A new speleothem record of the penultimate deglacial: Insights into spatial variability and centennial-scale instabilities of East Asian monsoon

• Published in: Quaternary Science Reviews
• Main Authors: Xue, Gang, Cai, Yanjun, Ma, Le, Cheng, Xing, Cheng, Hai, Edwards, R. Lawrence, Li, Dong, Tan, Liangcheng
• Format: Report
• Language: English
• Published: PERGAMON-ELSEVIER SCIENCE LTD 2019
• Subjects: Stalagmite; Oxygen isotope; Penultimate deglaciation; Weak monsoon interval; Coastline shift; CHINESE CAVE RECORDS; HIGH-RESOLUTION; NORTH-ATLANTIC; SUMMER MONSOON; CLIMATE RECONSTRUCTION; SHANDONG PENINSULA; OXYGEN ISOTOPES; YOUNGER DRYAS; DONGGE CAVE; HULU CAVE; Physical Geography; Geology; Geography; Physical; Geosciences; Multidisciplinary; Hulu; North Atlantic
• Online Access: http://ir.ieecas.cn/handle/361006/14140; https://doi.org/10.1016/j.quascirev.2019.02.023

We present a highly resolved oxygen isotope (delta O-18) record of the penultimate glacial-interglacial transition from a 230 Th-dated stalagmite (SDI) from the Shangxiaofeng Cave in north-eastern China. Our delta O-18 record reveals two prominent features. First, the SDI delta O-18 record documents a brief increase of delta O-18 between 128.5 and 128.1 ka BP. Though this event has been identified in several marine records, our radiogenic dated record precisely constraints the timing and duration of the climate deterioration suggesting that this YD-like event is likely an intrinsic feature of climate change during the ice age terminations. Additionally, the delta O-18 magnitude of the glacial-interglacial change (-0.7%0) is significantly smaller compared to the delta O-18 records from inland and relatively high elevation caves (Dongge, Sanbao and Yangkou caves) (1.4-2.4%o) but comparable to the Hulu Cave at low elevation and proximal to the shallow Bohai and Yellow seas (Kelly et al., 2006; Cheng et al., 2006; Wang et al., 2008; Cheng et al., 2009; Li et al., 2014). Assuming that the cave delta O-18 records mainly reflect precipitation isotope composition changes, the glacial-interglacial speleothem delta O-18 difference between the various Chinese caves could be related to changes in atmospheric circulations, changing effect of altitude between the various caves and climate mean states, and large-scale changes in regional land-sea coverage due to sea level changes. The latter leads to disappearance and expansion of Bohai and Yellow seas during glacial and interglacial episodes, respectively, and likely affect the amount and isotope composition of precipitation. Taken together, our study highlights that hydroclimate imprints of the East Asian Monsoon changes during the penultimate glacial-interglacial cycle were spatially heterogeneous and centennial-scale monsoonal hydroclimate instabilities are likely inherent features of deglacial climate transition. (C) 2019 Elsevier Ltd. All rights reserved.