Hi All. The northern segment of the Calaveras Fault near San Ramon hasn’t had a sizable earthquake since the USGS has been keeping records. The central segment produced a magnitude 6.1 earthquake in 1984, which severely damaged homes around Anderson Reservoir in Morgan Hill. That by the way was the strongest quake I had felt since leaving Japan.

The swarm of Nov. 2002 was perpendicular to the Calaveras fault as were the previous swarms.

The most recent (02/02/2003) swarm in the area of San Ramon/Dublin is significantly different from the previous swarms in that the quakes are fairly uniform in depth (10 miles), which in this case is deeper then most of the previous quakes and they are running parallel to the fault. They are located about 1 mile east of the fault.

According to the Unites States Geological Survey this swarm of small quakes over the weekend in the East Bay could be a warning of worse to come.

USGS Geologist David Schwartz says the quakes are most likely on the Calaveras fault.

"These earthquakes are the largest to occur on this part of the fault in 40-years and the depth at which they occurred is the depth that larger quakes usually start at," said Dr. David Schwartz.

During the Nov. swarm of last year it was pointed out then that those quakes didn’t necessarily mean that a larger quake was on its way. However if there was an increase in activity associated with the Calaveras fault then that could very well be the indication that something larger is on its way and it’s just a matter of time. Now the question is, is this recent swarm a little hint, or a big hint? Take Care…Don in creepy town