GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica

In the last 2 decades, Pine Island Glacier (PIG) experienced marked speedup, thinning, and grounding-line retreat, likely due to marine ice-sheet instability and ice-shelf basal melt. To better understand these processes, we combined 2008–2010 and 2012–2014 GPS records with dynamic firn model output...

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Published in:The Cryosphere
Main Authors: D. E. Shean, K. Christianson, K. M. Larson, S. R. M. Ligtenberg, I. R. Joughin, B. E. Smith, C. M. Stevens, M. Bushuk, D. M. Holland
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2017
Subjects:
geo
Online Access:https://doi.org/10.5194/tc-11-2655-2017
https://www.the-cryosphere.net/11/2655/2017/tc-11-2655-2017.pdf
https://doaj.org/article/798cfbee8ed9445dbeffd445c4dfc1ac
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spelling fttriple:oai:gotriple.eu:oai:doaj.org/article:798cfbee8ed9445dbeffd445c4dfc1ac 2023-05-15T13:53:01+02:00 GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica D. E. Shean K. Christianson K. M. Larson S. R. M. Ligtenberg I. R. Joughin B. E. Smith C. M. Stevens M. Bushuk D. M. Holland 2017-11-01 https://doi.org/10.5194/tc-11-2655-2017 https://www.the-cryosphere.net/11/2655/2017/tc-11-2655-2017.pdf https://doaj.org/article/798cfbee8ed9445dbeffd445c4dfc1ac en eng Copernicus Publications doi:10.5194/tc-11-2655-2017 1994-0416 1994-0424 https://www.the-cryosphere.net/11/2655/2017/tc-11-2655-2017.pdf https://doaj.org/article/798cfbee8ed9445dbeffd445c4dfc1ac undefined The Cryosphere, Vol 11, Pp 2655-2674 (2017) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2017 fttriple https://doi.org/10.5194/tc-11-2655-2017 2023-01-22T19:11:20Z In the last 2 decades, Pine Island Glacier (PIG) experienced marked speedup, thinning, and grounding-line retreat, likely due to marine ice-sheet instability and ice-shelf basal melt. To better understand these processes, we combined 2008–2010 and 2012–2014 GPS records with dynamic firn model output to constrain local surface and basal mass balance for PIG. We used GPS interferometric reflectometry to precisely measure absolute surface elevation (zsurf) and Lagrangian surface elevation change (Dzsurf∕ Dt). Observed surface elevation relative to a firn layer tracer for the initial surface (zsurf − zsurf0′) is consistent with model estimates of surface mass balance (SMB, primarily snow accumulation). A relatively abrupt ∼ 0.2–0.3 m surface elevation decrease, likely due to surface melt and increased compaction rates, is observed during a period of warm atmospheric temperatures from December 2012 to January 2013. Observed Dzsurf∕ Dt trends (−1 to −4 m yr−1) for the PIG shelf sites are all highly linear. Corresponding basal melt rate estimates range from ∼ 10 to 40 m yr−1, in good agreement with those derived from ice-bottom acoustic ranging, phase-sensitive ice-penetrating radar, and high-resolution stereo digital elevation model (DEM) records. The GPS and DEM records document higher melt rates within and near features associated with longitudinal extension (i.e., transverse surface depressions, rifts). Basal melt rates for the 2012–2014 period show limited temporal variability despite large changes in ocean temperature recorded by moorings in Pine Island Bay. Our results demonstrate the value of long-term GPS records for ice-shelf mass balance studies, with implications for the sensitivity of ice–ocean interaction at PIG. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelf Pine Island Pine Island Bay Pine Island Glacier The Cryosphere Unknown Island Bay ENVELOPE(-109.085,-109.085,59.534,59.534) Pine Island Bay ENVELOPE(-102.000,-102.000,-74.750,-74.750) Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) The Cryosphere 11 6 2655 2674
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic envir
geo
spellingShingle envir
geo
D. E. Shean
K. Christianson
K. M. Larson
