Millennial-scale alkenone sea surface temperature changes in the northern South China Sea during the past 45,000 years (MD972146)

摘要

Millennial-scale climate changes are well-expressed in Greenland ice core and North Atlantic marine records. The timing and the amplitude of the millennial-scale changes outside Greenland and the North Atlantic are poorly known, mainly due to the lack of high quality climatic archives with precise constraints of numerical dating. Here, we report a new, high-resolution AMS ~(14)C dated alkenone sea surface temperature (SST) record of the last 45,000 years from a marine sediment core (MD972146) retrieved from the northern South China Sea (SCS). The SST record shows millennial-scale oscillations during the intervals of since the Last Glacial Maximum (LGM, ～ 21,000 BP) to the present, and ～ 34-45 ka, that are nearly in-phase with those from the Northern Hemisphere (NH). SST oscillations during ～21-34 ka do not match well with the NH patterns, implying that a dominance of "non-NH" mechanisms may have governed the SST changes outside the NH high latitudes during the particular time interval. The "non-NH" climatic pattern during ～21-34 ka has been only reported from a SST record from the Okinawa Trough sediments (MD012404) and a grain size record from Chinese loess sequences (Gulang), but not from the other SCS records which had been investigated using lower resolution sampling and age dating.