Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica
Outburst floods from subglacial lakes beneath the Antarctic Ice Sheet modulate ice-flow velocities over periods of months to years. Although subglacial lake drainage events have been observed from satellite-altimetric data, little is known about their role in the long-term evolution of ice-sheet bas...
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ftcopernicus:oai:publications.copernicus.org:tc75553 2023-05-15T13:55:28+02:00 Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica Kirkham, James D. Hogan, Kelly A. Larter, Robert D. Arnold, Neil S. Nitsche, Frank O. Golledge, Nicholas R. Dowdeswell, Julian A. 2019-07-17 application/pdf https://doi.org/10.5194/tc-13-1959-2019 https://tc.copernicus.org/articles/13/1959/2019/ eng eng doi:10.5194/tc-13-1959-2019 https://tc.copernicus.org/articles/13/1959/2019/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-13-1959-2019 2020-07-20T16:22:44Z Outburst floods from subglacial lakes beneath the Antarctic Ice Sheet modulate ice-flow velocities over periods of months to years. Although subglacial lake drainage events have been observed from satellite-altimetric data, little is known about their role in the long-term evolution of ice-sheet basal hydrology. Here, we systematically map and model past water flow through an extensive area containing over 1000 subglacial channels and 19 former lake basins exposed on over 19 000 km 2 of seafloor by the retreat of Pine Island and Thwaites glaciers, West Antarctica. At 507 m wide and 43 m deep on average, the channels offshore of present-day Pine Island and Thwaites glaciers are approximately twice as deep, 3 times as wide, and cover an area over 400 times larger than the terrestrial meltwater channels comprising the Labyrinth in the Antarctic Dry Valleys. The channels incised into bedrock offshore of contemporary Pine Island and Thwaites glaciers would have been capable of accommodating discharges of up to 8.8×10 6 m 3 s −1 . We suggest that the channels were formed by episodic discharges from subglacial lakes trapped during ice-sheet advance and retreat over multiple glacial periods. Our results document the widespread influence of episodic subglacial drainage events during past glacial periods, in particular beneath large ice streams similar to those that continue to dominate contemporary ice-sheet discharge. Text Antarc* Antarctic Antarctica Ice Sheet Pine Island West Antarctica Copernicus Publications: E-Journals Antarctic The Antarctic West Antarctica Labyrinth ENVELOPE(160.833,160.833,-77.550,-77.550) The Cryosphere 13 7 1959 1981 |
institution |
Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Outburst floods from subglacial lakes beneath the Antarctic Ice Sheet modulate ice-flow velocities over periods of months to years. Although subglacial lake drainage events have been observed from satellite-altimetric data, little is known about their role in the long-term evolution of ice-sheet basal hydrology. Here, we systematically map and model past water flow through an extensive area containing over 1000 subglacial channels and 19 former lake basins exposed on over 19 000 km 2 of seafloor by the retreat of Pine Island and Thwaites glaciers, West Antarctica. At 507 m wide and 43 m deep on average, the channels offshore of present-day Pine Island and Thwaites glaciers are approximately twice as deep, 3 times as wide, and cover an area over 400 times larger than the terrestrial meltwater channels comprising the Labyrinth in the Antarctic Dry Valleys. The channels incised into bedrock offshore of contemporary Pine Island and Thwaites glaciers would have been capable of accommodating discharges of up to 8.8×10 6 m 3 s −1 . We suggest that the channels were formed by episodic discharges from subglacial lakes trapped during ice-sheet advance and retreat over multiple glacial periods. Our results document the widespread influence of episodic subglacial drainage events during past glacial periods, in particular beneath large ice streams similar to those that continue to dominate contemporary ice-sheet discharge. |
format |
Text |
author |
Kirkham, James D. Hogan, Kelly A. Larter, Robert D. Arnold, Neil S. Nitsche, Frank O. Golledge, Nicholas R. Dowdeswell, Julian A. |
spellingShingle |
Kirkham, James D. Hogan, Kelly A. Larter, Robert D. Arnold, Neil S. Nitsche, Frank O. Golledge, Nicholas R. Dowdeswell, Julian A. Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica |
author_facet |
Kirkham, James D. Hogan, Kelly A. Larter, Robert D. Arnold, Neil S. Nitsche, Frank O. Golledge, Nicholas R. Dowdeswell, Julian A. |
author_sort |
Kirkham, James D. |
title |
Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica |
title_short |
Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica |
title_full |
Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica |
title_fullStr |
Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica |
title_full_unstemmed |
Past water flow beneath Pine Island and Thwaites glaciers, West Antarctica |
title_sort |
past water flow beneath pine island and thwaites glaciers, west antarctica |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-1959-2019 https://tc.copernicus.org/articles/13/1959/2019/ |
long_lat |
ENVELOPE(160.833,160.833,-77.550,-77.550) |
geographic |
Antarctic The Antarctic West Antarctica Labyrinth |
geographic_facet |
Antarctic The Antarctic West Antarctica Labyrinth |
genre |
Antarc* Antarctic Antarctica Ice Sheet Pine Island West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Pine Island West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-13-1959-2019 https://tc.copernicus.org/articles/13/1959/2019/ |
op_doi |
https://doi.org/10.5194/tc-13-1959-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
7 |
container_start_page |
1959 |
op_container_end_page |
1981 |
_version_ |
1766262111678234624 |