A Holocene history of the Indian monsoon from Qilu Lake, southwestern China
A Holocene history of the Indian monsoon from Qilu Lake, southwestern China
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DOI：
10.1016/j.quascirev.2019.106051
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发表时间：
2020
影响因子：
4
通讯作者：
A. Hillman;Ryan F. O’Quinn;M. Abbott;D. Bain
中科院分区：
文献类型：
--
作者：
A. Hillman;Ryan F. O’Quinn;M. Abbott;D. Bain
了解过去印度夏季风(ISM)强度突变的规模、性质和强迫机制，对于描述未来在全球气候变化中的表现至关重要，特别是在百年时间尺度上。本文总结了云南齐鲁湖6200年来的氧同位素记录--中国。该湖对降水-蒸发平衡的变化很敏感，并沉淀了方解石，通过氧同位素分析可能提供了对过去水文气候的洞察。从5200 Cal 年BP开始，氧同位素向更高的值移动，这表明了一段时期的干旱和较低的湖泊水位，这种情况一直持续到3600 Car 年BP。此后，湖泊水位非常稳定，直到1500年 称为 年BP。在1500年 卡 年BP，发生了可测量的人为影响，导致红色的富铁集水区土壤输送到湖泊和更高的氧同位素值。这些变化很可能是为了扩大农业活动而清理土地的结果。齐鲁记录与北面10 公里的星云湖记录非常一致，有力地表明区域气候驱动因素导致了5200 年BP之后的变化，然后是3600~1500 年BP的稳定。这些记录与东葛洞的对比说明了蒸发富集在驱动氧同位素值从5200~3600 称为 年BP中的重要性。
Understanding the magnitude, nature, and forcing mechanisms of past abrupt changes in Indian Summer Monsoon (ISM) strength is central to characterizing future manifestations in the face of global climate change, particularly at centennial time scales. Here we summarize a 6200 year record of oxygen isotopes from Lake Qilu in Yunnan Province, China. The lake is sensitive to changes in precipitation-evaporation balance and precipitates calcite, potentially providing insight into past hydroclimate through oxygen isotope analysis. Beginning at 5200 cal years BP, oxygen isotopes shift to higher values, indicative of a period of aridity and lower lake levels which persist until 3600 cal years BP. Thereafter, lake levels are extraordinarily stable until 1500 cal years BP. At 1500 cal years BP, measurable anthropogenic impacts occur, resulting in the delivery of red, iron-rich catchment soil to the lake and higher oxygen isotope values. These changes are likely the result of land clearance for the expansion of agricultural activities. The Qilu record is remarkably consistent with the record from Xingyun Lake, 10 km to the north, strongly suggesting that regional climate drivers are responsible for the changes after 5200 cal years BP and then the stability from 3600 to 1500 cal years BP. Comparison of both these records with Dongge Cave illustrate the importance of evaporative enrichment in driving higher oxygen isotope values from 5200 to 3600 cal years BP.