Subannual-to-biannual-resolved travertine record of Asian Summer Monsoon dynamics in the early Holocene at the eastern margin of Tibetan Plateau. (June 2022)

• Record Type: Journal Article
• Authors: Sun, Hailong; Shen, Chuan-Chou; Wu, Chung-Che; Chen, Bo; Yin, Jianjun; Yan, Hao; Dong, Jinguo; An, Dejun; Tang, Shu; Zhang, Qingming
• Is Part Of: Applied geochemistry. Volume 141(2022)
• Publication Date: 2022-06
• Subjects: Travertine -- Asian summer monsoon -- Oxygen isotope -- Solar activity -- Freshwater outburst -- Early Holocene; Environmental geochemistry -- Periodicals; Water chemistry -- Periodicals; Geochemistry -- Social aspects -- Periodicals; Geochemistry -- Periodicals; 551.9
• DOI: 10.1016/j.apgeochem.2022.105305
• Languages: English
• ISSNs: 0883-2927

Abstract

Abstract: In this study, we present a subannual–biannual-resolved (0.9–2 years) ASM intensity record spanning from 11.6 to 10.0 ka BP (before 1950 AD) inferred from a 230 Th-dated travertine δ 18 O record at Zhangjia Ravine on the eastern margin of the Tibetan Plateau. The ZJG-1 δ 18 O sequence is characterized by high-frequency fluctuations at decadal to centennial scales. Fluctuating between −11.15‰ and −14.78‰ over the δ 18 O sequence, the fluctuation range gradually decreased from 11.6 to 10.0 ka BP. There are several abrupt changes in the δ 18 O sequence, which indicate that the ASM in the early Holocene was highly unstable. Comparison with marine records suggests that the Preboreal oscillation (PBO) event could be triggered by a freshwater outburst which led to/resulted in a sudden release of thousands of cubic kilometers of the meltwater to the North Atlantic Ocean. Furthermore, the climate oscillations during the PBO were associated with the complex interplay of solar activity and freshwater outburst, the freshwater outburst may amplify the effect of solar activity when it was in the minima. The rapid warming after the PBO event may be controlled by the common mechanism that induced the Dansgaard–Oeschger warming events during the last glacial period. The further pronounced increases of the travertine δ 18 O values occurred at about 10.3 ka BP, coinciding roughly with Bond 7 event, also caused by the freshwater outburst and solar activity. This study is not only important to understand the primary driving force of the ASM intensity in the early Holocene, but also essential for evaluate the probability of abrupt climate changes in the future. Highlights: Subannual–biannual-resolved Asian Summer Monsoon variations from 11.6 to 10.0 ka BP were reconstructed by travertine. Asian Summer Monsoon variations were instant response to changes in solar activity. The Preboreal oscillations were associated with the complex interplay of solar activity and freshwater outburst. The freshwater outburst may amplify the effect of solar activity in minima.