‘The Really Big One’? Get ready now, quake experts advise

This week’s New Yorker magazine article, “The Really Big One”, didn’t sugarcoat it: Seattle and several other Northwest cities are destined to be pummeled by a massive earthquake, on a date to be determined. (If you’re a loyal Seattle Times reader, you probably knew that already, based on our previous coverage.)

The destruction is inevitable — though maybe not as bad as the article’s prediction that everything west of Interstate 5 will be “toast.” And adequate preparation is required.

That was the message from a Reddit “Ask Me Anything” forum hosted by The Times Tuesday. Fielding questions were John Vidale of the Pacific Northwest Seismic Center, Debbie Goetz of Seattle’s Office of Emergency Management and The Times’ science reporter Sandi Doughton, who’s also authored a book, “Full Rip 9.0: The Next Big Earthquake in the Pacific Northwest.” More than 600 people chimed in with questions and comments.

The abridged version: Make sure homes are stocked with supplies for seven to 10 days. After a quake, it’s safer to stay where you are — hitting the streets will only lead to more congestion on the roads, which may be impassable anyway. Create a communications plan with loved ones, just in case. Get under a table or desk if you feel the earth move.

“Communications may black out, transportation may grind to a halt, stores conceivably could run out of goods for a while, but that doesn’t constitute ‘toast’ in one’s mind,” Vidale said.

You can’t predict when a quake might hit. There’s an 80 percent chance that an earthquake like the magnitude 6.8 Nisqually shaker in 2001 could happen in the next 50 years, Goetz said.

Much larger and more deadly quakes, like those triggered on the massive fault off the Northwest coast, are less frequent. Vidale said there is a 10 to 15 percent chance for a magnitude 9 quake along that subduction zone fault over the next 50 years. Put another way, the chances are one in 300 for such a quake each year.

At its high end, a quake there could reach magnitude 9.2, Vidale noted. Thousands of deaths are predicted, from the shaking and resulting tsunami.

Should such a large quake occur, “Parts of Seattle will definitely be isolated, which is why the recommendation is to be able to survive on your own for at least three days and perhaps a week,” Doughton wrote.

Many homes and structures will “fare relatively well,” Goetz said, especially wood-frame ones. And yes, Seattle will recover, Goetz said, linking to plans on the city’s website that detail ways to deal with disasters.

Doughton said that people shouldn’t be scared away because of the earthquake risk.

“My philosophy is be prepared, not paranoid — and enjoy the spectacular landscape provided to us by tectonic forces,” Doughton said.