Seismic station installation in Mount St. Helens's crater 1981 lava dome
Detailed Description
Seismic station installation in Mount St. Helens's crater 1981 lava dome. USGS, in conjunction with the University of Washington, maintain seismic stations at Mount St. Helens. An increase in seismicity (earthquakes) is often the first precursor to an approaching eruption.
Sources/Usage
Public Domain.