Eruptions Under the Sea

LEXINGTON, Ky. (April 14, 2010) - Volcanoes aren't the first landforms one might think of deep down on the ocean floor. Many geoscientists didn't think that explosive eruptions could exist there at all.

Adam Soule, associate scientist of geology and geophysics at the Woods Hole Oceanographic Institution, helped to discover the existence of these eruptions, and he can prove it.

Soule will speak on explosive volcanism in the deep ocean at  4 p.m. Thursday, April 15, in Room 303 of the University of Kentucky's Slone Research Building.

"My work focuses on magmatism and volcanism along the global mid-ocean ridge system," he said. "The mid-ocean ridge marks the edges of Earth's tectonic plates. Where those plates are pulling away from each other, magma is formed and creates new oceanic crust."

Geoscientists didn't always believe that eruptions could occur in the deep ocean, due to a lack of steam production and high seawater pressure above.

"Major advances in science come from questioning and reevaluating existing paradigms," said Dhananjay Ravat, chair of the Department of Earth and Environmental Sciences. "The evidence Dr. Soule and his colleagues have found suggest that in some places in world the oceanic ridges contain materials that would make volcanism there significantly explosive. And they are able to back up their findings with calculations as well."

"I use geophysical, observational, and geochemical evidence in tandem with theoretical modeling to answer fundamental questions about volcanism in a variety of settings," said Soule.

Ironically, more than 70 percent of the Earth's volcanic eruptions occurs at mid-ocean ridges, but due to the difficulty in reaching the seafloor, little is known about these eruptions, according to Soule.

Despite its size and importance, approximately 5 percent of the mid-ocean ridge system has been explored in detail, even though it's the largest magmatic system on the planet, producing three times more lava each year than all of the Earth's subaerial volcanoes combined.

"I study volcanic products at mid-ocean ridges to learn more about the construction of oceanic crust, timescales of eruption and lava transport along and away from them," Soule explained. "Mid-ocean ridge eruptions are closely linked to the generation, storage and transport of melt within the mantle and crust beneath and have important effects on hydrothermal circulation and biologic activity in these systems."

The Woods Hole Oceanographic Institution, located in Woods Hole, Mass., is the largest private nonprofit oceanographic institution in the world.

Soule's visit is a part of the Department of Earth and Environmental Sciences Spring 2010 weekly seminar series, which ends Thursday, April 22.

For more information, contact professor Kent Ratajeski at kent.ratajeski@uky.edu.