Abstract

There is intense interest in the future stability of the West Antarctic Ice Sheet (WAIS). Models range widely in their predictions and in the physics they include. We can constrain possible outcomes by observing what happened to ice sheets at previous times when the polar regions were warmer than present. The last interglacial (LIG) is a particularly important time because both Greenland and Antarctic temperature were higher than present and so was sea level.

Within the WACSWAIN (WArm Climate Stability of the West Antarctic ice sheet in the last INterglacial) project, in 2019 we retrieved a 651 metre ice core to the bed of Skytrain Ice Rise. This ice rise is adjacent to the Ronne Ice Shelf and the WAIS , and therefore sensitive to their extent. The ice core has been processed and analysed continuously for a range of analytes, and we can show that ice from the LIG is present.

I will start by describing the project, fieldwork and analyses. Eventually, I will show what happened to the ice around Skytrain Ice Rise in the LIG , and discuss how this fits with other evidence about LIG sea level.