Cascadia's Fault: The Deadly Earthquake That Will Devastate North America [Hardcover]

My wife and I moved to Eureka CA in 2009, and soon thereafter I developed an almost insatiable thirst for knowledge about this "megathrust earthquake" that I learned was apparently imminent for our area. Somehow I had an image in my mind of waves 1000 feet tall and bits of the coast being broken off and submerged under the sea permanently. That's the movies; but this book is about the reality - tectonic plate theory, subduction zones, megathrust earthquakes, and the catastrophic tsunamis that result from these events.

It's written mostly as a history of the process of discovery that led scientists from an initial position of believing that the Pacific Northwest was completely aseismic (without earthquakes), through the various clues and slowly dawning realization that yes, in fact our region does have really big 9.0+ megathrust earthquakes (and corresponding tsunamis) every few hundred years. In fact, the majority of the book might be a little frustrating for someone who's just wanting to find out "what's gonna happen", because mostly it's a historical account of scientific discovery, interspersed with tales and descriptions of previous large earthquakes. Impatient people can skip to the last nine pages or so, where he outlines a frankly terrifying (though imaginary) scenario that entails what a 9.2 quake might do to the modern Pacific Northwest: Think along the lines of most of the tall buildings in cities like Portland and Seattle collapsing (since even the new ones are not built to survive 4 minutes or more of strong shaking on a frequency that makes these buildings vibrate like great big tuning forks), and a tsunami 30 to 100 feet high which will pretty much wipe out entire coastal communities.

So, are we doomed? No. It's not all about terror and calamity - one important point that gets made repeatedly is that history has shown that simple education and knowledge can keep you alive in situations like this. This book is not so much a tactical "how to survive" type disaster preparedness guide, as a strategic "big picture" view - why and how is all this happening. That said, sprinkled throughout the book are many tidbits of wisdom about these events that certainly served to fill out my understanding of how they unfold, and how to survive them.

If I was going to nitpick, then the biggest weakness of the book, really, is the fact that so much of it is taken up with the historical tale of how the scientists went from thinking there are no earthquakes here, to thinking that there are earthquakes (but not being too sure about whether there were lots of smaller ones, or just fewer really big ones), to finally discovering the clues that told them that Yes, this area does in fact get really, really big earthquakes occasionally. It is a fascinating scientific detective story, but all the talk about turbidites, ocean sea floor cores, ancient tree rings and underwater mudslides, while interesting, isn't riveting reading when you already know the final outcome. Yes, it is all fascinating stuff, and Yes, I really enjoyed reading it. I just wish the end part on what might happen had been fleshed out a bit more, because let's face it - that's what most people who buy this book want to know. The subtitle of the book is, after all, "The coming earthquake and tsunami that could devastate North America", which makes it sound like it's talking about what's GOING to happen here. But it could perhaps more accurately have been "The history of how we found out about Cascadia", because most of it is about the past. To have to wade all through that history, which ends up with nothing more than the simple realization that "Yes, we do get these big earthquakes and tsunamis" feels a little redundant, because we know this now, and the big questions are all about what's coming next - the future, how do we prepare, and what specifically can we do about it. But like I said, this would be nit-picking - for what it is, the book is a wealth of information. I would heartily recommend it to anyone who is remotely interested in Cascadia, in particular anyone at all who lives in the Pacific Northwest of the USA, this is for you - read it and learn.

Another slight nitpick is the lack of footnotes or references - sometimes he talks about "a study", without any note about the actual title or how to find it. There is a list of recommended reading at the back, but it's organized by year and there was at least one instance in the text of a referenced study from 2009, whereas there weren't even any entries under 2009 in the reading list. But again, this is a minor point - if you are interested at all in Cascadia's subduction zone, then this book is a must-have.

Finally, I hadn't realized before buying this book that the author was also behind the making of the CBC documentary "Shockwave". I recently got this on DVD (direct from the publishers, Omnifilm), and it's a very good companion to the book if you can get hold of it. It's something else to see on TV the experiment that he describes, where they built a scale model of Seaside, Oregon in a wave tank and then film a scale tsunami wave as it overruns the town. Sobering stuff indeed.

The story Jerry Thompson has to tell is critically important, intriguing for anyone interested in science and as current as the 2011 earthquake and tsunami in northeast Japan. I just wish Thompson had told the story better.

