Sunday, April 16, 2006

Science-Enviroment- Giant Deep-Sea Volcano With "Moat of Death" Found

Giant Deep-Sea Volcano With "Moat of Death" Found

Beneath the waves of the South Pacific lies a volcanic realm nearly as strange as that featured in TV's hit drama Lost.
But instead of a mysterious island, scientists have found a bubbling submarine volcano whose weird features include a swirling vortex, a host of strange animals, and a fearsome zone of toxic waters dubbed the Moat of Death.
The volcano sits within the crater of a gigantic underwater mountain rising more than 4,500 meters (15,000 feet) from the ocean floor near the island of Samoa.
The seamount, called Vailulu'u, is an active volcano, with a 2-mile-wide (3.2-kilometer-wide) crater. The cone rising within it has been dubbed Nafanua, for the Samoan goddess of war.
Five years ago Hubert Staudigel of the Scripps Institution of Oceanography in La Jolla, California, and his colleagues mapped the mountain using remote-sensing techniques.
When they returned to the site in 2005 for a more thorough study with submersible vehicles, the scientists found that the seamount had grown a new, 300-meter (1,000-foot) lava cone, a sign of renewed volcanic activity.
The peak of the cone, 700 meters (2,300 feet) below sea level, turned out to be teeming with life.
"It was just full of eels," Staudigel said. "When we sent the submersible down, we found hundreds of eels scurrying out of the rock. Normally you'd see one or two."
Moat of Death

The moat lies between Vailulu'u's encircling crater and the rim of the cone inside it.
It's an extremely toxic environment, Staudigel said, where oxygen levels are dangerously low and volcanic vents fill the water with iron soot "almost like underwater smog."
The volcano is also spewing liquid carbon dioxide, which combines with seawater to make a deadly acidic mix.

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