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| Titel |
Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age |
| VerfasserIn |
S. A. Khan, K. K. Kjeldsen, K. H. Kjær, S. Bevan, A. Luckman, A. Aschwanden, A. A. Bjørk, N. J. Korsgaard, J. E. Box, M. van den Broeke, T. M. van Dam, A. Fitzner |
| 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 ; 8, no. 4 ; Nr. 8, no. 4 (2014-08-18), S.1497-1507 |
| Datensatznummer |
250116263
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| Publikation (Nr.) |
 copernicus.org/tc-8-1497-2014.pdf |
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| Zusammenfassung |
| Observations over the past decade show significant ice loss associated with
the speed-up of glaciers in southeast Greenland from 2003, followed by a
deceleration from 2006. These short-term, episodic, dynamic perturbations
have a major impact on the mass balance on the decadal scale. To improve the
projection of future sea level rise, a long-term data record that reveals
the mass balance beyond such episodic events is required. Here, we extend
the observational record of marginal thinning of Helheim and Kangerdlugssuaq
glaciers from 10 to more than 80 years. We show that, although the frontal
portion of Helheim Glacier thinned by more than 100 m between 2003 and 2006,
it thickened by more than 50 m during the previous two decades. In contrast,
Kangerdlugssuaq Glacier underwent minor thinning of 40–50 m from 1981 to
1998 and major thinning of more than 100 m after 2003. Extending the record
back to the end of the Little Ice Age (prior to 1930) shows no thinning of
Helheim Glacier from its maximum extent during the Little Ice Age to 1981,
while Kangerdlugssuaq Glacier underwent substantial thinning of 230 to
265 m. Comparison of sub-surface water temperature anomalies and variations
in air temperature to records of thickness and velocity change suggest that
both glaciers are highly sensitive to short-term atmospheric and ocean
forcing, and respond very quickly to small fluctuations. On century
timescales, however, multiple external parameters (e.g. outlet glacier
shape) may dominate the mass change. These findings suggest that special
care must be taken in the projection of future dynamic ice loss. |
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