Hi Martin. I wasn’t home for that 3.1Ml at San Juan Bautista. It appears the quake occurred on the Zayante-Vergeles fault. It appears to be part of the on going activity that started on that fault about two years ago. There have been numerous swarms in and around that area although this one is a little more south then the last ones.

The fault is 56K long and has a slip rate of 0.10mm per year. It is thought to be able to have a quake up to 6.8Ml although there is no record of there ever being a quake of that magnitude center there. Take Care…Don in creepy town.