6.4 M quake in eastern California, southwest of Searles Valley,
occurred as the result of shallow strike slip faulting
in the crust of the North America plate.
This was followed by numerous aftershocks,
the largest of which was a 4.7 M quake 2 minutes after.
But about an hour before,
there were smaller quakes (foreshocks)
including a 4.0 M one 30 minutes before.