Tidewater glacier surges initiated at the terminus
There have been numerous reports that surges of tidewater glaciers in Svalbard were initiated at the terminus and propagated up‐glacier, in contrast with downglacier‐propagating surges of land‐terminating glaciers. Most of these surges were poorly documented, and the cause of this behavior was unkno...
Published in: | Journal of Geophysical Research: Earth Surface |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2018
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/tidewater-glacier-surges-initiated-at-the-terminus(4eb24f26-fac0-4d77-b48a-f73c25088566).html https://doi.org/10.1029/2017JF004358 https://research-repository.st-andrews.ac.uk/bitstream/10023/16328/1/Benn_2018_JGRES_Tidewater_VoR.pdf |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/4eb24f26-fac0-4d77-b48a-f73c25088566 2023-05-15T16:22:08+02:00 Tidewater glacier surges initiated at the terminus Sevestre, Heïdi Benn, Douglas I. Luckman, Adrian Nuth, Christopher Kohler, Jack Lindbäck, Katrin Pettersson, Rickard 2018-04-26 application/pdf https://risweb.st-andrews.ac.uk/portal/en/researchoutput/tidewater-glacier-surges-initiated-at-the-terminus(4eb24f26-fac0-4d77-b48a-f73c25088566).html https://doi.org/10.1029/2017JF004358 https://research-repository.st-andrews.ac.uk/bitstream/10023/16328/1/Benn_2018_JGRES_Tidewater_VoR.pdf eng eng info:eu-repo/semantics/openAccess Sevestre , H , Benn , D I , Luckman , A , Nuth , C , Kohler , J , Lindbäck , K & Pettersson , R 2018 , ' Tidewater glacier surges initiated at the terminus ' , Journal of Geophysical Research - Earth Surface , vol. In press . https://doi.org/10.1029/2017JF004358 Glaciers Surges Tidewater Svalbard Remote sensing Dynamics article 2018 ftunstandrewcris https://doi.org/10.1029/2017JF004358 2022-06-02T07:48:35Z There have been numerous reports that surges of tidewater glaciers in Svalbard were initiated at the terminus and propagated up‐glacier, in contrast with downglacier‐propagating surges of land‐terminating glaciers. Most of these surges were poorly documented, and the cause of this behavior was unknown. We present detailed data on the recent surges of two tidewater glaciers, Aavatsmarkbreen and Wahlenbergbreen in Svalbard. High‐resolution time‐series of glacier velocities and evolution of crevasse patterns show that both surges propagated up‐glacier in abrupt steps. Prior to the surges, both glaciers underwent retreat and steepening, and in the case of Aavatsmarkbreen, we demonstrate that this was accompanied by a large increase in driving stress in the terminal zone. The surges developed in response to two distinct processes. 1) During the late quiescent phase, internal thermodynamic processes and/or retreat from a pinning point caused acceleration of the glacier front, leading to the development of terminal crevasse fields. 2) Crevasses allowed surface melt‐ and rain‐water to access the bed, causing flow acceleration and development of new crevasses up‐glacier. Upward migration of the surge coincided with stepwise expansion of the crevasse field. Geometric changes near the terminus of these glaciers appear to have led to greater strain heating, water production and storage at the glacier bed. Water routing via crevasses likely plays an important role in the evolution of surges. The distinction between internally triggered surges and externally triggered speed‐ups may not be straightforward. The behavior of these glaciers can be understood in terms of the enthalpy cycle model. Article in Journal/Newspaper glacier Svalbard Tidewater University of St Andrews: Research Portal Aavatsmarkbreen ENVELOPE(12.120,12.120,78.704,78.704) Svalbard Wahlenbergbreen ENVELOPE(14.283,14.283,78.483,78.483) Journal of Geophysical Research: Earth Surface 123 5 1035 1051 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
Glaciers Surges Tidewater Svalbard Remote sensing Dynamics |
