Tokyo Report

Japan Takes Large Southern Extension of Continental Shelf

The new authority to develop seabed resources may lead to further disputes with China.

Japan Takes Large Southern Extension of Continental Shelf
Credit: MSDF via Shutterstock

Japan’s new Cabinet announced on Tuesday that it had adopted an ordinance expanding the country’s continental shelf in two key southern locations, the Shikoku Basin Region just north of Okinotorishima Island, which is Japan’s southernmost land feature, and the Southern Oki-Daito Ridge Region. A map of the two areas can be seen here, courtesy of the Yomiuri Shimbun. The two new areas will give Japan the right to develop resources that may lie on or beneath the ocean floor, like rare earth elements (REE) that are key to many of Japan’s technology-intensive industries. The move may also stir disputes with China and South Korea, according to the U.N. commission that ruled on the extension.

The area encompassed by the new ordinance covers 177,000 square kilometers of ocean, based on a decision by the U.N.’s Commission on the Limits of the Continental Shelf in April 2012 after Japan applied for the extension. Based on the U.N. Convention on the Law of the Sea, a country may claim control of the seafloor beyond its 200 nautical mile exclusive economic zone (EEZ) up to 350 nautical miles if “it can prove the ocean floor is connected to the continental shelf,” according to the Japan Times.

However, the U.N. commission has delayed ruling on a third extension much farther south near the Philippines in the Southern Kyushu-Palau Ridge Region that is 252,000 square kilometers. This extension in combination with the other two would give Tokyo effective seabed development rights over a majority of the ocean floor between Japan, Guam, the Philippines and Taiwan, putting an economic choke point in between China and a conceptual “Second Island Chain” of influence.

Japanese interest in not only mining REE but also developing emerging energy sources like coalbed methane (CBM) is important given its near complete dependence on foreign energy and China’s dominance of the REE industry. Tokyo will likely seek to explore and develop these new concessions soon for practical economic purposes. However, the de facto extension of Japanese sovereignty significantly further south into waters where China is also seeking to increase its influence could prove to be yet another point of tension between the two countries.