Image: A photo of “creep” on the Hayward Fault. Nothing hit that curb – the earth moved at different rates, and the curb burst. (Leonard G/Wikimedia)
I went to a meeting about earthquake preparedness last night. I live in a little city south of Oakland, CA, atop something called the Hayward Fault. Sometime in the next thirty years, we are likely to see a big quake here, and I like to stay current in my knowledge about the fault, and get a sense of what I need to do to be ready for trouble.
Big earthquakes are no-kidding scary. Little ones are disorienting, because we don’t expect the ground to move. When I felt my first California earthquake, I wasn’t sure I had felt anything, until someone said, “That was an earthquake” and turned on the radio to find out about it. The biggest quake I felt before 1989 was a 5.3, and I thought a truck had run into the house. In the Loma Prieta Quake of 1989, I saw my china cabinet walk across the dining room floor as I ran to grab my youngest.
Earthquakes here are communal moments. We turn on the local news station to find out about it, or we go to Twitter. “Did you feel it?” “My dog alerted me just before it hit!” “My dishes rattled.” “Where was the epicenter?” “What was the magnitude?” Most locals agree that anything below a 5 is a minor thing. Anything much above a 5, though, is something else altogether.
Earthquakes happen because the earth’s crust is in motion, giant “plates” sliding over the surface of the planet. Earthquake zones are those places where two or more of those plates meet. Sometimes the plates creep quietly along. Sometimes they stick and then jerk into motion. Those are the quakes.
Tonight I learned something new that was even more astonishing. Some scientists think that “our” faults (the Hayward, the San Andreas, etc) “communicate” with other faults far away. I don’t begin to understand that, but I heard a respectable geologist say it tonight.
When I feel a tremblor I recite the blessing for earthquakes:
Yes, earthquakes are scary. They also create amazing landscapes – they are the reason that the California coast is so utterly beautiful. We can’t control them. And that is true for much of nature: even when we think we understand it, Mother Earth is older, wiser and stronger than any of us can imagine. What earthquakes have taught me is that the earth is very much alive.
It behooves us to maintain an awe for nature. We are accustomed to harnessing it for our own uses, but it never pays to underestimate the power of forces far beyond our control.