spellingShingle |
Glaciers Surges Tidewater Svalbard Remote sensing Dynamics Sevestre, Heïdi Benn, Douglas I. Luckman, Adrian Nuth, Christopher Kohler, Jack Lindbäck, Katrin Pettersson, Rickard Tidewater glacier surges initiated at the terminus |
topic_facet |
Glaciers Surges Tidewater Svalbard Remote sensing Dynamics |
description |
There have been numerous reports that surges of tidewater glaciers in Svalbard were initiated at the terminus and propagated up‐glacier, in contrast with downglacier‐propagating surges of land‐terminating glaciers. Most of these surges were poorly documented, and the cause of this behavior was unknown. We present detailed data on the recent surges of two tidewater glaciers, Aavatsmarkbreen and Wahlenbergbreen in Svalbard. High‐resolution time‐series of glacier velocities and evolution of crevasse patterns show that both surges propagated up‐glacier in abrupt steps. Prior to the surges, both glaciers underwent retreat and steepening, and in the case of Aavatsmarkbreen, we demonstrate that this was accompanied by a large increase in driving stress in the terminal zone. The surges developed in response to two distinct processes. 1) During the late quiescent phase, internal thermodynamic processes and/or retreat from a pinning point caused acceleration of the glacier front, leading to the development of terminal crevasse fields. 2) Crevasses allowed surface melt‐ and rain‐water to access the bed, causing flow acceleration and development of new crevasses up‐glacier. Upward migration of the surge coincided with stepwise expansion of the crevasse field. Geometric changes near the terminus of these glaciers appear to have led to greater strain heating, water production and storage at the glacier bed. Water routing via crevasses likely plays an important role in the evolution of surges. The distinction between internally triggered surges and externally triggered speed‐ups may not be straightforward. The behavior of these glaciers can be understood in terms of the enthalpy cycle model. |
format |
Article in Journal/Newspaper |
author |
Sevestre, Heïdi Benn, Douglas I. Luckman, Adrian Nuth, Christopher Kohler, Jack Lindbäck, Katrin Pettersson, Rickard |
author_facet |
Sevestre, Heïdi Benn, Douglas I. Luckman, Adrian Nuth, Christopher Kohler, Jack Lindbäck, Katrin Pettersson, Rickard |
author_sort |
Sevestre, Heïdi |
title |
Tidewater glacier surges initiated at the terminus |
title_short |
Tidewater glacier surges initiated at the terminus |
title_full |
Tidewater glacier surges initiated at the terminus |
title_fullStr |
Tidewater glacier surges initiated at the terminus |
title_full_unstemmed |
Tidewater glacier surges initiated at the terminus |
title_sort |
tidewater glacier surges initiated at the terminus |
publishDate |
2018 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/tidewater-glacier-surges-initiated-at-the-terminus(4eb24f26-fac0-4d77-b48a-f73c25088566).html https://doi.org/10.1029/2017JF004358 https://research-repository.st-andrews.ac.uk/bitstream/10023/16328/1/Benn_2018_JGRES_Tidewater_VoR.pdf |
long_lat |
ENVELOPE(12.120,12.120,78.704,78.704) ENVELOPE(14.283,14.283,78.483,78.483) |
geographic |
Aavatsmarkbreen Svalbard Wahlenbergbreen |
geographic_facet |
Aavatsmarkbreen Svalbard Wahlenbergbreen |
genre |
glacier Svalbard Tidewater |
genre_facet |
glacier Svalbard Tidewater |
op_source |
Sevestre , H , Benn , D I , Luckman , A , Nuth , C , Kohler , J , Lindbäck , K & Pettersson , R 2018 , ' Tidewater glacier surges initiated at the terminus ' , Journal of Geophysical Research - Earth Surface , vol. In press . https://doi.org/10.1029/2017JF004358 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2017JF004358 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
123 |
container_issue |
5 |
container_start_page |
1035 |
op_container_end_page |
1051 |
_version_ |
1766010106646888448 |