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| Titel |
Submarine melt rates under Greenland’s ice tongues |
| VerfasserIn |
Nat Wilson, Fiametta Straneo, Patrick Heimbach, Claudia Cenedese |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250147186
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| Publikation (Nr.) |
 EGU/EGU2017-11309.pdf |
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| Zusammenfassung |
| The few remaining ice tongues (ice-shelf like extensions) of Greenland’s glaciers are
undergoing rapid changes with potential implications for the stability of the ice sheet.
Submarine melting is recognized as a major contributor to mass loss, yet the magnitude and
spatial distribution of melt are poorly known or understood. Here, we use high resolution
satellite imagery to infer the magnitude and spatial variability of melt rates under
Greenland’s largest remaining ice tongues: Ryder Glacier, Petermann Glacier and
Nioghalvfjerdsbræ (79 North Glacier). We find that submarine plus aerial melt
approximately balance the ice flux from the grounded ice sheet for the first two while at
Nioghalvfjerdsbræ the total melt flux exceeds the inflow of ice indicating thinning of the
ice tongue. We also show that melt rates under the ice tongues vary considerably,
exceeding 60 m yr−1 near the grounding zone and decaying rapidly downstream.
Channels, likely originating from upstream subglacial channels, give rise to large melt
variations across the ice tongues. Using derived melt rates, we test simplified melt
parameterizations appropriate for ice sheet models and find the best agreement
with those that incorporate ice tongue geometry in the form of depth and slope. |
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