Apr 3, 2017
Bed elevation of Jakobshavn Isbræ, West Greenland, from high‐resolution airborne gravity and other data
by
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Geophysical Research Letters
- States that the Jakobshavn Isbræ, West Greenland, which holds a 0.6-m sea level volume equivalent, has been speeding up and retreating since the late 1990s
- States that the interpretation of its retreat has been hindered by difficulties in measuring its ice thickness with airborne radar depth sounders
- Employs high-resolution, helicopter-borne gravity data from 2012 to reconstruct its bed elevation within 50 km of the ocean margin using a three-dimensional inversion constrained by fjord bathymetry data offshore and a mass conservation algorithm inland
- Finds the glacier trough to be asymmetric and several 100 m deeper than estimated previously in the lower part
- Finds that from 1996-2016, the grounding line migrated at 0.6 km/yr from 700 m to 1,100 m depth
- Finds that upstream, the bed drops to 1,600 m over 10 km then slowly climbs to 1,200 m depth in 40 km
- Concludes Jakobshavn Isbræ will continue to retreat along a retrograde slope for decades to come