Delicate seafloor landforms reveal past Antarctic grounding-line retreat of kilometers per year.

A suite of grounding-line landforms on the Antarctic seafloor, imaged at submeter 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 ar...

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Bibliographic Details
Main Authors: Dowdeswell, JA, Batchelor, CL, Montelli, A, Ottesen, D, Christie, FDW, Dowdeswell, EK, Evans, J
Format: Article in Journal/Newspaper
Language:English
Published: American Association for the Advancement of Science (AAAS) 2020
Subjects:
37 Earth Sciences
3709 Physical Geography and Environmental Geoscience
3705 Geology
13 Climate Action
Antarctic
The Antarctic
Weddell Sea
Weddell
Antarc*
Ice Sheet
Online Access:https://www.repository.cam.ac.uk/handle/1810/306113
https://doi.org/10.17863/CAM.53192
Description
Summary:A suite of grounding-line landforms on the Antarctic seafloor, imaged at submeter 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 meters high and spaced 20 to 25 meters apart. We interpret these ridges as the product of squeezing up of soft sediment during the rise and fall of the retreating ice sheet grounding line during successive tidal cycles. Grounding-line retreat rates of 40 to 50 meters per day (>10 kilometers per year) are inferred during regional deglaciation of the Larsen shelf. If repeated today, such rapid mass loss to the ocean would have clear implications for increasing the rate of global sea level rise.

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