Holocene deglacial history of the north east Antarctic Peninsula - a review and new chronological constraints.

Johnson, J.S., Bentley, M.J., Roberts, S.J., Binnie, S.A. and Freeman, S.P.H.T. (2011) Holocene deglacial history of the north east Antarctic Peninsula - a review and new chronological constraints. Quaternary Science Reviews, 30, pp. 3791-3802. (doi:10.1016/j.quascirev.2011.10.011)

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Publisher's URL: http://dx.doi.org/10.1016/j.quascirev.2011.10.011

Abstract

The northeast Antarctic Peninsula (NEAP) region is currently showing signs of significant environmental change, evidenced by acceleration of glacial retreat and collapse of both Larsen-A and -B ice shelves within the past 15 years. However, data on the past extent of the eastern margin of the Antarctic Peninsula Ice Sheet (APIS) and its Holocene retreat history are sparse, and hence we cannot yet put the recent changes into a long-term context. In order to investigate the timing of deglaciation, we present 16 new cosmogenic 10Be surface exposure ages from sites on northern James Ross Island (Cape Lachman, Johnson Mesa and Terrapin Hill) and Seymour Island. The majority of the ages cluster around 6–10 ka, with three significantly older (25–31 ka). We combine these ages with existing terrestrial and marine radiocarbon deglaciation ages, and a compilation of existing swath bathymetry data, to quantify the temporal and spatial character of the regional glacial history. Ice had begun to retreat from the outer shelf by 18.3 ka, reaching Seymour Island by ∼8 ka. Northern James Ross Island began to deglaciate around the time of the Early Holocene Climatic Optimum (c. 11–9.5 ka). Deglaciation continued, and a transition from grounded to floating ice in Prince Gustav Channel occurred around 8 ka, separating the James Ross Island ice cap from the APIS. This occurred shortly before Prince Gustav Channel ice shelf began to disintegrate at 6.2 ka. Our results suggest there may be a bathymetric control on the spatial pattern of deglaciation in the NEAP.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Freeman, Professor Stewart
Authors: Johnson, J.S., Bentley, M.J., Roberts, S.J., Binnie, S.A., and Freeman, S.P.H.T.
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Quaternary Science Reviews
Publisher:Elsevier
ISSN:0277-3791
ISSN (Online):1873-457X
Published Online:20 November 2011

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