© Photograph by Adam Soule and Claire Willis/Woods Hole Oceanographic Institution. Map courtesy of Martin Jakobsson/Stockholm University, Robert Reves-Sohn and Adam Soule/Woods Hole Oceanographic Institution, and the AGAVE science team. Glassy, granular fragments of seafloor basalt (right) are a key piece of evidence that volcanoes along the Arctic Ocean's Gakkel Ridge (left) have exploded violently, and at unprecedented depths, according to a June 2008 study.
Buried under thick ice and frigid water, volcanic explosions are shaking the Arctic Ocean floor at depths previously thought impossible, according to a new study. Using robot-operated submarines, researchers have found deposits of glassy rock - evidence of eruptions - scattered over more than 5 square miles (15 square kilometers) of the seabed.
Explosive volcanic eruptions were not thought to be possible at depths below the critical pressure for steam formation, or 2 miles (3,000 meters). The deposits, however, were found at seafloor depths greater than 2.5 miles (4 kilometers).
"This kind of implosive seismicity is rare anywhere on Earth," said study author Robert Sohn, a geophysicist at the Massachusetts-based Woods Hole Oceanographic Institution.
The study appears today in the Journal Nature.