New aerial images of newly-created island at Fukutoku-Oka-no-ba volcano, Japan

The Japan Coast Guard has made another overflight of the newly-created island at Fukutoku-Okanoba volcano on August 26, 2021.

The island has grown in size since the last flight on August 16 and a large amount of pumice is still present near the volcano.

Image credit: Japan Coast Guard. Acquired August 26, 2021

Image credit: Japan Coast Guard. Acquired August 26, 2021

The island was discovered three days after a major eruption at the submarine Fukutoku-Oka-no-ba volcano on August 12 and 13, 2021.¹ 

According to the Tokyo VAAC, volcanic ash produced by the eruption rose up to 16.4 km (54 000 feet) above sea level at 23:50 UTC and drifted SSW toward the Philippines.

Eruption at Fukutoku-Oka-no-Ba submarine volcano. Image credit: JMA/Himawari-8, NII/NICT, TW. Acquired at 05:20 UTC on August 13, 2021

Image credit: Japan Coast Guard. Acquired August 15, 2021

Image credit: Japan Coast Guard. Acquired August 15, 2021

Iwo Jima (left) and new island (right) on August 15, 2021. Credit: Japan Coast Guard

Iwo Jima (left) and new island (right) on August 16, 2021. Credit: Japan Coast Guard

Image credit: Japan Coast Guard. Acquired August 16, 2021

Pumice created during an eruption at Fukutoku-Oka-no-ba. Image credit: Japan Coast Guard. Acquired August 16, 2021

The last eruptive episode at this volcano started on February 3, 2010, and lasted to ~April 8, 2010 (VEI 1).

Numerous eruptions were recorded in 20th century, two of them VEI 3 and three VEI 2.

New islands have been confirmed in the area in 1904, 1914, and 1986, with all having submerged. The one found in 1986 sank after around two months, according to the coast guard.​

Geological summary

Fukutoku-Oka-no-ba is a submarine volcano located 5 km (3.1 miles) NE of the pyramidal island of Minami-Ioto. Water discoloration is frequently observed from the volcano, and several ephemeral islands have formed in the 20^th century.

The first of these formed Shin-Ioto ("New Sulfur Island") in 1904, and the most recent island was formed in 1986.

The volcano is part of an elongated edifice with two major topographic highs trending NNW-SSE, and is a trachyandesitic volcano geochemically similar to Ioto.²

References:

¹ High-level eruption at Fukutoku-Oka-no-Ba submarine volcano, ash to 16.4 km (54 000 feet) a.s.l., Japan – The Watchers

² Fukutoku-Oka-no-Ba – Geological summary – GVP

Featured image: Fukutoku-oka-no-ba volcanic island on August 26, 2021. Credit: Japan Coast Guard