Last week’s 7.0 magnitude earthquake in Anchorage, Alaska, should serve as a wake-up call. Those of us living on Oregon’s Coast know about the Cascadia Subduction Zone and the threat posed by it. Two tectonic plates, the Juan de Fuca and the Continental Plate are locked in a Sumo match about 60 to 90 miles off the coast of Vancouver Island, Washington, Oregon, and northern California. The experts say when those two plates finally slip, we will see an earthquake of the likes not seen in recent times. Predictions of 9.0 or better are common when the seismologists speak of the anticipated Cascadia quake.
Friends in the Anchorage area sent photos of their workshop. It looked like a hardware store dumped a truckload of merchandise on the floor. Other news photos show busted roads, store goods scattered and videos of teeth-rattling action. Consider the Anchorage quake registered at a 7.0 magnitude and the amount of damage experienced was significant.
The most recent Cascadia quake occurred on Jan. 26, 1700. There were no white men living in the Northwest at that time, therefore no one kept written records. There was, however an orphan tsunami in Japan which wiped out several fishing villages. The Japanese called it an orphan tsunami as there was no earthquake, hence no warning preceding the damage. Experts surmised an earthquake occurred elsewhere on the planet. Later they connected the dots and coupled with First-Nations lore handed down from one generation to the next, concluded the two were connected.
Core samples taken from estuaries up and down the Pacific Northwest coast tell a story of multiple earthquakes over the past 10,000 years. Over that period of time, the Pacific Northwest has experienced 41 subduction zone earthquakes. Divide 10,000 by 41 and the answer is 243. There's a 243 year average between subduction zone earthquakes. With the most recent in January 1700, we’re due. Overdue in fact! We are now nearly 319 years into a 243-year cycle.
According to Kathryn Schulz, writing for the New Yorker Magazine, “Twenty-two per cent of Oregon’s coastal population is 65 or older. Twenty-nine per cent of the state’s population is disabled, and that figure rises in many coastal counties.”
Local authorities are quoted “We can’t save them, I’m not going to sugarcoat it and say, ‘Oh, yeah, we’ll go around and check on the elderly.’ No. We won’t.” Nor will anyone save the tourists. Washington State Park properties within the inundation zone see an average of 17,029 guests a day. Oregon authorities estimate up to 150,000 people visit Oregon’s beaches on summer weekends. “Most of them won’t have a clue as to how to evacuate, and the beaches are the hardest place to evacuate from.”
Schulz continues, “There are estimates that in the I-5 corridor it will take between one and three months after the earthquake to restore electricity, a month to a year to restore drinking water and sewer service, six months to a year to restore major highways, and eighteen months to restore health-care facilities. On the coast, those numbers go up. Whoever chooses or has no choice but to stay there will spend three to six months without electricity, one to three years without drinking water and sewage systems, and three or more years without hospitals. Those estimates do not apply to the tsunami-inundation zone, which will remain all but uninhabitable for years.”
I never write to cause concern or fear, but to motivate folks to awareness and action. If a shocking analysis brings action, so be it.