Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up
The floating ice shelves and glacier tongues which fringe the Antarctic continent are important because they help buttress ice flow from the ice sheet interior. Dynamic feedbacks associated with glacier calving have the potential to reduce buttressing and subsequently increase ice flow into the ocea...
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ftcopernicus:oai:publications.copernicus.org:tc52546 2023-05-15T13:54:27+02:00 Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up Miles, Bertie W. J. Stokes, Chris R. Jamieson, Stewart S. R. 2018-09-27 application/pdf https://doi.org/10.5194/tc-11-427-2017 https://tc.copernicus.org/articles/11/427/2017/ eng eng doi:10.5194/tc-11-427-2017 https://tc.copernicus.org/articles/11/427/2017/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-11-427-2017 2020-07-20T16:23:50Z The floating ice shelves and glacier tongues which fringe the Antarctic continent are important because they help buttress ice flow from the ice sheet interior. Dynamic feedbacks associated with glacier calving have the potential to reduce buttressing and subsequently increase ice flow into the ocean. However, there are few high temporal resolution studies on glacier calving, especially in East Antarctica. Here we use ENVISAT ASAR wide swath mode imagery to investigate monthly glacier terminus change across six marine-terminating outlet glaciers in Porpoise Bay (76° S, 128° E), Wilkes Land (East Antarctica), between November 2002 and March 2012. This reveals a large near-simultaneous calving event in January 2007, resulting in a total of ∼ 2900 km 2 of ice being removed from glacier tongues. We also observe the start of a similar large near-simultaneous calving event in March 2016. Our observations suggest that both of these large calving events are driven by the break-up of the multi-year sea ice which usually occupies Porpoise Bay. However, these break-up events appear to have been driven by contrasting mechanisms. We link the 2007 sea ice break-up to atmospheric circulation anomalies in December 2005 weakening the multi-year sea ice through a combination of surface melt and a change in wind direction prior to its eventual break-up in January 2007. In contrast, the 2016 break-up event is linked to the terminus of Holmes (West) Glacier pushing the multi-year sea ice further into the open ocean, making the sea ice more vulnerable to break-up. In the context of predicted future warming and the sensitivity of sea ice to changes in climate, our results highlight the importance of interactions between landfast sea ice and glacier tongue stability in East Antarctica. Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelves Sea ice Wilkes Land Copernicus Publications: E-Journals Antarctic Asar ENVELOPE(134.033,134.033,68.667,68.667) Buttress ENVELOPE(-57.083,-57.083,-63.550,-63.550) East Antarctica Porpoise Bay ENVELOPE(128.667,128.667,-66.750,-66.750) The Antarctic Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) The Cryosphere 11 1 427 442 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The floating ice shelves and glacier tongues which fringe the Antarctic continent are important because they help buttress ice flow from the ice sheet interior. Dynamic feedbacks associated with glacier calving have the potential to reduce buttressing and subsequently increase ice flow into the ocean. However, there are few high temporal resolution studies on glacier calving, especially in East Antarctica. Here we use ENVISAT ASAR wide swath mode imagery to investigate monthly glacier terminus change across six marine-terminating outlet glaciers in Porpoise Bay (76° S, 128° E), Wilkes Land (East Antarctica), between November 2002 and March 2012. This reveals a large near-simultaneous calving event in January 2007, resulting in a total of ∼ 2900 km 2 of ice being removed from glacier tongues. We also observe the start of a similar large near-simultaneous calving event in March 2016. Our observations suggest that both of these large calving events are driven by the break-up of the multi-year sea ice which usually occupies Porpoise Bay. However, these break-up events appear to have been driven by contrasting mechanisms. We link the 2007 sea ice break-up to atmospheric circulation anomalies in December 2005 weakening the multi-year sea ice through a combination of surface melt and a change in wind direction prior to its eventual break-up in January 2007. In contrast, the 2016 break-up event is linked to the terminus of Holmes (West) Glacier pushing the multi-year sea ice further into the open ocean, making the sea ice more vulnerable to break-up. In the context of predicted future warming and the sensitivity of sea ice to changes in climate, our results highlight the importance of interactions between landfast sea ice and glacier tongue stability in East Antarctica. |
format |
Text |
author |
Miles, Bertie W. J. Stokes, Chris R. Jamieson, Stewart S. R. |
spellingShingle |
Miles, Bertie W. J. Stokes, Chris R. Jamieson, Stewart S. R. Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up |
author_facet |
Miles, Bertie W. J. Stokes, Chris R. Jamieson, Stewart S. R. |
author_sort |
Miles, Bertie W. J. |
title |
Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up |
title_short |
Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up |
title_full |
Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up |
title_fullStr |
Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up |
title_full_unstemmed |
Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up |
title_sort |
simultaneous disintegration of outlet glaciers in porpoise bay (wilkes land), east antarctica, driven by sea ice break-up |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-11-427-2017 https://tc.copernicus.org/articles/11/427/2017/ |
long_lat |
ENVELOPE(134.033,134.033,68.667,68.667) ENVELOPE(-57.083,-57.083,-63.550,-63.550) ENVELOPE(128.667,128.667,-66.750,-66.750) ENVELOPE(120.000,120.000,-69.000,-69.000) |
geographic |
Antarctic Asar Buttress East Antarctica Porpoise Bay The Antarctic Wilkes Land |
geographic_facet |
Antarctic Asar Buttress East Antarctica Porpoise Bay The Antarctic Wilkes Land |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelves Sea ice Wilkes Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelves Sea ice Wilkes Land |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-11-427-2017 https://tc.copernicus.org/articles/11/427/2017/ |
op_doi |
https://doi.org/10.5194/tc-11-427-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
1 |
container_start_page |
427 |
op_container_end_page |
442 |
_version_ |
1766260328426897408 |