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)

A member of a Chinese scientific expedition team checks the depth of Lake Yamzhog Yumco for survey in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

Members of a Chinese scientific expedition team prepare a rubber dinghy for survey in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

A member of a Chinese scientific expedition team detects underwater topography of Lake Yamzhog Yumco via a sonar device in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

Members of a Chinese scientific expedition team take out the sediment core of Lake Yamzhog Yumco in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

Members of a Chinese scientific expedition team use a drill to get the sediment core of Lake Yamzhog Yumco in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

A member of a Chinese scientific expedition team prepares devices for survey in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

Members of a Chinese scientific expedition team mark the sediment core of Lake Yamzhog Yumco in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

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)

Members of a Chinese scientific expedition team take a boat via a navigation system to the main area of Lake Yamzhog Yumco for survey in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)

Members of a Chinese scientific expedition team use a drill to get the sediment core of Lake Yamzhog Yumco in Nanggarze County of Shannan, southwest China's Tibet Autonomous Region, July 22, 2019. 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)