A 3000-yr annually laminated stalagmite record of the Last Glacial Maximum from Hulu Cave, China

A high-resolution, annual layer-counted and Th-230-dated multi-proxy record is constructed from a stalagmite in Hulu Cave, China. These proxies, including delta O-18, annual layer thickness (ALT), gray level (GL) and Sr/Ca, cover a time span of similar to 3000 yr from 21 to 24 ka. The physical proxies (ALT and GL) and the geochemical index (Sr/Ca), all primarily reflecting karst hydrological processes, vary in concert and their coherence is supported by wavelet analyses. Variations in the delta O-18 data agree with fluctuations in the ALT and Sr/Ca records on multi-decadal to centennial scales, suggesting that the Hulu delta O-18 signal is strongly associated with varying local rainfall amounts on short timescales. A monsoon failure event at similar to 22.2 ka correlates with a decrease in tropical rainfall, a reduction in global CH4 and an ice-rafted event in the North Atlantic. This correlation highlights roles of the Asian monsoon and tropical hydrological cycle in modulating global CH4, because the high-latitude emission was inhibited during the Last Glacial Maximum (LGM). Spectral analysis of the delta O-18 record displays peaks at periodicities of 139, 59, 53, 43, 30, 23 and 19-15 yr. The absence of typical centennial solar cycles may be related to muted changes in ocean circulation during the LGM. (C) 2015 University of Washington. Published by Elsevier Inc. All rights reserved.