Hi All. Thought I would share with you what I have learned about the mini PBOs in the Bay Area.

As you can see the ones that are in place now are about 15 miles apart with a couple of exceptions. This is the area between the site at Ohlone Park, Hercules and Wildcat Mountain near Petaluma, which hasn’t been installed at this time. The other is at St. Mary's College, Moraga, which also hasn’t been installed.

Each site covers a little more then 35 miles so there will be an overlap in the areas covered by the site. The newly designed tensor strain meters appear to faithfully record strain signals over a broad frequency range. In May of 2002 the Ohlone Park site recorded the strain for an M>2.0 quake a little less then 10 miles away. However an absolute minimum of 3 strain sites must indicate an increase in strain before a major quake warring will be given. In this case the more sites that are showing an increase in strain the better the odds are of having a major quake. The site showing the greatest amount of strain is presumed to be the most likely area for a major quake.

The sites at San Rafael and Ohlone Park are capable of detecting a strain build up on the Rodgers Creek Fault, but only the most southern segment of the fault. If the strain build up is large enough the site at the Marin Headlands will also detect the strain. Take Care…Don in creepy town