China's research icebreaker Xuelong, or Snow Dragon, sails at the Prydz Bay in Antarctica, Nov. 29, 2018. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)

Photo taken on Nov. 30, 2018 shows penguins at the Prydz Bay in Antarctica. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)

Photo taken on Nov. 30, 2018 shows penguins at the Prydz Bay in Antarctica. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)

Photo taken on Nov. 29, 2018 shows icebergs at the Prydz Bay in Antarctica. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)

Photo taken on Nov. 29, 2018 shows icebergs at the Prydz Bay seen from China's research icebreaker Xuelong in Antarctica. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)

Photo taken on Nov. 30, 2018 shows plate ices at the Prydz Bay in Antarctica. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)

Photo taken on Nov. 30, 2018 shows penguins at the Prydz Bay in Antarctica. Xuelong, carrying a research team on the country's 35th Antarctic expedition, set sail from Shanghai on Nov. 2 and passed Prydz Bay, the last sea area before arriving at China's Zhongshan Station in Antarctica. (Xinhua/Liu Shiping)