Unrest in the world…

September 26, 2004 | Science | By: Mark VandeWettering

Mount St. Helens before...and after...Volcanic unrest, that is. It appears that Mount St. Helens is rumbling a bit, enough so that scientists have posted a warning of volcanic unrest.

Seismic activity at Mount St. Helens has changed significantly during the past 24 hours and the changes make us believe that there is an increased likelihood of a hazardous event, which warrants release of this Notice of Volcanic Unrest. The swarm of very small, shallow earthquakes (less than Magnitude 1) that began on the morning of 23 September peaked about mid-day on 24 September and slowly declined through yesterday morning. However, since then the character of the swarm has changed to include more than ten larger earthquakes (Magnitude 2-2.8), the most in a 24-hr period since the eruption of October 1986. In addition, some of the earthquakes are of a type that suggests the involvement of pressurized fluids (water and steam) or perhaps magma. The events are still occurring at shallow depths (less than one mile) below the lava dome that formed in the crater between 1980 and 1986.

Shake, rattle and roll.

I remember observing the eruption from the relatively safe area around Portland, but we still got inches of ash on the ground. Quite a mess. Let’s hope for a more mild show.