Heat flux and the North East Greenland Ice Stream
vEGU21: Gather Online | 19-30 April 2021 The prominent North East Greenland Ice Stream (NEGIS) is an exceptionally large ice stream in the Greenland Ice sheet. It is over 500 km long, originates almost at the central ice divide, and contributes significantly to overall ice drainage from the Greenlan...
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ftcsic:oai:digital.csic.es:10261/242349 2024-02-11T10:03:26+01:00 Heat flux and the North East Greenland Ice Stream Bons, P. D. de Riese, Tamara Franke, Steven Llorens, Maria-Gema Sachau, Till Stoll, Nicolas Weikusat, Ilka Zhang,Yu 2021-04-19 http://hdl.handle.net/10261/242349 unknown Publisher's version Sí http://hdl.handle.net/10261/242349 open North East Greenland Ice Stream (NEGIS) actas de congreso http://purl.org/coar/resource_type/c_f744 2021 ftcsic 2024-01-16T11:09:21Z vEGU21: Gather Online | 19-30 April 2021 The prominent North East Greenland Ice Stream (NEGIS) is an exceptionally large ice stream in the Greenland Ice sheet. It is over 500 km long, originates almost at the central ice divide, and contributes significantly to overall ice drainage from the Greenland Ice sheet. Surface velocities in the inland part of the ice stream are several times higher inside NEGIS than in the adjacent ice sheet. Modelling NEGIS is still a challenge as it remains unclear what actually causes and controls the ice stream. An elevated geothermal heat flux is one of the factors that are being considered to trigger or drive the fast flow inside NEGIS. Unfortunately, the geothermal heat flux below NEGIS and its upstream area is poorly constrained and estimates vary from close to the global average for continental crust (ca. 60 mW/m2) to values as high as almost 1000 mW/m2. The latter would cause about 10 cm/yr of melting at the base of the ice sheet. We present a brief survey of global geothermal heat flux data, especially from known hotspots, such as Iceland and Yellowstone. Heat fluxes in these areas that are known to be among the hottest on Earth rarely, if ever, exceed 300 mW/m2. A plume hotspot or its trail can therefore not cause heat fluxes at the high end of the suggested range. Other potential factors, such as hydrothermal fluid flow and radiogenic heat, also cannot raise the heat flux significantly. We conclude that the heat flux at NEGIS is very unlikely to exceed 100-150 mW/m2, and future modelling studies on NEGIS should thus be mindful of implementing realistic geothermal heat flux values. If NEGIS is not the result of an exceptionally high heat flux, we are left with the exciting challenge to find the true trigger of this fascinating structure. Conference Object East Greenland Greenland Ice Sheet Iceland Digital.CSIC (Spanish National Research Council) Greenland |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
topic |
North East Greenland Ice Stream (NEGIS) |
spellingShingle |
North East Greenland Ice Stream (NEGIS) Bons, P. D. de Riese, Tamara Franke, Steven Llorens, Maria-Gema Sachau, Till Stoll, Nicolas Weikusat, Ilka Zhang,Yu Heat flux and the North East Greenland Ice Stream |
topic_facet |
North East Greenland Ice Stream (NEGIS) |
description |
vEGU21: Gather Online | 19-30 April 2021 The prominent North East Greenland Ice Stream (NEGIS) is an exceptionally large ice stream in the Greenland Ice sheet. It is over 500 km long, originates almost at the central ice divide, and contributes significantly to overall ice drainage from the Greenland Ice sheet. Surface velocities in the inland part of the ice stream are several times higher inside NEGIS than in the adjacent ice sheet. Modelling NEGIS is still a challenge as it remains unclear what actually causes and controls the ice stream. An elevated geothermal heat flux is one of the factors that are being considered to trigger or drive the fast flow inside NEGIS. Unfortunately, the geothermal heat flux below NEGIS and its upstream area is poorly constrained and estimates vary from close to the global average for continental crust (ca. 60 mW/m2) to values as high as almost 1000 mW/m2. The latter would cause about 10 cm/yr of melting at the base of the ice sheet. We present a brief survey of global geothermal heat flux data, especially from known hotspots, such as Iceland and Yellowstone. Heat fluxes in these areas that are known to be among the hottest on Earth rarely, if ever, exceed 300 mW/m2. A plume hotspot or its trail can therefore not cause heat fluxes at the high end of the suggested range. Other potential factors, such as hydrothermal fluid flow and radiogenic heat, also cannot raise the heat flux significantly. We conclude that the heat flux at NEGIS is very unlikely to exceed 100-150 mW/m2, and future modelling studies on NEGIS should thus be mindful of implementing realistic geothermal heat flux values. If NEGIS is not the result of an exceptionally high heat flux, we are left with the exciting challenge to find the true trigger of this fascinating structure. |
format |
Conference Object |
author |
Bons, P. D. de Riese, Tamara Franke, Steven Llorens, Maria-Gema Sachau, Till Stoll, Nicolas Weikusat, Ilka Zhang,Yu |
author_facet |
Bons, P. D. de Riese, Tamara Franke, Steven Llorens, Maria-Gema Sachau, Till Stoll, Nicolas Weikusat, Ilka Zhang,Yu |
author_sort |
Bons, P. D. |
title |
Heat flux and the North East Greenland Ice Stream |
title_short |
Heat flux and the North East Greenland Ice Stream |
title_full |
Heat flux and the North East Greenland Ice Stream |
title_fullStr |
Heat flux and the North East Greenland Ice Stream |
title_full_unstemmed |
Heat flux and the North East Greenland Ice Stream |
title_sort |
heat flux and the north east greenland ice stream |
publishDate |
2021 |
url |
http://hdl.handle.net/10261/242349 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland Ice Sheet Iceland |
genre_facet |
East Greenland Greenland Ice Sheet Iceland |
op_relation |
Publisher's version Sí http://hdl.handle.net/10261/242349 |
op_rights |
open |
_version_ |
1790599670309847040 |