The last event with this type of aftershock sequence was probably the Hector Mine earthquake
in October, 1999. That aftershock sequence continued for many months. However, aftershocks
occurring where the sub-surface temperature is relatively high tend to occur near the beginning
of the sequence, so don't expect this aftershock sequence to last for more than a few days
since the Baja area is over a hot spot in the mantle.

When a strike-slip event occurs, residual strain is concentrated at the two ends of
the fault rupture. Depending on the slip, this either adds strain or reduces it from the
ends of the fault which ruptured. This strain is often taken up by other nearby faults
bringing them closer to failure or reducing strain on them and putting the next quake
off by some time.

On many long strike slip faults - like the Anatolian Fault in northern Turkey or the San Andreas, which are nearly identical in their length and detailed structure, one earthquake
can strain the next segment of the fault bringing the next earthquake sooner than
expected on that segment, that in turn strains the next segment triggering the next
earthquake along the fault etc. It is difficult to see this on the San Andreas because of
the many side-faults which take up some of the strain, but it probably does occur
there too. Studies have shown that the regions of greatest residual strain after earthquakes
in California are usually the most likely areas to experience the next sizable earthquake.

And Don, I did notice that sequence of 6 events of Ml>=2 in Ocotillo as well. That
area appears to be in the region where strain has been increased by the earthquake
today. It is certainly an area to watch. By the way, you mentioned your data regarding
the potential of a quake in this area about this time. Did you have this data before the
quake today? If so, how did you decide to forecast quakes at Avenal and Bishop
and not in Baja? Just curious.