Abrupt weakening of the Indian summer monsoon at 8.2 kyr BP
Abrupt weakening of the Indian summer monsoon at 8.2 kyr BP
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DOI：
10.1016/j.epsl.2014.01.026
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发表时间：
2014-04-01
影响因子：
5.3
通讯作者：
Petrie, Cameron A.
中科院分区：
文献类型：
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作者：
Dixit, Yama;Hodell, David A.;Petrie, Cameron A.
印度西北Riwasa古湖泊的生物碳酸盐氧同位素记录提供了印度夏季风（ISM）的历史，时间跨度约为11 ~ 6 kyr B.P.。全新世早期湖泊开始沉积，湖泊深度在9.4 kyr b.p.左右显著加深，表明夏季日照强迫使ISM增强。这个高湖位被突然的干燥打断，其标志是在大约8.3 kyr B.P.的地下暴露期间形成的12厘米的石灰岩硬地。硬地表面的底部与北大西洋“8.2 kyr B.P.冷却事件”的开始相吻合，该事件与冰川爆发洪水和大西洋经向翻转环流的减缓有关。硬地面提供了强有力的证据，表明印度次大陆的ISM在8.2 kyr b.p.范围内减弱，并支持了先前亚洲季风与北大西洋气候之间存在强烈遥相关的结果。湖泊沉积在大约7.9 kyr B.P.恢复，表明古里瓦萨湖8.2 kyr的干涸是ISM对北大西洋强迫的突然反应。(C) 2014年作者。这是一篇基于CC by许可（http://creativecommons.org/licenses/by/3.0/）的开放获取文章。
An oxygen isotope record of biogenic carbonate from paleolake Riwasa in northwestern (NW) India provides a history of the Indian Summer Monsoon (ISM) from similar to 11 to 6 kyr B.P. The lake was dry throughout the Late Glacial period when aeolian sands were deposited. Lacustrine sedimentation commenced in the early Holocene and the lake deepened significantly at similar to 9.4 kyr B.P., indicating a strengthening of the ISM in response to summer insolation forcing. This high lake stand was interrupted by an abrupt desiccation, which is marked by a 12-cm limestone hardground that formed during a period of sub-aerial exposure after similar to 8.3 kyr B.P. The base of the hardground surface coincides with the beginning of the '8.2-kyr B.P. cooling event' in the North Atlantic that has been associated with a glacial outburst flood and slowdown of Atlantic meridional overturning circulation. The hardground provides robust evidence of a weakening of the ISM on the Indian subcontinent at similar to 8.2 kyr B.P., and supports previous results of a strong teleconnection between monsoon Asia and North Atlantic climate. Lacustrine sedimentation resumed at similar to 7.9 kyr B.P. suggesting the 8.2-kyr desiccation of paleolake Riwasa represented an abrupt response of the ISM to forcing from the North Atlantic. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).