Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland
This paper explores changing ice–water interactions during jökulhlaups from Grænalón, a 5 × 108 m3 subaerial lake dammed by Skeiðarárjökull, Iceland. Unstable drainage of Graenalón since the early 20th century has resulted in 45 jökulhlaups whose hydrologic character has varied enormously. Geomorphi...
Published in: | Annals of Glaciology |
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International Glaciological Society
2005
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Online Access: | http://eprints.staffs.ac.uk/1733/ https://doi.org/10.3189/172756405781813771 |
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ftustaffordshire:oai:eprints.staffs.ac.uk:1733 2023-05-15T13:29:25+02:00 Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland Roberts, Matthew J. Pálsson, Finnur Gudmundsson, Magnús Tumi Björnsson, Helgi TWEED, Fiona 2005-01-01 http://eprints.staffs.ac.uk/1733/ https://doi.org/10.3189/172756405781813771 unknown International Glaciological Society Roberts, Matthew J., Pálsson, Finnur, Gudmundsson, Magnús Tumi, Björnsson, Helgi and TWEED, Fiona (2005) Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland. Annals of Glaciology, 40 (1). pp. 133-138. ISSN 02603055 F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2005 ftustaffordshire https://doi.org/10.3189/172756405781813771 2023-03-02T23:14:36Z This paper explores changing ice–water interactions during jökulhlaups from Grænalón, a 5 × 108 m3 subaerial lake dammed by Skeiðarárjökull, Iceland. Unstable drainage of Graenalón since the early 20th century has resulted in 45 jökulhlaups whose hydrologic character has varied enormously. Geomorphic observations and geophysical measurements from the inlet and outlet zones of the subglacial floodwater tract constrained the hydromechanical factors governing ice–water interactions at Grænalón. To date, three distinct drainage regimes have occurred in response to the changing surface elevation of Grænalón. Shifts from one drainage regime to another involved pronounced changes in jökulhlaup magnitude, timing and cyclicity. Present hydraulic conditions for lake drainage differ from the classical view of a pressure-coupled lake draining directly beneath an ice dam. Instead, lowamplitude drawdown occurs at regular, frequent intervals when hydrostatic pressure in a shallow, rock–ice trench enables water to flow beneath a sagging ice barrier. Floodwater exits Skeiðarárjökull in a supercooled state due to rapid hydraulic displacement from an overdeepened subglacial basin. Article in Journal/Newspaper Annals of Glaciology glacier Iceland Staffordshire University: STORE - Staffordshire Online Repository Dammed Lake ENVELOPE(-68.258,-68.258,68.496,68.496) Skeiðarárjökull ENVELOPE(-17.208,-17.208,64.056,64.056) Annals of Glaciology 40 133 138 |
institution |
Open Polar |
collection |
Staffordshire University: STORE - Staffordshire Online Repository |
op_collection_id |
ftustaffordshire |
language |
unknown |
topic |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F800 Physical and Terrestrial Geographical and Environmental Sciences Roberts, Matthew J. Pálsson, Finnur Gudmundsson, Magnús Tumi Björnsson, Helgi TWEED, Fiona Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland |
topic_facet |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
This paper explores changing ice–water interactions during jökulhlaups from Grænalón, a 5 × 108 m3 subaerial lake dammed by Skeiðarárjökull, Iceland. Unstable drainage of Graenalón since the early 20th century has resulted in 45 jökulhlaups whose hydrologic character has varied enormously. Geomorphic observations and geophysical measurements from the inlet and outlet zones of the subglacial floodwater tract constrained the hydromechanical factors governing ice–water interactions at Grænalón. To date, three distinct drainage regimes have occurred in response to the changing surface elevation of Grænalón. Shifts from one drainage regime to another involved pronounced changes in jökulhlaup magnitude, timing and cyclicity. Present hydraulic conditions for lake drainage differ from the classical view of a pressure-coupled lake draining directly beneath an ice dam. Instead, lowamplitude drawdown occurs at regular, frequent intervals when hydrostatic pressure in a shallow, rock–ice trench enables water to flow beneath a sagging ice barrier. Floodwater exits Skeiðarárjökull in a supercooled state due to rapid hydraulic displacement from an overdeepened subglacial basin. |
format |
Article in Journal/Newspaper |
author |
Roberts, Matthew J. Pálsson, Finnur Gudmundsson, Magnús Tumi Björnsson, Helgi TWEED, Fiona |
author_facet |
Roberts, Matthew J. Pálsson, Finnur Gudmundsson, Magnús Tumi Björnsson, Helgi TWEED, Fiona |
author_sort |
Roberts, Matthew J. |
title |
Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland |
title_short |
Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland |
title_full |
Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland |
title_fullStr |
Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland |
title_full_unstemmed |
Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland |
title_sort |
ice–water interactions during floods from grænalón glacier-dammed lake, iceland |
publisher |
International Glaciological Society |
publishDate |
2005 |
url |
http://eprints.staffs.ac.uk/1733/ https://doi.org/10.3189/172756405781813771 |
long_lat |
ENVELOPE(-68.258,-68.258,68.496,68.496) ENVELOPE(-17.208,-17.208,64.056,64.056) |
geographic |
Dammed Lake Skeiðarárjökull |
geographic_facet |
Dammed Lake Skeiðarárjökull |
genre |
Annals of Glaciology glacier Iceland |
genre_facet |
Annals of Glaciology glacier Iceland |
op_relation |
Roberts, Matthew J., Pálsson, Finnur, Gudmundsson, Magnús Tumi, Björnsson, Helgi and TWEED, Fiona (2005) Ice–water interactions during floods from Grænalón glacier-dammed lake, Iceland. Annals of Glaciology, 40 (1). pp. 133-138. ISSN 02603055 |
op_doi |
https://doi.org/10.3189/172756405781813771 |
container_title |
Annals of Glaciology |
container_volume |
40 |
container_start_page |
133 |
op_container_end_page |
138 |
_version_ |
1766000580012015616 |