Earthquake Storms: The Fascinating History and Volatile Future of the San Andreas Fault. By John Dvorak. New York: Pegasus Books. 2014.
Earthquake Storms is indeed a fascinating history, not only of the San Andreas Fault that runs along the western edge of California, but also of the State of California itself, the cities of San Francisco and Los Angeles, the building of the Golden Gate Bridge, the California Gold Rush, the development of the oil industry in California, the growth of the science of geology, the increasing understanding of earthquakes, the development of the Richter scale, the Trojan War, paleoseismology, as well as the future of the San Andreas Fault and the prospects of predicting earthquakes, in addition to many other interesting side roads. The book is well written, well researched and has depth as well as breadth. It is a stimulating panorama that includes colorful depictions of the personalities whose curiosity and dogged persistence made the breakthroughs that moved our understanding of earthquakes forward. Dvorak makes interesting connections between personal peculiarities and psychological needs of individuals and the influence it had on their work as a researchers and scientists.
Until the latter half of the twentieth century earthquakes were mysterious, apparently random events, that could be enormously destructive. But people had no clue why they occurred when and where they did and what caused them. The destructive potential of earthquakes has grown with the growth of civilization and the construction of large cities on or near the faults in the earth where earthquakes occur, and this in turn has stimulated the study of earthquakes and their causes. Earthquake Storms documents this growing interest and understanding of earthquakes beginning in the nineteenth century with dramatic strides forward in the twentieth. However, this understanding has not reached a point where earthquakes can be foreseen with the kind of accuracy that has come to forecasting the weather. Dvorak cites a 2008 report by the Working Group on California Earthquake Probabilities that asserts a 31% probability of a magnitude 6.8 or stronger quake along the Hayward Fault, which runs along the eastern side of San Francisco Bay from Richmond, through Berkeley, Oakland, Hayward and Fremont, within the next thirty years. (p. 235) Not exactly something you can make plans around, but it does emphasize the need to strengthen buildings and infrastructure for the inevitable traumas that will be visited upon them.
While this book is well thought out, well organized, and coherently written, it does have one major drawback, and that is a dearth of maps, drawings, diagrams, and illustrations that would make some of these concepts and descriptions a lot easier to grasp. Dvorak does include eight pages of black and white photographs that are very interesting and helpful, but the book needs a lot more. I would recommend another fifty pages of maps and illustrations. I’ll give you an example.
When the North American plate began to drift over the Farallon-Pacific’s spreading central region, a transform fault formed, and then a peculiar feature developed at either end of that fault. The feature, known as a triple junction, is a place where the boundaries of three tectonic plates meet. In this case, two of the plates are the North American and Pacific plates; the third, which is actually what remains of the Farallon plate, has been given a different name depending on whether it is north or south of the transform fault. At the north end, the surviving part of the Farallon plate is now known as the Gorda plate and the point where the three plates meet is the Mendocino triple junction, because the point is currently located near Cape Mendocino. At the south end is the Cocos plate — a remnant of the Farallon plate — and the Rivera triple junction. What is important here is that, because of the directions in which the various plates are moving, neither the Mendocino nor the Rivera triple junction is stationary; both migrate. And they migrate in opposite directions, the Mendocino triple junction to the north and the Rivera to the south. As time progresses, the transform boundary between the Pacific and North American plates lengthens. And that brings us back to the San Francisquito-Fenner-Clemens Well Fault. (p. 211)
Can you visualize that all right? Maybe you don’t really need a map. It should be no problem to anyone who is steeped in the geology and geography of California. But how many people would that be? This book is written, supposedly, for a wide audience. But doesn’t Dvorak know that Americans are among the most geographically illiterate people in the developed world? According to National Geographic and Roper surveys:
About 11 percent of young citizens of the U.S. couldn’t even locate the U.S. on a map. The Pacific Ocean’s location was a mystery to 29 percent; Japan, to 58 percent; France, to 65 percent; and the United Kingdom, to 69 percent.1
If people cannot even find the Pacific Ocean on a map, how are they going to visualize the Mendocino and Rivera triple junctions that are moving in opposite directions? Dvorak does this all through the book. He is very good at verbal descriptions, but he expects his reader to have encyclopedic knowledge of geography and a vivid imagination for the movements of large objects, how they interact, the stresses they create, and the outcome of these colliding forces that would be worthy of an experienced civil engineer. It may be bad news to the publisher, but his book needs illustrations and photographs on nearly every other page, perhaps another hundred. There are so many things that Dvorak describes very well in words, but they cry out for a picture that would simplify the cumbersome description.
