Modelling the coupling of flood discharge with glacier flow during jokulhlaups
We explore a mathematical model that couples together a thermomechanically evolving subglacial channel, distributed cavity drainage, and basal sliding along a subglacial flood path fed by a jökulhlaup lake. It allows water transfer between channel and cavities and a migrating subglacial water divide...
Published in: | Annals of Glaciology |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
International Glaciological Society
2013
|
Subjects: | |
Online Access: | https://eprints.whiterose.ac.uk/92059/ https://eprints.whiterose.ac.uk/92059/7/kingslake_ng_2013.pdf https://doi.org/10.3189/2013AoG63A331 |
id |
ftleedsuniv:oai:eprints.whiterose.ac.uk:92059 |
---|---|
record_format |
openpolar |
spelling |
ftleedsuniv:oai:eprints.whiterose.ac.uk:92059 2023-05-15T13:29:24+02:00 Modelling the coupling of flood discharge with glacier flow during jokulhlaups Kingslake, J. Ng, F. 2013-07 text https://eprints.whiterose.ac.uk/92059/ https://eprints.whiterose.ac.uk/92059/7/kingslake_ng_2013.pdf https://doi.org/10.3189/2013AoG63A331 en eng International Glaciological Society https://eprints.whiterose.ac.uk/92059/7/kingslake_ng_2013.pdf Kingslake, J. and Ng, F. (2013) Modelling the coupling of flood discharge with glacier flow during jokulhlaups. Annals of Glaciology, 54 (63). 25 - 31. ISSN 0260-3055 Article PeerReviewed 2013 ftleedsuniv https://doi.org/10.3189/2013AoG63A331 2023-01-30T21:36:52Z We explore a mathematical model that couples together a thermomechanically evolving subglacial channel, distributed cavity drainage, and basal sliding along a subglacial flood path fed by a jökulhlaup lake. It allows water transfer between channel and cavities and a migrating subglacial water divide or 'seal' to form between floods. Notably, it accounts for full coupling between the lake and subglacial drainage in terms of both discharge and pressure, unlike models that neglect the pressure coupling by imposing a known history of lake discharge at the channel inlet. This means that flood hydrographic evolution and its impact on glacier motion are consistently determined by our model. Numerical simulations for a model alpine lake yield stable limit cycles simulating repeating jökulhlaups, with the channel drawing water from the cavities at a varying rate that modulates basal sliding during each flood. A wave of fast sliding propagates down-glacier at flood initiation, followed by deceleration as the growing channel sucks water from the cavities. These behaviours cannot be correctly simulated without the full coupling. We show that the flood's peak discharge, its initiation threshold and the magnitude of the 'fast sliding' wave decrease with the background water supply to the cavities. Article in Journal/Newspaper Annals of Glaciology White Rose Research Online (Universities of Leeds, Sheffield & York) Alpine Lake ENVELOPE(-129.182,-129.182,55.529,55.529) Annals of Glaciology 54 63 25 31 |
institution |
Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
We explore a mathematical model that couples together a thermomechanically evolving subglacial channel, distributed cavity drainage, and basal sliding along a subglacial flood path fed by a jökulhlaup lake. It allows water transfer between channel and cavities and a migrating subglacial water divide or 'seal' to form between floods. Notably, it accounts for full coupling between the lake and subglacial drainage in terms of both discharge and pressure, unlike models that neglect the pressure coupling by imposing a known history of lake discharge at the channel inlet. This means that flood hydrographic evolution and its impact on glacier motion are consistently determined by our model. Numerical simulations for a model alpine lake yield stable limit cycles simulating repeating jökulhlaups, with the channel drawing water from the cavities at a varying rate that modulates basal sliding during each flood. A wave of fast sliding propagates down-glacier at flood initiation, followed by deceleration as the growing channel sucks water from the cavities. These behaviours cannot be correctly simulated without the full coupling. We show that the flood's peak discharge, its initiation threshold and the magnitude of the 'fast sliding' wave decrease with the background water supply to the cavities. |
format |
Article in Journal/Newspaper |
author |
Kingslake, J. Ng, F. |
spellingShingle |
Kingslake, J. Ng, F. Modelling the coupling of flood discharge with glacier flow during jokulhlaups |
author_facet |
Kingslake, J. Ng, F. |
author_sort |
Kingslake, J. |
title |
Modelling the coupling of flood discharge with glacier flow during jokulhlaups |
title_short |
Modelling the coupling of flood discharge with glacier flow during jokulhlaups |
title_full |
Modelling the coupling of flood discharge with glacier flow during jokulhlaups |
title_fullStr |
Modelling the coupling of flood discharge with glacier flow during jokulhlaups |
title_full_unstemmed |
Modelling the coupling of flood discharge with glacier flow during jokulhlaups |
title_sort |
modelling the coupling of flood discharge with glacier flow during jokulhlaups |
publisher |
International Glaciological Society |
publishDate |
2013 |
url |
https://eprints.whiterose.ac.uk/92059/ https://eprints.whiterose.ac.uk/92059/7/kingslake_ng_2013.pdf https://doi.org/10.3189/2013AoG63A331 |
long_lat |
ENVELOPE(-129.182,-129.182,55.529,55.529) |
geographic |
Alpine Lake |
geographic_facet |
Alpine Lake |
genre |
Annals of Glaciology |
genre_facet |
Annals of Glaciology |
op_relation |
https://eprints.whiterose.ac.uk/92059/7/kingslake_ng_2013.pdf Kingslake, J. and Ng, F. (2013) Modelling the coupling of flood discharge with glacier flow during jokulhlaups. Annals of Glaciology, 54 (63). 25 - 31. ISSN 0260-3055 |
op_doi |
https://doi.org/10.3189/2013AoG63A331 |
container_title |
Annals of Glaciology |
container_volume |
54 |
container_issue |
63 |
container_start_page |
25 |
op_container_end_page |
31 |
_version_ |
1766000367637626880 |