High-resolution reconstruction of variation in aeolian dust (Kosa) deposition at ODP site 797, the Japan Sea, during the last 200 ka

Abstract

In order to reconstruct past variations in the east Asian monsoon and to establish a direct link between terrestrial and marine climatic records, we evaluated the temporal variation in aeolian dust (Kosa or yellow sand) flux to the Japan Sea using the late Quaternary hemipelagic sediments in the sea. Contributions of four detrital subcomponents, identified by Irino and Tada [Geochem. J. 34(1) (2000) 59] as Kosa derived from “typical” loess, Kosa from “weathered” loess and fine and coarse arc-derived detritus, have varied in millennial scale, as well as in glacial–interglacial scale, during the last 200 ka. Millennial scale variability of Kosa from “typical” loess suggests the change in dust availability controlled by high-frequency variation in summer monsoon precipitation in the central to east Asia during the last 200 ka, whereas variation in Kosa from “weathered” loess suggests the change in transport pathway of dust which was probably affected by the winter monsoon variation.