Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland
We used satellite-derived surface temperatures and time-lapse photography to infer temporal variations in the proglacial ice melange at Jakobshavn Isbræ, a large and rapidly retreating outlet glacier in Greenland. We used satellite-derived surface temperatures and time-lapse photography to infer tem...
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International Glaciological Society
2014
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ftunivalaska:oai:scholarworks.alaska.edu:11122/11187 2023-05-15T15:16:37+02:00 Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland Cassotto, Ryan Fahnestock, Mark Amundson, Jason M. Truffer, Martin Joughin, Ian 2014-09-29 http://hdl.handle.net/11122/11187 unknown International Glaciological Society Cassotto, R., M. Fahnestock, J. M. Amundson, M. Truffer, and I. Joughin (2015), Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland, J. Glaciol., 61(225), 76– 88, doi:10.3189/2015JoG13J235. http://hdl.handle.net/11122/11187 Journal of Glaciology arctic glaciology calving ice/ocean interactions remote sensing sea-ice dynamics 2014 ftunivalaska https://doi.org/10.3189/2015JoG13J235 2023-02-23T21:37:38Z We used satellite-derived surface temperatures and time-lapse photography to infer temporal variations in the proglacial ice melange at Jakobshavn Isbræ, a large and rapidly retreating outlet glacier in Greenland. We used satellite-derived surface temperatures and time-lapse photography to infer temporal variations in the proglacial ice melange at Jakobshavn Isbræ, a large and rapidly retreating outlet glacier in Greenland. Freezing of the melange-covered fjord surface during winter is indicated by a decrease in fjord surface temperatures and is associated with (1) a decrease in ice melange mobility and (2) a drastic reduction in iceberg production. Vigorous calving resumes in spring, typically abruptly, following the steady up-fjord retreat of the sea-ice/ice-melange margin. An analysis of pixel displacement from time-lapse imagery demonstrates that melange motion increases prior to calving and subsequently decreases following several events. We find that secular changes in ice melange extent, character and persistence can influence iceberg calving, and therefore glacier dynamics over daily-to-monthly timescales, which, if sustained, will influence the mass balance of an ice sheet. This research was supported by funds from the Gordon and Betty Moore Foundation (GBMF2627), NASA (NNX08AN74G), the US National Science Foundation (ANT0944193 and ANS0909552) and the New Hampshire Space Grant Consortium (NNX10AL97H). We thank CH2M HILL Polar Services and Air Greenland for logistics support, and PASSCAL (Program for the Array Seismic Studies of theContinental Lithosphere) for the use of seismic instrumentation. Ian Joughin derived TerraSAR-X velocities and terminus positions from images provided by the German (DLR) space agency under NASA grant NNX08AL98A. We acknowledgethe use of Rapid Response imagery from the Land Atmosphere Near-real time Capability for EOS (LANCE) system operated by the NASA/GSFC/Earth Science Data and Information System (ESDIS) with funding provided by NASA HQ. Glacier surface elevations were ... Other/Unknown Material Arctic glacier Greenland Ice Sheet Iceberg* Jakobshavn Jakobshavn isbræ Journal of Glaciology Sea ice University of Alaska: ScholarWorks@UA Arctic Greenland Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) Journal of Glaciology 61 225 76 88 |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
unknown |
topic |
arctic glaciology calving ice/ocean interactions remote sensing sea-ice dynamics |
spellingShingle |
arctic glaciology calving ice/ocean interactions remote sensing sea-ice dynamics Cassotto, Ryan Fahnestock, Mark Amundson, Jason M. Truffer, Martin Joughin, Ian Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland |
topic_facet |
arctic glaciology calving ice/ocean interactions remote sensing sea-ice dynamics |
description |
We used satellite-derived surface temperatures and time-lapse photography to infer temporal variations in the proglacial ice melange at Jakobshavn Isbræ, a large and rapidly retreating outlet glacier in Greenland. We used satellite-derived surface temperatures and time-lapse photography to infer temporal variations in the proglacial ice melange at Jakobshavn Isbræ, a large and rapidly retreating outlet glacier in Greenland. Freezing of the melange-covered fjord surface during winter is indicated by a decrease in fjord surface temperatures and is associated with (1) a decrease in ice melange mobility and (2) a drastic reduction in iceberg production. Vigorous calving resumes in spring, typically abruptly, following the steady up-fjord retreat of the sea-ice/ice-melange margin. An analysis of pixel displacement from time-lapse imagery demonstrates that melange motion increases prior to calving and subsequently decreases following several events. We find that secular changes in ice melange extent, character and persistence can influence iceberg calving, and therefore glacier dynamics over daily-to-monthly timescales, which, if sustained, will influence the mass balance of an ice sheet. This research was supported by funds from the Gordon and Betty Moore Foundation (GBMF2627), NASA (NNX08AN74G), the US National Science Foundation (ANT0944193 and ANS0909552) and the New Hampshire Space Grant Consortium (NNX10AL97H). We thank CH2M HILL Polar Services and Air Greenland for logistics support, and PASSCAL (Program for the Array Seismic Studies of theContinental Lithosphere) for the use of seismic instrumentation. Ian Joughin derived TerraSAR-X velocities and terminus positions from images provided by the German (DLR) space agency under NASA grant NNX08AL98A. We acknowledgethe use of Rapid Response imagery from the Land Atmosphere Near-real time Capability for EOS (LANCE) system operated by the NASA/GSFC/Earth Science Data and Information System (ESDIS) with funding provided by NASA HQ. Glacier surface elevations were ... |
author |
Cassotto, Ryan Fahnestock, Mark Amundson, Jason M. Truffer, Martin Joughin, Ian |
author_facet |
Cassotto, Ryan Fahnestock, Mark Amundson, Jason M. Truffer, Martin Joughin, Ian |
author_sort |
Cassotto, Ryan |
title |
Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland |
title_short |
Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland |
title_full |
Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland |
title_fullStr |
Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland |
title_full_unstemmed |
Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland |
title_sort |
seasonal and interannual variations in ice melange and its impact on terminus stability, jakobshavn isbræ, greenland |
publisher |
International Glaciological Society |
publishDate |
2014 |
url |
http://hdl.handle.net/11122/11187 |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) |
geographic |
Arctic Greenland Jakobshavn Isbræ |
geographic_facet |
Arctic Greenland Jakobshavn Isbræ |
genre |
Arctic glacier Greenland Ice Sheet Iceberg* Jakobshavn Jakobshavn isbræ Journal of Glaciology Sea ice |
genre_facet |
Arctic glacier Greenland Ice Sheet Iceberg* Jakobshavn Jakobshavn isbræ Journal of Glaciology Sea ice |
op_relation |
Cassotto, R., M. Fahnestock, J. M. Amundson, M. Truffer, and I. Joughin (2015), Seasonal and interannual variations in ice melange and its impact on terminus stability, Jakobshavn Isbræ, Greenland, J. Glaciol., 61(225), 76– 88, doi:10.3189/2015JoG13J235. http://hdl.handle.net/11122/11187 Journal of Glaciology |
op_doi |
https://doi.org/10.3189/2015JoG13J235 |
container_title |
Journal of Glaciology |
container_volume |
61 |
container_issue |
225 |
container_start_page |
76 |
op_container_end_page |
88 |
_version_ |
1766346924290473984 |