Late glacial history of the Ross Sea sector of the West Antarctic Ice Sheet: evidence from englacial layering at Talos Dome, East Antarctica

Abstract

The timing of West Antarctic Ice Sheet (WAIS) expansion and retreat during the last glacial cycle is crucial to evaluating the processes controlling ice sheet fluctuations. There is currently debate as to whether grounded ice across what is now the Ross Ice Shelf decayed during the early Holocene or at a time coincident with meltwater pulse 1a. Here we show, from analysis of englacial radio-echo layering across Talos Dome in Oates Land, East Antarctica, that the pattern of snowfall has been relatively consistent for the past 8,000–10,000 years. This was preceded by a transition from glacial maximum-type accumulation at between 10,000 and 20,000 years. We interpret glacial maximum accumulation rates to correspond with the expansion of the grounded WAIS across the Ross shelf, so preventing storm tracks from accessing Victoria Land as they do today (as identified previously at Taylor Dome). The return to modern-type accumulation after 8,000 years is consistent with geological evidence for WAIS retreat. No large-scale alteration in accumulation is observed around 14,000 years ago, during the time of meltwater pulse 1a.