Man-made earthquakes contribute to more shaking at Mount St. Helens
Scientists studying Mount St. Helens are detecting far more earthquakes than usual, and they’re adding to the seismic activity with explosions of their own.
Researchers are taking part in a study aimed at mapping out the inner workings of the mountain.
“There are about 3,000 instruments (at St. Helens.) One part of the experiment is to watch the earthquakes taking place naturally,” explained University of Washington and state seismologist John Vidale. Many small earthquakes that might have gone undetected before are being picked up because of the extra equipment at the mountain.
According to Vidale, the sensors have detected as many as 19 Magnitude-1 earthquakes in the past four days on Mount St. Helens and stretching through the Portland-Vancouver area.
The other part of the experiment includes detonating 15 man-made explosions in the last week that register as small quakes.
“There will be another (man-made) explosion in the next week, to send the energy under Mount St. Helens to see with all of our seismometers,” said Vidale.
Scientists hope to create an X-ray of sorts, of the inner workings of the mountain, in order to better show where the magma has puddled up, as well as where magma chambers exist.
Instruments used to measure the activity will be at Mount St. Helens for the next two years. Vidale said he suspects it will take them even longer to analyze the data.
“We’re just starting, so I’m sure we’ll find something,” Vidale said.
Along with better understanding Mount St. Helens, scientists hope the research will improve volcanic monitoring and advance warning systems for other volcanoes.
Scientists from four universities including the University of Washington, Oregon State University, Lamont-Doherty Earth Observatory at Columbia University, and Rice University are taking part in the study, along with the U.S. Geological Survey and ETH-Zurich in Switzerland.
It’s too soon in the research process for scientists to use their information to make any predictions about the next time the most active volcano in the Cascades will erupt again. Mount St. Helens erupted in 1980, and erupted again in 2004.