The Northwest seems to thrive on disaster lit. Our shelves are lined with books telling us about the cataclysms to come. Last summer there was "Full Rip 9.0," which explained the dynamics of the earthquake faults under our feet and the potential for The Big One. Now, timed with the 50th anniversary of the Alaska "Good Friday" earthquake of 1964 (March 27), we get "The Next Tsunami" by Bonnie Henderson (Oregon State University Press, $19.95), which tells how we came to understand the Pacific Northwest's tectonic plates and their potential impact on the coast.
The '64 Alaska quake, most known for its images of a devastated downtown Anchorage, killed nearly 130 people. Most victims died from quake-related tsunamis — as far away as northern California. The displacement of land and seabed and underwater slides spread damage over thousands of miles. Even the vibrations from the quake were felt a long ways off. At 9.2, it was the largest recorded earthquake in North American history. Houseboats on Seattle's Lake Union were sloshed by the turbulence. Even the Space Needle swayed.
But the biggest delayed reaction was the Pacific tsunami that swept the coast from Alaska southward and caused damage in Washington, Oregon and California. My main memory of the event, aside from TV images, comes from the sister of a childhood friend whose family was vacationing that March weekend at Ocean Shores. Their motel was evacuated and she was quoted in the newspaper asking something like, "Mommy, what do you wear to a tidal wave?"
That question of preparation is still with us. Stay on or near the coast these days and you might hear tsunami sirens, you'll certainly see signs for evacuation routes. But as Henderson's book points out, all of that is based on relatively new scientific discoveries. Indeed, the whole idea of continental drift, plate tectonics and the role of floating plates in earthquakes and tsunamis was still being hotly debated in the 1960s.
Henderson's focus is on the science — particularly the geology — and how it came together in the wake of the Alaska disaster to teach us that the plates were active, that subduction zones — such as the meeting point off our coast of the North American and Juan de Fuca plates — occasionally cause massive quakes and tsunamis. The phenomenon is ancient, but how it works has been pieced together only in recent decades.
Henderson digs into the details of how scientists — many of them young, up-and-comers and different-drummer-marchers — began to put it all together in the 70s, 80s and 90s. She introduces interesting characters and builds the story one finding, one paper, one grant at a time — how faults on land and sea were linked; how core samples in lowland coastal zones showed signs of having been suddenly inundated with sand and salt water; how guys with picks, shovels, chainsaws and sharp eyes went out to find the history of the Northwest's altered landscape.
Sometimes, the personal stories of the scientists get a little too detailed — reading as if the book was written for them and their families. Still, it draws a picture of how so much independent scientific work collectively built up a picture of the Pacific coast as tectonically active, not dormant, and sometimes the result of catastrophic events.
It’s easy to be complacent living on an ancient landscape that often seems serene. I remember my mother telling me that all of the Cascade volcanoes were asleep and at no risk of erupting. In 1980, Mt. St. Helens put an end to that myth. But it is also true that some of the major events — like massive subduction quakes — only happen once in a great while. It is very difficult for humans to process information like, "It could happen tomorrow, or in 500 years." Still, the science has pointed to preparedness — upgrading seismic building codes, rethinking coastal development, telling people what to do when they feel the ground shake.
Easily one of the most interesting parts of “The Next Tsunami” is the story of the researchers who began combing through Pacific coast Native American stories — generally regarded as "myths" or legends. They quickly discovered that some, like one told by members of the Northern California Yurok tribe about a massive flood and the thundering landscape, described nothing symbolic in the Joseph Campbell sense but, Henderson writes, were actually centuries-old "news" stories with a simple instructive message: If you see this happening, RUN!
Geologists reading such indigenous accounts were able to identify specific, accurate phenomena like the raising or lowering of land and the liquefaction of the soil, events later confirmed in the geologic record. The major coast-altering quake of January 1700 was the most recent Big One in our neck of the woods, confirmed by things such as centuries-old records in Japan and the tree-rings of dead old cedars and spruce on the Washington coast.
Whatever the time intervals, the science shows that that 300-year-old subduction quake will not be our last. In fact, it's part of a longstanding continuum of plate activity.
"The Next Tsunami" is for the reader who wants to get their boots dirty, reading about the field work that has peeled back the layers of understanding of our coast and landscape. You'll slog along rivers, in salt marshes and read the rings of ancient stumps. You'll learn how the barnacles on the Alaskan coast provided a key clue to what caused the earthquake of '64.
Henderson understands that the real knowing of a place is in the details, and made sense of by individuals who have made it their business to dig, literally, into the past to discover our future. Their goal is to tell a story, like the Indian oral histories, that we can project forward as a warning to our offspring.
The book is a must-add to your shelf of Northwest disaster lit and serves a reminder for those who live on water to head for the high ground when things start to shake. You wont have time to build an ark.