Along the San Andreas Fault

The San Andreas Fault Cutting Through the Carrizo Plain

Yesterday, as we were motoring along the Soda Lake Road through the heart of the Carrizo Plain, Bill Korn said something that made me sit up. “Those mountains on the right have nothing to do with the ones on the left.” The truth of that remark hit me between the eyes. The Plain was a boundary between two tectonic plates—the North American Plate on the right, which was moving ever so slowly to the southwest, and the Pacific Plate, containing most of the population of California, was as slowly heading northwest in the direction of Alaska. And Bill was right, the two mountain chains, separated from each other by only a few miles, had no resemblance.

The movement amounts to an average of only a few millimeters a year, but there have been times that the motion has been more catastrophic. In 1857, the Fort Tejon Earthquake created the strange Chinese scenery of the Devil’s Punchbowl on the north slope of the San Gabriels. Then there was the 1906 temblor and fire that leveled San Francisco and the 1989 Loma Prieto quake. There will be more, a lot more, but hopefully spread over many years. I have lived through the 1971 Sylmar Quake and the 1994 Northridge Quake, both of which had me gelid with fear.

A Map of the San Andreas Fault

Perhaps I dwell too much in my blog posts about volcanoes, earthquakes, hundred year floods, and other disasters. That is because I realize how fragile our lives are. Most people would rather not think about such things, even if they are inevitable. So they build unreinforced brick houses on fault lines or live on the banks of rivers that frequently overflow their banks. Then there are those Guatemalan peasants who live on the slopes of volcanoes because the earth there is so conducive to growing coffee beans and other crops.