You mean 300 years. This is all off of memory, which is risky for me with each passing year, but I think there have bene trenches on the Coachella segment, and the last earthquake was around 320 years ago (or at least more than 300). The faults in the link are liable to be cross faults: NE-SW left lateral faults. It is also logical that there would be some secondary strands parallel to the San Andreas. In 1987 a cross fault had a M6.2 left-lateral earthquake, which facilitated a M6.6 right-lateral quake on the superstition hills fault 1/2 day later. Relocated seismicity with focal mechanisms (e.g., Armbruster, Seeber et al 1998 AGU abstract, I presented the poster) and Magistrate and probably others now including Nicholson, show a right lateral fault cutting through part of the Brawley zone...so the San Andreas does not just end where mapped. There is a large geothermal field in the Brawley area and a geologist there said they would not work with us because they did not like the lead PIs papers (with Nicholson in some cases) suggesting that San Andreas could be triggered.

I know a fair amount about this area because I was a secondary co-PI on a proposal to do deeper seismic reflection data in Salton Sea that was submitted 4 times before we gave up. I think the last version was actually less good that the earlier ones: the number of collaborators and thus the budget got out of hand.

Other times, on revising a proposal, it clearly gets better, but the reviews get worse (mapping offshore southern California Continental Borderland with HW, last year studying vertical motions in and around Los Angeles (I was lead).

Let's see, this post is getting long...but: SCEC and USGS have a major effort going
to understand the southern San Andreas (SOSAFE).

Chris