Mid-Holocene sea-surface temperature reconstruction using fossil corals from Kume Island, Ryukyu, Japan

Abstract

The relative warmth and stability of the Holocene was punctuated by several brief cold events. Whereas these cold events on a global scale are widely reported, the lack of records from regions such as the East China Sea (ECS) results in an incomplete understanding of the underlying cooling mechanism. Here, we present a coral-based paleo-SST (sea-surface temperature) reconstruction from the ECS to constrain Holocene variability in the Kuroshio Western Boundary Current and the East Asian Monsoon (EAM). Our new data confirm that cold conditions prevailed at 3.8 cal kyr BP, which is consistent with the previously-reported Pulleniatina Minimum Event (PME). While this previous reconstruction could not reveal seasonal differences, our high-resolution data indicate a differing seasonal SST response between summer and winter. This result provides an important insight into understanding the mechanism of the millennium scale cold event in the ECS, the region affected by EAM.