Ice-stream initiation, duration and thinning on James Ross Island, northern Antarctic Peninsula

• Published in: Quaternary Science Reviews
• Main Authors: Glasser, N.F., Davies, Bethan, Carrivick, J.L., Rodes, A., Hambrey, M.J., Smellie, J.L., Domack, E.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 2014
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; Ice Sheet; James Ross Island; Ross Island
• Online Access: https://centaur.reading.ac.uk/36320/

Predicting the future response of the Antarctic Ice Sheet to climate change requires an understanding of the ice streams that dominate its dynamics. Here we use cosmogenic isotope exposure-age dating (26Al, 10Be and 36Cl) of erratic boulders on ice-free land on James Ross Island, north-eastern Antarctic Peninsula, to define the evolution of Last Glacial Maximum (LGM) ice in the adjacent Prince Gustav Channel. These data include ice-sheet extent, thickness and dynamical behaviour. Prior to ∼18 ka, the LGM Antarctic Peninsula Ice Sheet extended to the continental shelf-edge and transported erratic boulders onto high-elevation mesas on James Ross Island. After ∼18 ka there was a period of rapid ice-sheet surface-lowering, coincident with the initiation of the Prince Gustav Ice Stream. This timing coincided with rapid increases in atmospheric temperature and eustatic sea-level rise around the Antarctic Peninsula. Collectively, these data provide evidence for a transition from a thick, cold-based LGM Antarctic Peninsula Ice Sheet to a thinner, partially warm-based ice sheet during deglaciation.