Yesterday’s 4.2 magnitude earthquake was reported in today’s Chronicle this way: Quake rattles East Bay. The sub-hed? Magnitude 4.2 temblor causes little damage but may be foreshock
Since every earthquake is seen as a possible precursor to the “big one,” the foreshock reference feels like a bit of dramatic license. But I did read A Dangerous Place: California’s Unsettling Fate by Marc Reisner a few weeks ago. In this short, posthumously published book, Reisner quickly scans the history of the growth of California cities, especially San Francisco and the rest of the Bay Area.
Not surprisingly for the author of the justly famous Cadillac Desert (subtitled “The American West and Its Disappearing Water”), Reisner harps on the fragility of the water supplies of both Northern and Southern California. The aquaducts were not news to me. The novel danger to me was the levees in the Central Valley.
If the levees fail, at least two things happen.
First, of course, many people and even more farms are flooded, as the Delta’s salt water pushes up into the now-settled farmland several feet below the top of the levees.
Second, the water supply to Southern California is disrupted mightily, since the pipeline bringing water from Northern California to Souther California are shut off if the intakes are now brackish.
Technology exists in other places, but the farmland and food distribution infrastructure of the Central Valley has few parallels around the world. California’s economy — and therefore the United States economy — would suffer mightily.
After this introduction to all the possible dangers, Reisner creates a “what if” scenario in the last half of the book, “documenting” what happens when (not if) a magnitude 7 quake hits. This is scary, in a matter-of-fact way, though not as interesting as the first half of the book.
If you’re going to read Reisner, start with Cadillac Desert instead. But for a quick, fact-based scare about the earthquake risk we all ignore to live here, read A Dangerous Place.
The book was published in 2003, but was written by Reisner before his death in 2000, so he put the date of 2005 out there for his scenario. Reading the alternate (future?) history two years after the fact doesn’t change anything: the risk remains, and it always will.
However, it is possible that the replacement of the eastern span of the Bay Bridge might be done before a big quake hits… but it’s telling that Reisner in 2000 envisioned the bridge being replaced by 2007, not in time for his imagined 2005 quake.
The currest estimate? 2013. (source)