Aerial photo taken on July 22, 2019 shows a Chinese scientific expedition team taking a boat to the main area of Lake Yamzhog Yumco for survey in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region. Chinese scientists are working on a survey to measure the depth of a major lake in southwest China's Tibet Autonomous Region, sources with the Chinese Academy of Sciences (CAS) said Tuesday. Lake Yamzhog Yumco with an area of about 590 square km is located in Nanggarze County in the city of Shannan. Yamzhog Yumco along with Lake Namtso and Lake Manasarovar are regarded as the three holy lakes of Tibet. (Xinhua/Jigme Dorje)