Satellite-derived submarine melt rates and mass balance (2011-2015) for Greenland's largest remaining ice tongues

TitleSatellite-derived submarine melt rates and mass balance (2011-2015) for Greenland's largest remaining ice tongues
Publication TypeJournal Article
Year of Publication2017
AuthorsWilson N., Straneo F, Heimbach P.
JournalCryosphere
Volume11
Pagination2773-2782
Date Published2017/12
Type of ArticleArticle
ISBN Number1994-0416
Accession NumberWOS:000417066300003
Keywordsdynamics; glaciers; jakobshavn isbrae; model; northeast greenland; ocean waters; petermann gletscher; radar interferometry; sheet; Shelf
Abstract

Ice-shelf-like floating extensions at the termini of Greenland glaciers are undergoing rapid changes with potential implications for the stability of upstream glaciers and the ice sheet as a whole. While submarine melting is recognized as a major contributor to mass loss, the spatial distribution of submarine melting and its contribution to the total mass balance of these floating extensions is incompletely known and understood. Here, we use high-resolution World-View satellite imagery collected between 2011 and 2015 to infer the magnitude and spatial variability of melt rates under Greenland's largest remaining ice tongues - Nioghalvf-jerdsbr-(79 North Glacier, 79N), Ryder Glacier (RG), and Petermann Glacier (PG). Submarine melt rates under the ice tongues vary considerably, exceeding 50ma(-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. We compare the total melt rates to the influx of ice to the ice tongue to assess their contribution to the current mass balance. At Petermann Glacier and Ryder Glacier, we find that the combined submarine and aerial melt approximately balances the ice flux from the grounded ice sheet. At Nioghalvfjerdsbr the total melt flux (14.2 +/- 0.96 km(3) a(-)1 w. e., water equivalent) exceeds the inflow of ice (10.2 +/- 0.59 km(3) a(-1) w.e.), indicating present thinning of the ice tongue.

DOI10.5194/tc-11-2773-2017
Short TitleCryosphere
Student Publication: 
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