Asian Summer Monsoon Changes Inferred From a Stalagmite δ18O Record in Central China During the Last Glacial Period

Frontiers in Earth Science

Zenglin Hong²  R. Lawrence Edwards³  Hai Cheng³  Yanjun Cai⁴  Qingmin Chen⁵  Juangang Ren⁶  Qianzhou Luo⁷  Peng Wang⁹  Yu Zhang⁹  Yi Hu⁹  Li Tang⁹  Junliang Zhang⁹  Yan Wang⁹  Gang Xue^1,10  Jie Zhou^1,11  Xing Cheng^1,11 

[1] 0Research Center of Intelligent Geological Survey, Northwestern Polytechnical University, Xi’an, China;1Key Laboratory of Mine Geological Hazards Mechanism and Control, Ministry of Natural Resources, Xi’an, China;Department of Earth Sciences, University of Minnesota, Minneapolis, MN, United States;Institute of Global Environmental Change, Xi’an Jiaotong University, Xi’an, China;Shaanxi Experimental Center of Geological Survey, Shaanxi Institute of Geological Survey, Xi’an, China;Shaanxi Geological Science and Technology Center, Shaanxi Institute of Geological Survey, Xi’an, China;Shaanxi Hygrogeology Engineering Geology and Environment Geology Survey Center, Shaanxi Institute of Geological Survey, Xi’an, China;Shaanxi Institute of Geological Survey, Xi’an, China;Shaanxi Mineral Resources and Geological Survey, Shaanxi Institute of Geological Survey, Xi’an, China;State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an, China;State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Science, Xi’an, China;

关键词: speleothem;    last glacial;    Indian summer monsoon;    East Asian summer monsoon;    time scales;    Chinese stalagmite δ18O;   

DOI  :  10.3389/feart.2022.863829

来源: DOAJ

【 摘 要 】

The reconstruction of Asian summer monsoon (ASM) changes during the last glacial period is of great significance for better understanding monsoon dynamics. The phase relationship between the Indian summer monsoon (ISM) and East Asian summer monsoon (EASM) subsystems on different timescales is still unclear. The comparative analysis of speleothem records in the ISM region, EASM region, and central China helps to clarify the relationship between the ISM and EASM. Based on the well-dated isotope records of stalagmite DDH-B15 from the Didonghe (DDH) Cave in Hanzhong, Shaanxi, we reconstructed ASM changes during the past 34–13 thousand years before the present (kyr BP). The small average error (61 years) of 18 uranium-series ages enables a precise comparison of the stalagmite δ18O record with other well-dated records from the orbital to the millennial timescales. The δ18O signal of the DDH-B15 stalagmite is controlled by changes of the low latitude northern hemisphere summer insolation (NHSI) on the orbital timescale. It records cold Heinrich Stadial (HS) and Dansgaard–Oeschger (DO) cycles which are originated from the northern high latitude on the millennial time scale. The δ18O changes of stalagmites from the three regions are similar on the millennial and centennial timescales. But on the orbital-suborbital timescale, stalagmite δ18O changes during the last glacial cycle have different characteristics. The stalagmite δ18O values in eastern China became gradually negative, and the stalagmite δ18O values in the Indian monsoon domain showed a increasing trend, but the stalagmite δ18O values in Central China adopted an intermediate state between the EASM and ISM. Then we argued that the δ18O value of stalagmites in Central China is a mixed signal of the ISM and EASM, which indicates a change of the water vapor source as an important influence on the Chinese stalagmite δ18O record.

【 授权许可】

Unknown