Abstract

The West Antarctic Ice Sheet (WAIS) is thinning at an accelerating rate, and several numerical models suggest that full ice sheet collapse could be underway. Two of the region’s largest ice streams, Thwaites Glacier (aka Doomsday Glacier) and neighbouring Pine Island Glacier, have long been considered the weak underbelly of WAIS , and should they collapse, would raise global sea level by over 1 m. However, with only a few decades of observational data, it remains uncertain whether the changes we are seeing are irreversible, or whether the ice sheet has a propensity to self-stabilise and possibly readvance. In this talk I will present results of palaeo studies from the Amundsen Sea sector of WAIS which help to put these recent changes into a longer-term context. While the palaeo record reveals a range of dynamical behaviour(s) – some similar to the present day – it also serves to highlight that the current phase of anthropogenic warming is driving large scale, and potentially, irreversible ice sheet retreat.