More than 45 aftershocks of magnitude 2 or larger have been recorded in the first three days including 6 magnitude 3 or greater events. These were a magnitude 3 event at 9:21 pm Thursday May 2, magnitude 3.1 at 9:02 am Friday May 3, magnitude 3.6 on Saturday May 4 at 7:38 am, and mag 3.1 on Sunday May 5 at 4:06 am. Aftershocks are likely to continue for months, although at a diminishing rate. Most will be too small to be felt; occasional earthquakes in the magnitude 3 range or even as large as magnitude 4 may still be felt.

The last widely felt earthquake causing some minor damage in the Seattle area was the Robinson Point earthquake on January 28, 1995. It was located near Robinson Point about 40 miles southwest of the May 2 earthquake at a depth of 11 miles. It had a magnitude of 5.1.

The location of the Duvall earthquake was not a complete surprise to seismologists who consider the Seattle/Puget Sound area to be one of the continental United State's more seismically active regions. A magnitude 5.2 earthquake occurred at virtually the same location on July 17, 1932. This old earthquake is thought to have a shallow depth of focus and caused a similar pattern of felt effects as the Duvall earthquake. New maps by the U.S. Geological Survey (currently in the final review process) showing the long term probabilities for future strong ground acceleration in the United States, show the Seattle region is second only to the coastal regions of California. You can view these maps at http://gldage.cr.usgs.gov/eq/