Hazards Awareness

By far the biggest hazard facing Portland and surrounding communities is a Cascadia Megathrust Subduction Zone earthquake (magnitude 9+). While a direct nuclear blast would be devastating, its range is limited. A Cascadia subduction zone earthquake would unleash far more energy, and devastate a much larger region (approximately 84,000 square miles in size – from southern Canada to northern California, from the Pacific Ocean to the Cascade Mountains).

A subduction zone megathrust earthquake is far more powerful than most earthquakes we hear about, and Cascadia is among the largest of this breed of earthquake. There have only been a few in recorded history which are anywhere on par with Cascadia. The December 26, 2004 Sumatra earthquake (which caused the Indian Ocean tsunami) is probably the closest one. That earthquake actually altered the earth’s gravitational field! We heard very little about the earthquake itself because it occurred away from a heavily populated large land mass. That will not be the case in Cascadia.

While we face a variety of threats, such as terrorism, accidents, and natural disasters, if you’re prepared for Cascadia, you’re prepared for almost any kind of disaster. And there is no doubt that Cascadia is coming. The only question is when?

This web-book is a living document. Our initial focus is Cascadia (as that is our worst-case scenario); in time we will include information on a wider range of hazards.