Recent, very rapid retreat of a temperate glacier in SE Iceland
I celand's glaciers are particularly sensitive to climate change, and their margins respond to trends in air temperature. Most Icelandic glaciers have been in retreat since c . 1990, and almost all since 1995. Using ice‐front measurements, photographic and geomorphological evidence, we examined...
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crwiley:10.1111/bor.12014 2024-06-23T07:53:03+00:00 Recent, very rapid retreat of a temperate glacier in SE Iceland Bradwell, Tom Sigurđsson, Oddur Everest, Jez 2013 http://dx.doi.org/10.1111/bor.12014 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12014 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12014 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12014 en eng Wiley http://creativecommons.org/licenses/by/3.0/ Boreas volume 42, issue 4, page 959-973 ISSN 0300-9483 1502-3885 journal-article 2013 crwiley https://doi.org/10.1111/bor.12014 2024-06-13T04:20:55Z I celand's glaciers are particularly sensitive to climate change, and their margins respond to trends in air temperature. Most Icelandic glaciers have been in retreat since c . 1990, and almost all since 1995. Using ice‐front measurements, photographic and geomorphological evidence, we examined the record of ice‐front fluctuations of V irkisjökull– F alljökull, a steep high‐mass‐turnover outlet glacier in maritime SE I celand, in order to place recent changes in a longer‐term (80‐year) context. Detailed geomorphological mapping identifies two suites of annual push moraines: one suite formed between c . 1935 and 1945, supported by lichenometric dating; the other between 1990 and 2004. Using moraine spacing as a proxy for ice‐front retreat rates, we show that average retreat rates during the 1930s and 1940s (28 m a −1 ) were twice as high as during the period from 1990 to 2004 (14 m a −1 ). Furthermore, we show that both suites of annual moraines are associated with above‐average summer temperatures. Since 2005, however, retreat rates have increased considerably – averaging 35 m a −1 – with the last 5 years representing the greatest amount of ice‐front retreat (∼190 m) in any 5‐year period since measurements began in 1932. We propose that this recent, rapid, ice‐front retreat and thinning in a decade of unusually warm summers has resulted in a glaciological threshold being breached, with subsequent large‐scale stagnation of the glacier terminus (i.e. no forward movement) and the cessation of annual push‐moraine formation. Breaching this threshold has, we suggest, caused further very rapid non‐uniform retreat and downwasting since 2005 via a system feedback between surface melting, glacier thinning, decreased driving stress and decreased forward motion. Article in Journal/Newspaper glacier Iceland Wiley Online Library Boreas 42 4 959 973 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
I celand's glaciers are particularly sensitive to climate change, and their margins respond to trends in air temperature. Most Icelandic glaciers have been in retreat since c . 1990, and almost all since 1995. Using ice‐front measurements, photographic and geomorphological evidence, we examined the record of ice‐front fluctuations of V irkisjökull– F alljökull, a steep high‐mass‐turnover outlet glacier in maritime SE I celand, in order to place recent changes in a longer‐term (80‐year) context. Detailed geomorphological mapping identifies two suites of annual push moraines: one suite formed between c . 1935 and 1945, supported by lichenometric dating; the other between 1990 and 2004. Using moraine spacing as a proxy for ice‐front retreat rates, we show that average retreat rates during the 1930s and 1940s (28 m a −1 ) were twice as high as during the period from 1990 to 2004 (14 m a −1 ). Furthermore, we show that both suites of annual moraines are associated with above‐average summer temperatures. Since 2005, however, retreat rates have increased considerably – averaging 35 m a −1 – with the last 5 years representing the greatest amount of ice‐front retreat (∼190 m) in any 5‐year period since measurements began in 1932. We propose that this recent, rapid, ice‐front retreat and thinning in a decade of unusually warm summers has resulted in a glaciological threshold being breached, with subsequent large‐scale stagnation of the glacier terminus (i.e. no forward movement) and the cessation of annual push‐moraine formation. Breaching this threshold has, we suggest, caused further very rapid non‐uniform retreat and downwasting since 2005 via a system feedback between surface melting, glacier thinning, decreased driving stress and decreased forward motion. |
format |
Article in Journal/Newspaper |
author |
Bradwell, Tom Sigurđsson, Oddur Everest, Jez |
spellingShingle |
Bradwell, Tom Sigurđsson, Oddur Everest, Jez Recent, very rapid retreat of a temperate glacier in SE Iceland |
author_facet |
Bradwell, Tom Sigurđsson, Oddur Everest, Jez |
author_sort |
Bradwell, Tom |
title |
Recent, very rapid retreat of a temperate glacier in SE Iceland |
title_short |
Recent, very rapid retreat of a temperate glacier in SE Iceland |
title_full |
Recent, very rapid retreat of a temperate glacier in SE Iceland |
title_fullStr |
Recent, very rapid retreat of a temperate glacier in SE Iceland |
title_full_unstemmed |
Recent, very rapid retreat of a temperate glacier in SE Iceland |
title_sort |
recent, very rapid retreat of a temperate glacier in se iceland |
publisher |
Wiley |
publishDate |
2013 |
url |
http://dx.doi.org/10.1111/bor.12014 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12014 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12014 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12014 |
genre |
glacier Iceland |
genre_facet |
glacier Iceland |
op_source |
Boreas volume 42, issue 4, page 959-973 ISSN 0300-9483 1502-3885 |
op_rights |
http://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.1111/bor.12014 |
container_title |
Boreas |
container_volume |
42 |
container_issue |
4 |
container_start_page |
959 |
op_container_end_page |
973 |
_version_ |
1802644527032303616 |