Tidewater glacier response to individual calving events
Tidewater glaciers have been observed to experience instantaneous, stepwise increases in velocity during iceberg-calving events due to a loss of resistive stresses. These changes in stress can potentially impact tidewater glacier stability by promoting additional calving and affecting the viscous de...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/12861 2023-05-15T16:57:10+02:00 Tidewater glacier response to individual calving events Amundson, Jason M. Truffer, Martin Zwinger, Thomas 2022-03-15 http://hdl.handle.net/11122/12861 en_US eng Cambridge University Press Amundson JM, Truffer M, Zwinger T (2022). Tidewater glacier response to individual calving events. Journal of Glaciology 1–10. https://doi.org/10.1017/ jog.2022.26 http://hdl.handle.net/11122/12861 Journal of Glaciology Tidewater glaciers Calving Velocity Iceberg-calving events Perturbation theory Article 2022 ftunivalaska 2023-02-23T21:38:01Z Tidewater glaciers have been observed to experience instantaneous, stepwise increases in velocity during iceberg-calving events due to a loss of resistive stresses. These changes in stress can potentially impact tidewater glacier stability by promoting additional calving and affecting the viscous delivery of ice to the terminus. Using flow models and perturbation theory, we demonstrate that calving events and subsequent terminus readvance produce quasi-periodic, sawtooth oscillations in stress that originate at the terminus and propagate upstream. The stress perturbations travel at speeds much greater than the glacier velocities and, for laterally resisted glaciers, rapidly decay within a few ice thickness of the terminus. Consequently, because terminus fluctuations due to individual calving events tend to be much higher frequency than climate variations, individual calving events have little direct impact on the viscous delivery of ice to the terminus. This suggests that the primary mechanism by which calving events can trigger instability is by causing fluctuations in stress that weaken the ice and lead to additional calving and sustained terminus retreat. Our results further demonstrate a stronger response to calving events in simulations that include the full stress tensor, highlighting the importance of accounting for higher order stresses when developing calving parameterizations. © The Author(s), 2022. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. Yes Article in Journal/Newspaper Journal of Glaciology Tidewater University of Alaska: ScholarWorks@UA |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Tidewater glaciers Calving Velocity Iceberg-calving events Perturbation theory |
spellingShingle |
Tidewater glaciers Calving Velocity Iceberg-calving events Perturbation theory Amundson, Jason M. Truffer, Martin Zwinger, Thomas Tidewater glacier response to individual calving events |
topic_facet |
Tidewater glaciers Calving Velocity Iceberg-calving events Perturbation theory |
description |
Tidewater glaciers have been observed to experience instantaneous, stepwise increases in velocity during iceberg-calving events due to a loss of resistive stresses. These changes in stress can potentially impact tidewater glacier stability by promoting additional calving and affecting the viscous delivery of ice to the terminus. Using flow models and perturbation theory, we demonstrate that calving events and subsequent terminus readvance produce quasi-periodic, sawtooth oscillations in stress that originate at the terminus and propagate upstream. The stress perturbations travel at speeds much greater than the glacier velocities and, for laterally resisted glaciers, rapidly decay within a few ice thickness of the terminus. Consequently, because terminus fluctuations due to individual calving events tend to be much higher frequency than climate variations, individual calving events have little direct impact on the viscous delivery of ice to the terminus. This suggests that the primary mechanism by which calving events can trigger instability is by causing fluctuations in stress that weaken the ice and lead to additional calving and sustained terminus retreat. Our results further demonstrate a stronger response to calving events in simulations that include the full stress tensor, highlighting the importance of accounting for higher order stresses when developing calving parameterizations. © The Author(s), 2022. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. Yes |
format |
Article in Journal/Newspaper |
author |
Amundson, Jason M. Truffer, Martin Zwinger, Thomas |
author_facet |
Amundson, Jason M. Truffer, Martin Zwinger, Thomas |
author_sort |
Amundson, Jason M. |
title |
Tidewater glacier response to individual calving events |
title_short |
Tidewater glacier response to individual calving events |
title_full |
Tidewater glacier response to individual calving events |
title_fullStr |
Tidewater glacier response to individual calving events |
title_full_unstemmed |
Tidewater glacier response to individual calving events |
title_sort |
tidewater glacier response to individual calving events |
publisher |
Cambridge University Press |
publishDate |
2022 |
url |
http://hdl.handle.net/11122/12861 |
genre |
Journal of Glaciology Tidewater |
genre_facet |
Journal of Glaciology Tidewater |
op_relation |
Amundson JM, Truffer M, Zwinger T (2022). Tidewater glacier response to individual calving events. Journal of Glaciology 1–10. https://doi.org/10.1017/ jog.2022.26 http://hdl.handle.net/11122/12861 Journal of Glaciology |
_version_ |
1766048444439330816 |