Another example would be his descriptions of rocks and mineral specimens.
I draw attention to this particular component of the conglomerate because it is easy to identify. About one out of every ten boulders, cobbles, or pebbles in the conglomerate is this purple rock peppered with pink flecks of feldspar crystals, which adds to its attractiveness and ease of identification. (p. 205)
A picture would do a much better job of fixing the image of this mineral in the mind, and I think it would also make the point he is trying to get across more accessible as well. In this subject material, which is very visual to begin with, descriptions of the movements of land masses and geographical features almost require pictures and illustrations. He really needs to do a second edition, updated and improved with lots of visual imagery.
One lesson that you can’t help but take away from this book is that earthquakes are inevitable and the San Andreas fault, as well as many other faults all throughout California, are ticking time bombs that will certainly go off as major seismic events in the foreseeable future, with powerful and terrible effect. The title of the book, Earthquake Storms, refers to another realization, first argued for by Amos Nur in the 1990s, that earthquakes tend to occur in clusters, or as Dvorak calls them, storms. Once you have a major earthquake, the chance of having another one of equal or stronger magnitude is actually greater than it was before the first event. He likened a fault’s slippage to the opening of a zipper that catches on successive teeth as it slides down the chain. Amos Nur has suggested that such a series of successive earthquakes over a period of decades may have contributed to the end of the Bronze Age 3300 years ago. (pp. 226-28) Dvorak points out several examples of successive major quakes along fault lines within relatively short spans of time, including along the San Andreas.
It is also worth mentioning, Kathryn Schulz’s recent, excellent article in the New Yorker that describes a much more monumental disaster waiting to happen on the Cascadia fault off the Pacific Northwest. The Cascadia Fault, has been quiet for over three hundred years, in contrast to the San Andreas, which has been quite active in recent times. In other words, the Cascadia Fault, while not considered overdue in a statistical sense, has been ominously quiet for a very long time, and when it does give way, could prove cataclysmic for the Pacific Northwest. Schulz points out that faults have a maximum magnitude in the strength of earthquake they can produce that is based on the length and width of the fault and the amount that the fault can slip. She does not discuss the science of this in any detail and Dvorak does not mention the earthquake magnitude potential of faults at all. But for the San Andreas Fault, Schulz claims that 8.2 is the maximum magnitude it can generate — which is a pretty good shake that will wreak a lot of havoc. But it pales in comparison to the potential awaiting in the Cascadia Fault off the Pacific Northwest coast. If the Cascadia gives way in a really big way the result could be anywhere from 8.0 to 9.2, which would leave much of the Pacific Northwest, which is profoundly unprepared for such an event, in rubble.
Generally, I would heartily recommend this book, especially to well educated people who live in California. But it could be equally relevant and illuminating for people all around the world who live in earthquake zones were it to be revised and expanded to include illustrations that would make the text much easier to follow and the conceptual arguments easier to visualize.
Notes
1. National Geographic News, October 28, 2010. http://news.nationalgeographic.com/news/2002/11/1120_021120_GeoRoperSurvey.html
See also the National Geographic/ Roper study from 2006 on Geographic Literacy.
Click to access FINALReport2006GeogLitsurvey.pdf
2. The Really Big One. By Kathryn Schulz. The New Yorker, July 20, 2015, pp. 52-59.
