As
I was pondering that question Cal Tech seismologist Lucy Jones
appeared on the news coverage I was watching. She said this was the
largest earthquake we have had in over twenty years. But, she added,
it is not surprising that we just had an earthquake of that
magnitude. What is surprising is that we went so long without one.
She explained that earthquakes with a magnitude of 6 or above occur
roughly every ten years and that it is usually twenty years between
earthquakes with a magnitude of or greater than 7. So a Californian
approaching my age has been through a hell of a lot of earthquakes;
whereas a Californian younger than 35 probably would not remember any
significant temblor that struck prior to this one. All right, but
that is not where this story ends; it is not a wrap. We were soon
rocking again because the quake I have been writing about was the
foreshock and the mainshock that followed it had a magnitude of
7.1. Where I live the intensity of this mainshock seemed to be as
great as the intensity of the 1992 Landers earthquake, and that is not just a window rattler even a hundred miles from the epicenter.
Welcome to the club my young friends! The odds of a foreshock being followed by such a large mainshock is only around 5%, but the odds greatly favor you experiencing another earthquake of 7 or greater during your lifetime!
Welcome to the club my young friends! The odds of a foreshock being followed by such a large mainshock is only around 5%, but the odds greatly favor you experiencing another earthquake of 7 or greater during your lifetime!