posted on 2020-04-22, 13:35authored byJA Dowdeswell, CL Batchelor, A Montelli, D Ottesen, FDW Christie, EK Dowdeswell, Jeffrey EvansJeffrey Evans
A suite of grounding-line landforms on the Antarctic seafloor, imaged at unprecedented sub-meter horizontal resolution from an autonomous underwater vehicle, enables calculation of ice-sheet retreat rates from a complex of grounding-zone wedges on the Larsen continental shelf, western Weddell Sea. The landforms are delicate sets of up to 90 ridges, <1.5 m high and spaced 20-25 m apart. We interpret these ridges as the product of squeezing up of soft sediment during the rise and fall of the ice-shelf grounding line during successive tidal cycles. Each ridge is preserved as the grounding line retreats. Grounding-line retreat rates of 40-50 m/day (>10 km/yr) are inferred during regional deglaciation of the Larsen shelf after the Last Glacial Maximum. If repeated today, such rapid mass loss to the ocean would have clear implications for increasing the rate of global sea-level rise.
Funding
Flotilla Foundation and Marine Archaeology Consultants Switzerland.
C.L.B. was in receipt of a grant from the Norwegian VISTA programme.
History
School
Social Sciences
Department
Geography and Environment
Published in
Science
Volume
368
Issue
6494
Pages
1020 - 1024
Publisher
American Association for the Advancement of Science (AAAS)
This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science Journal 368 (6494), 29 May 2020, doi: 10.1126/science.aaz3059.