Antarctic basal environment shaped by high-pressure flow through a subglacial river system
File(s)
Accepted version
Author(s)
Dow, Christine
Ross, Neil
Jeofry, Hafeez
Siu, Kevin
Siegert, Martin
Type
Journal Article
Abstract
The stability of ice sheets and their contributions to sea level are modulated by high-pressure water that lubricates the base of the ice, facilitating rapid flow into the ocean. In Antarctica, subglacial processes are poorly characterized, limiting understanding of ice-sheet flow and its sensitivity to climate forcing. Here, using numerical modelling and geophysical data, we provide evidence of extensive, up to 460 km long, dendritically organized subglacial hydrological systems that stretch from the ice-sheet interior to the grounded margin. We show that these channels transport large fluxes (~24 m3 s−1) of freshwater at high pressure, potentially facilitating enhanced ice flow above. The water exits the ice sheet at specific locations, appearing to drive ice-shelf melting in these areas critical for ice-sheet stability. Changes in subglacial channel size can affect the water depth and pressure of the surrounding drainage system up to 100 km either side of the primary channel. Our results demonstrate the importance of incorporating catchment-scale basal hydrology in calculations of ice-sheet flow and in assessments of ice-shelf melt at grounding zones. Thus, understanding how marginal regions of Antarctica operate, and may change in the future, requires knowledge of processes acting within, and initiating from, the ice-sheet interior.
Date Issued
2022-10-27
Date Acceptance
2022-09-23
Citation
Nature Geoscience, 2022, 15, pp.892-898
ISSN
1752-0894
Publisher
Nature Research
Start Page
892
End Page
898
Journal / Book Title
Nature Geoscience
Volume
15
Copyright Statement
© The Author(s) 2022. Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
Subjects
Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
WEDDELL SEA SECTOR
ICE SHELF CAVITY
GROUNDING LINE
SHEET MODEL
WATER
DRAINAGE
CHANNEL
BENEATH
MELT
MELTWATER
Meteorology & Atmospheric Sciences
Publication Status
Published