A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion
GPS campaigns on glaciers during jökulhlaups show how subglacial floods affect glacier motion and shed light on the dynamics of such floods. Three such campaigns have been carried out on southern and western Vatnajökull, southeast Iceland, over known jökulhlaup paths. Two slowly rising jökulhlaups f...
Published in: | Annals of Glaciology |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press
2016
|
Subjects: | |
Online Access: | https://doi.org/10.1017/aog.2016.8 https://doaj.org/article/b132ae01712943faaaaaa7d1f0ac67f3 |
id |
ftdoajarticles:oai:doaj.org/article:b132ae01712943faaaaaa7d1f0ac67f3 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:b132ae01712943faaaaaa7d1f0ac67f3 2023-05-15T13:29:36+02:00 A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion Bergur Einarsson Eyjólfur Magnússon Matthew J. Roberts Finnur Pálsson Thorsteinn Thorsteinsson Tómas Jóhannesson 2016-07-01T00:00:00Z https://doi.org/10.1017/aog.2016.8 https://doaj.org/article/b132ae01712943faaaaaa7d1f0ac67f3 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0260305516000082/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2016.8 0260-3055 1727-5644 https://doaj.org/article/b132ae01712943faaaaaa7d1f0ac67f3 Annals of Glaciology, Vol 57, Pp 47-61 (2016) glacier flow glacier hydrology jökulhlaups (GLOFs) subglacial lakes Meteorology. Climatology QC851-999 article 2016 ftdoajarticles https://doi.org/10.1017/aog.2016.8 2023-03-12T01:31:57Z GPS campaigns on glaciers during jökulhlaups show how subglacial floods affect glacier motion and shed light on the dynamics of such floods. Three such campaigns have been carried out on southern and western Vatnajökull, southeast Iceland, over known jökulhlaup paths. Two slowly rising jökulhlaups from Grímsvötn and two rapidly rising jökulhlaups from the western and eastern Skaftá cauldrons were captured in these campaigns, with maximum discharge ranging from 240 to 3300 m3 s−1. Glacier surface movements measured in these campaigns are presented along with the corresponding discharge curves. The measurements are interpreted as indicating: (1) initiation of rapidly rising jökulhlaups with a propagating subglacial pressure wave, (2) decreased glacier basal friction during jökulhlaups, (3) subglacial accumulation of water in slowly rising jökulhlaups and (4) lifting of the glacier caused by subglacial water pressure exceeding overburden in both rapidly and slowly rising jökulhlaups. The latter two observations are inconsistent with assumptions that are typically made in theoretical and numerical modelling of jökulhlaups. Both viscous and elastic deformation of the glacier as well as turbulent hydraulic fracture at the ice/bedrock interface are important in the dynamics of the subglacial pressure wave at the front of rapidly rising jökulhlaups. Article in Journal/Newspaper Annals of Glaciology glacier Iceland Vatnajökull Directory of Open Access Journals: DOAJ Articles Skaftá ENVELOPE(-17.933,-17.933,63.783,63.783) Vatnajökull ENVELOPE(-16.823,-16.823,64.420,64.420) Annals of Glaciology 57 72 47 61 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
glacier flow glacier hydrology jökulhlaups (GLOFs) subglacial lakes Meteorology. Climatology QC851-999 |
spellingShingle |
glacier flow glacier hydrology jökulhlaups (GLOFs) subglacial lakes Meteorology. Climatology QC851-999 Bergur Einarsson Eyjólfur Magnússon Matthew J. Roberts Finnur Pálsson Thorsteinn Thorsteinsson Tómas Jóhannesson A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion |
topic_facet |
glacier flow glacier hydrology jökulhlaups (GLOFs) subglacial lakes Meteorology. Climatology QC851-999 |
description |
GPS campaigns on glaciers during jökulhlaups show how subglacial floods affect glacier motion and shed light on the dynamics of such floods. Three such campaigns have been carried out on southern and western Vatnajökull, southeast Iceland, over known jökulhlaup paths. Two slowly rising jökulhlaups from Grímsvötn and two rapidly rising jökulhlaups from the western and eastern Skaftá cauldrons were captured in these campaigns, with maximum discharge ranging from 240 to 3300 m3 s−1. Glacier surface movements measured in these campaigns are presented along with the corresponding discharge curves. The measurements are interpreted as indicating: (1) initiation of rapidly rising jökulhlaups with a propagating subglacial pressure wave, (2) decreased glacier basal friction during jökulhlaups, (3) subglacial accumulation of water in slowly rising jökulhlaups and (4) lifting of the glacier caused by subglacial water pressure exceeding overburden in both rapidly and slowly rising jökulhlaups. The latter two observations are inconsistent with assumptions that are typically made in theoretical and numerical modelling of jökulhlaups. Both viscous and elastic deformation of the glacier as well as turbulent hydraulic fracture at the ice/bedrock interface are important in the dynamics of the subglacial pressure wave at the front of rapidly rising jökulhlaups. |
format |
Article in Journal/Newspaper |
author |
Bergur Einarsson Eyjólfur Magnússon Matthew J. Roberts Finnur Pálsson Thorsteinn Thorsteinsson Tómas Jóhannesson |
author_facet |
Bergur Einarsson Eyjólfur Magnússon Matthew J. Roberts Finnur Pálsson Thorsteinn Thorsteinsson Tómas Jóhannesson |
author_sort |
Bergur Einarsson |
title |
A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion |
title_short |
A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion |
title_full |
A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion |
title_fullStr |
A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion |
title_full_unstemmed |
A spectrum of jökulhlaup dynamics revealed by GPS measurements of glacier surface motion |
title_sort |
spectrum of jökulhlaup dynamics revealed by gps measurements of glacier surface motion |
publisher |
Cambridge University Press |
publishDate |
2016 |
url |
https://doi.org/10.1017/aog.2016.8 https://doaj.org/article/b132ae01712943faaaaaa7d1f0ac67f3 |
long_lat |
ENVELOPE(-17.933,-17.933,63.783,63.783) ENVELOPE(-16.823,-16.823,64.420,64.420) |
geographic |
Skaftá Vatnajökull |
geographic_facet |
Skaftá Vatnajökull |
genre |
Annals of Glaciology glacier Iceland Vatnajökull |
genre_facet |
Annals of Glaciology glacier Iceland Vatnajökull |
op_source |
Annals of Glaciology, Vol 57, Pp 47-61 (2016) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0260305516000082/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2016.8 0260-3055 1727-5644 https://doaj.org/article/b132ae01712943faaaaaa7d1f0ac67f3 |
op_doi |
https://doi.org/10.1017/aog.2016.8 |
container_title |
Annals of Glaciology |
container_volume |
57 |
container_issue |
72 |
container_start_page |
47 |
op_container_end_page |
61 |
_version_ |
1766001390739521536 |