• 研究论文 •

### 可可西里地区中更新世以来气候演化周期特征分析

1. 1.山西师范大学地理科学学院,临汾 041000
2.陕西师范大学地理科学与旅游学院,西安 710119
• 收稿日期:2020-01-06 接受日期:2020-07-20 出版日期:2021-03-10 发布日期:2021-05-10
• 作者简介:田庆春（1982-）,男,内蒙古呼和浩特人,博士,副教授,硕士生导师,主要研究方向为全球变化与第四纪环境演变。E-mail: tianqch2006@126.com
• 基金资助:
国家自然科学基金项目(41701223)

### Characteristics of climate evolution cycle since the Middle Pleistocene in the Hoh Xil area

TIAN Qingchun1(), PEI Yu1, SHI Peihong2

1. 1. College of Geographical Science, Shanxi Normal University, Linfen 041000, Shanxi, China
2. School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China
• Received:2020-01-06 Accepted:2020-07-20 Online:2021-03-10 Published:2021-05-10

Abstract:

As one of the most important geological events in the Cenozoic era, the Tibetan Plateau's (TP) uplift has profoundly influenced the Asian and global climate and environmental evolution. Therefore, the TP has become the focus of geography research subject at home and abroad and has obtained great achievements. However, there are still many problems to be further explored. In this study, Hoh Xil, the hinterland of TP, was taken as the research area, and a 106-meter lake sedimentary borehole called BDQ06 was obtained in August 2006, geographically at 35°13′05″N and 93°55′52.2″E. The grain size and total organic carbon of lake sediments are chosen as climatic indicators. The approaches of Power Spectrum Analysis (PSA), Singular Spectrum Analysis (SSA), and the Continuous Wavelet Transform (CWT) are used to analyze the climate evolution cycle. Based on paleomagnetism's chronological framework, paleoclimatic cycle evolution since the last 929 ka has been investigated. The results show that the quasi-periodic components of the earth's eccentricity (100 ka), obliquity (41 ka), and precession (23 ka and 19 ka) exist in the BDQ06 hole. Meanwhile, the periodic components of 84, 66, 54, 36, 31, 27, 17, 15, 12, 11.5, 10 ka, and so on are found in the record. All this indicates that the climate changes in the Hoh Xil area are influenced not only by the earth's orbital parameters but also by other factors in the inner of the earth system. Furthermore, CWT and SSA show that different climate cycles can be superimposed in the same period and exist in different periods. Besides, an obvious climate transition has been observed at 780 ka. The dominant period is 41 ka though the period of 100 ka existed in the record ahead of this time point. However, after 780 ka, the controlling period shifted to 100 ka. Moreover, the climatic periodic characteristic has become gradually complicated since 580 ka BP, which is possibly affected by the change of hydrodynamic conditions caused by the TP's tectonic uplift. We concluded that although the Hoh Xil's climate cycle characteristics are consistent with global features, but they have apparent regional characteristics. Also, the periodic signals of grain size and total organic carbon are not wholly consistent, so the significance of climate proxy indicators needs to be further explored.