Smoke billows from a new island off the coast of Nishinoshima, seen left above, a small, uninhabited island in the Ogasawara chain, far south of Tokyo. The Japan Coast Guard and earthquake experts said a volcanic eruption has raised the new island in the seas to the far south of Tokyo. | AP Photo | Japan Coast Guard

Smoke billows from a new island off the coast of Nishinoshima, seen left above, a small, uninhabited island in the Ogasawara chain, far south of Tokyo. The Japan Coast Guard and earthquake experts said a volcanic eruption has raised the new island in the seas to the far south of Tokyo. | AP Photo | Japan Coast Guard

TOKYO (AP) — A volcanic eruption has raised an island in the seas to the far south of Tokyo, the Japanese coast guard and earthquake experts say.

Advisories from the coast guard and the Japan Meteorological Agency said the islet is about 200 meters (660 feet) 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 approximately 30 islands are 1,000 kilometers (620 miles) south of Tokyo, and along with the rest of Japan are part of the seismically active Pacific "Ring of Fire."

The coast guard issued an advisory Wednesday warning of heavy black smoke from the eruption. Television footage seen Thursday showed heavy smoke, billowing steam and waters roiling over the crater.

MSN Weather: NASA photos of volcanos as seen from space

A volcanologist with the coast guard, Ito Hiroshi, told the FNN news network that it was possible the new island might be eroded away.

"But it also could remain permanently," he said.

The last time the volcanos in the area are known to have erupted was in the mid-1970s. Much of the volcanic activity occurs under the sea, which extends thousands of meters deep along the Izu-Ogasawara-Marianas Trench.

Bing: Photos of volcanos

___

Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.