The drivers of inter-annual outlet glacier terminus change in Victoria Land, Oates Land and George V Land, East Antarctica (1972-2013)

Abstract

Recent work has highlighted the potential sensitivity of marine-terminating outlet glaciers to decadal-scale changes in the ocean-climate system in some regions of East Antarctica. However, compared to Greenland and West Antarctica (including the Antarctic Peninsula), very little is known about the drivers of shorter-term inter-annual variation of outlet glaciers in East Antarctica. In this thesis, the terminus positions of 135 glaciers along the coastline of Victoria Land, Oates Land and George V Land were mapped from 1972 to 2013. These three regions span a range of climatic and oceanic conditions and contain a variety of different glacier types, including both land- and marine-terminating glaciers. Over the longest time step (1972-2013), 36% of glacier termini in the study area advanced, 25% of glacier termini retreated, with the remainder showing no discernible change. However, glacier terminus positions fluctuated at inter-annual time-scales, and the magnitude of these changes varied between regions. George V Land exhibited the most extreme fluctuations in terminus positions and Victoria Land exhibited the least. While potential links were found between sea-ice concentrations and glacier change on inter-annual time-scales, there was little correlation between air temperatures and short-term glacier behaviour. Marine-terminating glaciers experienced larger changes in terminus position compared with terrestrial glaciers, and within marine-terminating glaciers, glaciers with a floating unconstrained tongue exhibited the largest variations in terminus position. It is concluded that unlike in Greenland, West Antarctica, the Antarctic Peninsula and localised regions of East Antarctica (e.g. Wilkes Land), there is no clear trend of glacier retreat in the study area and most of the variations are more closely linked to glacier size and terminus type.