The West Antarctic Ice Sheet (WAIS) is primarily marine-based and, therefore, sensitive to climatic and oceanographic changes. Over the past several decades, the WAIS has been undergoing dramatic mass loss, contributing to sea-level rise faster than any other continental ice sheet on Earth. Model simulations predict a complete/partial WAIS collapse soon, resulting in a catastrophic sea-level rise of 3.3-4.3 meters. However, model predictions can produce diverging results and have significant uncertainties associated with estimating the timing of the ice sheet collapse and sea-level rise. The IPCC (2007) 4th Assessment Report highlighted that the response of continental ice sheets to climate change and their contribution to global sea-level rise is the most significant unknown variable in predicting future sea-level change. In this study, we have reconstructed the Pliocene erosional history of West Antarctica using radiogenic isotopes of Nd (143Nd/144Nd) measured in the detrital phase of sediment core samples retrieved from the Amundsen Sea embayment during the IODP 379 expedition in 2019. Our results, together with the multi-proxy data from the sediment core, enable us to test the hypothesis related to stability and dynamics (waxing-waning and collapse events) of the WAIS and its impact on sea level changes during the geologic period, i.e., Pliocene epoch, the most recent geological analogue for modern/or near-future climate (IPCC, 2013). The detrital 143Nd/144Nd record from the study site shows a dramatic shift from less radiogenic values during the warm Pliocene to more radiogenic values during the Pliocene-Pleistocene transition, indicating erosional shift associated with the ice-sheet dynamics of the Pine Island and Thwaits glaciers. It indicates a dynamic ice sheet during the Pliocene and the sensitivity of the WAIS to the climate transition from the warm Pliocene greenhouse to Pleistocene icehouse conditions.
