The boat above is the Saishomaru, a Japanese fishing boat that is on display in the Columbia River Maritime Museum in Astoria, Oregon. It washed ashore at Cape Disappointment, Washington, part of a pulse of tsunami debris that flowed to the U.S. West Coast after the 2011 tsunami that devastated Japan and killed over 18,000 people.
I was reminded of this debris when I read in the local paper Thursday that earthquake scientists who are studying earthquake faults in this region are puzzling over the inactivity of the Cascadia fault zone that runs along the West Coast from Northern California to Vancouver Island. Compared with other zones in the region, this one is “extraordinarily quiet” — not a good thing, geologically speaking. Most faults do some slipping and sliding, which relieves the stress that builds as the massive plates of the earth’s crust strike and move across one another. Scientists are concerned that the Cascadia fault may be “locked,” or stuck in one place as pressure to move mounts up, in this case over centuries. The more pressure that builds, the bigger the quake — and tsunami — that is eventually released. It could release a magnitude 9.0 quake, truly a monster tremor.
It might never happen in our lifetimes. I certainly hope it doesn’t. But the earthquake and tsunami in Japan is a frightening reminder of what might happen here.