A case for cold-based continental ice sheets — a transient thermal model
Abstract A finite-difference numerical model is used to simulate the temperature profile at the center of an ice sheet throughout the course of a glaciation. The ice sheet is gradually built to a thickness of 3000 m over about 10 000 years, starting on permafrost. A geothermal heat flux is applied a...
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Language: | English |
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Cambridge University Press (CUP)
1996
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Online Access: | http://dx.doi.org/10.1017/s0022143000030513 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030513 |
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crcambridgeupr:10.1017/s0022143000030513 2024-03-03T08:45:17+00:00 A case for cold-based continental ice sheets — a transient thermal model Heine, Jan T. Mctigue, David F. 1996 http://dx.doi.org/10.1017/s0022143000030513 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030513 en eng Cambridge University Press (CUP) Journal of Glaciology volume 42, issue 140, page 37-42 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1996 crcambridgeupr https://doi.org/10.1017/s0022143000030513 2024-02-08T08:40:23Z Abstract A finite-difference numerical model is used to simulate the temperature profile at the center of an ice sheet throughout the course of a glaciation. The ice sheet is gradually built to a thickness of 3000 m over about 10 000 years, starting on permafrost. A geothermal heat flux is applied at large depth. For an initial surface temperature of –12.5°C, our model shows that basal melting occurs 72000 years after the onset of the glaciation. The important parameters determining the basal temperatures are the initial temperature of the ice and substrate, the rate of downward advection of cold ice and, to a lesser extent, the thickness of the ice sheet. The growth history of the ice sheet does not significantly influence the time at which basal melting occurs. Our results show the possibility that the central parts of the continental ice sheets were cold-based for a significant part of their existence. Heating due to the geothermal heat flux cannot account for basal melting during most or all of a glacial cycle. These results may help to explain the existence of preserved land forms under the ice sheets. Article in Journal/Newspaper Ice Ice Sheet Journal of Glaciology permafrost Cambridge University Press Journal of Glaciology 42 140 37 42 |
institution |
Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Heine, Jan T. Mctigue, David F. A case for cold-based continental ice sheets — a transient thermal model |
topic_facet |
Earth-Surface Processes |
description |
Abstract A finite-difference numerical model is used to simulate the temperature profile at the center of an ice sheet throughout the course of a glaciation. The ice sheet is gradually built to a thickness of 3000 m over about 10 000 years, starting on permafrost. A geothermal heat flux is applied at large depth. For an initial surface temperature of –12.5°C, our model shows that basal melting occurs 72000 years after the onset of the glaciation. The important parameters determining the basal temperatures are the initial temperature of the ice and substrate, the rate of downward advection of cold ice and, to a lesser extent, the thickness of the ice sheet. The growth history of the ice sheet does not significantly influence the time at which basal melting occurs. Our results show the possibility that the central parts of the continental ice sheets were cold-based for a significant part of their existence. Heating due to the geothermal heat flux cannot account for basal melting during most or all of a glacial cycle. These results may help to explain the existence of preserved land forms under the ice sheets. |
format |
Article in Journal/Newspaper |
author |
Heine, Jan T. Mctigue, David F. |
author_facet |
Heine, Jan T. Mctigue, David F. |
author_sort |
Heine, Jan T. |
title |
A case for cold-based continental ice sheets — a transient thermal model |
title_short |
A case for cold-based continental ice sheets — a transient thermal model |
title_full |
A case for cold-based continental ice sheets — a transient thermal model |
title_fullStr |
A case for cold-based continental ice sheets — a transient thermal model |
title_full_unstemmed |
A case for cold-based continental ice sheets — a transient thermal model |
title_sort |
case for cold-based continental ice sheets — a transient thermal model |
publisher |
Cambridge University Press (CUP) |
publishDate |
1996 |
url |
http://dx.doi.org/10.1017/s0022143000030513 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000030513 |
genre |
Ice Ice Sheet Journal of Glaciology permafrost |
genre_facet |
Ice Ice Sheet Journal of Glaciology permafrost |
op_source |
Journal of Glaciology volume 42, issue 140, page 37-42 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000030513 |
container_title |
Journal of Glaciology |
container_volume |
42 |
container_issue |
140 |
container_start_page |
37 |
op_container_end_page |
42 |
_version_ |
1792500812560203776 |