Photo taken on June 21, 2017 shows a drill machine on the trial mining site in the Shenhu area of the South China Sea. China has extracted about 235,000 cubic meters of the combustible ice from the South China Sea, beating previous expectations for the mining operation. Wednesday afternoon marked six weeks of an ongoing mining operation in waters near the Pearl River estuary, without being disrupted by this year's second typhoon Merbok. [Photo/Xinhua]