How Often Do Cascadia’s Megaquakes Occur?

16 May 2018–Devastating magnitude 8.0 to 9.0 megathrust earthquakes and accompanying tsunamis appear to have hit the U.S. Pacific Northwest and Southwest Canada about every 500 years on average. But some scientists think the recurrence interval between some of these large earthquakes may be shorter—along the lines of every 300 … Continue Reading »