China's 13th scientific expedition team to the Arctic Ocean recently laid out seven submarine magnetotelluric instruments in a specific chronological order at the bottom of the sea for carrying out sophisticated studies on a volcanic field of Gakkel Ridge. Chinese scientists set off for the 13th Arctic Ocean scientific expedition aboard the Xuelong 2, the country's first domestically built polar icebreaker, from Shanghai on July 12. The team recovered those instruments seven days after the deployment.