Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet.
Ice-stream tributaries connect the relatively slow moving interior of the West-Antarctic Ice Sheet (WAIS) with the fast-flowing Siple Coast ice streams. Basal water underneath these ice streams reduces basal resistance and enables the fast motion of the ice. Basal melting being the only source for t...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.614.8433 2023-05-15T14:01:51+02:00 Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. Stefan Vogel Slawek Tulaczyk Ian Joughin The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.614.8433 http://www.es.ucsc.edu/~svogel/Yakutat2002-36A028.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.614.8433 http://www.es.ucsc.edu/~svogel/Yakutat2002-36A028.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.es.ucsc.edu/~svogel/Yakutat2002-36A028.pdf text ftciteseerx 2016-01-08T14:41:48Z Ice-stream tributaries connect the relatively slow moving interior of the West-Antarctic Ice Sheet (WAIS) with the fast-flowing Siple Coast ice streams. Basal water underneath these ice streams reduces basal resistance and enables the fast motion of the ice. Basal melting being the only source for this water it is important to include the distribution of basal melting and freezing into numerical models assessing the stability of the WAIS. However, it is very difficult to constrain its distribution from existing field observations. Past borehole observations confirmed the presence of a wet bed at Byrd Station in the WAIS interior and at different locations within Siple Coast ice streams. However, the recent discovery of a 12-to-25-m-thick sediment-laden bubble-free basal ice layer at the UpC boreholes indicates that basal freezing is either currently occurring or had occurred upstream during the last glacial-interglacial cycle. We use a flowline model of ice thermodynamics to assess and quantify the spatial and temporal distribution of basal melting and freezing beneath Ice Stream C tributaries taking into account the geothermal flux, shear heating and heat conduction away from the bed. Under the assumption that the ice was moving over a weak bed (τb = 1-10 kPa) our model is able to reproduce a layer of frozen-on ice similar in thickness to the UpC Sticky Spot basal ice layer. Increased basal melting in the early Holocene possibly could have initiated the Holocene decay of the WAIS, whereas increased freezing rates over the past few thousand years could have decreased the amount of basal water in the system, resulting in a strengthening of the bed. This is consistent with current force-budget calculations for ice-stream tributaries and with observed stoppages and slowdowns of ice streams. Text Antarc* Antarctic Ice Sheet Ice Stream C Unknown Antarctic Byrd Byrd Station ENVELOPE(-119.533,-119.533,-80.017,-80.017) Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) West Antarctic Ice Sheet |
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Open Polar |
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Unknown |
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ftciteseerx |
language |
English |
description |
Ice-stream tributaries connect the relatively slow moving interior of the West-Antarctic Ice Sheet (WAIS) with the fast-flowing Siple Coast ice streams. Basal water underneath these ice streams reduces basal resistance and enables the fast motion of the ice. Basal melting being the only source for this water it is important to include the distribution of basal melting and freezing into numerical models assessing the stability of the WAIS. However, it is very difficult to constrain its distribution from existing field observations. Past borehole observations confirmed the presence of a wet bed at Byrd Station in the WAIS interior and at different locations within Siple Coast ice streams. However, the recent discovery of a 12-to-25-m-thick sediment-laden bubble-free basal ice layer at the UpC boreholes indicates that basal freezing is either currently occurring or had occurred upstream during the last glacial-interglacial cycle. We use a flowline model of ice thermodynamics to assess and quantify the spatial and temporal distribution of basal melting and freezing beneath Ice Stream C tributaries taking into account the geothermal flux, shear heating and heat conduction away from the bed. Under the assumption that the ice was moving over a weak bed (τb = 1-10 kPa) our model is able to reproduce a layer of frozen-on ice similar in thickness to the UpC Sticky Spot basal ice layer. Increased basal melting in the early Holocene possibly could have initiated the Holocene decay of the WAIS, whereas increased freezing rates over the past few thousand years could have decreased the amount of basal water in the system, resulting in a strengthening of the bed. This is consistent with current force-budget calculations for ice-stream tributaries and with observed stoppages and slowdowns of ice streams. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Stefan Vogel Slawek Tulaczyk Ian Joughin |
spellingShingle |
Stefan Vogel Slawek Tulaczyk Ian Joughin Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. |
author_facet |
Stefan Vogel Slawek Tulaczyk Ian Joughin |
author_sort |
Stefan Vogel |
title |
Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. |
title_short |
Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. |
title_full |
Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. |
title_fullStr |
Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. |
title_full_unstemmed |
Distribution of basal melting and freezing beneath tributaries of Ice Stream C: Implication for the Holocene decay of the West Antarctic Ice Sheet. |
title_sort |
distribution of basal melting and freezing beneath tributaries of ice stream c: implication for the holocene decay of the west antarctic ice sheet. |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.614.8433 http://www.es.ucsc.edu/~svogel/Yakutat2002-36A028.pdf |
long_lat |
ENVELOPE(-119.533,-119.533,-80.017,-80.017) ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
Antarctic Byrd Byrd Station Siple Siple Coast West Antarctic Ice Sheet |
geographic_facet |
Antarctic Byrd Byrd Station Siple Siple Coast West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Ice Sheet Ice Stream C |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Stream C |
op_source |
http://www.es.ucsc.edu/~svogel/Yakutat2002-36A028.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.614.8433 http://www.es.ucsc.edu/~svogel/Yakutat2002-36A028.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766271910710083584 |