Wow. Pretty good jolt today. I was sitting in my office when I began to feel some high frequency shaking, starting weak, but then growing sharply in intensity. I’ve been in California long enough that such things don’t usually perturb me too much, but this one was as strong as I can remember in the twenty years I’ve been living here (I missed the Loma Prieta earthquake in 1989). The noise was loud. Less rolling than I’ve felt before, but lots of energy in fast shaking. I bolted out of my office, but didn’t even make it twenty feet before it stopped. So, what did I do? Headed back to my desk to check the Internet.

Turns out it was a 3.9 (downgraded from an early estimate of 4.2) but less than three miles or so from where I am. Here’s the seismogram from Pinole Ridge:

A pretty good ride. I think I’ll head home a bit early to make sure the cat is okay.