Photo taken on Feb. 15, 2019 shows a penguin and a seal on an iceberg in Antarctica. China's research icebreaker Xuelong, with 126 crew members aboard on the 35th Antarctic research mission, on Thursday local time left the Zhongshan Station on its way back to China. It is expected to arrive in Shanghai in mid-March. (Xinhua/Liu Shiping)

Photo taken on Feb. 15, 2019 shows penguins on an iceberg in Antarctica. 

Photo taken on Feb. 15, 2019 shows penguins on an iceberg in Antarctica. 

Photo taken on Feb. 15, 2019 shows penguins on an iceberg in Antarctica.

Photo taken on Feb. 15, 2019 shows newly formed ice in the sea of Antarctica. 

Photo taken on Feb. 15, 2019 shows penguins on an iceberg in Antarctica. 

Photo taken on Feb. 15, 2019 shows penguins in the waters of Antarctica. 

Photo taken on Feb. 15, 2019 shows an iceberg detached from an ice shelf in Antarctica.

Photo taken on Feb. 15, 2019 shows the edge of the West Ice Shelf in Antarctica. 

China's research icebreaker Xuelong sails in waters near the West Ice Shelf in Antarctica, on Feb. 15, 2019. 

Photo taken on Feb. 15, 2019 shows icebergs in waters near the West Ice Shelf in Antarctica.