Advisories from the coast guard and the Japan Meteorological Agency said the islet is about 200 meters (660 feet) in diameter.
A volcanologist with the coast guard told 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."
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