BEIJING, April 8 (Xinhua) -- China's 42nd Antarctic expedition team has successfully completed the country's first hot-water drilling test in the Antarctic ice sheet, achieving a depth of 3,413 meters, the Ministry of Natural Resources said on Tuesday.
This marks a breakthrough beyond the previous international record of 2,540 meters for hot-water drilling in polar regions.
The research team successfully completed the drilling test on Feb. 5 this year in the area of the Qilin subglacial lake, which was independently named by China, according to Guo Jingxue, head of the "subglacial lake" team of China's 42nd Antarctic expedition and a senior engineer at the Polar Research Institute of China.
The subglacial lake is buried beneath an ice sheet more than 3,000 meters thick and is located approximately 120 kilometers from China's Antarctic Taishan Station.
The Antarctic subglacial lakes have long been sealed in an extreme environment of high pressure, low temperature, darkness and low nutrient levels, Guo said, adding that drilling into these lakes represents a frontier of international scientific research aimed at studying ancient environmental changes on Earth, predicting future climate change, exploring the boundaries of life and expanding human knowledge.
The primary goal of this field test was to conduct an Antarctic application demonstration of a deep ice sheet hot-water drilling system, said Zhang Nan, a member of the "subglacial lake" team and a professor at Jilin University.
By drilling through the ice sheet above the Qilin subglacial lake, the team aims to provide a contamination-free access and key technical support for subsequent in-situ observations of subglacial lakes, as well as for the collection of water and sediment samples from the lake bed.
Drilling through a 3,413-meter-thick ice sheet not only tests interdisciplinary technical support but also demonstrates strong comprehensive logistical capabilities.
The field test involved multiple challenging stages, including sea ice and inland material transport, equipment assembly and debugging, hot-water drilling operations, and process contamination monitoring.
The success of this polar hot-water drilling test marks that China has acquired the capability to conduct drilling research in over 90 percent of the Antarctic ice sheet and the entire Arctic ice sheet.
Hot-water drilling is a non-mechanical drilling technique that melts ice using high-temperature and high-pressure hot water. It offers high drilling speed, capable of penetrating a kilometer-thick ice layer within one day, and can reach great depths, exceeding 3,000 meters in polar regions, according to the journal Drilling Engineering.
Since water is used as the medium, there is no risk of contaminating subglacial lakes or oceans with drilling fluids.
Compared with traditional mechanical ice drills, hot-water drilling offers stronger penetration capability, higher drilling efficiency, easier access to large boreholes and cleaner operation, said Li Bing, a member of the "subglacial lake" team and a professor at China University of Geosciences (Beijing).
It can efficiently reach key interfaces such as subglacial lakes, the undersides of ice shelves and subglacial bedrock, making it the mainstream technology used globally for studying the deep environments of polar ice sheets and ice shelves, Li noted.
The "subglacial lake" team of China's 42nd Antarctic expedition consisted of 28 members from nine research institutions and universities nationwide. ■
