Rate of late Quaternary ice-cap thinning on King George Island, South Shetland Islands, West Antarctica definded by cosmogenic 36Cl surface exposure dating

Abstract

Glacial landforms on the Barton and Weaver peninsulas of King George Island in the South Shetland Islands, West Antarctica were mapped and dated using terrestrial cosmogenic 36Cl methods to provide the first quantitative terrestrial record for late Quaternary deglaciation in the South Shetland Islands. 36Cl ages on glacially eroded and striated bedrock surfaces range from 15.5+2.5 kyr to 1.0+0.7 kyr. The 36Cl ages are younger with decreasing altitude, indicating progressive downwasting of the southwestern part of the Collins Ice Cap at a rate of -12mm/yr since 15.5+2.5 kyr ago, supporting the previously published marine records for the timing and estimate of the rate of deglaciation in this region.