Nishinoshima island of the Ogasawara Islands in Tokyo has grown more than eight times larger about a year after a new island appeared and merged with it due to an underwater volcanic eruption.
One year will have passed Thursday since the emergence of the new island was confirmed. The original Nishinoshima island and the new island then coalesced, and the land area has continued to expand due to lava being discharged from the eruption.
The volcanic eruption has continued. From a Yomiuri Shimbun aircraft, which flew over the island on Friday, volcanic smoke intermittently arising from the island was observed.
Nobuo Geshi, senior researcher of the National Institute of Advanced Industrial Science and Technology who is an expert on volcanic geology, observed the island aboard the Yomiuri aircraft.
"The momentum of the eruption has not weakened even after nearly a year, and the original part of Nishinoshima island has almost been swallowed in the lava," Geshi said.
There are, so far, no signs of the eruption ending. He said, "The lava flows mainly to the north of the island and is filling shallow waters. The size of the island will continue to expand."
According to Geshi, rocks accumulated in the central part of Nishinoshima island, forming a hill shaped like an upside-down bowl.
The hill is 400m to 500m in diameter and about 100m high. Geshi said that from a volcanic vent atop the hill, liquid lava and rocks several m long were actively belching out together with gray volcanic smoke.
It was Nov 20 last year when the Japan Coast Guard confirmed the new island had appeared. It is unknown when the volcanic eruption began.
On Dec 26, the new island and the original Nishinoshima island, which was about 500m northwest of the new one, coalesced.