By Ha Er-rui | 2026-05-28

Chinese researchers have released the country's first geochemical atlas of seabed sediments in its eastern waters, a move analysts say highlights Beijing's growing focus on critical minerals, maritime claims and undersea strategic capabilities.

The atlas, published in April by the China Geological Survey, covers the Bohai, Yellow and East China seas and draws on measured surface sediment and machine-learning data from more than 20,000 stations, according to Xinhua. Researchers used the data to map the distribution of elements across the seabed.

Researchers mapped the distribution and concentration of dozens of elements, including iron, manganese, copper and rare earth elements. The researchers described the atlas as a "navigation chart" for marine development and environmental protection in the region.

It, however, does not include the South China Sea.

Seabed mapping

The atlas "can enable more precise targeting of seabed mineral resources, reducing blind exploration, Dou Yanguang, a researcher at the Qingdao Institute of Marine Geology under the China Geological Survey and one of the study's authors, said. The report said it provides "precise data to support regional spatial planning, ecological protection, and resource exploration."

However, China's domination of rare earth and critical mineral supply chains has fueled concern over the strategic value of such data, especially as Beijing has repeatedly used export controls as a policy tool.

Seabed mapping of this kind can serve both scientific and military purposes, particularly by improving China's understanding of underwater terrain and subsea conditions, Bruce Jones, a Brookings Institution scholar of naval affairs and foreign policy, told The New York Times in April.

Military ambitions

"With mapping of this nature, you can use it for science, and you can use it for warfare," Jones said. "It's a rare earth play, it's a scientific play, and it's a strategic play all at once."

China is investing heavily to become a leading oceanographic power, narrowing the gap with the United States while expanding its military capabilities and building the knowledge needed for underwater warfare, said Jones.

China uses scientific and conservation activities to assert authority over disputed waters, Sun Yun, a scholar at the Washington-based Stimson Center, said.

Publicly releasing the atlas, she said, "could be interpreted as China making a statement that it commands this maritime domain."

China has submitted proposals to the United Nations seeking to extend its continental shelf claims beyond standard limits using geological evidence, a move Japan says encroaches on its Exclusive Economic Zone.

Such claims have provided significant impetus to ocean exploration efforts, Larry Mayer, director of the Center for Coastal and Ocean Mapping at the University of New Hampshire, told The New York Times.

Chinese deep-sea exploration vessels have been spotted near Alaska's Aleutian Islands, while Beijing has reportedly tested seabed mining equipment in waters claimed by the Philippines and Taiwan.

Deliberately omitting S. China Sea

Meanwhile, the atlas's geographic scope may carry legal and geopolitical significance, some analysts say.

The atlas's exclusion of the South China Sea may be deliberate, Wang Zhe-ren, an assistant research fellow at Taiwan's Institute for National Defense and Security Research (INDSR), and INDSR associate research fellow Hung Ming-te wrote on their institute's site.

They cited a 2016 South China Sea arbitration ruling by The Hague that threw out Beijing's "nine-dash line" claims. The ruling prompted China to focus instead on the East China and Yellow seas, where no international court has spoken, they said.

Resource race

According to the International Energy Agency, China accounts for almost two-thirds of global rare earth mining production and 92% of global refined output. Japan and the United States are stepping up deep-sea resource development to reduce dependence on Chinese supply chains, with each backing the other's seabed mining efforts.

Japan announced a major deep-sea rare earth development breakthrough earlier this year, extracting rare-earth-rich mud from depths of more than 6,000 meters in what Tokyo described as a world first.

The US government also has made seabed mining a priority. It is seeking to issue mining licenses in areas near Pacific territories, including American Samoa. The moves underscore intensifying geopolitical competition over deep-sea critical minerals.