Hmm. seems less inflamstory than the headlines.

Actually the Northridge size frequency is one per 20 years along the san andreas region.

For Catatstrophic earthquake prediction read below.

The last event at the Gorda subduction segment (Petrolia extending to the area S. of Lassen and inland as far as Owens valley was approx 14C 1350? The ? is the error bar surrounding the real date of the pull apart based eruption of the Mono-Inyo supervolcano. The subsequent activity of that volcano has been related to minor events caused by minor rifting of the owens valley with the mass of the Owens block putting a "squelch" on major caldera forming eruptions for the time being until such time as the lid separating the Mono crescent magma chamber @ 10Km depth drops through and reconnects with the main gas supercharged pluton at somewhere between 15-20Km down.

Currently the recompression wave has reached the Owens rift valley SE. of the megathrust @ Petrolia and the high level volcanic intrusives @ Mammoth Mt. Long Valley & Coso are behaing in "Zit" mode.

Prior volcanic response dating indicates that the recurrence time for r/lx (rebound/Long duration, Mercalli X) event quakes in the Gorda segment is about 750 years with an error bar of about a century. These events are backarc type that decompress the crust at least as far SE. as the Owens rift and occasionally as far back as the Nevada border, and Gulf of Califiornia rift.

It also appers that the relative convergence rate is a mite slow compared with the historic results and this result is mirrored in other areas of convergence where major r/lx is due (ie. the pressure is sufficient to slow the convergence resulting in a deformation wave spreading back through both convergent plates prior to the r/lx @ the megathrust.

The Deformation wave is currently enough to affect the san Andreas and jog active movement at the faults closer to the coast and more transpressive with time. This effect also delays the timing of movement along the transform and increases thrust activity in the range N. of L.A. through which the fault passes. Also bear in mind the compression/rift/transform event at landers in the E. of the range with the compression phenomenon noted. which was an effect of the spreading now transferring from Owens valley to the Gulf of california rift.
The corresponding descending plate (Gorda plate) is backed up as far as the rift, Transform/compressive quakes are now ongoing at the Mendocino transform, but they also are slowing their rate as a result of subduction beginning in the L.A region. The back up extends as far as the transform off the Oregon coast which is now again a mixed trans/comp/rift system.

The math indicates an r/lx due about 750 years after the 14C date C1350?. The real date of the event would be slightly earlier, and the error bar is alsdo significant.
The error bar for the 750 year date itself from prior example counts is again +-100 years which means we are already in the windo for r/lx in the Petrolia region.

Have a nice day: Ag