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
Language:English
Published: Wiley 2023-11-01
Subjects:
Arctic
geophysics
remote sensing
saline permafrost
thermokarst lakes
Online Access:https://doi.org/10.1029/2023GL105552
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.
ISSN:0094-8276
1944-8007

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