NEW RSL CONSTRAINTS FOR NW SCOTLAND FROM OPTICALLY STIMULATED LUMINESCENCE DATED MARINE DEPOSITS

The response of ice sheets to climate change has the potential to significantly accelerate the rate of sea-level rise by the end of the century. However, predicting the future interaction between sea-level and ice sheets remains challenging without a comprehensive understanding of past interactions. Therefore, gaining further insight into this interaction is crucial for forecasting future sea-levels. In this study, we provide new constraints on the late Pleistocene relative sea level (RSL) history at 10 sites along the eastern flanks of the Minch Ice Stream (MnIS). Optically stimulated luminescence dating of raised marine deposits was used to determine the age of the oldest preserved RSL indicators immediately after ice-sheet retreat. Although slightly older than earlier assumptions, our ages confirm the early deglacial age of ~18-21 ka for the earliest post-LGM (Last Glacial Maximum) raised shorelines of NW Scotland with declining marine limits north of the Isle of Skye. Our new OSL ages suggest deglaciation of the MnIS may have been earlier than originally thought, although our large error bars require further investigation. Reconstructing RSL will provide important constraints for Glacial Isostatic Adjustment (GIA) models for NW Scotland as well as shed light on ice-stream behavior of the former MnIS.