S. R. M. Ligtenberg
I. R. Joughin
B. E. Smith
C. M. Stevens
M. Bushuk
D. M. Holland
GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
topic_facet envir
geo
description In the last 2 decades, Pine Island Glacier (PIG) experienced marked speedup, thinning, and grounding-line retreat, likely due to marine ice-sheet instability and ice-shelf basal melt. To better understand these processes, we combined 2008–2010 and 2012–2014 GPS records with dynamic firn model output to constrain local surface and basal mass balance for PIG. We used GPS interferometric reflectometry to precisely measure absolute surface elevation (zsurf) and Lagrangian surface elevation change (Dzsurf∕ Dt). Observed surface elevation relative to a firn layer tracer for the initial surface (zsurf − zsurf0′) is consistent with model estimates of surface mass balance (SMB, primarily snow accumulation). A relatively abrupt ∼ 0.2–0.3 m surface elevation decrease, likely due to surface melt and increased compaction rates, is observed during a period of warm atmospheric temperatures from December 2012 to January 2013. Observed Dzsurf∕ Dt trends (−1 to −4 m yr−1) for the PIG shelf sites are all highly linear. Corresponding basal melt rate estimates range from ∼ 10 to 40 m yr−1, in good agreement with those derived from ice-bottom acoustic ranging, phase-sensitive ice-penetrating radar, and high-resolution stereo digital elevation model (DEM) records. The GPS and DEM records document higher melt rates within and near features associated with longitudinal extension (i.e., transverse surface depressions, rifts). Basal melt rates for the 2012–2014 period show limited temporal variability despite large changes in ocean temperature recorded by moorings in Pine Island Bay. Our results demonstrate the value of long-term GPS records for ice-shelf mass balance studies, with implications for the sensitivity of ice–ocean interaction at PIG.
format Article in Journal/Newspaper
author D. E. Shean
K. Christianson
K. M. Larson
S. R. M. Ligtenberg
I. R. Joughin
B. E. Smith
C. M. Stevens
M. Bushuk
D. M. Holland
author_facet D. E. Shean
K. Christianson
K. M. Larson
S. R. M. Ligtenberg
I. R. Joughin
B. E. Smith
C. M. Stevens
M. Bushuk
D. M. Holland
author_sort D. E. Shean
title GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
title_short GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
title_full GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
title_fullStr GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
title_full_unstemmed GPS-derived estimates of surface mass balance and ocean-induced basal melt for Pine Island Glacier ice shelf, Antarctica
title_sort gps-derived estimates of surface mass balance and ocean-induced basal melt for pine island glacier ice shelf, antarctica
publisher Copernicus Publications
publishDate 2017
url https://doi.org/10.5194/tc-11-2655-2017
https://www.the-cryosphere.net/11/2655/2017/tc-11-2655-2017.pdf
https://doaj.org/article/798cfbee8ed9445dbeffd445c4dfc1ac
long_lat ENVELOPE(-109.085,-109.085,59.534,59.534)
ENVELOPE(-102.000,-102.000,-74.750,-74.750)
ENVELOPE(-101.000,-101.000,-75.000,-75.000)
geographic Island Bay
Pine Island Bay
Pine Island Glacier
geographic_facet Island Bay
Pine Island Bay
Pine Island Glacier
genre Antarc*
Antarctica
Ice Sheet
Ice Shelf
Pine Island
Pine Island Bay
Pine Island Glacier
The Cryosphere
genre_facet Antarc*
Antarctica
Ice Sheet
Ice Shelf
Pine Island
Pine Island Bay
Pine Island Glacier
The Cryosphere
op_source The Cryosphere, Vol 11, Pp 2655-2674 (2017)
op_relation doi:10.5194/tc-11-2655-2017
1994-0416
1994-0424
https://www.the-cryosphere.net/11/2655/2017/tc-11-2655-2017.pdf
https://doaj.org/article/798cfbee8ed9445dbeffd445c4dfc1ac
op_rights undefined
op_doi https://doi.org/10.5194/tc-11-2655-2017
container_title The Cryosphere
container_volume 11
container_issue 6
container_start_page 2655
op_container_end_page 2674
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