Another strike-slip quake, an 8.2, followed the 8.6. The seismologists must be sleeping; there is nothing on the SCEC site and nothing on Iris, and it has been 7 or 8 hours. They must all be depressed from having all their proposals rejected.

OK, as I posted elsewhere on this thread, to get a strike-slip of 8.6 on a fault like the San Andreas, you would have to have a huge amount of slip over a huge distance. The largest ones like 1906 and 1857 are close to 8.0 or 7.9.
What makes the 8.6 even more remarkable is that the first few aftershocks are within 3 deg of longitude and 1 deg of latitude, so within about 350 km. If the rupture is only 350 km-long, it must have ruptured from the sea floor to unusually deep. Plus, it must have had unsually large slip. two of the large aftershocks were 2 the ESE, and 4 of them were a little north of east. So, not a single fault. I vote that the ESE nodal plane of the M8.6 is the one that broke, and there was some triggered quakes off to the south.

These were before the M8.2 That epicenter was about 250 km to the SSE of the epicenter of the M8.6. After that, harder to tell which quake aftershocks were associated to. But some aftershocks at that southern latitude just now to the east of the M8.2 suggests that this one also ruptured the WNW-ESE nodal plane.

If I am correct, two great strike slip quakes on parallel faults a couple hundred km apart.

HW (heartland wife) actually got a proposal funded along with Nano Seeber to survey after the 2004 quake, so she is familiar with the ocean fabric and a tear in the ocean slab. She just finished a class (in Heartland, I'm at UCSB), so I'll call her in a bit. I'll call Nano now.

Chris