Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry
In this thesis, I use synthetic aperture radar (SAR) and radar altimeter data to make new observations of Antarctic and Greenland ice sheet grounding lines. I use ERS SAR data acquired between 1992 and 2011 to map the Petermann Glacier grounding line on 17 occasions using quadruple difference interf...
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ftwhiterose:oai:etheses.whiterose.ac.uk:11356 2023-05-15T13:24:15+02:00 Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry Hogg, Anna Elizabeth 2015-08 text https://etheses.whiterose.ac.uk/11356/ https://etheses.whiterose.ac.uk/11356/1/PhD_HOGG.pdf en eng University of Leeds https://etheses.whiterose.ac.uk/11356/1/PhD_HOGG.pdf Hogg, Anna Elizabeth (2015) Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry. PhD thesis, University of Leeds. cc_by_nc_sa CC-BY-NC-SA Thesis NonPeerReviewed 2015 ftwhiterose 2023-01-30T21:22:01Z In this thesis, I use synthetic aperture radar (SAR) and radar altimeter data to make new observations of Antarctic and Greenland ice sheet grounding lines. I use ERS SAR data acquired between 1992 and 2011 to map the Petermann Glacier grounding line on 17 occasions using quadruple difference interferometric SAR (QDInSAR). Over the 19-year period, the grounding line position varied by 0.5 km, on average, with no significant trend over time. Although tidal forcing explains a fraction (34 %) of the movement, localised variations in the glacier thickness could explain it all were they to alter the glaciers hydrostatic balance as they advect downstream – a hitherto unconsidered possibility that would reduce the accuracy with which changes in grounding line position can be detected. Next, I developed a new technique for detecting grounding lines using differential range direction offset tracking (DRDOT) in incoherent SAR data. I then applied this technique to a sequence of 11 TerraSAR-X images acquired in 2009 over Petermann Glacier. The DRDOT technique is able to reproduce the shape and location of the grounding line with an estimated lateral precision of 0.8 km and, although this is 30 times poorer than QDInSAR, provides a complementary method given the paucity of coherent SAR data. Finally, I developed another new method for detecting the grounding line as the break in ice sheet surface slope computed from CryoSat-2 elevation measurements. I then applied this technique to map grounding lines in the sectors of Antarctica buttressed by the Filchner-Ronne, Ekström, Larsen-C, and Amundsen Sea ice shelves. The technique is able to map the grounding line to within 4.5 km, on average, and, although this is far poorer than either QDInSAR or DRDOT, it is computationally efficient and can succeed where SAR-based methods fail, offering an additional complementary approach. Thesis Amundsen Sea Antarc* Antarctic Antarctica glacier Greenland Ice Sheet Ice Shelves Petermann glacier Sea ice White Rose eTheses Online (Universities Leeds, Sheffield, York) Antarctic Amundsen Sea Greenland |
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Open Polar |
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White Rose eTheses Online (Universities Leeds, Sheffield, York) |
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ftwhiterose |
language |
English |
description |
In this thesis, I use synthetic aperture radar (SAR) and radar altimeter data to make new observations of Antarctic and Greenland ice sheet grounding lines. I use ERS SAR data acquired between 1992 and 2011 to map the Petermann Glacier grounding line on 17 occasions using quadruple difference interferometric SAR (QDInSAR). Over the 19-year period, the grounding line position varied by 0.5 km, on average, with no significant trend over time. Although tidal forcing explains a fraction (34 %) of the movement, localised variations in the glacier thickness could explain it all were they to alter the glaciers hydrostatic balance as they advect downstream – a hitherto unconsidered possibility that would reduce the accuracy with which changes in grounding line position can be detected. Next, I developed a new technique for detecting grounding lines using differential range direction offset tracking (DRDOT) in incoherent SAR data. I then applied this technique to a sequence of 11 TerraSAR-X images acquired in 2009 over Petermann Glacier. The DRDOT technique is able to reproduce the shape and location of the grounding line with an estimated lateral precision of 0.8 km and, although this is 30 times poorer than QDInSAR, provides a complementary method given the paucity of coherent SAR data. Finally, I developed another new method for detecting the grounding line as the break in ice sheet surface slope computed from CryoSat-2 elevation measurements. I then applied this technique to map grounding lines in the sectors of Antarctica buttressed by the Filchner-Ronne, Ekström, Larsen-C, and Amundsen Sea ice shelves. The technique is able to map the grounding line to within 4.5 km, on average, and, although this is far poorer than either QDInSAR or DRDOT, it is computationally efficient and can succeed where SAR-based methods fail, offering an additional complementary approach. |
format |
Thesis |
author |
Hogg, Anna Elizabeth |
spellingShingle |
Hogg, Anna Elizabeth Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry |
author_facet |
Hogg, Anna Elizabeth |
author_sort |
Hogg, Anna Elizabeth |
title |
Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry |
title_short |
Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry |
title_full |
Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry |
title_fullStr |
Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry |
title_full_unstemmed |
Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry |
title_sort |
locating ice sheet grounding lines using satellite radar interferometry and altimetry |
publisher |
University of Leeds |
publishDate |
2015 |
url |
https://etheses.whiterose.ac.uk/11356/ https://etheses.whiterose.ac.uk/11356/1/PhD_HOGG.pdf |
geographic |
Antarctic Amundsen Sea Greenland |
geographic_facet |
Antarctic Amundsen Sea Greenland |
genre |
Amundsen Sea Antarc* Antarctic Antarctica glacier Greenland Ice Sheet Ice Shelves Petermann glacier Sea ice |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica glacier Greenland Ice Sheet Ice Shelves Petermann glacier Sea ice |
op_relation |
https://etheses.whiterose.ac.uk/11356/1/PhD_HOGG.pdf Hogg, Anna Elizabeth (2015) Locating Ice Sheet Grounding Lines Using Satellite Radar Interferometry and Altimetry. PhD thesis, University of Leeds. |
op_rights |
cc_by_nc_sa |
op_rightsnorm |
CC-BY-NC-SA |
_version_ |
1766378267057586176 |