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| Titel |
Pine Island glacier ice shelf melt distributed at kilometre scales |
| VerfasserIn |
P. Dutrieux, D. G. Vaughan, H. F. J. Corr, A. Jenkins, P. R. Holland, I. Joughin, A. H. Fleming |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 7, no. 5 ; Nr. 7, no. 5 (2013-09-26), S.1543-1555 |
| Datensatznummer |
250085166
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| Publikation (Nr.) |
 copernicus.org/tc-7-1543-2013.pdf |
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| Zusammenfassung |
| By thinning and accelerating, West Antarctic ice streams are contributing
about 10% of the observed global sea level rise. Much of this ice loss
is from Pine Island Glacier, which has thinned since at least 1992, driven by
changes in ocean heat transport beneath its ice shelf and retreat of the
grounding line. Details of the processes driving this change, however, remain
largely elusive, hampering our ability to predict the future behaviour of
this and similar systems. Here, a Lagrangian methodology is developed to
measure oceanic melting of such rapidly advecting ice. High-resolution
satellite and airborne observations of ice surface velocity and elevation are
used to quantify patterns of basal melt under the Pine Island Glacier ice
shelf and the associated adjustments to ice flow. At the broad scale, melt
rates of up to 100 m yr−1 occur near the grounding line, reducing
to 30 m yr−1 just 20 km downstream. Between 2008 and 2011, basal
melting was largely compensated by ice advection, allowing us to estimate an
average loss of ice to the ocean of 87 km3 yr−1, in close
agreement with 2009 oceanographically constrained estimates. At smaller
scales, a network of basal channels typically 500 m to 3 km wide is
sculpted by concentrated melt, with kilometre-scale anomalies reaching
50% of the broad-scale basal melt. Basal melting enlarges the channels
close to the grounding line, but farther downstream melting tends to diminish
them. Kilometre-scale variations in melt are a key component of the complex
ice–ocean interaction beneath the ice shelf, implying that greater
understanding of their effect, or very high resolution models, are required
to predict the sea-level contribution of the region. |
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