When West Coast residents contemplate “the Big One,” public attention almost always turns to California’s famous San Andreas Fault. Yet, seismologists have long been eyeing a far more catastrophic threat lurking offshore: the 600-mile Cascadia Subduction Zone stretching from Northern California all the way to Vancouver Island.

Experts warn there is a 15% chance of a full megathrust rupture within the next 50 years, and a 29% chance by the year 2100. Such a massive event could trigger a magnitude 9.0 earthquake followed by a devastating, wall-of-water tsunami.

And some Oregon communities might be almost entirely decimated not if, but when, such a tragedy might strike. For more on the impending catastrophe, see below.

A sobering new study published by the Oregon Department of Emergency Management (OEM) highlights the stark life-or-death realities facing Pacific Northwest coastal communities when the inevitable mega-quake strikes.…