How many and what size of earthquakes occur near Seattle?
In the 20th century, there were eleven earthquakes of magnitude 5 or greater that have occurred near Puget Sound: in 1904 (M 5.3), 1909 (M 6.0), 1932 (M 5.2), 1939 (M 6.2), 1945 (M5.9) 1946 (M 6.4), 1949 (M 7.0), 1965 (M 6.5), 1995 (M 5.0), 1996 (M 5.3), and 1999 (M 5.1). Most of the events are associated with deep Benioff zone earthquake activity that effects the Pacific Northwest Region. The 1995 and 1996 events were shallow crustal events. Click Here for a drawing of the three different source zones for earthquake activity in the Pacific Northwest. • Q: How many and what size of earthquakes occur near Portland? A: In this century there have been three significant earthquakes near Portland: in 1877 (M 5.3), 1962 (M 5.5), and 1993 (M 5.5). Additionally, Portland has been damaged by earthquakes that occurred in the Puget Sound region, such as the 1949 magnitude 7.1 event near Olympia, WA, and the 1965 magnitude 6.5 event located between Seattle and Tacoma. • Q: Could a big earthquake i
