From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model
>Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermomechanically coupled model on 1 km horizontal re...
Published in: | The Cryosphere |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2017
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-11-1913-2017 https://doaj.org/article/e0055a6fad764186be7cda35a1e230c7 |
id |
ftdoajarticles:oai:doaj.org/article:e0055a6fad764186be7cda35a1e230c7 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:e0055a6fad764186be7cda35a1e230c7 2023-05-15T13:52:25+02:00 From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model J. Feldmann A. Levermann 2017-08-01T00:00:00Z https://doi.org/10.5194/tc-11-1913-2017 https://doaj.org/article/e0055a6fad764186be7cda35a1e230c7 EN eng Copernicus Publications https://www.the-cryosphere.net/11/1913/2017/tc-11-1913-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-11-1913-2017 1994-0416 1994-0424 https://doaj.org/article/e0055a6fad764186be7cda35a1e230c7 The Cryosphere, Vol 11, Pp 1913-1932 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-1913-2017 2022-12-31T00:49:19Z >Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermomechanically coupled model on 1 km horizontal resolution includes an enthalpy-based formulation of the thermodynamics, a nonlinear stress-balance-based sliding law and a very simple subglacial hydrology. The simulated unforced surging is characterized by rapid ice streaming through a bed trough, resulting in abrupt discharge of ice across the grounding line which is eventually calved into the ocean. We visualize the central feedbacks that dominate the subsequent phases of ice buildup, surge and stabilization which emerge from the interaction between ice dynamics, thermodynamics and the subglacial till layer. Results from the variation of surface mass balance and basal roughness suggest that ice sheets of medium thickness may be more susceptible to surging than relatively thin or thick ones for which the surge feedback loop is damped. We also investigate the influence of different basal sliding laws (ranging from purely plastic to nonlinear to linear) on possible surging. The presented mechanisms underlying our simulations of self-maintained, periodic ice growth and destabilization may play a role in large-scale ice-sheet surging, such as the surging of the Laurentide Ice Sheet, which is associated with Heinrich events, and ice-stream shutdown and reactivation, such as observed in the Siple Coast region of West Antarctica. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica Directory of Open Access Journals: DOAJ Articles West Antarctica Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) The Cryosphere 11 4 1913 1932 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 J. Feldmann A. Levermann From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
>Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermomechanically coupled model on 1 km horizontal resolution includes an enthalpy-based formulation of the thermodynamics, a nonlinear stress-balance-based sliding law and a very simple subglacial hydrology. The simulated unforced surging is characterized by rapid ice streaming through a bed trough, resulting in abrupt discharge of ice across the grounding line which is eventually calved into the ocean. We visualize the central feedbacks that dominate the subsequent phases of ice buildup, surge and stabilization which emerge from the interaction between ice dynamics, thermodynamics and the subglacial till layer. Results from the variation of surface mass balance and basal roughness suggest that ice sheets of medium thickness may be more susceptible to surging than relatively thin or thick ones for which the surge feedback loop is damped. We also investigate the influence of different basal sliding laws (ranging from purely plastic to nonlinear to linear) on possible surging. The presented mechanisms underlying our simulations of self-maintained, periodic ice growth and destabilization may play a role in large-scale ice-sheet surging, such as the surging of the Laurentide Ice Sheet, which is associated with Heinrich events, and ice-stream shutdown and reactivation, such as observed in the Siple Coast region of West Antarctica. |
format |
Article in Journal/Newspaper |
author |
J. Feldmann A. Levermann |
author_facet |
J. Feldmann A. Levermann |
author_sort |
J. Feldmann |
title |
From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model |
title_short |
From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model |
title_full |
From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model |
title_fullStr |
From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model |
title_full_unstemmed |
From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the Parallel Ice Sheet Model |
title_sort |
from cyclic ice streaming to heinrich-like events: the grow-and-surge instability in the parallel ice sheet model |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-1913-2017 https://doaj.org/article/e0055a6fad764186be7cda35a1e230c7 |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
West Antarctica Siple Siple Coast |
geographic_facet |
West Antarctica Siple Siple Coast |
genre |
Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica |
op_source |
The Cryosphere, Vol 11, Pp 1913-1932 (2017) |
op_relation |
https://www.the-cryosphere.net/11/1913/2017/tc-11-1913-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-11-1913-2017 1994-0416 1994-0424 https://doaj.org/article/e0055a6fad764186be7cda35a1e230c7 |
op_doi |
https://doi.org/10.5194/tc-11-1913-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
4 |
container_start_page |
1913 |
op_container_end_page |
1932 |
_version_ |
1766256691848937472 |