San Diego County was shaken Monday by a magnitude-4.7 earthquake
that began on the San Jacinto fault, a system that partly runs
through the northeastern edge of the county. We discussed the
significance of the event with Tom Rockwell, a San Diego State
University seismologist who has studied the fault for many
years. Q: Monday’s quake occurred on a fault that has recorded
three other sizable shakers since 2001. What’s going on? A: That
is an interesting question. There seems to be a bit of change in
the behavior of this section of the San Jacinto fault, and it
might indicate that that fault is highly stressed. Whether this
is leading to a larger event — who knows? But we should
definitely be prepared for a larger event in the future, just as
we are for all of the faults that can affect us. Q: When was the
last time that the San Jacinto produced a really large quake? A:
It happened on Nov. 22, 1800. The quake measured at least 7.3,
and it caused damage to adobe structures in San Diego and in San
Juan Capistran