PP54A-04
Evidence for a substantial West Antarctic ice sheet contribution to meltwater pulses and abrupt global sea level rise
Friday, 18 December 2015: 16:45
2012 (Moscone West)
Christopher Joseph Fogwill1, Chris SM Turney2, Nicholas R Golledge3, David M Etheridge4, Mauro Rubino5, David Thornton4, John Woodward6, Kate Winter6, Tas D van Ommen7, Andrew David Moy7, Mark A Curran8, Camilla Rootes9, Andres Rivera10 and Helen Millman2, (1)University of New South Wales, Climate Change Research Centre, Sydney, Australia, (2)University of New South Wales, Sydney, Australia, (3)Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand, (4)CSIRO, Aspendale, Australia, (5)Seconda Università di Napoli,, Dipartimento di Matematica e Fisica, Napoli, Italy, (6)Northumbria University, Geography, Newcastle-Upon-Tyne, United Kingdom, (7)Australian Antarctic Division, Kingston, Australia, (8)Australian Antarctic Division, Hobart, Australia, (9)University of Sheffield, Sheffield, United Kingdom, (10)CECS-Center for Scientific Studies, Glaciology Department, Valdvia, Chile
Abstract:
During the last deglaciation (21,000 to 7,000years ago) global sea level rise was punctuated by several abrupt meltwater spikes triggered by the retreat of ice sheets and glaciers world-wide. However, the debate regarding the relative timing, geographical source and the physical mechanisms driving these rapid increases in sea level has catalyzed debate critical to predicting future sea level rise and climate. Here we present a unique record of West Antarctic Ice Sheet elevation change derived from the Patriot Hills blue ice area, located close to the modern day grounding line of the Institute Ice Stream in the Weddell Sea Embayment. Combined isotopic signatures and gas volume analysis from the ice allows us to develop a record of local ice sheet palaeo-altitude that is assessed against independent regional high-resolution ice sheet modeling studies, allowing us to demonstrate that past ice sheet elevations across this sector of the WSE were considerably higher than those suggested by current terrestrial reconstructions. We argue that ice in the WSE had a significant influence on both pre and post LGM sea level rise including MWP-1A (~14.6 ka) and during MWP-1B (11.7-11.6 ka), reconciling past sea level rise and demonstrating for the first time that this sector of the WAIS made a significant and direct contribution to post LGM sea level rise.
