Observations of Buried Lake Drainage on the Antarctic Ice Sheet.

Between 1992 and 2017, the Antarctic Ice Sheet (AIS) lost ice equivalent to 7.6 ± 3.9 mm of sea level rise. AIS mass loss is mitigated by ice shelves that provide a buttress by regulating ice flow from tributary glaciers. However, ice-shelf stability is threatened by meltwater ponding, which may ini...

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Bibliographic Details
Main Authors: Dunmire, D, Lenaerts, JTM, Banwell, AF, Wever, N, Shragge, J, Lhermitte, S, Drews, R, Pattyn, F, Hansen, JSS, Willis, IC, Miller, J, Keenan, E
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union (AGU) 2020
Subjects:
Antartica
GPR
glaciology
hydrofracture
hydrology
meltwater
Antarctic
The Antarctic
Buttress
Antarc*
Antarctica
antartic*
Ice Sheet
Ice Shelf
Ice Shelves
Online Access:https://www.repository.cam.ac.uk/handle/1810/314848
https://doi.org/10.17863/CAM.61954
Description
Summary:Between 1992 and 2017, the Antarctic Ice Sheet (AIS) lost ice equivalent to 7.6 ± 3.9 mm of sea level rise. AIS mass loss is mitigated by ice shelves that provide a buttress by regulating ice flow from tributary glaciers. However, ice-shelf stability is threatened by meltwater ponding, which may initiate, or reactivate preexisting, fractures, currently poorly understood processes. Here, through ground penetrating radar (GPR) analysis over a buried lake in the grounding zone of an East Antarctic ice shelf, we present the first field observations of a lake drainage event in Antarctica via vertical fractures. Concurrent with the lake drainage event, we observe a decrease in surface elevation and an increase in Sentinel-1 backscatter. Finally, we suggest that fractures that are initiated or reactivated by lake drainage events in a grounding zone will propagate with ice flow onto the ice shelf itself, where they may have implications for its stability.

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