Undersea Volcano Erupts, May Form New Island

Volcano Stains Sea

Photograph courtesy Japan Coast Guard

During a lull in the Fukutoku-Okanoba eruption on February 3, some of the waters above the undersea volcano bubble and take on yellowish green colors, while others are cloudy with displaced sand and grit.

"This is a volcano that is active fairly frequently, and we have minor events as many as several times a decade," Doi said.  The last Fukutoku-Okanoba eruption occurred in July 2005.

(Related video: "Deep-Sea Eruption, Odd Animals Seen [Near Guam].")

Published February 10, 2010

Nearby Volcanic Island

Photograph courtesy Japan Coast Guard

The February 3 submarine-volcano eruption took place about 3 miles (4.8 kilometers) north-northeast of volcanic South Iwo Jima (pictured). The island is part of Japan's Bonin Islands, which also include famous World War II battle site of Iwo Jima, some 37 miles (60 kilometers) north of South Iwo Jima.

During previous Fukutoku-Okanoba eruptions, lava has broken the sea surface, creating islands—the same basic process that created the Hawaiian Islands. But waves have always quickly washed away any Fukutoku-Okanoba islands, preventing them from becoming anything more than short-lived lava mounds.

As for the February eruption, said Doi, of the Japan Meteorological Agency, "We have seen no evidence of an island being created yet, but it is possible, and we will continue to monitor the situation."

(Also see: "Photos: Chile Volcano Erupts With Ash and Lightning.")

Published February 10, 2010

Watch This Space?

Photograph courtesy Japan Coast Guard

Discolored water stains the sea surface in the wake of the February 3 undersea-volcano eruption off Japan.

Fukutoku-Okanaba is believed to have erupted seven times since 1904, when its activities were first recorded.  On three of those occasions, temporary islands were formed, but all later sank below the surface again.

The most recent of the volcano's short-lived additions to Japan's Bonin archipelago was born on January 18, 1986, although the island disappeared by March 8 of that same year.

The island that resulted from a 1914 Fukutoku-Okanaba eruption was about five miles (eight kilometers) wide and was nearly a hundred stories tall. That island lasted more than two years.

(See aerial pictures of volcanoes around the world.)

Published February 10, 2010

Where There's Smoke ...

Photograph courtesy Japan Coast Guard

At around 7:45 a.m on February 3, 2010, the Yashima crew, on a routine survey, first noticed smoke coming from the surface of the ocean (pictured) near South Iwo Jima, according to Japan Coast Guard spokesperson Tomoyuki Suzuki. The smoke was the crew's first sign that something big was brewing.

In addition to noticing the smoke, the crew heard the blast and "felt" the pressure of the initial blast, Suzuki said.

The Yashima is continuing to monitor the site, he said, but the crew is keeping a safe distance, as the emissions include poisonous gases, including sulphur dioxide and carbon dioxide (volcano safety tips).

Published February 10, 2010