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The Mid‐Brunhes Event and West Antarctic ice sheet stability
Author(s) -
Holden P. B.,
Edwards N. R.,
Wolff E. W.,
Valdes P. J.,
Singarayer J. S.
Publication year - 2011
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.1525
Subject(s) - deglaciation , geology , antarctic ice sheet , ice sheet , climatology , abrupt climate change , ice sheet model , glacial period , interglacial , ice core , pleistocene , climate change , oceanography , paleontology , global warming , ice stream , cryosphere , effects of global warming , sea ice
The complex cyclical nature of Pleistocene climate, driven by the evolving orbital configuration of the Earth, is well known but not well understood. A major climatic transition took place at the Mid‐Brunhes Event (MBE), ca. 430 ka ago after which the amplitude of the ca.100 ka climate oscillations increased, with substantially warmer interglacials, including periods warmer than present. Recent modelling has indicated that while the timing of these warmer‐than‐present transient (WPT) events is consistent with southern warming due to a deglaciation‐forced slowdown of the Atlantic Meridional Overturning Circulation, the magnitude of warming requires a local amplification, for which a candidate is the feedback of significant West Antarctic Ice Sheet (WAIS) retreat. We here extend this argument, based on the absence of WPTs in the early ice core record (450–800 ka ago), to hypothesize that the MBE could be a manifestation of decreased WAIS stability, triggered by ongoing subglacial erosion. Copyright © 2011 John Wiley & Sons, Ltd.