Thursday, May 18, 2006

On Shaky Ground

Reading Simon Winchester's A Crack in the Edge of the World was a scary learning experience. The book itself was not scary. What was scary was constantly remembering the 6.7 Northridge earthquake. Every now and then Winchester or one of his sources would say something that would bring the memories back in a flood. What I remember most is the noise so whenever Winchester would mention the sound of the earth moving, I'd get chills. One particular passage sums it all up nicely:

The terrible roar filled the ears and seemed to fill the mind and heart, dazing perception, arresting thought and, for a few panting breaths, or while you held your breath in dreadful anticipation of immediate and cruel death, you felt that life had already past and waited for the end, as a victim with his head on the block awaits the fall of the uplifted ax.
Now, granted, a 6.7 is not the estimated 8.2 of the 1906 San Francisco quake, but I did expect at any moment for my apartment roof to fall in on me. It didn't. But I can never forget the noise or the terror of it. Putting that aside, the book isn't just about the San Francisco earthquake. It is also about geology and why there are things like earthquakes in the first place. Winchester takes the reader through the very formation of the continents. I was surprised to learn that the knowledge of plate tectonics has only been around since the 1960s. From the world picture he narrows his focus bit by bit to the United State and then to California. It was in his discussion of California geology that I learned the most. I grew up in CA so you'd think I'd know most of this stuff but I was pleasantly surprised. Finally Winchester focuses on San Francisco, the earthquake and its aftermath (you can see video footage of it here). The city, and many others in CA are built right on top of the San Andreas fault. He drives home again and again that the fault will slip like it did in 1906. It will be big. It will be devastating. We humans are very silly creatures to believe otherwise. But having grown up in CA, hearing year after year the Big One will come, and when year after year nothing happens, I understand how easy it is to believe the geologists don't know what they are talking about. But the stress is building up and there is a 62 percent probability that an earthquake of magnitude 6.7 or larger will occur in San Francisco before 2032. By the end of the book I was smugly telling myself how smart I am to have moved to Minnesota where there are no earthquakes. I am safe. But it turns out no one is safe from the movement of the earth's plates. The plates float on a sea of magma and there are places on the crust that are thinner than others. There are volcanoes. There is Yellowstone. I recall a childhood family camping trip to Yellowstone. Along with the mountains, moose, and waterfalls we saw Old Faithful and, it seemed, just about every mudpot in the park. The park people tell you how hot the bubbling stink is, warn you to be careful and not fall in. So of course, my Dad had to hold me over the edge, laughing while I screamed. Ha. Ha. Anyway, Winchester says that on purely statistical grounds, Yellowstone, which is already one of the biggest explosive "volcanic complexes" on dry land, is ready to erupt at any time. If, or perhaps when, the eruption happens huge areas of the western states will be covered in volcano guts. The wind blows my direction from Yellowstone so no doubt, we'll be sucking up ash and who knows what else here. I've got most of Wyoming and all of South Dakota to protect my lovely state from the worst of it, but no matter how you look at it, a supervolcanic eruption is not going to be pretty for anyone. After reading this book I can no longer fool myself into thinking there is anywhere on earth that is absolutely safe to live. To consider the continents as we know them to be stable places, to expect them to always be shaped the way they are and for them to always be at the same longitude and latitude is delusional. Rocks are not solid. If you are prone to fits of paranoia, do not read this book. However, if you love disater movies, this is a read for you.