EcoAlert: A dozen massive volcanoes reaching nearly 10,000 feet above the ocean floor found near Antarctica

110712-VolcanoesPhoto-hmed-1155a.grid-6x2

A chain of a dozen undersea  volcanoes some reaching nearly 10,000 feet above the ocean floor , and several of them active, have been near Antarctica, south of the South Sandwich Islands — desolate, ice-covered volcanoes that rise above the southern Atlantic Ocean about halfway between South America and South Africa which erupted as recently as 2008. It was the first such discovery in that region.


"That's a big volcano. That's a very big volcano. If that was on land it would be quite remarkable," said Philip Leat, a volcanologist with the British Antarctic Survey who led a seafloor mapping expedition to the region in 2007 and 2010. "We knew there were other volcanoes in the area, but we didn't go trying to find volcanoes," Leat told OurAmazingPlanet. "We just went because there was a big blank area on the map and we had no idea what was there; we just wanted to fill in the seafloor."

"So it's very exciting," he said. "You go along and suddenly you see the bottom start to rise up underneath you, and you don't know how shallow it's going to get."

At one point, in the dead of night, the team encountered a volcano so large it looked as though the RRS James Clark Ross, the team's research vessel, might actually crash into the hidden summit. "It was quite frightening, actually," Leat said. The onboard instruments revealed that some of the peaks rise within 160 feet of the ocean's surface.

The team mapped an area about 100 miles wide and nearly the length of Britain. The missing parts of the image are where islands blocked the mapping sonar.

Though the peaks are largely invisible without the aid of 3-D mapping technology, Leat said their conelike silhouette is a dead giveaway. "There's no other way of getting that shape on the seafloor," he said. In addition, the researchers dredged up rocky material from several peaks and found it rife with volcanic ash, lumps of pumice and black lava.

The find backed up reports from a ship that visited the area in 1962, which indicated a hidden volcano had erupted in the region.

The Daily Galaxy via ouramazingplanet.com

"The Galaxy" in Your Inbox, Free, Daily