June 10, 2025
China is preparing to drill through the earth's crust and reach the mantle. If the drilling ship reaches the mantle boundary, it will be a scientific breakthrough comparable to landing on the moon, the researchers believe.
China has launched an ambitious deep-sea drilling project with the Meng Xiang ("Dream") drillin ship, which aims to reach the boundary between the earth's crust and mantle - the Mohorovičić discontinuity (Moho boundary, or just Moho) for the first time in history. The ship will begin drilling in the South China Sea at the end of 2025. This is reported by Xinhua and Nature Geoscience.
What is Meng Xiang?
Meng Xiang is the first Chinese deep-sea drilling vessel built by China Geological Survey. The ship is 179.8 m long, 32.8 m wide, and has a displacement of 42,600 tons. It carries a crew of 180 people, can operate for 120 days without entering a port and travel 15,000 nautical miles (27,780 km). Its drilling rig reaches 11 km below sea level.
"Meng Xiang is a mobile national laboratory," says Zhou Yang, head of the Guangzhou Marine Geological Survey production control group.
The ship is equipped with nine laboratories for geology, microbiology and oceanology, as well as a drilling mud recycling system that reduces harm to the sea.
The main goal of the project
Meng Xiang aims at the Moho discontinuity, the boundary between the crust (5-10 km thick under the ocean) and the mantle, which makes up 80% of the Earth's volume. Moho boundary, discovered in 1909 by Croatian seismologist Andrija Mohorovičić, is a place where light rocks of the crust are replaced by dense rocks of the mantle. Direct samples of the mantle can reveal how the Earth formed, continents moved, and life originated.
"Deep—sea samples will provide scientists with direct evidence to study plate tectonics, crustal evolution, and ancient climates," said Xu Zhenqiang, director of the Guangzhou Marine Geological Survey.
Exploration work for oil, gas and methane hydrates ("combustible ice") is also planned, which is important for China's energy sector. However, drilling in the South China Sea, where China claims 90% of the territory disputed by Vietnam, the Philippines and Malaysia, could increase tensions.
"If Meng Xiang is suspected of exploring for resources in disputed waters, it will cause diplomatic conflicts," writes The Times of India.
How are they planning to drill up to the mantle
Drilling at a depth of 11 km is a difficult task. At such depths, the pressure reaches 2,000 atmospheres and the temperature is 150-300 °C. Rocks become brittle, then plastic, like red-hot putty, which makes it difficult for the drill to work. Meng Xiang will use titanium rods and diamond crowns, as well as a drilling fluid circulation system to prevent the well from collapsing. The ship stabilizes in rough seas, withstanding typhoons of up to 12 points. His first expedition is scheduled for 2026, and full drilling to Moho by 2030. Environmentalists fear methane leaks that increase ocean acidity.
Chinese scientists note that if Meng Xiang reaches Moho boundary, it will be compared to landing on the moon.
Sources:
https://www.nature.com/articles/s41561-025-01675-7
https://english.news.cn/20250608/c94a6e6f484d48d8b8d25a16db5dcebb/c.html