New magma chambers revealed beneath Mount St. Helens

COLUMBIA, Wash., Nov. 9 (UPI) -- Until recently, scientists had confirmed the existence of a single magma chamber, located directly beneath the caldera of Mount St. Helens.

But scientists have found three more sizable chambers deep below and to the east of the peak. The chambers were revealed by imagery captured as part of an ongoing effort to map the volcano's underground plumbing.

A team of university scientists and researchers from the United States Geological Survey presented the new images and information at last week's Geological Society of America meeting in Baltimore.

The images were created by setting off explosive devices all around Mount St. Helens. Because seismic waves travels more slowly through liquid and plasma than solid rock, researchers can use them to map magma.

Their analysis located two chambers, located 3 to 8 miles below sea level. Another larger chamber was found 9 to 25 miles below sea level. Much of that chamber sits directly beneath the original chamber. But it is more expansive, stretching several miles east. Researchers believe it is currently feeding magma to the chamber above. All four chambers, researchers say, are connected.

Scientists believe significant movement of magma between the chambers trigger earthquakes. And these earthquakes further facilitate the flow of magma.

A series of isolated earthquakes preceded the volcano's last violent eruption in 1980, and tremors began to rumble between 2004 and 2008 as Mount St. Helens again bubbled over, though much more gently.

"We can only now understand that those earthquakes are connecting those magma reservoirs," Eric Kiser, from Rice University in Houston, Texas, told Science. "They could be an indication that you have migration of fluid between the two bodies."

The new maps help explain past explosions, and they may also improve geologists' ability to predict the next big one. But to get an even a better sense of what's happening down there, scientists need some live action.

"If the mountain ever wakes up again, we could put out more informative statements about why things are happening," USGS researcher Seth Moran told the Daily News.