There was a M4.2 today just north of the surface location of the San Andreas fault. It was mostly reverse with a little right-lateral on the NE-dipping nodal plane. Most likely was not on the San Andreas, but, if the quake was deeper than the initial report, could the San Andreas dip northeast here and be capabale of small thrust quakes? I know from striations in outcrop that a north branch of the Santa Cruz Island fault at the east coast of Santa Cruz Island had a left-lateral earthquake (rake about 21 deg) preceded by a reverse-left oblique (rake over 60 deg) on a fault break a couple meters south (all within 9 m-thick fault zone, 100% exposed). You could tell which came first by gypsum crystal growth on fault surfaces.
I really should do field work again, but can't seem to get excited about it...
Chris