Japan’s Chikyu Pulls Rare Earth Mud from Six Kilometres Down

About 1,900 kilometres southeast of Tokyo, deep below a patch of the Pacific that most ships never cross, Japan's drilling ship Chikyu completed a mission that researchers say has no precedent. It pulled rare earth-bearing mud from roughly 6,000 metres down. Nobody had done that continuously before.

The results, announced July 25. Medium and heavy rare earth elements make up around 54 percent of the total rare earth content in the recovered sediment. Dysprosium and gadolinium were among the minerals identified, along with yttrium. These go into permanent magnets for electric vehicles, wind turbines, and guided weapons.

Minamitorishima, the remote island at the centre of the drilling area, sits far east of Japan's main islands. Getting mud up from 6,000 metres is a different challenge from any shallow-water extraction. Chikyu is a purpose-built scientific drilling ship operated by Japan's Agency for Marine-Earth Science and Technology, and it carried equipment designed to handle deep-ocean sediment.

A full extraction trial is planned for early 2027. The target is 350 tonnes of mud per day. Japan and the United States have both been looking for ways to source these minerals outside China, which currently dominates the global rare earth supply chain.

For context on following specialist vessels at sea, read about identifying ship types, offshore satellite AIS tracking, and examining vessel route history.