Chinese explores work nearby a crack on an ice layer above the ocean to find a safe transportation route to Zhongshan Research Station from Xuelong (Snow Dragon) icebreaker in the Antarctic area on Dec 4, 2013. The Chinese research vessel and icebreaker Xuelong for the 30th scientific expedition to Antarctica is going to prepare its first unloading mission after arriving at an area about 19 nautical miles away from China's Zhangshan Research Station. [Photo/Xinhua]