Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data
The Amundsen Sea sector of West Antarctica Ice Sheet is losing mass at a rate that has more than doubled in the past four decades, and continues to increase. Pine Island Glacier (PIG), the second largest drainage basins in this sector, experienced the fastest grounding-line retreat and its ice-mass...
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ftawi:oai:epic.awi.de:37937 2023-05-15T13:24:15+02:00 Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data Muto, Atsuhiro Peters, Leo E. Gohl, Karsten Sassgen, Ingo Alley, Richard B. Anandakrishnan, Sridhar Riverman, Kiya L. 2015 https://epic.awi.de/id/eprint/37937/ https://hdl.handle.net/10013/epic.45500 unknown Muto, A. , Peters, L. E. , Gohl, K. orcid:0000-0002-9558-2116 , Sassgen, I. , Alley, R. B. , Anandakrishnan, S. and Riverman, K. L. (2015) Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data , International Symposium on Contemporary Ice-Sheet Dynamics: ocean interaction, meltwater and non-linear effects, Cambridge, UK, 16 August 2015 - 21 August 2015 . hdl:10013/epic.45500 EPIC3International Symposium on Contemporary Ice-Sheet Dynamics: ocean interaction, meltwater and non-linear effects, Cambridge, UK, 2015-08-16-2015-08-21 Conference notRev 2015 ftawi 2021-12-24T15:40:28Z The Amundsen Sea sector of West Antarctica Ice Sheet is losing mass at a rate that has more than doubled in the past four decades, and continues to increase. Pine Island Glacier (PIG), the second largest drainage basins in this sector, experienced the fastest grounding-line retreat and its ice-mass loss increased more rapidly than any others in the last two decades. The large mass imbalance of PIG is attributed to the increased sub-ice-shelf melting by the incursion of relatively warm Circumpolar Deep Water (CDW) beneath the PIG ice shelf (PIGIS), although the lack of precise bathymetry data have restricted thorough understanding of the ice-ocean interactions. Here we present updated bathymetry and sediment distribution beneath PIGIS, modeled by inversion of aerogravity data with constraints from active-source seismic and autonomous underwater vehicle data, and the regional gravity anomaly derived from satellite gravity observations. Modeled bathymetry shows that the submarine ridge beneath the middle of PIGIS appears to continue across the width of the ice shelf, with no major deep troughs crossing it, consistent with previously predicted sub-ice-shelf ocean circulation. However, the relatively low resolution of the aerogravity data and limitations in our inversion method leave a slight possibility that there is an undetected, few kilometer-scale narrow trough that may alter this predicted sub-ice-shelf ocean circulation. Modeled sediment distribution indicates that the submarine ridge marks the transition from a thick sedimentary basin (soft, smooth bed for ice flow) around the current grounding zone of the main PIG trunk to a region of thin-to-no sediment with some exposed crystalline basement (rough, resistant bed for ice flow) that extends seaward into Pine Island Bay. We hypothesize that this transition in basal conditions caused the post-Last Glacial Maximum retreat of PIG to stabilized near this geological boundary. Conference Object Amundsen Sea Antarc* Antarctica Ice Sheet Ice Shelf Pine Island Pine Island Bay Pine Island Glacier West Antarctica Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) West Antarctica Amundsen Sea Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Island Bay ENVELOPE(-109.085,-109.085,59.534,59.534) Pine Island Bay ENVELOPE(-102.000,-102.000,-74.750,-74.750) |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The Amundsen Sea sector of West Antarctica Ice Sheet is losing mass at a rate that has more than doubled in the past four decades, and continues to increase. Pine Island Glacier (PIG), the second largest drainage basins in this sector, experienced the fastest grounding-line retreat and its ice-mass loss increased more rapidly than any others in the last two decades. The large mass imbalance of PIG is attributed to the increased sub-ice-shelf melting by the incursion of relatively warm Circumpolar Deep Water (CDW) beneath the PIG ice shelf (PIGIS), although the lack of precise bathymetry data have restricted thorough understanding of the ice-ocean interactions. Here we present updated bathymetry and sediment distribution beneath PIGIS, modeled by inversion of aerogravity data with constraints from active-source seismic and autonomous underwater vehicle data, and the regional gravity anomaly derived from satellite gravity observations. Modeled bathymetry shows that the submarine ridge beneath the middle of PIGIS appears to continue across the width of the ice shelf, with no major deep troughs crossing it, consistent with previously predicted sub-ice-shelf ocean circulation. However, the relatively low resolution of the aerogravity data and limitations in our inversion method leave a slight possibility that there is an undetected, few kilometer-scale narrow trough that may alter this predicted sub-ice-shelf ocean circulation. Modeled sediment distribution indicates that the submarine ridge marks the transition from a thick sedimentary basin (soft, smooth bed for ice flow) around the current grounding zone of the main PIG trunk to a region of thin-to-no sediment with some exposed crystalline basement (rough, resistant bed for ice flow) that extends seaward into Pine Island Bay. We hypothesize that this transition in basal conditions caused the post-Last Glacial Maximum retreat of PIG to stabilized near this geological boundary. |
format |
Conference Object |
author |
Muto, Atsuhiro Peters, Leo E. Gohl, Karsten Sassgen, Ingo Alley, Richard B. Anandakrishnan, Sridhar Riverman, Kiya L. |
spellingShingle |
Muto, Atsuhiro Peters, Leo E. Gohl, Karsten Sassgen, Ingo Alley, Richard B. Anandakrishnan, Sridhar Riverman, Kiya L. Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data |
author_facet |
Muto, Atsuhiro Peters, Leo E. Gohl, Karsten Sassgen, Ingo Alley, Richard B. Anandakrishnan, Sridhar Riverman, Kiya L. |
author_sort |
Muto, Atsuhiro |
title |
Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data |
title_short |
Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data |
title_full |
Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data |
title_fullStr |
Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data |
title_full_unstemmed |
Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data |
title_sort |
subglacial bathymetry and sediment distribution beneath pine island glacier ice shelf modeled using aerogravity and in situ geophysical data |
publishDate |
2015 |
url |
https://epic.awi.de/id/eprint/37937/ https://hdl.handle.net/10013/epic.45500 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(-109.085,-109.085,59.534,59.534) ENVELOPE(-102.000,-102.000,-74.750,-74.750) |
geographic |
West Antarctica Amundsen Sea Pine Island Glacier Island Bay Pine Island Bay |
geographic_facet |
West Antarctica Amundsen Sea Pine Island Glacier Island Bay Pine Island Bay |
genre |
Amundsen Sea Antarc* Antarctica Ice Sheet Ice Shelf Pine Island Pine Island Bay Pine Island Glacier West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctica Ice Sheet Ice Shelf Pine Island Pine Island Bay Pine Island Glacier West Antarctica |
op_source |
EPIC3International Symposium on Contemporary Ice-Sheet Dynamics: ocean interaction, meltwater and non-linear effects, Cambridge, UK, 2015-08-16-2015-08-21 |
op_relation |
Muto, A. , Peters, L. E. , Gohl, K. orcid:0000-0002-9558-2116 , Sassgen, I. , Alley, R. B. , Anandakrishnan, S. and Riverman, K. L. (2015) Subglacial bathymetry and sediment distribution beneath Pine Island Glacier ice shelf modeled using aerogravity and in situ geophysical data , International Symposium on Contemporary Ice-Sheet Dynamics: ocean interaction, meltwater and non-linear effects, Cambridge, UK, 16 August 2015 - 21 August 2015 . hdl:10013/epic.45500 |
_version_ |
1766378290588680192 |