China wants to drill into the Earth's mantle

Not to the center of the earth, but at least to unprecedented depths. To this end, the country's largest research vessel has been built and will commence its scientific operations in a few months' time.

The Meng Xiang – is almost 180 meters long and 33 meters wide and displaces 46,000 tons. The ship, which cost around 470 million US dollars, was developed and built entirely in China. There is space on board for 180 people to live and work on the ship. The ship has nine laboratories in which geologists, geochemists, microbiologists and oceanographers, among others, can carry out their work.

The ship's most important task will be to drill through the so-called Mohorovičić discontinuity, or Moho for short, into the Earth's mantle. This is the part of the earth that lies beneath the earth's crust on which we move. On land, this is between 15 and 20 kilometers thick. Under the seabed, however, it is only 5 to 15 kilometers to the Moho.

Meng Xiang to drill deeper than ever before

Meng Xiang should be able to drill up to 11 kilometers into the seabed. No one has ever reached this depth before. So far, we only have indirect knowledge of this area, based on seismographic measurements or minerals brought to the surface by volcanic activity. Meng Xiang is to collect samples in these regions for the first time and bring them to the surface.

Meng Xiang could be deployed in the Pacific or Indian Oceans. Moho could be the shallowest under the mountain ridges. The water there is about 4000 meters deep, and the Moho is another 6000 meters below that.

However, it will be some time before it reaches such depths: Temperatures of several hundred degrees Celsius and very high pressure prevail in the upper part of the earth's mantle. This can cause a borehole to collapse. To prevent this, drilling mud has to be pumped into the hole from the ship. This requires a new type of circulation system. This should be available by 2030 at the latest.

Searching for oil and gas deposits

In addition to its scientific tasks, the Meng Xiang will also perform commercial tasks: The ship will also be used for the exploration of undersea gas and oil fields.

The Meng Xiang was officially put into service in November 2024. The ship completed its first test voyage in December. The first scientific drillings are planned for early 2026, wrote Zhen Sun, geologist at the Guangzhou Marine Geological Survey and chief scientist of the Meng Xiang, recently in the journal Nature Geoscience.

The scientific community has high hopes for future research campaigns: "This ship has the ability to answer fundamental climate, oceanographic, microbiological and geoscientific questions – for the next 50 years," Dutch paleoceanographer Peter Bijl told the journal Science some time ago.

(wpl)