There were 2 big quakes in california in 1812: one on the San Andreas fault at Wrightwood (and some long distance no doubt along the fault), and another 13 days later....whose location is in dispute...it used to be assumed in was beneath Santa Barbara Channel because it had a tsunami...(which is still my preferred location...maybe near Santa Rosa Island...even thought the tsunami may have been triggered by a submarine slide which may have been triggered by a somewhat distant quake....
Chris