Changes in productivity and ice-rafting input in the Amundsen Sea during the Late Pleistocene: Implications on the evolution of surface-ocean environment and the West Antarctic Ice Sheet

The Amundsen Sea is the core area of the melting West Antarctic Ice Sheet (WAIS) in the recent global warming process. Productivity proxies and ice rafted debris (IRD) contents in core ANT34-A5-7 collected from the Amundsen Sea during the 34th Chinese Antarctic Research Expedition were investigated, to reveal the changes of the surface-ocean environment and the evolution history of the WAIS since the MIS (Marine Isotope Stage) 6. Results show increased (decreased) productivity during interglacial (glacial) periods. In particular, the higher productivity level than the Holocene productivity ones during the MIS 5.5 was accompanied by significant WAIS melting. These findings could be interpreted as warmer sea surface, less sea ice, and stronger upwelling of the circum-polar deep water in the Amundsen Sea during the MIS 5.5. This study provided valuable information for predicting future climate changes.