Cascadia is offshore from North America’s continental plate
Cascadia’s Fault by Jerry Thompson acquaints readers with America’s earthquake and tsunami, which may devastate the Pacific Northwest sometime earlier or later in the twenty-first century.
Moderate, strong, major, and great belong with the words which nobody likes to hear regarding earthquakes since they respectively describe magnitudes 6, 7, 8, and 9. Even a magnitude 6 can be disturbing, as in the case of the Parkfield area stretch of California’s San Andreas fault rupturing six times since 1857. But its devastation does not come anywhere near that of magnitudes 9.2 on March 27, 1964, in Alaska and 9.5 on May 22, 1960, in Chile.
Some seismologists expect Cascadia to rupture catastrophically after three quiet centuries since 1700.