03:44 PM PDT on Thursday, May 25, 2006

By FRANK MUNGEAM, kgw.com Staff

NEWPORT, Ore. -- In a research paper published in the magazine Nature, two Oregon State University adjunct professors who work at the Hatfield Marine Science Center in Newport describe the results of their study of a remarkable undersea volcano located in the Pacific Ocean's "Ring of Fire."

Submarine Ring of Fire exploration program 2006, NOAA.

The research team used a submarine to study, photograph and film the volcano Daikoku in the Mariana Arc, provided some of the closest observations ever of a volcano, thanks to the help of an underwater robot.

"We were forced to evacuate the remotely operated vehicle, 'Jason II,' several times to avoid getting it enveloped in volcanic clouds," said Bill Chadwick, an Oregon State University volcanologist and one of the authors of the study. "But at other times, we could observe the eruption from only 10 feet away - something you could never do on land. So in some ways, we were able to see processes more clearly at the bottom of the ocean than we ever could on land. That was surprising."

In their Nature article, the authors outline their 2004 discovery of an active crater on the south side of Rota's summit they named "Brimstone Pit" that was discharging a "pulsating, opaque, yellowish smoky plume with characteristics unlike any known hydrothermal plumes." The plume would fluctuate in volume and intensity, punctuated by explosions of sulfurous clouds.

Submarine Ring of Fire 2006 exploration program, NOAA

The researchers also describe their return visit to the site in 2005, when Rota showered their ROV with volcanic "bombs," globs of semi-molten sulfur and debris about 15 centimeters in size that shot out 50 meters above Brimstone Pit.

The science team also found microbial mats and hydrothermal vent-dependent animals on Rota, including two different species of alvinocaridid shrimp that numbered as many as 200 per square meter.

This year, they found that at least one of the shrimp species was supplementing its diet by eating dead mid-water fish that fell to the seafloor - apparently killed by the toxic cloud above the volcano.

Read more about the Ring of Fire