It's computer generated and not yet checked by seismologist, but the USGS page shows a 3.1 SE of San Clemente Island, near the San Clemente fault, which is a long, active right-lateral fault. Legg, Goldfinger et al dove on this in a small sub a couple years ago and found vertical seafloor scarps....and it shows up distinctly on high-resolution bathymetric maps. There is a bit of a debate on how hazard this fault is to the mainland-Legg points out it is the same distance from downtown L.A. as is the San Andreas, and modeling of 3D ground motion from quakes on the San Andreas to LA showed bad news-long duration ground motion at the frequencies that are bad for tall buildings (Olsen and Archuleta...). But, the crust is not as thick offshore so the area of fault broken per km of length might not be as much for the San Clemente fault.......Chris