Finalized:Wednesday, November 1, 2017
Author(s):Morlighem, Mathieu & others
Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.
Morlighem, Mathieu & Williams, Chris & Rignot, E & An, Lu & Arndt, Jan Erik & Bamber, Jonathan & Catania, G & Chauché, N & A. Dowdeswell, J & Dorschel, Boris & Fenty, Ian & Hogan, K.A. & Howat, Ian & Hubbard, Alun & Jakobsson, Martin & Jordan, Tom & Kjeldsen, Kristian & Millan, Romain & Mayer, Larry & Zinglersen, Karl. (2017). BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation: BEDMACHINE GREENLAND V3. Geophysical Research Letters. 44. 10.1002/2017GL074954.This material is based upon work supported by the National Science Foundation under Grant No. 1541390. Opinions, findings, conclusions or recommendations expressed are those of the authors and do not reflect the views of the NSF.