Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012
pre-print A pulse is a type of unstable glacier flow intermediate between normal flow and surging. Using Landsat MSS, TM and ETM+ imagery and feature-tracking software, a time series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of Ruth Glacier, Alaska. Peaks...
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ftunivutah:oai:collections.lib.utah.edu:ir_uspace/713110 2023-05-15T16:20:24+02:00 Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 Forster, Richard R. Turrin, James B.; Sauber, Jeanne M.; Hall, Dorothy K.; Bruhn, Ronald L. College of Social & Behavioral Science Geography 2014-01-01 application/pdf 1,326,442 bytes. https://collections.lib.utah.edu/ark:/87278/s6gf43nm eng eng International Glaciological Society uspace,19076 https://collections.lib.utah.edu/ark:/87278/s6gf43nm (c)International Glaciological Society http://www.igsoc.org/ Text 2014 ftunivutah 2021-06-03T18:24:04Z pre-print A pulse is a type of unstable glacier flow intermediate between normal flow and surging. Using Landsat MSS, TM and ETM+ imagery and feature-tracking software, a time series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of Ruth Glacier, Alaska. Peaks in ice velocity were found in 1981, 1989, 1997, 2003 and 2010, approximately every 7 years. During these peak years the ice velocity increased 300%, from approximately 40ma-1 to 160ma-1. Based on the spatio-temporal behavior of Ruth Glacier during the pulse cycles, we suggest the pulses are due to enhanced basal motion via deformation of a subglacial till. The cyclical nature of the pulses is interpreted to be due to a thin till, with low permeability, that causes incomplete drainage of the till between the pulses, followed by eventual recharge and dilation of the till. These findings suggest care is needed when attempting to correlate changes in regional climate with decadal-scale changes in velocity, because in some instances basal conditions may have a greater influence on ice dynamics than climate. Text glacier Alaska The University of Utah: J. Willard Marriott Digital Library |
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The University of Utah: J. Willard Marriott Digital Library |
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English |
description |
pre-print A pulse is a type of unstable glacier flow intermediate between normal flow and surging. Using Landsat MSS, TM and ETM+ imagery and feature-tracking software, a time series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of Ruth Glacier, Alaska. Peaks in ice velocity were found in 1981, 1989, 1997, 2003 and 2010, approximately every 7 years. During these peak years the ice velocity increased 300%, from approximately 40ma-1 to 160ma-1. Based on the spatio-temporal behavior of Ruth Glacier during the pulse cycles, we suggest the pulses are due to enhanced basal motion via deformation of a subglacial till. The cyclical nature of the pulses is interpreted to be due to a thin till, with low permeability, that causes incomplete drainage of the till between the pulses, followed by eventual recharge and dilation of the till. These findings suggest care is needed when attempting to correlate changes in regional climate with decadal-scale changes in velocity, because in some instances basal conditions may have a greater influence on ice dynamics than climate. |
author2 |
College of Social & Behavioral Science Geography |
format |
Text |
author |
Forster, Richard R. Turrin, James B.; Sauber, Jeanne M.; Hall, Dorothy K.; Bruhn, Ronald L. |
spellingShingle |
Forster, Richard R. Turrin, James B.; Sauber, Jeanne M.; Hall, Dorothy K.; Bruhn, Ronald L. Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 |
author_facet |
Forster, Richard R. Turrin, James B.; Sauber, Jeanne M.; Hall, Dorothy K.; Bruhn, Ronald L. |
author_sort |
Forster, Richard R. |
title |
Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 |
title_short |
Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 |
title_full |
Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 |
title_fullStr |
Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 |
title_full_unstemmed |
Effects of bedrock lithology and subglacial till on the motion of Ruth Glacier, Alaska, deduced from five pulses from 1973 to 2012 |
title_sort |
effects of bedrock lithology and subglacial till on the motion of ruth glacier, alaska, deduced from five pulses from 1973 to 2012 |
publisher |
International Glaciological Society |
publishDate |
2014 |
url |
https://collections.lib.utah.edu/ark:/87278/s6gf43nm |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_relation |
uspace,19076 https://collections.lib.utah.edu/ark:/87278/s6gf43nm |
op_rights |
(c)International Glaciological Society http://www.igsoc.org/ |
_version_ |
1766008313058689024 |