China’s Mengxiang vessel sets national record in deep-sea drilling
China has reached a new milestone in deep-sea exploration, with the research vessel Mengxiang drilling to nearly 5,000 meters and recovering basalt samples from the South China Sea basin. The cores and data obtained during the expedition expand China’s capabilities in studying the geological history of the ocean and ultra-deepwater resources.
According to the Ministry of Natural Resources, researchers used a domestically developed drilling system during a 30-day voyage to recover a 4.27-meter basalt sample. China has now become the third country, after the United States and Japan, to obtain hard-rock samples from a deep ocean basin using a drilling vessel.
“From our current position, we drilled down 4,929.17 meters, extracting 109 meters of core with a 61.7 percent recovery rate. Meanwhile, we retrieved about 4.3 meters of basalt core samples at a depth of around 4,300 meters,” said Wang Mingxin, an engineer with the Guangzhou Marine Geological Survey and leader of the drilling team aboard the Mengxiang.
He said the results demonstrated the advantages of the vessel’s light-tonnage, modular and multifunctional design, enabling it to undertake both oil and gas exploration and scientific core sampling.
During the expedition, the research team also conducted prolonged operations with two remotely operated vehicles. The ROVs operated for more than 358 hours in total at a depth of 4,000 meters, with one continuous operation lasting as long as 103 hours. Researchers said the performance reached internationally advanced levels.
For the first time, the team followed the standards of the International Ocean Discovery Program to carry out a full range of sample-processing operations on board, including cataloging, cutting, scanning, testing and storage. This gave the researchers full-process operational capabilities for ultra-deepwater scientific drilling.
The samples and data collected during the voyage provide important evidence for studying the expansion of the South China Sea and the evolution of the ancient marine environment. They also support research into the exploration and development of ultra-deepwater energy resources.
“The sediment was initially black and rich in organic matter, indicating a sudden die-off of marine organisms and the subsequent dissolution of their calcareous shells. It later turned green, signaling a partial recovery of oxygen levels despite remaining hypoxic, and eventually turned red, indicating an oxygen-rich environment,” said Sun Zhen, a researcher with the Guangzhou Marine Geological Survey and chief scientist of the voyage.
He said the changes could help researchers better understand the scale and duration of extinction events triggered by massive magma eruptions.
A total of 170 researchers from nine institutions took part in the expedition. The voyage was organized by the China Geological Survey and implemented by the Guangzhou Marine Geological Survey.
Mengxiang, China’s first domestically built ocean drilling vessel, was officially commissioned in 2024. As reported by CCTV+, the expedition demonstrated the vessel’s capabilities in ultra-deepwater drilling and scientific exploration of the ocean floor.
