Scientific researchers of Jiaolong attend a welcome ceremony in Qingdao, east China's Shandong Province, June 23, 2017. Chinese submersible Jiaolong returned to the national deep sea center at east China's Qingdao on Friday, ending a four-month expedition. The submersible made 30 dives during the country's 38th oceanic scientific expedition and descended to nearly 6,700 meters in the Yap Trench in the west Pacific, close to its record depth of 7,062 meters in 2012. (Xinhua/Zhang Xudong)
