The Chinese icebreaker Xuelong, carrying the 349 members of China's 35th research mission to Antarctica, returned to Shanghai safely on Tuesday, about a month earlier than originally scheduled due to a collision with an iceberg.
Despite the Jan 19 collision in the Amundsen Sea, the crew managed to carry out comprehensive research at five stations, including Changcheng, Zhongshan and Taishan, aerial geophysical remote sensing observation in the southeast polar ice cap, and marine surveys in the Amundsen Sea.
"Our team obtained valuable data and samples on the expedition, and filled the scientific gaps in the investigation of the Amundsen Sea area," said Li Yuhong, an assistant researcher from No 3 Marine Institute of the Department of Natural Resources, who joined the 35th expedition.
Scientists discovered the possible presence of krill breeding grounds around Peter I Island in the Amundsen Sea area. The distribution of phytoplankton in the eastern Amundsen Sea area was preliminarily proved through the first application of a trace metal sampling method developed by China.
At Changcheng station, scientists conducted ecological environment monitoring, glacier monitoring and regular meteorological observation projects. Seismic stations there have been upgraded, and a radar sea-level observation system has been constructed, the administration said.
Nearly 200 kilograms of samples of soil, water, animal and plant specimens and other materials, were collected at Changcheng station. Scientists also established the country's first polar region sodium fluorescence laser Doppler radar room at Zhongshan station. During its trial run, about 51 hours of valid data and 2.5 GB of original data were collected.
The research team also completed its first test drilling without a drill pipe core in polar ice bedrock, which helped the scientists obtain the first few samples of bedrock under the ice cores at the station. The construction of Taishan station was also completed during the expedition.
Xuelong left Shanghai on Nov 2 and arrived at Zhongshan Station on Nov 30. The icebreaker entered the Amundsen Sea in early January for a marine survey but experienced "the worst sea conditions since departure", according to an earlier report by China Ocean News.
On Jan 19, the ship was caught in a sudden thick fog on the Amundsen Sea and collided with an iceberg, Cheng Xiao, dean of the College of Global Change and Earth System Science at Beijing Normal University, told Xinhua.
An increase of cyclones in the area since the start of 2019 has greatly increased the number of floating ice fragments, while in 2018 the area was a single large ice sheet, Chen said. The floating ice drifted to the north, pushed by the wind, which also affected navigation on Xuelong's trip home, he added.
The collision broke the ship's mast and left about 250 metric tons of snow and ice on its front deck. The rest of the ship was undamaged.
The difficult ice conditions and active cyclones in the Amundsen Sea have vexed Chinese explorers for decades. It was not until March that China's 34th expedition successfully completed the first marine survey of the sea.