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Repeated large-scale retreat and advance of Totten Glacier indicated by inland bed erosion

Citation

Aitken, ARA and Roberts, JL and van Ommen, TD and Young, DA and Golledge, NR and Greenbaum, JS and Blankenship, DD and Siegert, MJ, Repeated large-scale retreat and advance of Totten Glacier indicated by inland bed erosion, Nature, 533, (7603) pp. 385-389. ISSN 0028-0836 (2016) [Refereed Article]

Copyright Statement

© 2016 Macmillan Publishers

DOI: doi:10.1038/nature17447

Abstract

Climate variations cause ice sheets to retreat and advance, raising or lowering sea level by metres to decametres. The basic relationship is unambiguous, but the timing, magnitude and sources of sea-level change remain unclear; in particular, the contribution of the East Antarctic Ice Sheet (EAIS) is ill defined, restricting our appreciation of potential future change. Several lines of evidence suggest possible collapse of the Totten Glacier into interior basins during past warm periods, most notably the Pliocene epoch, causing several metres of sea-level rise. However, the structure and long-term evolution of the ice sheet in this region have been understood insufficiently to constrain past ice-sheet extents. Here we show that deep ice-sheet erosion—enough to expose basement rocks—has occurred in two regions: the head of the Totten Glacier, within 150 kilometres of today’s grounding line; and deep within the Sabrina Subglacial Basin, 350–550 kilometres from this grounding line. Our results, based on ICECAP aerogeophysical data, demarcate the marginal zones of two distinct quasi-stable EAIS configurations, corresponding to the ‘modern-scale’ ice sheet (with a marginal zone near the present ice-sheet margin) and the retreated ice sheet (with the marginal zone located far inland). The transitional region of 200–250 kilometres in width is less eroded, suggesting shorter-lived exposure to eroding conditions during repeated retreat–advance events, which are probably driven by ocean-forced instabilities. Representative ice-sheet models indicate that the global sea-level increase resulting from retreat in this sector can be up to 0.9 metres in the modern-scale configuration, and exceeds 2 metres in the retreated configuration.

Item Details

Item Type:Refereed Article
Keywords:Totten Glacier, East Antarctic Ice Sheet, sea-level increase, ice-sheet models
Research Division:Earth Sciences
Research Group:Physical Geography and Environmental Geoscience
Research Field:Glaciology
Objective Division:Environment
Objective Group:Climate and Climate Change
Objective Field:Effects of Climate Change and Variability on Antarctic and Sub-Antarctic Environments (excl. Social Impacts)
Author:Roberts, JL (Dr Jason Roberts)
Author:van Ommen, TD (Dr Tas van Ommen)
ID Code:109343
Year Published:2016
Web of Science® Times Cited:13
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2016-06-09
Last Modified:2016-12-08
Downloads:0

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