From the University of Washington Pacific Northwest Seismic Network:
-- Each point represents the sum of energy released by all earthquakes in a 14 day period, Energy is computed in 14 day time windows, every 7 days, Strain energy is plotted in ergs1/2, Green triangles, if shown, represent phreatic explosions, Cyan triangles, if shown, represent dome-building eruptions, and Red triangles, if shown, represent explosive magmatic eruptions. |
Link to:
[University of Washington Geophysics Program, Pacific Northwest Seismic Network's
Mount St. Helens Page] ...