Radar evidence of ponded subglacial water in Greenland
The thermal state at the bed of a large ice sheet is a critical boundary condition governing its future evolution. Radar surveys provide an opportunity for direct but remote observation of the ice-sheet bed, and therefore offer a means of constraining numerical ice-sheet models at the ice–bed interf...
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Cambridge University Press
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ftdoajarticles:oai:doaj.org/article:3d62570e8e5143bf9f76da97eb2c424c 2023-05-15T14:57:41+02:00 Radar evidence of ponded subglacial water in Greenland GORDON K. A. OSWALD SOROUSH REZVANBEHBAHANI LEIGH A. STEARNS 2018-10-01T00:00:00Z https://doi.org/10.1017/jog.2018.60 https://doaj.org/article/3d62570e8e5143bf9f76da97eb2c424c EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143018000606/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.60 0022-1430 1727-5652 https://doaj.org/article/3d62570e8e5143bf9f76da97eb2c424c Journal of Glaciology, Vol 64, Pp 711-729 (2018) Arctic glaciology ice and climate melt-basal radio-echo sounding Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2018 ftdoajarticles https://doi.org/10.1017/jog.2018.60 2023-03-12T01:30:59Z The thermal state at the bed of a large ice sheet is a critical boundary condition governing its future evolution. Radar surveys provide an opportunity for direct but remote observation of the ice-sheet bed, and therefore offer a means of constraining numerical ice-sheet models at the ice–bed interface. Here we have processed results of radar surveys of the Greenland Ice Sheet undertaken by the Program for Arctic Regional Climate Assessment (PARCA) between 1999 and 2003, to explore this opportunity. We consider the robustness of the measurements in the context of uncertain dielectric losses in the ice sheet, concluding that the observed radar signal characteristics reflect the character of the bed itself rather than that of uncertain englacial absorption. However, the identification of thaw is restricted to areas where subglacial water has sufficient depth to influence the radar reflection. We derive a map of inferred areas of subglacial thaw, and compare our results with other studies predicting regions with temperate bed. We show that in many areas the radar inferences of ponded water lie within areas predicted to be thawed by modelling and radiostratigraphy. There is clear disagreement in certain areas, suggesting the presence of high geothermal flux anomalies. Article in Journal/Newspaper Arctic Arctic Regional Climate Assessment Greenland Ice Sheet Journal of Glaciology PARCA Program for Arctic Regional Climate Assessment Directory of Open Access Journals: DOAJ Articles Arctic Greenland Journal of Glaciology 64 247 711 729 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic glaciology ice and climate melt-basal radio-echo sounding Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Arctic glaciology ice and climate melt-basal radio-echo sounding Environmental sciences GE1-350 Meteorology. Climatology QC851-999 GORDON K. A. OSWALD SOROUSH REZVANBEHBAHANI LEIGH A. STEARNS Radar evidence of ponded subglacial water in Greenland |
topic_facet |
Arctic glaciology ice and climate melt-basal radio-echo sounding Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
The thermal state at the bed of a large ice sheet is a critical boundary condition governing its future evolution. Radar surveys provide an opportunity for direct but remote observation of the ice-sheet bed, and therefore offer a means of constraining numerical ice-sheet models at the ice–bed interface. Here we have processed results of radar surveys of the Greenland Ice Sheet undertaken by the Program for Arctic Regional Climate Assessment (PARCA) between 1999 and 2003, to explore this opportunity. We consider the robustness of the measurements in the context of uncertain dielectric losses in the ice sheet, concluding that the observed radar signal characteristics reflect the character of the bed itself rather than that of uncertain englacial absorption. However, the identification of thaw is restricted to areas where subglacial water has sufficient depth to influence the radar reflection. We derive a map of inferred areas of subglacial thaw, and compare our results with other studies predicting regions with temperate bed. We show that in many areas the radar inferences of ponded water lie within areas predicted to be thawed by modelling and radiostratigraphy. There is clear disagreement in certain areas, suggesting the presence of high geothermal flux anomalies. |
format |
Article in Journal/Newspaper |
author |
GORDON K. A. OSWALD SOROUSH REZVANBEHBAHANI LEIGH A. STEARNS |
author_facet |
GORDON K. A. OSWALD SOROUSH REZVANBEHBAHANI LEIGH A. STEARNS |
author_sort |
GORDON K. A. OSWALD |
title |
Radar evidence of ponded subglacial water in Greenland |
title_short |
Radar evidence of ponded subglacial water in Greenland |
title_full |
Radar evidence of ponded subglacial water in Greenland |
title_fullStr |
Radar evidence of ponded subglacial water in Greenland |
title_full_unstemmed |
Radar evidence of ponded subglacial water in Greenland |
title_sort |
radar evidence of ponded subglacial water in greenland |
publisher |
Cambridge University Press |
publishDate |
2018 |
url |
https://doi.org/10.1017/jog.2018.60 https://doaj.org/article/3d62570e8e5143bf9f76da97eb2c424c |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Arctic Regional Climate Assessment Greenland Ice Sheet Journal of Glaciology PARCA Program for Arctic Regional Climate Assessment |
genre_facet |
Arctic Arctic Regional Climate Assessment Greenland Ice Sheet Journal of Glaciology PARCA Program for Arctic Regional Climate Assessment |
op_source |
Journal of Glaciology, Vol 64, Pp 711-729 (2018) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143018000606/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.60 0022-1430 1727-5652 https://doaj.org/article/3d62570e8e5143bf9f76da97eb2c424c |
op_doi |
https://doi.org/10.1017/jog.2018.60 |
container_title |
Journal of Glaciology |
container_volume |
64 |
container_issue |
247 |
container_start_page |
711 |
op_container_end_page |
729 |
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1766329812960411648 |