Scientists from across the country are planning a two-year study in Southwest Washington to better understand the source of volcanic magma under Mount St. Helens.
Kenneth Creager, a professor of earth and space sciences at the University of Washington who is leading the study, said the main goal will be to understand the plumbing system of the mountain.
“We want to understand how volcanoes work and how the magma recharges in the system,” Creager said. “And if you know all of that, then you can help give people warnings above ground.”
The project, called “Imaging Magma Under St. Helens,” will take place on land from Mount Rainier south to the Columbia River and from Interstate 5 east to Mount Adams.
The entire project, scheduled to be complete in the summer of 2016, could also improve the way volcanoes are monitored and enhance advance warning systems at Mount St. Helens.
The project will be broken down into three parts; passive-source seismic monitoring, active-source seismic monitoring and magnetotelluric monitoring, which uses fluctuations in Earth’s electromagnetic field to produce images beneath the surface.
Steve Malone, a University of Washington professor and former Pacific Northwest Seismic Network director, said monitoring instruments will be installed next spring when the project is set to begin.
“We are at the point now where we have some of the sites for our instruments picked out and are working with the Forest Service,” Malone said.
Federal environmental permits still need to be obtained to work inside the Gifford Pinchot National Forest and the Mount St. Helens National Volcanic Monument.
Scientists chose Mount St. Helens because it is the most active volcano in the Cascades, erupting in 1980 and 2004.
“We already know what the geology looks like from previous studies,” Malone said. “But it seems once you get five kilometers below, things get a little hazy. We really don’t know how the magma gets into the system.”
Malone said the scientists need to collect at least 18 months of data to have accurate findings.
Scientists will use solar-powered seismometers at 70 sites for the passive-source seismic monitoring to record local earthquakes and large quakes that occur much farther away.
The active-source seismic monitoring, planned for next summer, will use 6,800 seismometer sites.
The magnetotelluric monitoring, used for observing fluctuations in Earth’s electromagnetic field, will take place at 150 sites.
Along with UW, the other participants in the project include Oregon State University, Lamont-Doherty Earth Observatory of Columbia University, Rice University and the U.S. Geological Survey.
The cost of the project is estimated at $1 million and is being funded by each institution and the National Science Foundation.
2013 The Chronicle (Centralia, Wash.). Visit The Chronicle (Centralia, Wash.) at www.chronline.com. Distributed by MCT Information Services.