LHASA, July 13 (Xinhua) -- The core drilling project in Nam Co, the world's highest saltwater lake in southwest China's Xizang Autonomous Region, achieved a drilling depth exceeding 400 meters. It is of great significance in the country's lake drilling and paleoclimate study, according to scientists.

　　At 06:35 p.m. on Friday, the multinational joint scientific expedition team extracted a lake sediment core from a depth of 402.2 meters under the lake bed of Nam Co, surpassing the previous maximum depth of 153.44 meters in lake drilling on the Qinghai-Xizang Plateau.

　　Nam Co is an enclosed lake that gathers information about rocks, soil, vegetation, rivers and human activities in the catchment, making the lake significant for environmental changes research, according to Wang Junbo, one of the leaders of the scientific expedition team.

　　"By studying lake sediment cores, we can gain a deeper understanding of the climate and environmental changes on the Qinghai-Xizang Plateau over the past one million years and provide a science base for future climate forecasts," said Wang, who is also a researcher at the Institute of Ti betan Plateau Research (ITP), Chinese Academy of Sciences.

　　Nam Co, located in the Qinghai-Xizang Plateau, with a lake-surface elevation of over 4,700 meters, is the second-largest lake in the region and an important scientific research base.

　　The scientific expedition, launched in early June, is a joint effort by an ITP research team looking at lake and environmental changes, along with scientists and drilling technicians from Germany, Switzerland, Britain and the United States.

　　According to Zhu Liping, another leaders of the scientific expedition team and a researcher at the ITP, the drilling of the lake sediment core in Nam Co is the highest-altitude drilling project under the International Continental Scientific Drilling Program.

　　Zhu said the collected lake sediment cores will be transferred to and scanned at the ITP and permanently retained there for further analyses.

　　"The breakthrough in drilling will promote high-level research on lake drilling in China and can exhibit international impacts on relevant scientific research cooperation," Zhu added.