Earthquake Sources
The Cascadia region is a tectonic-plate boundary between the subducting oceanic Juan de Fuca, Gorda, and Explorer Plates and the over-riding continental North America Plate. Over millions of years, these plates converge at an average rate of about 4 cm/yr. A variety of earthquake types occur as a consequence of this convergence including:
- Cascadia subduction interface earthquakes;
- Crustal earthquakes;
- Distant tsunamis from other earthquake regions;
- Earthquake swarms;
- Intraplate earthquakes; and
- Volcanic earthquakes.
