Rapid growth of newly-formed island near Iwo Jima, Japan

On November 1, 2023, a new island was born approximately 1 km (0.62 miles) off the southern coast of Iwoto Island, Japan, following intense volcanic activity. This latest addition to the Ogasawara island chain, now nearly merging with Iwoto, was first identified by military personnel stationed there.

On the morning of November 1, 2023, military personnel at the Maritime Self-Defense Force’s (MSDF) base on Iwoto Island (historically known as Iwo Jima), were startled by loud noises and the sight of soil and debris erupting into the sky.

This phenomenon marked the formation of a new island, a mere 1 km (0.62 miles) off Iwoto’s southern coast, part of Japan’s Ogasawara island chain.

The volcanic activity that led to the island’s creation had been hinted at since October 21, with frequent tremors indicating volcanic unrest.

The Global Volcanism Program reported that the eruption originated from a vent located near Okinahama on the island’s southeast side. Observers noted explosions every few minutes during an overflight on October 30, which ejected dark material up to 20 m (65 feet) above the ocean’s surface.

The newly formed island, initially observed as a black-colored landmass surrounded by floating pumice, was recorded by the Sentinel-2 satellite on November 2. At that time, it measured approximately 230 m (754 feet) in length and 200 m (656 feet) in width. Since then, the island has shown significant growth, approaching a size that nearly merges it with the nearby Iwo Jima.

Sentinel-2 satellite image acquired on November 27 shows the newly-formed island’s northern tip just 220 m (720 feet) from the nearest coast of Iwo Jima.

Featured image credit: Niijima Coast Guard. Acquired on November 23, 2023