Dynamic changes in outlet glaciers in northern Greenland from 1948 to 2015
<p>The Greenland Ice Sheet (GrIS) is losing mass in response to recent climatic and oceanic warming. Since the mid-1990s, tidewater outlet glaciers across the ice sheet have thinned, retreated, and accelerated, but recent changes in northern Greenland have been comparatively understudied....
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-10-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/12/3243/2018/tc-12-3243-2018.pdf |
| Summary: | <p>The Greenland Ice Sheet (GrIS) is losing mass in response to
recent climatic and oceanic warming. Since the mid-1990s, tidewater outlet
glaciers across the ice sheet have thinned, retreated, and accelerated, but
recent changes in northern Greenland have been comparatively understudied.
Consequently, the dynamic response (i.e. changes in surface elevation and
velocity) of these outlet glaciers to changes at their termini, particularly
calving from floating ice tongues, is poorly constrained. Here we use
satellite imagery and historical maps to produce an unprecedented 68-year
record of terminus change across 18 major outlet glaciers and combine this
with previously published surface elevation and velocity datasets. Overall,
recent (1995–2015) retreat rates were higher than at any time in the
previous 47 years (since 1948). Despite increased retreat rates from the
1990s, there was distinct variability in dynamic glacier behaviour depending
on whether the terminus was grounded or floating. Grounded glaciers
accelerated and thinned in response to retreat over the last 2 decades,
while most glaciers terminating in ice tongues appeared dynamically
insensitive to recent ice tongue retreat and/or total collapse. We also
identify glacier geometry (e.g. fjord width, basal topography, and ice tongue
confinement) as an important influence on the dynamic adjustment of glaciers
to changes at their termini. Recent grounded outlet glacier retreat and ice
tongue loss across northern Greenland suggest that the region is undergoing
rapid change and could soon contribute substantially to sea level rise via
the loss of grounded ice.</p> |
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| ISSN: | 1994-0416 1994-0424 |