Mt. St. Helens, Quakes increase-movement detected

It's not like anything scientists have seen in the past which makes it more dangerous.
Movement detected on Mount St. Helens' lava dome

The chief scientist studying Mount St. Helens said a “startling” amount of movement on the lava dome was detected early Wednesday morning.


“A rather large mass of rock that is about 300 yards high by 400 or 500 yards across, something is moving it up and northward,” said chief scientist Jeff Wynn, with U.S. Geological Survey. “In the last two hours, the seismic activity has been accelerating to the highest levels we’ve seen since the swarm began last Thursday, both in frequency and intensity.”


Tests show that the dome moved about four centimeters to the north and about two centimeters upward.


Wynn described the movement as “similar to what scientists saw just before the 1986 eruption.” That's when the mountain had what’s called a dome-building eruption that was preceded by swarms of earthquakes.

“We’re looking at an unusually high level of seismic activity that we had never seen before. The seismic energy is just amazing,” Wynn said Tuesday. “The earthquakes are pretty much nonstop now… there’s constant rock breaking going on.”


Wynn said an explosion is more likely than an eruption. He said scientists are also leading away from the theory that the seismic activity may be weather-related.

Those of us in Portland have one thing to feel good about, the wind will blow any ash to the east, away from the metro area. I still remember cleaning volcanic ash out of my gutters 25 years ago.