University of Canterbury, PhD

The Antarctic Ice Sheets at the Last Glacial Maximum: A Retreat History from In-Situ Cosmogenic Nuclides

Since the Last Glacial Maximum (LGM), approximately 22-17 ka, a rapidly warming climate melted ice sheets and raised sea levels by ~130 meters. The role that Antarctica played in this rise and the configuration of the LGM ice sheet margins are still poorly understood. The Darwin/Hatherton system, within the Transantarctic Mountains, is a key area that contains a wide range of well preserved glacial landforms. These represent the former extents of ice masses and archive the history of glacial advance and recession. New research from this area has suggested up to 800 meters of thickened ice approximately 2 million years ago and moraines, assumed to be the limit of LGM ice expansion, date to 30-40 ka. This shows that while early Quaternary expansion was large; ice volume at the LGM is little changed from the present. Further work in this area will allow the configuration of the Antarctic ice sheets post- LGM to be understood, leading to predictions of their response to current and future climate change and its effect on sea level rise.