World Bulletin / News Desk
Advisories from the coast guard and the Japan Meteorological Agency said the islet is 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 620 miles south of Tokyo, and along with the rest of Japan are part of the seismically active Pacific Ring of Fire.
Television footage showed heavy smoke, ash and rocks exploding from the crater, as steam billowed into the sky.
Japan's chief government spokesman welcomed the news of yet another bit, however tiny, of new territory.