Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers
Englacial cave systems were mapped using speleological techniques in three debris-covered glaciers in the Khumbu Himal, Nepal. Detailed three-dimensional mapping of the cave systems and observations of relationships with structures in the surrounding ice show conduits formed by a mechanism directly...
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/2d29ee0c-24ce-41a2-b01a-ceeda857f3f1 2023-05-15T16:57:28+02:00 Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers Gulley, J Benn, Douglas Iain 2007-08 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/structual-control-of-englacial-drainage-systems-in-himalayan-debriscovered-glaciers(2d29ee0c-24ce-41a2-b01a-ceeda857f3f1).html http://www.scopus.com/inward/record.url?scp=37549011387&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Gulley , J & Benn , D I 2007 , ' Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers ' , Journal of Glaciology , vol. 53 , no. 182 , pp. 399-412 . TEMPERATE GLACIERS WATER-FLOW ICE STORGLACIAREN ENVIRONMENTS HAZARDS SWEDEN RADAR article 2007 ftunstandrewcris 2021-12-26T14:14:13Z Englacial cave systems were mapped using speleological techniques in three debris-covered glaciers in the Khumbu Himal, Nepal. Detailed three-dimensional mapping of the cave systems and observations of relationships with structures in the surrounding ice show conduits formed by a mechanism directly analogous to speleogenesis in limestone karst. The highest, oldest parts of all passages developed along debris-filled crevasse traces with hydraulic conductivity in the range 10(-4) to 10(-5) m s(-1). Conduits form when these hydraulically efficient pathways bridge between areas with different hydraulic potential. They then evolve by grading (through head-ward migration of nick points and vertical incision) to local base level, often the surface of supraglacial lakes. Most supraglacial lakes on Himalayan glaciers are perched above the elevation of the terminal stream, and exist for a few years before draining through englacial conduits. As a result, near-surface drainage evolution is frequently interrupted by base-level fall, and conduits may record multiple phases of incision. Conduits commonly migrate laterally during incision, undermining higher levels of the ice and encouraging collapse. Voids can be created by fluvial processes and collapse of crevassed ice. The oft-noted resemblance of the surface morphology of debris-covered glaciers to karst landscapes thus extends to the subsurface, and karst hydrology provides a framework for understanding englacial drainage. Article in Journal/Newspaper Journal of Glaciology University of St Andrews: Research Portal |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
TEMPERATE GLACIERS WATER-FLOW ICE STORGLACIAREN ENVIRONMENTS HAZARDS SWEDEN RADAR |
spellingShingle |
TEMPERATE GLACIERS WATER-FLOW ICE STORGLACIAREN ENVIRONMENTS HAZARDS SWEDEN RADAR Gulley, J Benn, Douglas Iain Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers |
topic_facet |
TEMPERATE GLACIERS WATER-FLOW ICE STORGLACIAREN ENVIRONMENTS HAZARDS SWEDEN RADAR |
description |
Englacial cave systems were mapped using speleological techniques in three debris-covered glaciers in the Khumbu Himal, Nepal. Detailed three-dimensional mapping of the cave systems and observations of relationships with structures in the surrounding ice show conduits formed by a mechanism directly analogous to speleogenesis in limestone karst. The highest, oldest parts of all passages developed along debris-filled crevasse traces with hydraulic conductivity in the range 10(-4) to 10(-5) m s(-1). Conduits form when these hydraulically efficient pathways bridge between areas with different hydraulic potential. They then evolve by grading (through head-ward migration of nick points and vertical incision) to local base level, often the surface of supraglacial lakes. Most supraglacial lakes on Himalayan glaciers are perched above the elevation of the terminal stream, and exist for a few years before draining through englacial conduits. As a result, near-surface drainage evolution is frequently interrupted by base-level fall, and conduits may record multiple phases of incision. Conduits commonly migrate laterally during incision, undermining higher levels of the ice and encouraging collapse. Voids can be created by fluvial processes and collapse of crevassed ice. The oft-noted resemblance of the surface morphology of debris-covered glaciers to karst landscapes thus extends to the subsurface, and karst hydrology provides a framework for understanding englacial drainage. |
format |
Article in Journal/Newspaper |
author |
Gulley, J Benn, Douglas Iain |
author_facet |
Gulley, J Benn, Douglas Iain |
author_sort |
Gulley, J |
title |
Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers |
title_short |
Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers |
title_full |
Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers |
title_fullStr |
Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers |
title_full_unstemmed |
Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers |
title_sort |
structual control of englacial drainage systems in himalayan debris-covered glaciers |
publishDate |
2007 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/structual-control-of-englacial-drainage-systems-in-himalayan-debriscovered-glaciers(2d29ee0c-24ce-41a2-b01a-ceeda857f3f1).html http://www.scopus.com/inward/record.url?scp=37549011387&partnerID=8YFLogxK |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Gulley , J & Benn , D I 2007 , ' Structual Control of Englacial Drainage Systems in Himalayan Debris-Covered Glaciers ' , Journal of Glaciology , vol. 53 , no. 182 , pp. 399-412 . |
op_rights |
info:eu-repo/semantics/restrictedAccess |
_version_ |
1766049028758306816 |