Ice-stream demise dynamically conditioned by trough shape and bed strength



Bradwell, T, Small, D, Fabel, D, Smedley, RK ORCID: 0000-0001-7773-5193, Clark, CD, Saher, MH, Callard, SL, Chiverrell, RC ORCID: 0000-0002-7307-2756, Dove, D, Moreton, SG
et al (show 3 more authors) (2019) Ice-stream demise dynamically conditioned by trough shape and bed strength. Science Advances, 5 (4).

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Abstract

Ice sheet mass loss is currently dominated by fast-flowing glaciers (ice streams) terminating in the ocean as ice shelves and resting on beds below sea level. The factors controlling ice-stream flow and retreat over longer time scales (>100 years), especially the role of three-dimensional bed shape and bed strength, remain major uncertainties. We focus on a former ice stream where trough shape and bed substrate are known, or can be defined, to reconstruct ice-stream retreat history and grounding-line movements over 15 millennia since the Last Glacial Maximum. We identify a major behavioral step change around 18,500 to 16,000 years ago—out of tune with external forcing factors—associated with the collapse of floating ice sectors and rapid ice-front retreat. We attribute this step change to a marked geological transition from a soft/weak bed to a hard/strong bed coincident with a change in trough geometry. Both these factors conditioned and ultimately hastened ice-stream demise.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 25 Apr 2019 09:43
Last Modified: 26 Aug 2022 11:52
DOI: 10.1126/sciadv.aau1380
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3038317