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Sensitivity of Pine Island Glacier to observed ocean forcing
Author(s) -
Christianson Knut,
Bushuk Mitchell,
Dutrieux Pierre,
Parizek Byron R.,
Joughin Ian R.,
Alley Richard B.,
Shean David E.,
Abrahamsen E. Povl,
Anandakrishnan Sridhar,
Heywood Karen J.,
Kim TaeWan,
Lee Sang Hoon,
Nicholls Keith,
Stanton Tim,
Truffer Martin,
Webber Benjamin G. M.,
Jenkins Adrian,
Jacobs Stan,
Bindschadler Robert,
Holland David M.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070500
Subject(s) - geology , glacier , ice stream , oceanography , antarctic ice sheet , thinning , ice sheet , climatology , antarctic sea ice , glacier ice accumulation , ice shelf , ocean heat content , sea ice , cryosphere , ocean current , geomorphology , geography , forestry
We present subannual observations (2009–2014) of a major West Antarctic glacier (Pine Island Glacier) and the neighboring ocean. Ongoing glacier retreat and accelerated ice flow were likely triggered a few decades ago by increased ocean‐induced thinning, which may have initiated marine ice sheet instability. Following a subsequent 60% drop in ocean heat content from early 2012 to late 2013, ice flow slowed, but by < 4%, with flow recovering as the ocean warmed to prior temperatures. During this cold‐ocean period, the evolving glacier‐bed/ice shelf system was also in a geometry favorable to stabilization. However, despite a minor, temporary decrease in ice discharge, the basin‐wide thinning signal did not change. Thus, as predicted by theory, once marine ice sheet instability is underway, a single transient high‐amplitude ocean cooling has only a relatively minor effect on ice flow. The long‐term effects of ocean temperature variability on ice flow, however, are not yet known.