Geoffrey J. Bamber, Jonathan L. |
spellingShingle |
Dawson, Geoffrey J. Bamber, Jonathan L. Measuring the location and width of the Antarctic grounding zone using CryoSat-2 |
author_facet |
Dawson, Geoffrey J. Bamber, Jonathan L. |
author_sort |
Dawson, Geoffrey J. |
title |
Measuring the location and width of the Antarctic grounding zone using CryoSat-2 |
title_short |
Measuring the location and width of the Antarctic grounding zone using CryoSat-2 |
title_full |
Measuring the location and width of the Antarctic grounding zone using CryoSat-2 |
title_fullStr |
Measuring the location and width of the Antarctic grounding zone using CryoSat-2 |
title_full_unstemmed |
Measuring the location and width of the Antarctic grounding zone using CryoSat-2 |
title_sort |
measuring the location and width of the antarctic grounding zone using cryosat-2 |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-2071-2020 https://tc.copernicus.org/articles/14/2071/2020/ |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(71.000,71.000,-69.750,-69.750) ENVELOPE(-61.000,-61.000,-78.500,-78.500) ENVELOPE(73.317,73.317,-52.983,-52.983) ENVELOPE(-78.000,-78.000,-76.000,-76.000) ENVELOPE(-67.000,-67.000,-79.750,-79.750) ENVELOPE(-47.500,-47.500,-83.083,-83.083) ENVELOPE(-80.000,-80.000,-77.833,-77.833) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Dronning Maud Land Amundsen Sea Ross Ice Shelf Amery Amery Ice Shelf Ronne Ice Shelf The Sentinel Evans Ice Stream Doake Ice Rumples Support Force Glacier Carlson Inlet |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Dronning Maud Land Amundsen Sea Ross Ice Shelf Amery Amery Ice Shelf Ronne Ice Shelf The Sentinel Evans Ice Stream Doake Ice Rumples Support Force Glacier Carlson Inlet |
genre |
Amery Ice Shelf Amundsen Sea Antarc* Antarctic Antarctic Peninsula Dronning Maud Land Evans Ice Stream Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ice Shelves Ronne Ice Shelf Ross Ice Shelf Support Force Glacier |
genre_facet |
Amery Ice Shelf Amundsen Sea Antarc* Antarctic Antarctic Peninsula Dronning Maud Land Evans Ice Stream Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ice Shelves Ronne Ice Shelf Ross Ice Shelf Support Force Glacier |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-14-2071-2020 https://tc.copernicus.org/articles/14/2071/2020/ |
op_doi |
https://doi.org/10.5194/tc-14-2071-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
6 |
container_start_page |
2071 |
op_container_end_page |
2086 |
_version_ |
1766363700345700352 |