A 150 Year Climate Change History Reconstructed by Lake Sediment of Nam Co, Tibetan Plateau

Key words: 
• Tibetan Plateau /
• Nam Co /
• lake sediment /
• climate change

Abstract: Nam  Co in high-altitude area is the ideal place to study the past climatic and environmental changes. In this paper, we tried to compare the measured lake sediment results of Nam Co with meteorological data in local stations and  chose  some proxies to reconstruct the climate and environment change record in the past 150 years in this area. The values of TOC, grain size, Sr/Ba and Rb/Sr had clear environment significance and reflected the climate change well. Geochemical multi-proxies of lake core NMC09 showed the final result  as follows, the climate was characterized with warm and humid from 1 850~1 900 A.D.. During the period of 1 900~1 950 A.D., it was a cold-wet period, and had transformed to the warm and humid period gradually since 1920s. After the 1950s it had main trend of rising temperature although it had a little climate fluctuations, and the lake did not shrink obviously in spite of reduced precipitation. It suggested that rising temperature could lead to glacier melting accelerated to supply the run-off into Nam Co.