Volcanic eruption adds new island to Japan's far southern Ogasawara chain
A volcanic eruption has raised an island in the seas to the south of Tokyo, the Japanese coastguard and earthquake experts say.
Advisories from the coastguard and the Japan Meteorological Agency said the islet was about 200 metres in diameter.
It is just off the coast of Nishinoshima, a small, uninhabited island in the Ogasawara chain, which is also known as the Bonin Islands.
The about 30 islands are 1,000 kilometres south of Tokyo, and, along with the rest of Japan, are part of the seismically active Pacific "ring of fire".
The coastguard issued an advisory on Wednesday warning of heavy black smoke from the eruption. Television footage seen yesterday showed heavy smoke, ash and rocks exploding from the crater, as steam billowed into the sky.
Hiroshi Ito, a vulcanologist with the coastguard, told the FNN news network that it was possible the new island might be eroded away. "But it also could remain permanently," he said.
Similar eruptions in the early 1970s and mid-80s created tiny islets in Japan's territory that have since been partially or completely washed away by the ocean.
Much of the volcanic activity occurs under the sea, which extends thousands of metres deep along the Izu-Ogasawara-Marianas Trench.
Japan's chief government spokesman welcomed the news, joking that he hoped the outcrop would mark an expansion of Tokyo's maritime territory - a reference to diplomatic rows with China and South Korea over ownership of other islands far from the tiny islet.
Video: New Japan islet created in volcano eruption
"This has happened before and in some cases the islands disappeared," Yoshihide Suga said when asked if the government was planning on naming the new island. "If it becomes a fully fledged island, we would be happy to have more territory."
The Japanese archipelago includes thousands of islands. In some cases, they help anchor claims to wide expanses of ocean sitting over potentially lucrative energy and mineral resources.
Japan has plans to build port facilities and transplant fast-growing coral fragments on to Okinotorishima, two rocky outcroppings even further south of Tokyo, to boost its claim in a territorial dispute with China.
In September Pakistan saw the birth of a new island - a mound of mud and rock 20 metres high and 90 metres wide created by a huge earthquake that hit the country's southwest.
The island near the port of Gwadar caused astonishment when it emerged from the Arabian Sea, but experts also said it was unlikely to last long.
Additional reporting by Agence France-Presse