High basal melting forming a channel at the grounding line of Ross Ice Shelf, Antarctica

Antarctica's ice shelves are thinning at an increasing rate, affecting their buttressing ability. Channels in the ice shelf base unevenly distribute melting, and their evolution provides insight into changing subglacial and oceanic conditions. Here we used phase-sensitive radar measurements to...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Marsh, Oliver J., Fricker, Helen A., Siegfried, Matthew R., Christianson, Knut, Nicholls, Keith W, Corr, Hugh F. J., Catania, Ginny
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2016
Subjects:
Ross Ice Shelf
Mercer
Whillans
Whillans Ice Stream
Kamb Ice Stream
Antarc*
Antarctica
Ice Shelf
Ice Shelves
Online Access:http://nora.nerc.ac.uk/id/eprint/513057/
https://nora.nerc.ac.uk/id/eprint/513057/1/Marsh_et_al-2016-Geophysical_Research_Letters%20%281%29.pdf
https://doi.org/10.1002/2015GL066612
Description
Summary:Antarctica's ice shelves are thinning at an increasing rate, affecting their buttressing ability. Channels in the ice shelf base unevenly distribute melting, and their evolution provides insight into changing subglacial and oceanic conditions. Here we used phase-sensitive radar measurements to estimate basal melt rates in a channel beneath the currently stable Ross Ice Shelf. Melt rates of 22.2 ± 0.2 m a−1 (>2500% the overall background rate) were observed 1.7 km seaward of Mercer/Whillans Ice Stream grounding line, close to where subglacial water discharge is expected. Laser altimetry shows a corresponding, steadily deepening surface channel. Two relict channels to the north suggest recent subglacial drainage reorganization beneath Whillans Ice Stream approximately coincident with the shutdown of Kamb Ice Stream. This rapid channel formation implies that shifts in subglacial hydrology may impact ice shelf stability.

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