Onshore Thermokarst Primes Subsea Permafrost Degradation

The response of permafrost to marine submergence can vary between ice-rich late Pleistocene deposits and the thermokarst basins that thawed out during the Holocene. We hypothesize that inundated Alases offshore thaw faster than submerged Yedoma. To test this hypothesis, we estimated depths to the to...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Angelopoulos, Michael, Overduin, Pier Paul, Jenrich, Maren, Nitze, Ingmar, Günther, Frank, Strauss, Jens, Westermann, Sebastian, Schirrmeister, Lutz, Kholodov, Alexander, Krautblatter, Michael, Grigoriev, Mikhail N., Grosse, Guido
Format: Article in Journal/Newspaper
Language:English
Published: 2022
Subjects:
Arctic
Ice
permafrost
Thermokarst
Siberia
Online Access:http://hdl.handle.net/10852/92623
http://urn.nb.no/URN:NBN:no-95222
https://doi.org/10.1029/2021GL093881
Description
Summary:The response of permafrost to marine submergence can vary between ice-rich late Pleistocene deposits and the thermokarst basins that thawed out during the Holocene. We hypothesize that inundated Alases offshore thaw faster than submerged Yedoma. To test this hypothesis, we estimated depths to the top of ice-bearing permafrost offshore of the Bykovsky Peninsula in northeastern Siberia using electrical resistivity surveys. The surveys traversed submerged lagoon deposits, drained and refrozen Alas deposits, and undisturbed Yedoma from the coastline to 373 m offshore. While the permafrost degradation rates of the submerged Yedoma were in the range of similar sites, the submerged Alas permafrost degradation rates were up to 170urn:x-wiley:00948276:media:grl62785:grl62785-math-0001 faster. Remote sensing analyses suggest that 54urn:x-wiley:00948276:media:grl62785:grl62785-math-0002 of lagoons wider than 500 m along northeast Siberian and northwest American coasts originated in thermokarst basins. Given the abundance of thermokarst basins and lakes along parts of the Arctic coastline, their effect on subsea permafrost degradation must be similarly prevalent.

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