A Japanese expert says volcanic eruptions near the Pacific island of Ioto, also known as Iwojima, have created a new islet.

Associate Professor Maeno Fukashi of the University of Tokyo's Earthquake Research Institute conducted an aerial survey over Ioto Island, which is part of the Ogasawara island chain, on October 30.

He observed black plumes, which contained rocks, spewing out of the sea every few minutes, about one kilometer off the southern coast of Ioto.

He said that the plumes reached heights of more than 50 meters. He added that some of the rocks thrown up into the air by the eruptions were several meters in size.

Maeda suspects that steam eruptions, caused by magma coming into contact with seawater, are taking place.

He said that a round and blackish islet measuring about 100 meters in diameter was formed north of the plumes.

Maeno said the surface of the islet is covered with rugged rocks. He noted this suggests that rocks thrown up by the eruptions piled up and created the islet.

A volcanic vent has not been observed on the little island, but floating bands of pumice have been seen around it. There has also apparently been a noticeable change in the color of the seawater around the islet.

Maeno indicated it is likely that eruptions are occurring at two or more locations.

He said eruptions have occurred in the area before. But the associate professor said it had been a long time since volcanic activity there had reached the level at which it could cause magma to create an islet.

He also said there are reports that the islet is still expanding. He added it is possible that the little island will keep expanding, if eruptions continue to occur.