Breaking the ice: Identifying hydraulically-forced crevassing

Hudson, T.S.; Brisbourne, A.M. ORCID: https://orcid.org/0000-0002-9887-7120; White, R.S.; Kendall, J.M.; Arthern, R. ORCID: https://orcid.org/0000-0002-3762-8219; Smith, A.M. ORCID: https://orcid.org/0000-0001-8577-482X. 2020 Breaking the ice: Identifying hydraulically-forced crevassing. Geophysical Research Letters, 47 (21), e2020GL090597. 9, pp. https://doi.org/10.1029/2020GL090597

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Official URL: https://agupubs.onlinelibrary.wiley.com/doi/10.102...

Abstract/Summary

Hydraulically‐forced crevassing is thought to reduce the stability of ice shelves and ice sheets, affecting structural integrity and providing pathways for surface meltwater to the bed. It can cause ice shelves to collapse and ice sheets to accelerate into the ocean. However, direct observations of the hydraulically‐forced crevassing process remain elusive. Here we report a novel method and observations that use icequakes to directly observe crevassing and determine the role of hydrofracture. Crevasse icequake depths from seismic observations are compared to a theoretically derived maximum‐dry‐crevasse‐depth. We observe icequakes below this depth, suggesting hydrofracture. Furthermore, icequake source mechanisms provide insight into the fracture process, with predominantly opening cracks observed, which have opening volumes of hundredths of a cubic meter. Our method and findings provide a framework for studying a critical process that is key for the stability of ice shelves and ice sheets, and therefore future sea‐level rise projections.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1029/2020GL090597
ISSN:	0094-8276
Additional Keywords:	Seismology, Glaciology, Crevassing, Hydrofracture, Surface waves, Sea‐level rise
Date made live:	20 Oct 2020 14:03 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/528529

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1029/2020GL090597

ISSN:

0094-8276

Additional Keywords:

Seismology, Glaciology, Crevassing, Hydrofracture, Surface waves, Sea‐level rise

Date made live:

20 Oct 2020 14:03 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/528529