Abrupt changes in Indian summer monsoon strength during the last deglaciation and early Holocene based on stable isotope evidence from Lake Chenghai, southwest China

Sun, Weiwei, Zhang, Enlou, Shulmeister, James, Bird, Michael I., Chang, Jie, and Shen, Jie (2019) Abrupt changes in Indian summer monsoon strength during the last deglaciation and early Holocene based on stable isotope evidence from Lake Chenghai, southwest China. Quaternary Science Reviews, 218. pp. 1-9.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: https://doi.org/10.1016/j.quascirev.2019...
 
6
1


Abstract

Identifying variability and the mechanisms driving variability in the Indian summer monsoon (ISM) since the last deglaciation is critical for understanding past hydroclimatic change. In this study, we present an accelerator mass spectrometry radiocarbon dated record of delta O-18 variations in authigenic carbonates derived from Lake Chenghai in southwest China, a region that receives moisture mainly from the Indian Ocean. The delta O-18 values vary from -11.9 to +0.1 parts per thousand, providing a detailed record of variations in ISM precipitation delta O-18 values, and lake hydrological balance. The record shows that the ISM generally strengthened in the post-glacial between 15.6 and 8.8 cal ka BP, but that three centennial to millennial-scale drought events were superimposed on the long-term trend. Drought events, as indicated by substantial positive shifts in 8 18 0 value, occurred from 15.6 +/- 0.2 to 14.4 +/- 0.2, 12.5 +/- 0.2 to 11.7 +/- 0.2 and 10.1 +/- 0.1 to 10.0 +/- 0.1 cal ka BP, corresponding to the Heinrich 1, Younger Dryas, and Bond 7 cold events in the North Atlantic region, respectively. The timings of these droughts are suggested to be related to meltwater discharge into the North Atlantic. The weakened Atlantic Meridional Overturning circulation, which leads in turn to the southward migration of the intertropical convergence zone and cooling in the tropical Indian Ocean.

Item ID: 60408
Item Type: Article (Research - C1)
ISSN: 1873-457X
Keywords: Heinrich 1, Younger dryas, Bond cold event, Stable oxygen isotope, Lake chenghai, Authigenic carbonates
Copyright Information: (C) 2019 Elsevier Ltd. All rights reserved.
Funders: Program of Global Change and Mitigation (GCM), National Natural Science Foundation of China (NNSF)
Projects and Grants: GCM (2016YFA0600502), NNSF grant 41702183, NNSF grant 41572337, NNSF grant 41430530
Date Deposited: 04 Sep 2019 07:34
FoR Codes: 37 EARTH SCIENCES > 3703 Geochemistry > 370303 Isotope geochemistry @ 50%
37 EARTH SCIENCES > 3709 Physical geography and environmental geoscience > 370905 Quaternary environments @ 50%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970104 Expanding Knowledge in the Earth Sciences @ 100%
Downloads: Total: 1
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page