After an underwater volcano erupted in late October, a new island has formed close to Japan’s Ogasawara island group, a remarkable natural phenomena. This nameless island is 100 meters in diameter and was created by phreatomagmatic eruptions that occurred from the interplay of magma and ocean. The underwater volcano, known as Ioto in Japan, is located about a kilometer off the southern shore of Iwo Jima. It began erupting on October 21 and has since produced a rapid build-up of rocks and volcanic ash on the shallow seabed.
The volcano’s top emerged above the water’s surface in just ten days, and by early November, it had grown into a new island with a circumference of around 100 meters and an elevation of up to 20 meters above sea level. The formation of a new island is a notable development, according to Yuji Usui, an analyst in the volcanic division of the Japan Meteorological Agency, who emphasized the significance of this event despite the fact that volcanic activity has grown recently near Iwo Jima.
Even though the island was first formed, it has since diminished due to a decrease in volcanic activity. Because of its “crumbly” nature, the island is prone to wave erosion.
It’s interesting to note that this island’s creation is similar to that of another island that formed in 2013 and eventually combined with Nishinoshima, an island in the Ogasawara group. Over time, Nishinoshima expanded to a diameter of around two kilometers, stemming from an underwater volcanic eruption.
Since October 21, there have been regular reports of volcanic tremors on Iwo Jima, which are followed by eruptions off the island’s southern shore, according to the Japan Meteorological Agency.
This area has seen increased volcanic activity. Iwo Jima is located south of Ogasawara Island and about 60 kilometers north of the underwater volcano Fukutoku-Okanoba, which had a major underwater eruption in 2021.
Interestingly, geological activity in this region predates recorded history. A phreatomagmatic eruption and a magmatic eruption occurred in July 2022 off the southeast coast of Iwo Jima. June and October eruptions that followed highlighted the active geological processes in this region of the Pacific Ring of Fire.