A Rapid Cooling Event Over The Western Pacific Region During The Middle Bronze Age

Climate change in the mid-to-late Holocene transition is very important for predicting future climate trends and understanding the relationship between abrupt climate change and the development of past human civilization. In this study, Sr/Ca ratios and delta O-18 records with the annual resolution extracted from four fossil corals that were growing during the Middle Bronze Age Cold Epoch (MBACE) were used to reconstruct sea surface temperature (SST) and seawater delta O-18 (delta O-18(sw)) in the South China Sea (SCS) during the mid-to-late Holocene transition. The results indicate that the SCS experienced a rapid cooling and wetting event during the period of similar to 3,500-3,800 years BP (before present year 1950). Specifically, the average SST and delta O-18(sw) declined rapidly by similar to 3 degrees C and similar to 0.65 parts per thousand, respectively, over an interval of similar to 100 years from similar to 3,850 years BP to similar to 3,750 years BP. This rapid climate change pattern recorded in coral archives broadly agrees with those in foraminiferal and stalagmite records from adjacent land and ocean areas. Consistent with other records from the North Atlantic, this cold event in the Asia-Western Pacific region that occurred during the MBACE and was originally identified in the North Atlantic and European regions should have occurred at the global scale, which might be caused by changes in the Asian summer monsoon linked with solar irradiance and/or the North Atlantic climate. In addition, this rapid climate change might support the occurrence and timing of the outburst flood event during the Xia Dynasty and might have led to the fall of the Xia Dynasty.