Earlier Today, Monday, Mt. St. Helens was hit by a series of earthquakes that sent rumblings felt as far away as Hood River, and Clackamas.

the USGS (United States Geological Service) measured one of the quakes at 4.3 on the Richter Scale, and a series of lesser tremors at 2.5 to 3.3.  The University of Washington Seismology Lap also measured the quakes.  While earthquakes were the very first indication of activity months prior to the mountain blowing up in 1980, seismologists indicate these were caused by movement with faults several miles below the surface, not by volcanic activity as was in 1980.