This editorial will appear in Sunday’s print edition.
If the horrifying, heartbreaking images coming out of Japan don’t frighten Northwesterners into preparing for the proverbial Big One, nothing will.
More than 1,000 are feared dead after Friday’s earthquake, the most powerful to strike Japan. We here in the Northwest feel particular empathy for what the Japanese are experiencing, because earthquake experts say what happened there is almost exactly what will happen along our coastline: a massive rupture of an offshore subduction zone, resulting in huge tsunami waves.
The Cascadia subduction zone ruptures about every 400 to 500 years, maybe even more frequently. The last time was in 1700, which we know from the meticulous record-keeping of the Japanese, who documented the tsunami that struck them that year caused by the Cascadia quake.
Do the math.
Friday’s earthquake off Japan’s northeast coast created tsunami waves that devastated its coastline, then sped across the Pacific. They did some damage in Hawaii and on the West Coast and are blamed for at least one death. But Americans had hours to prepare for the event, and warning sirens and other measures spurred thousands to move away from vulnerable coastal areas.
Fortunately, the waves weren’t as powerful as they could have been. The evacuation was a useful exercise, but when the Cascadia quake strikes, people will not have hours to get away. When the earth rumbles, they will need to get to high ground fast. They won’t have time to gas up the car, pick up some supplies and check the Internet for news.
While the Northwest coastline isn’t as heavily populated as Japan’s, there’s still potential for thousands of deaths, depending on the location and strength of the earthquake.
We here in the South Sound won’t be as affected by a rupture of the Cascadia subduction zone as the coastline will be, but we have our own seismic faults to worry about. The images we have been seeing out of Tokyo – a city that is as prepared as any for big earthquakes and has some of the world’s toughest building codes – should give us pause.
That city is 231 miles away from the epicenter of Friday’s quake, yet it still sustained significant damage. If a quake greater than magnitude 7.0 were to occur on one of the many faults that underlie the Puget Sound region, it’s likely that we would fare much worse.
Japan’s sorrow should be our wakeup call.