Paleoenvironmental changes in the northern area of the East China Sea during the past 42,000 years

The core was divided into four periods based on Q-mode factor analysis of the planktonic foraminiferal assemblage, i.e. (1) a strong upwelling period from 42 to 24 ka, indicated by abundant occurrence of Globigerina bulloides, (2) a cold and low salinity water mass period from 24 to 14 ka, suggested by increase of Neogloboquadrina pachyderma, Neogloboquadrina incompta, and Globigerina quinqueloba, (3) a transitional period from cold to warm water masses from 14 to 8 ka, as indicated by the increase of warm water species such as Pulleniatina obliquiloculata and Globigerinoides ruber, and (4) the present-day warm Kuroshio Current condition after 8 ka. The Kuroshio Current flowed into the ECS since the last 42 ka and weakened during the last glacial maximum (LGM) due to the expansion of the coastal water in the northern part of the ECS.