Alaska Earthquake Oregon (copy)

A tsunami evacuation sign warns motorists in Cannon Beach. The big earthquake off the coast of Alaska Tuesday triggered a tsunami watch for the Oregon Coast during the predawn hours, and while no tidal wave materialized, officials said it is a wake-up call.

Rick Bowmer, Associated Press

You might have forgotten to write this on your calendar,  so here's a reminder: Friday marks the 318th anniversary of the most recent massive earthquake along the Cascadia subduction zone, the fault that lies offshore from Vancouver Island down to Northern California.

And if you needed another reminder about the power of nature, we got another one just this week, in the form of a magnitude 7.9 earthquake that struck just off the coast of Alaska in the early morning hours of Tuesday.

Now, that earthquake was not triggered by the Cascadia subduction zone, but it did set off worries about possible tsunami waves along the West Coast. In fact, a tsunami watch went out overnight to coastal residents in Oregon.  Because the quake occurred near Alaska, Oregon Coast residents in theory would have had hours to move to higher ground.

As it turned out, the feared tsunami waves did not materialize, because the quake moved more horizontally than up and down, minimizing the amount of water displaced.

And that was just as well, because many coastal residents simply slept through the tsunami alert.

So, yes, we have work to do as we prepare for the next inevitable earthquake.

Issuing the tsunami watch wasn't merely an academic exercise: A 1964 earthquake off Alaska triggered a tsunami three stories high that hit Oregon, killing several people.

And that, of course, was well before scientists had much of an understanding of the power that could be unleashed by an earthquake along the Cascadia subduction zone. In the case of an earthquake along the fault, the resulting tsunami would pound the Oregon Coast in minutes, not hours — all the more reason to sign up for a tsunami alert if you live on the coast (and to keep your phone or other device close to your bed so you can hear it if the alert comes at night).

Scientists believe that on average over the last 6,000 years, the subduction zone has let loose with a magnitude 8 or 9 quake once every 202 years. So the fact that we're about to mark the 318th anniversary of the last big Cascadia quake isn't particularly reassuring. 

It's easy to get fatalistic about trying to prepare for a big natural disaster like an earthquake. In fact, some residents in Seaside, the Oregon city considered most vulnerable to a tsunami, have declined to sign up for an alert. Maybe they're thinking, what's the point?

But you don't have to fall into that trap.

Nor do you have to drop everything and fly into a frenzy of preparation work; that's a good way to get overwhelmed in a hurry.

Even though we're overdue for a big earthquake from Cascadia, chances are that it isn't going to happen today or tomorrow or next week or even next month.

That gives you the opportunity to prepare methodically, step by step. Plenty of websites offer easy-to-follow instructions on preparing. Some of the steps are as simple as picking up some additional food and bottled water every time you visit the grocery store.

And every step makes you better equipped to cope in the weeks following a disaster. Remember that it might be weeks before emergency workers make their way to your neighborhood in the wake of a disaster. Every little step you take to prepare increases your readiness to get through those critical first few days.

It could very well be that you have a plan in place, compete with a step-by-step list, but maybe it's been a while since you updated it. Or maybe you started working down the list with the best of intentions but got sidetracked by the cut and thrust of daily life.

That's why the events of this week are so useful: They send a reminder that this would be a good time to shake the dust off your list. (mm)


Managing Editor

Load comments