While the San Andreas fault gets all the publicity, it's not the most dangerous earthquake fault in America, or even on the west coast. That dubious honor goes to the Cascadia fault, where the easterly edge of the Juan de Fuca Plate is being stuffed under the northwest coast of North America. Extending from northern Vancouver Island to northern California, the plate is jammed. Locked up tight. At the rate of about 4mm a year, pressure is building. It doesn't sound like much, but the last major quake was in 1700, and based upon field work measured ML8.7-9.0, about the same magnitude (and for about the same reasons) as the disastrous 2011 quake off northeastern Japan. Geologists estimate a 37% chance of a major ML 9 quake in the next 50 years. Such a quake and attendant tsunamis would be disastrous, if anything worse than those videos of what happened in Japan.

Thompson tells the story of how the new science of plate tectonics developed, and specifically how those developments helped create an understanding of the geology and the risk the Cascadia fault presents. It's approximately what John McPhee did in By John McPhee: Annals of the Former World, but focused on the Juan de Fuca Plate. And Thompson isn't the writer that John McPhee is. Thompson very nearly makes an interesting story tedious.

Partly, I think, that's because Thompson is a newspaper reporter and the skills that develop a 1,000 word feature piece for a newspaper don't lend themselves to a 342 page book. Partly it's because Thompson feels compelled to say plate tectonics was a revolution without doing an especially good job of saying why. I'm a geology minor; I was at the University of Oregon when some of the early research was going on. It was the most exciting time I've had in a classroom, with professors fresh off research ships studying the geology of the area, telling us what they had found and inviting us to develop their ideas with them. We took field trips to the Oregon coast to study uplifted relic beaches. We visited the "ghost forest" of cedars. We dug muddy trenches in the Siuslaw River estuary.

All or almost all of that excitement is missing from Thompson's book. I do give him points for not being alarmist. There is indeed a terrible risk for which the Pacific Northwest is horribly underprepared. But this isn't going to be the book that seizes the imagination of elected officials or the voters and gets them to start planning.

Three stars for the importance of the subject. It _should_ be read by everyone living in Oregon, Washington or B.C. that's within 300 vertical feet of tidewater. But I can't blame them if they don't make it through the book.

"Cascadia's Fault" is at some level two books. The better of the two is the story of how geologists around the world discovered how sea floors subside between floating continents to create "subduction zones" where volcanoes and earthquakes are common and often deadly. The famous "Ring of Fire" around the Pacific Ocean, for example, is the surface manifestation of several interrelated subduction zones.

Bound up in this historical narrative is the detective story of how scientists learned that the Cascadia Subduction Zone lies offshore and beneath the Pacific Northwest. They even know, to a high degree of certainty, that the last major earthquake along this fault occurred at about 9:00 pm on January 26, 1700--it may have exceeded 9.0 on the Richter Scale, and it sent an "orphan tsunami" across the Pacific that heavily damaged Japan. Native American legends and careful study of land subsidence along the West Coast show that the tsunami waves were even more devastating on this side of the ocean.

Thompson is on shakier ground (so to speak) in the "other" book, in which he speculates about what the complete release of the Cascadia Subduction Zone would do to the West Coast. As a journalist and documentary film maker, Thompson can't resist the urge to make the earthquake as awful as possible. He argues that one outcome could be 15+ meter tsunamis that devastate essentially all of the coastal communities on the West Coast from British Columbia all the way to California, as well as trans-Pacific waves that would hit Hawaii, Japan and elsewhere. The 9.0 quake itself would be widespread enough--and more to the point, long enough--to make the tall buildings in Seattle, Vancouver, Sacramento, San Francisco and Portland behave like tuning forks, with predictably catastrophic results. He may be right, but he doesn't explain why we didn't see quite that much devastation in similar-sized earthquakes in Japan, Chile and Indonesia. It may be that the Cascadia fault and the West Coast are different in a way that makes the worst-case outcome more likely, but "Cascadia's Fault" doesn't clearly explain why we should fear the worst (not to say that we don't have plenty to be nervous about).

All in all, Thompson tells a detective story that people living on the West Coast need to understand. For one thing, if I'm on the beach in Oregon and a large quake hits, I will head for high ground long before anyone sounds the alarm--Thompson convinced me that the sirens will go off right about the time the tsunami hits the coast, and I don't plan to hang around to see if he might be mistaken about that. And for those trapped in cities like Seaside, whose outbound bridges are apt to be wrecked in the quake itself, the best response to the emergency might be "vertical evacuation"--if a tsunami does come ashore, people who fled immediately to the top of a parking structure may fare better than those caught in a traffic jam on a low-lying road headed out of town.

Sobering stuff, indeed, and one hopes that our emergency planners read this book and think about its implications. Remember, Japan is extremely well prepared for earthquakes and tsunamis, and its coast was devastated--and thousands of people killed--by the March 2011 subduction zone quake and tsunami. The West Coast of the United States is not nearly as well prepared, since such huge quakes are much rarer on this side of Pacific.