Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery
Systematically monitoring Greenland's outlet glaciers is central to understanding the timescales over which their flow and sea level contributions evolve. In this study we use data from the new Sentinel-1a/b satellite constellation to generate 187 velocity maps, covering four key outlet glacier...
Published in: | The Cryosphere |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Copernicus Publications
2018
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Online Access: | https://doi.org/10.5194/tc-12-2087-2018 https://www.the-cryosphere.net/12/2087/2018/tc-12-2087-2018.pdf https://doaj.org/article/91ab8cdbc941489d82a282ec44be2f54 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:91ab8cdbc941489d82a282ec44be2f54 2023-05-15T16:21:08+02:00 Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery A. Lemos A. Shepherd M. McMillan A. E. Hogg E. Hatton I. Joughin 2018-06-01 https://doi.org/10.5194/tc-12-2087-2018 https://www.the-cryosphere.net/12/2087/2018/tc-12-2087-2018.pdf https://doaj.org/article/91ab8cdbc941489d82a282ec44be2f54 en eng Copernicus Publications doi:10.5194/tc-12-2087-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/2087/2018/tc-12-2087-2018.pdf https://doaj.org/article/91ab8cdbc941489d82a282ec44be2f54 undefined The Cryosphere, Vol 12, Pp 2087-2097 (2018) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/tc-12-2087-2018 2023-01-22T17:32:56Z Systematically monitoring Greenland's outlet glaciers is central to understanding the timescales over which their flow and sea level contributions evolve. In this study we use data from the new Sentinel-1a/b satellite constellation to generate 187 velocity maps, covering four key outlet glaciers in Greenland: Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm. These data provide a new high temporal resolution record (6-day averaged solutions) of each glacier's evolution since 2014, and resolve recent seasonal speedup periods and inter-annual changes in Greenland outlet glacier speed with an estimated certainty of 10 %. We find that since 2012, Jakobshavn Isbræ has been decelerating, and now flows approximately 1250 m yr−1 (10 %), slower than 5 years previously, thus reversing an increasing trend in ice velocity that has persisted during the last decade. Despite this, we show that seasonal variability in ice velocity remains significant: up to 750 m yr−1 (14 %) at a distance of 12 km inland of the terminus. We also use our new dataset to estimate the duration of speedup periods (80–95 days) and to demonstrate a strong relationship between ice front position and ice flow at Jakobshavn Isbræ, with increases in speed of ∼ 1800 m yr−1 in response to 1 km of retreat. Elsewhere, we record significant seasonal changes in flow of up to 25 % (2015) and 18 % (2016) at Petermann Glacier and Zachariæ Isstrøm, respectively. This study provides a first demonstration of the capacity of a new era of operational radar satellites to provide frequent and timely monitoring of ice sheet flow, and to better resolve the timescales over which glacier dynamics evolve. Article in Journal/Newspaper glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Nioghalvfjerdsfjorden Petermann glacier The Cryosphere Unknown Greenland Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) Nioghalvfjerdsfjorden ENVELOPE(-21.500,-21.500,79.500,79.500) The Cryosphere 12 6 2087 2097 |
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Open Polar |
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language |
English |
topic |
geo envir |
spellingShingle |
geo envir A. Lemos A. Shepherd M. McMillan A. E. Hogg E. Hatton I. Joughin Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery |
topic_facet |
geo envir |
description |
Systematically monitoring Greenland's outlet glaciers is central to understanding the timescales over which their flow and sea level contributions evolve. In this study we use data from the new Sentinel-1a/b satellite constellation to generate 187 velocity maps, covering four key outlet glaciers in Greenland: Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm. These data provide a new high temporal resolution record (6-day averaged solutions) of each glacier's evolution since 2014, and resolve recent seasonal speedup periods and inter-annual changes in Greenland outlet glacier speed with an estimated certainty of 10 %. We find that since 2012, Jakobshavn Isbræ has been decelerating, and now flows approximately 1250 m yr−1 (10 %), slower than 5 years previously, thus reversing an increasing trend in ice velocity that has persisted during the last decade. Despite this, we show that seasonal variability in ice velocity remains significant: up to 750 m yr−1 (14 %) at a distance of 12 km inland of the terminus. We also use our new dataset to estimate the duration of speedup periods (80–95 days) and to demonstrate a strong relationship between ice front position and ice flow at Jakobshavn Isbræ, with increases in speed of ∼ 1800 m yr−1 in response to 1 km of retreat. Elsewhere, we record significant seasonal changes in flow of up to 25 % (2015) and 18 % (2016) at Petermann Glacier and Zachariæ Isstrøm, respectively. This study provides a first demonstration of the capacity of a new era of operational radar satellites to provide frequent and timely monitoring of ice sheet flow, and to better resolve the timescales over which glacier dynamics evolve. |
format |
Article in Journal/Newspaper |
author |
A. Lemos A. Shepherd M. McMillan A. E. Hogg E. Hatton I. Joughin |
author_facet |
A. Lemos A. Shepherd M. McMillan A. E. Hogg E. Hatton I. Joughin |
author_sort |
A. Lemos |
title |
Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery |
title_short |
Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery |
title_full |
Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery |
title_fullStr |
Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery |
title_full_unstemmed |
Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015–2017, from Sentinel 1-a/b SAR imagery |
title_sort |
ice velocity of jakobshavn isbræ, petermann glacier, nioghalvfjerdsfjorden, and zachariæ isstrøm, 2015–2017, from sentinel 1-a/b sar imagery |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-2087-2018 https://www.the-cryosphere.net/12/2087/2018/tc-12-2087-2018.pdf https://doaj.org/article/91ab8cdbc941489d82a282ec44be2f54 |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) ENVELOPE(-21.500,-21.500,79.500,79.500) |
geographic |
Greenland Jakobshavn Isbræ Nioghalvfjerdsfjorden |
geographic_facet |
Greenland Jakobshavn Isbræ Nioghalvfjerdsfjorden |
genre |
glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Nioghalvfjerdsfjorden Petermann glacier The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Nioghalvfjerdsfjorden Petermann glacier The Cryosphere |
op_source |
The Cryosphere, Vol 12, Pp 2087-2097 (2018) |
op_relation |
doi:10.5194/tc-12-2087-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/2087/2018/tc-12-2087-2018.pdf https://doaj.org/article/91ab8cdbc941489d82a282ec44be2f54 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-12-2087-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
6 |
container_start_page |
2087 |
op_container_end_page |
2097 |
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