Dynamic changes in marine-terminating outlet glaciers in Greenland and West Antarctica indicate that their contribution to sea level rise has accelerated in the last few decades (Shepherd et al., 2018). This is largely due to increased velocity, thinning and retreat, which has been linked to both atmospheric and oceanic warming. In contrast, the world’s largest ice sheet – the East Antarctic Ice Sheet (EAIS) – has generally been perceived as much less vulnerable. However, mass loss has been detected in some regions (e.g. Wilkes Land: Rignot et al., 2019), and recent work suggests that its marine-terminating outlet glaciers respond rapidly to external forcing at decadal time-scales (Miles et al., 2013; 2016; 2017; Greene et al., 207). Recent studies have also noted the widespread movement and ponding of surface meltwater on numerous East Antarctic ice shelves (Stokes et al., 2019), including some that exert a significant buttressing effect on inland ice flow and which may be vulnerable to collapse via meltwater-driven hydrofracturing. This suggests that the EAIS may be more vulnerable to future climate change than previously thought, and numerical modelling suggests that some regions grounded below sea level may be close to the threshold of instability (Mengel and Levermann, 2014; DeConto and Pollard, 2016).
Despite growing evidence for the potential vulnerability of the EAIS, and unlike in Greenland and West Antarctica, there are few detailed observations of many of its large marine-terminating outlet glaciers (Figure 1). As such, we know very little about what controls the behaviour of outlet glaciers in the EAIS. To address this issue, the overall aim of this project is to use remote sensing observations to explore the sensitivity of major East Antarctic outlet glaciers to oceanic and atmospheric forcing.
The primary research questions are:
• To what extent are EAIS outlet glaciers sensitive to atmospheric or oceanic forcing?
• How does outlet glacier response to forcing vary between different climatic or topographic settings in East Antarctica?
• How do specific glacier characteristics increase or decrease sensitivity to various forcings (e.g. the presence of ice tongues, ice shelves, bed topography)?
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Figure 1: Major outlet glaciers draining the East Antarctic Ice Sheet in Victoria Land.