Thermal legacy of a large paleolake in Taylor Valley, East Antarctica, as evidenced by an airborne electromagnetic survey

Previous studies of the lakes of the McMurdo Dry Valleys have attempted to constrain lake level history, and results suggest the lakes have undergone hundreds of meters of lake level change within the last 20 000 years. Past studies have utilized the interpretation of geologic deposits, lake chemist...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: K. F. Myers, P. T. Doran, S. M. Tulaczyk, N. T. Foley, T. S. Bording, E. Auken, H. A. Dugan, J. A. Mikucki, N. Foged, D. Grombacher, R. A. Virginia
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2021
Subjects:
geo
envir
East Antarctica
Fryxell
Lake Fryxell
McMurdo Dry Valleys
Taylor Dome
Taylor Valley
Antarc*
Antarctica
Ice
ice core
Ice Sheet
permafrost
The Cryosphere
Online Access:https://doi.org/10.5194/tc-15-3577-2021
https://tc.copernicus.org/articles/15/3577/2021/tc-15-3577-2021.pdf
https://doaj.org/article/e9cafb2d9a644f4cb00564c07869c059
Description
Summary:Previous studies of the lakes of the McMurdo Dry Valleys have attempted to constrain lake level history, and results suggest the lakes have undergone hundreds of meters of lake level change within the last 20 000 years. Past studies have utilized the interpretation of geologic deposits, lake chemistry, and ice sheet history to deduce lake level history; however a substantial amount of disagreement remains between the findings, indicating a need for further investigation using new techniques. This study utilizes a regional airborne resistivity survey to provide novel insight into the paleohydrology of the region. Mean resistivity maps revealed an extensive brine beneath the Lake Fryxell basin, which is interpreted as a legacy groundwater signal from higher lake levels in the past. Resistivity data suggest that active permafrost formation has been ongoing since the onset of lake drainage and that as recently as 1500–4000 years BP, lake levels were over 60 m higher than present. This coincides with a warmer-than-modern paleoclimate throughout the Holocene inferred by the nearby Taylor Dome ice core record. Our results indicate Mid to Late Holocene lake level high stands, which runs counter to previous research finding a colder and drier era with little hydrologic activity throughout the last 5000 years.

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