Area of the Cascadia subduction zone, including the Cascade Volcanic Arc (red triangles), site of recurring megathrust earthquakes at average intervals of about 500 years, including the Cascadia Earthquake of 1700. USGS
Detailed imaging of Mount Rainier (red triangle) shows subduction zone in glorious detail | Ars Technica - Seismic+EM section across Cascadia subduction zone: sea water driven off slab, magma rising up. The colors represent electrical resistivity, with red being low. Contour lines show temperature in degrees Celsius. Small red circles show the centers of earthquakes.
Cascadia Subduction Zone Earthquake and Tsunami by Safer Coastlines Published on Jan 9, 2014 James Roddey explains the potential dangers of living near the Cascadia Subduction Zone. Can generate a magnitude 9 earthquake and devastating tsunami.