Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet
Repeat-pass ICESat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite seve...
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ftunivnewcastle:oai:eprint.ncl.ac.uk:191729 2023-05-15T13:51:13+02:00 Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet Siegert MJ Ross N Corr HFJ Smith B Jordan TA Bingham RG Ferraccioli F Rippin DM Le Brocq A 24-06-2014 application/pdf https://eprint.ncl.ac.uk/fulltext.aspx?url=191729/72ED6F7E-DFBA-48F3-9867-2D41BE77E866.pdf&pub_id=191729 unknown European Geosciences Union The Cryosphere, 24-06-2014 Article 2014 ftunivnewcastle 2020-06-11T23:19:37Z Repeat-pass ICESat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite several attempts (notable exceptions are Lake Whillans and three in the Adventure Subglacial Trench). Here we present targeted RES and radar altimeter data from an "active lake" location within the upstream Institute Ice Stream, into which at least 0.12 km 3 of water was previously calculated to have flowed between October 2003 and February 2008. We use a series of transects to establish an accurate depiction of the influences of bed topography and ice surface elevation on water storage potential. The location of surface height change is downstream of a subglacial hill on the flank of a distinct topographic hollow, where RES reveals no obvious evidence for deep (> 10 m) water. The regional hydropotential reveals a sink coincident with the surface change, however. Governed by the location of the hydrological sink, basal water will likely "drape" over topography in a manner dissimilar to subglacial lakes where flat strong specular RES reflections are measured. The inability of RES to detect the active lake means that more of the Antarctic ice sheet bed may contain stored water than is currently appreciated. Variation in ice surface elevation data sets leads to significant alteration in calculations of the local flow of basal water indicating the value of, and need for, high-resolution altimetry data in both space and time to establish and characterise subglacial hydrological processes. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Institute Ice Stream The Cryosphere Newcastle University Library ePrints Service Adventure Subglacial Trench ENVELOPE(132.000,132.000,-74.000,-74.000) Antarctic Institute Ice Stream ENVELOPE(-75.000,-75.000,-82.000,-82.000) The Antarctic Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) |
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Newcastle University Library ePrints Service |
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ftunivnewcastle |
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description |
Repeat-pass ICESat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite several attempts (notable exceptions are Lake Whillans and three in the Adventure Subglacial Trench). Here we present targeted RES and radar altimeter data from an "active lake" location within the upstream Institute Ice Stream, into which at least 0.12 km 3 of water was previously calculated to have flowed between October 2003 and February 2008. We use a series of transects to establish an accurate depiction of the influences of bed topography and ice surface elevation on water storage potential. The location of surface height change is downstream of a subglacial hill on the flank of a distinct topographic hollow, where RES reveals no obvious evidence for deep (> 10 m) water. The regional hydropotential reveals a sink coincident with the surface change, however. Governed by the location of the hydrological sink, basal water will likely "drape" over topography in a manner dissimilar to subglacial lakes where flat strong specular RES reflections are measured. The inability of RES to detect the active lake means that more of the Antarctic ice sheet bed may contain stored water than is currently appreciated. Variation in ice surface elevation data sets leads to significant alteration in calculations of the local flow of basal water indicating the value of, and need for, high-resolution altimetry data in both space and time to establish and characterise subglacial hydrological processes. |
format |
Article in Journal/Newspaper |
author |
Siegert MJ Ross N Corr HFJ Smith B Jordan TA Bingham RG Ferraccioli F Rippin DM Le Brocq A |
spellingShingle |
Siegert MJ Ross N Corr HFJ Smith B Jordan TA Bingham RG Ferraccioli F Rippin DM Le Brocq A Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet |
author_facet |
Siegert MJ Ross N Corr HFJ Smith B Jordan TA Bingham RG Ferraccioli F Rippin DM Le Brocq A |
author_sort |
Siegert MJ |
title |
Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet |
title_short |
Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet |
title_full |
Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet |
title_fullStr |
Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet |
title_full_unstemmed |
Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet |
title_sort |
boundary conditions of an active west antarctic subglacial lake: implications for storage of water beneath the ice sheet |
publisher |
European Geosciences Union |
publishDate |
2014 |
url |
https://eprint.ncl.ac.uk/fulltext.aspx?url=191729/72ED6F7E-DFBA-48F3-9867-2D41BE77E866.pdf&pub_id=191729 |
long_lat |
ENVELOPE(132.000,132.000,-74.000,-74.000) ENVELOPE(-75.000,-75.000,-82.000,-82.000) ENVELOPE(-64.250,-64.250,-84.450,-84.450) |
geographic |
Adventure Subglacial Trench Antarctic Institute Ice Stream The Antarctic Whillans |
geographic_facet |
Adventure Subglacial Trench Antarctic Institute Ice Stream The Antarctic Whillans |
genre |
Antarc* Antarctic Ice Sheet Institute Ice Stream The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet Institute Ice Stream The Cryosphere |
op_source |
The Cryosphere, 24-06-2014 |
_version_ |
1766254983052787712 |