Basal melt and freezing rates from first noble gas samples beneath an ice shelf

Huhn, Oliver; Hattermann, Tore; Davis, Peter E.D. ORCID: https://orcid.org/0000-0002-6471-6310; Dunker, Erich; Hellmer, Hartmut H.; Nicholls, Keith W. ORCID: https://orcid.org/0000-0002-2188-4509; Østerhus, Svein; Rhein, Monika; Schröder, Michael; Sültenfuß, Jürgen. 2018 Basal melt and freezing rates from first noble gas samples beneath an ice shelf. Geophysical Research Letters, 45 (16). 8455-8461. https://doi.org/10.1029/2018GL079706

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Official URL: http://dx.doi.org/10.1029/2018GL079706

Abstract/Summary

A climatically‐induced acceleration in ocean‐driven melting of Antarctic ice shelves would have consequences for both the discharge of continental ice into the ocean and thus global sea level, and for the formation of Antarctic Bottom Water and the oceanic meridional overturning circulation. Using a novel gas‐tight in‐situ water sampler, noble gas samples have been collected from six locations beneath the Filchner Ice Shelf, the first such samples from beneath an Antarctic Ice shelf. Helium and neon are uniquely suited as tracers of glacial meltwater in the ocean. Basal meltwater fractions range from 3.6% near the ice shelf base to 0.5% near the sea floor, with distinct regional differences. We estimate an average basal melt rate for the Filchner‐Ronne Ice Shelf of 177 ± 95 Gt/year, independently confirming previous results. We calculate that up to 2.7% of the meltwater has been refrozen, and we identify a local source of crustal helium.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1029/2018GL079706
ISSN:	00948276
Additional Keywords:	ice shelf-ocean interaction, basal glacial melting and refreezing, ice shelf cavity, noble gases helium and neon, Antarctica, Filcher-Ronne Ice Shelf
Date made live:	15 Aug 2018 09:21 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/520707

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1029/2018GL079706

ISSN:

00948276

Additional Keywords:

ice shelf-ocean interaction, basal glacial melting and refreezing, ice shelf cavity, noble gases helium and neon, Antarctica, Filcher-Ronne Ice Shelf

Date made live:

15 Aug 2018 09:21 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/520707