Rapid Holocene thinning of an East Antarctic outlet glacier
Details of Research
TitleRapid Holocene thinning of an East Antarctic outlet glacier driven by marine ice sheet instabilityAbstractOutlet glaciers grounded on a bed that deepens inland and extends below sea level are potentially vulnerable to 'mĀarine ice sheet instability'. This instability, which may lead to runaway ice loss, has been simulated in models, but its consequences have not been directly observed in geological records. Here we provide new surface-exposure ages from an outlet of the East Antarctic Ice Sheet that reveal rapid glacier thinning occurred approximately 7,000 years ago, in the absence of large environmental changes. Glacier thinning persisted for more than two and a half centuries, resulting in hundreds of metres of ice loss. Numerical simulations indicate that ice surface drawdown accelerated when the otherwise steadily retreating glacier encountered a bedrock trough. Together, the geological reconstruction and numerical simulations suggest that centennial-scale glacier thinning arose from unstable grounding line retreat. Capturing these instability processes in ice sheet models is important for predicting Antarctica's future contribution to sea level change. Copyright 2015 Macmillan Publishers Limited. All rights reserved.AcknowledgementsWe acknowledge field support from Antarctica New Zealand. R.S.J. was supported by a VUW Victoria Doctoral Scholarship. A.N.M. and N.R.G. were supported by the New Zealand Government (MBIE) Past Antarctic Climate and Future Implications program. Sample preparation and measurement were supported by the Antarctic Research Centre's Endowed Development Fund and School of Geography, Environment and Earth Sciences (VUW). C.J.F. is supported by the Australian Research Council. S.L.G. is supported by a Swedish Research Council grant. We thank E.G.C. Smith for assistance with regression analysis, D.A. Young for airborne radar data (ICECAP), R.M. McKay for critical discussions and three anonymous reviewers who helped to improve the manuscript.Funding DetailsAntarctica New Zealand; ARC, Antarctica New Zealand; Antarctica New Zealand
TypeArticleCitationJones, R., Mackintosh, A., Norton, K., Golledge, N., Fogwill, C., Kubik, P., Christl, M. and Greenwood, S. (2015). Rapid Holocene thinning of an East Antarctic outlet glacier driven by marine ice sheet instability. Nature Communications, 6 IdentifierJones2015Relevancerank5
Greenwood, S., Rapid Holocene thinning of an East Antarctic outlet glacier , [Jones2015]. Antarctica NZ, accessed 01/04/2023, https://adam.antarcticanz.govt.nz/nodes/view/63573, 10.1038/ncomms9910
