Last updated October 10, 2018

Bed elevation of Jakobshavn Isbræ, West Greenland, from high‐resolution airborne gravity and other data

  • 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