Mount St. Helens

  • 4.1 Magnitude

    A magnitude 4.1 earthquake, unlike any that had been previously detected in the area, occurred just northwest of the summit of Mount St. Helens. Seismologists were uncertain as to whether or not these first earthquakes were related to volcanic activity. They decided to deploy additional seismometers in order to better monitor future activity.
  • Earthquakes

    Earthquakes and steam-driven explosions occur off and on during this period.
  • Red & Blue Zones

    State officials asked the governor to close a large area around the volcano. The plan called for a Red Zone (no public access) and a Blue Zone (restricted access). Emergency services officials are frustrated because the public appeared to remain unaware of the danger.
  • Small Explosions & Earthquakes

    Small explosions of steam and ash are emitted from the volcano. Intermittent earthquakes up to magnitude 4.9.
  • Evacuation

    Police and other law enforcers escorted about 50 carloads of property owners into the Red Zone to retrieve possessions.
  • Eruption