Variable deceleration of Whillans Ice Stream, West Antarctica
The Whillans Ice Stream Ice Plain (WIP) has been slowing since at least 1963. Prior constraints on this slowdown were consistent with a constant long-term deceleration rate. New observations of ice velocity from 11 continuous and 3 seasonal GPS sites indicate the deceleration rate varies through tim...
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | https://doi.org/10.1002/2013JF002958 http://ecite.utas.edu.au/93182 |
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ftunivtasecite:oai:ecite.utas.edu.au:93182 2023-05-15T13:37:24+02:00 Variable deceleration of Whillans Ice Stream, West Antarctica Beem, LH Tulaczyk, SM King, MA Bougamont, M Fricker, HA Christoffersen, P 2014 https://doi.org/10.1002/2013JF002958 http://ecite.utas.edu.au/93182 en eng Wiley-Blackwell Publishing, Inc http://dx.doi.org/10.1002/2013JF002958 http://purl.org/au-research/grants/arc/FT110100207 Beem, LH and Tulaczyk, SM and King, MA and Bougamont, M and Fricker, HA and Christoffersen, P, Variable deceleration of Whillans Ice Stream, West Antarctica, Journal of Geophysical Research: Earth Surface, 119, (2) pp. 212-224. ISSN 2169-9003 (2014) [Refereed Article] http://ecite.utas.edu.au/93182 Engineering Geomatic Engineering Geodesy Refereed Article PeerReviewed 2014 ftunivtasecite https://doi.org/10.1002/2013JF002958 2019-12-13T21:56:04Z The Whillans Ice Stream Ice Plain (WIP) has been slowing since at least 1963. Prior constraints on this slowdown were consistent with a constant long-term deceleration rate. New observations of ice velocity from 11 continuous and 3 seasonal GPS sites indicate the deceleration rate varies through time including on interannual time scales. Between 2009 and 2012 WIP decelerated at a rate (6.1 to 10.9 2 m/yr 2 ) that was double the multidecadal average (3.0 to 5.6 2 m/yr 2 ). To identify the causes of slowdown, we used new and prior velocity estimates to constrain longitudinal and transverse force budget models as well as a higher-order inverse model. All model results support the conclusion that the observed deceleration of WIP is caused by an increase in basal resistance to motion at a rate of 10 to 40 Pa/yr. Subglacial processes that may be responsible for strengthening the ice stream bed include basal freeze on, changes in subglacial hydrology, or increases in the area of resistant basal substrate through differential erosion. The observed variability in WIP deceleration rate suggests that dynamics in subglacial hydrology, plausibly driven by basal freeze on and/or activity of subglacial lakes, plays a key role in modulating basal resistance to ice motion in the region. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal West Antarctica Whillans Ice Stream eCite UTAS (University of Tasmania) West Antarctica Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) Whillans Ice Stream ENVELOPE(-145.000,-145.000,-83.667,-83.667) Journal of Geophysical Research: Earth Surface 119 2 212 224 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Engineering Geomatic Engineering Geodesy |
spellingShingle |
Engineering Geomatic Engineering Geodesy Beem, LH Tulaczyk, SM King, MA Bougamont, M Fricker, HA Christoffersen, P Variable deceleration of Whillans Ice Stream, West Antarctica |
topic_facet |
Engineering Geomatic Engineering Geodesy |
description |
The Whillans Ice Stream Ice Plain (WIP) has been slowing since at least 1963. Prior constraints on this slowdown were consistent with a constant long-term deceleration rate. New observations of ice velocity from 11 continuous and 3 seasonal GPS sites indicate the deceleration rate varies through time including on interannual time scales. Between 2009 and 2012 WIP decelerated at a rate (6.1 to 10.9 2 m/yr 2 ) that was double the multidecadal average (3.0 to 5.6 2 m/yr 2 ). To identify the causes of slowdown, we used new and prior velocity estimates to constrain longitudinal and transverse force budget models as well as a higher-order inverse model. All model results support the conclusion that the observed deceleration of WIP is caused by an increase in basal resistance to motion at a rate of 10 to 40 Pa/yr. Subglacial processes that may be responsible for strengthening the ice stream bed include basal freeze on, changes in subglacial hydrology, or increases in the area of resistant basal substrate through differential erosion. The observed variability in WIP deceleration rate suggests that dynamics in subglacial hydrology, plausibly driven by basal freeze on and/or activity of subglacial lakes, plays a key role in modulating basal resistance to ice motion in the region. |
format |
Article in Journal/Newspaper |
author |
Beem, LH Tulaczyk, SM King, MA Bougamont, M Fricker, HA Christoffersen, P |
author_facet |
Beem, LH Tulaczyk, SM King, MA Bougamont, M Fricker, HA Christoffersen, P |
author_sort |
Beem, LH |
title |
Variable deceleration of Whillans Ice Stream, West Antarctica |
title_short |
Variable deceleration of Whillans Ice Stream, West Antarctica |
title_full |
Variable deceleration of Whillans Ice Stream, West Antarctica |
title_fullStr |
Variable deceleration of Whillans Ice Stream, West Antarctica |
title_full_unstemmed |
Variable deceleration of Whillans Ice Stream, West Antarctica |
title_sort |
variable deceleration of whillans ice stream, west antarctica |
publisher |
Wiley-Blackwell Publishing, Inc |
publishDate |
2014 |
url |
https://doi.org/10.1002/2013JF002958 http://ecite.utas.edu.au/93182 |
long_lat |
ENVELOPE(-64.250,-64.250,-84.450,-84.450) ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
geographic |
West Antarctica Whillans Whillans Ice Stream |
geographic_facet |
West Antarctica Whillans Whillans Ice Stream |
genre |
Antarc* Antarctica Antarctica Journal West Antarctica Whillans Ice Stream |
genre_facet |
Antarc* Antarctica Antarctica Journal West Antarctica Whillans Ice Stream |
op_relation |
http://dx.doi.org/10.1002/2013JF002958 http://purl.org/au-research/grants/arc/FT110100207 Beem, LH and Tulaczyk, SM and King, MA and Bougamont, M and Fricker, HA and Christoffersen, P, Variable deceleration of Whillans Ice Stream, West Antarctica, Journal of Geophysical Research: Earth Surface, 119, (2) pp. 212-224. ISSN 2169-9003 (2014) [Refereed Article] http://ecite.utas.edu.au/93182 |
op_doi |
https://doi.org/10.1002/2013JF002958 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
119 |
container_issue |
2 |
container_start_page |
212 |
op_container_end_page |
224 |
_version_ |
1766091298798829568 |