Rapid Saline Permafrost Thaw Below a Shallow Thermokarst Lake in Arctic Alaska

Abstract Permafrost warming and degradation is well documented across the Arctic. However, observation‐ and model‐based studies typically consider thaw to occur at 0°C, neglecting the widespread occurrence of saline permafrost in coastal plain regions. In this study, we document rapid saline permafr...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Benjamin M. Jones, Mikhail Z. Kanevskiy, Andrew D. Parsekian, Helena Bergstedt, Melissa K. Ward Jones, Rodrigo C. Rangel, Kenneth M. Hinkel, Yuri Shur
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2023
Subjects:
Arctic
geophysics
remote sensing
saline permafrost
thermokarst lakes
Geophysics. Cosmic physics
QC801-809
Ice
permafrost
Thermokarst
Alaska
Online Access:https://doi.org/10.1029/2023GL105552
https://doaj.org/article/997d2b8600794defaaf178ccb2fc802e
Description
Summary:Abstract Permafrost warming and degradation is well documented across the Arctic. However, observation‐ and model‐based studies typically consider thaw to occur at 0°C, neglecting the widespread occurrence of saline permafrost in coastal plain regions. In this study, we document rapid saline permafrost thaw below a shallow arctic lake. Over the 15‐year period, the lakebed subsided by 0.6 m as ice‐rich, saline permafrost thawed. Repeat transient electromagnetic measurements show that near‐surface bulk sediment electrical conductivity increased by 198% between 2016 and 2022. Analysis of wintertime Synthetic Aperture Radar satellite imagery indicates a transition from a bedfast to a floating ice lake with brackish water due to saline permafrost thaw. The regime shift likely contributed to the 65% increase in thermokarst lake lateral expansion rates. Our results indicate that thawing saline permafrost may be contributing to an increase in landscape change rates in the Arctic faster than anticipated.

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