Mount St. Helens Update: Earthquakes Increase Overnight
From Kiro TV:
MOUNT ST. HELENS, Wash. -- Mount St. Helens quieted down after spewing a plume of steam and ash -- but only briefly.
Within hours of the eruption Friday, seismic readings suggested pressure was building again inside the volcano, which had been dormant for 18 years.
The article continues:
The earthquakes started Sept. 23 and grew steadily stronger, finally reaching a magnitude of 3.3 Thursday and Friday. After the eruption, they stopped for several hours, said Wynn, of the U.S. Geological Survey.
Then, the tremors resumed, hitting a one-per-minute pace, said Bill Steele at the University of Washington seismic laboratory. A couple exceeded magnitude 2.
A few more steam explosions are likely, Steele said, "until enough debris is cleared, and then there is a significant chance that lava could be extruded at the surface."
Tom Pierson, a USGS geologist, said officials will monitor the site "on a very intense scale until we can determine that the thing has really gone back to sleep."