When Mt. St. Helens blew it’s top in 1980 it did so in a very unusual manner. Rather than pop the cork and send lave flowing down over it’s sides, or exploding upward and spewing lava, smoke, and ash in every direction for many miles, it blew sideways. For several months before the blast a huge lava dome formed on the north side of the mountain growing daily as these things do. When the big day came it started to lift but the massive weight of the dome collapsed back into the explosive upwelling blocking off the top and forcing the blast to go sideways to the north. Hill size rocks flew out of the blast landing several miles away along with a cubic mile of what was the top of the mountain.
In the above picture, along with a profusion of wildflowers, you can see the top edge of the blast crater and, in the foreground of the mountain, the new lava dome that has been building for the last 28 years.
Note the new lava dome on the left and, for scale, the helicopter (arrow). (Click on the Picture for a new window and again for a larger view.)
Erosion in the floor of the crater. Note the waterfall just left of center on the erosion rim. That is wind driven dust, not smoke or steam. St. Helens is still more or less quiescent at this time.
You can see that the recovery has been very slow on this side of the mountain on south facing slopes (facing the crater) but on the north facing slopes colonies of Cardswell Penstemon, Lupines, and foxglove are in abundance. This is because when the eruption occurred in May there was a lot more snow on the north facing slopes, protecting the plants, and , of course, much of the force of the blast would have been more severe on the south facing slopes.
The Johnston’s Ridge Visitor Center is exceptionally well done and there is a very informative and interesting movie about the eruption. At the close of the movie the screen rises up to this view. ⇓
Mount Rainier National Park is just up the road from here and several folks we have met deemed it a must see, so we will go check it out next.