Observations of Buried Lake Drainage on the Antarctic Ice Sheet

• Published in: Geophysical Research Letters
• Main Authors: Dunmire, D. (author), Lenaerts, J.T.M. (author), Banwell, Alison (author), Wever, N. (author), Shragge, J. (author), Lhermitte, S.L.M. (author), Drews, R. (author), Pattyn, F. (author), Hansen, J.S.S. (author), Willis, I.C. (author), Miller, J. (author), Keenan, E. (author)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Antartica; glaciology; GPR; hydrofracture; hydrology; meltwater; Antarc*; Antarctic; Antarctica; antartic*; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: http://resolver.tudelft.nl/uuid:27f2180b-367b-4dd2-8f4f-66636b105f3a; https://doi.org/10.1029/2020GL087970

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. Mathematical Geodesy and Positioning