Seismologists trying to see 50 miles down into Mount St. Helens


by Pat Dooris, KGW Staff

Posted on June 21, 2014 at 3:01 PM

Updated Saturday, Jun 21 at 3:11 PM

SKAMANIA COUNTY, Wash. -- Scientists are beginning the largest experiment of its kind on and around Mount St. Helens.

They’ll use passive seismometers, electromagnetic fields and active blasts to gain glimpses of the structure of the earth deep below the mountain.

They want to see 50 miles down.

“Yeah well, the earth, it’s a hard place to get yourself down into,” said Geoff Abers, a seismologist from Cornell University. He grew up in Los Angeles and was fascinated by earthquakes and volcanoes. Now he’s spending part of his summer with other scientists working on the huge experiment.

With modern technology, they hope to see the deep plumbing system beneath Mount St. Helens.

With the help of Seth Moran from the US Geological Survey and two grad students, Abers is burying a seismometer on the Southeast flank of the mountain. It’s one of 70 that will sit in holes spread over 45 square miles around the mountain.

Each will carefully record the smallest movements in the earth over the next two years. Variations in patterns will give scientists images of things they can’t see in the way MRIs or CAT Scans allow doctors to look inside our bodies.

“The imaging lab is producing the energy. It’s happening all right around, you know, in the MRI the tube is going boomp, boomp, boomp,” said Moran from the USGS.

“In our case, we don’t have the ability to create our own energy at least in this type experiment, the passive experiment. What we’re using is the earth. Earthquakes from near, from far as our energy sources,” he said.

It’s the only experiment of its kind in the world.

“This is probably the first array anywhere at this scale that’s designed to do this sort of deep imaging, the look at the plumbing of a volcano at its early phases,” said Abers the seismologist from Cornell.

Scientists say it could take four years to gather and examine the results. In the end they hope it will give them a better image of how the magma flows beneath Mt. St. Helens and help predict future eruptions.