Hi Michael. I used the same catalog that you used. At least it looks the same with one minor exception. The one you used shows the first quake in 1983 and ends in 1995. The catalog indicates from 1973 to present. The one I use is the same one, but I used a different URL to get to it. http://neic.usgs.gov/neis/epic/epic_circ.html. This tells me that there are at least two or more catalogs. Not that there are two separate catalogs, but more then one URL to get to it, which can and does have an affect on the outcome of the data you see.

However it changes very little in that there are no quakes listed from 1973 to 1983 and none after 1995 with the one you use and none from 1973 to 1984 and none after 1995 in the one I use. Again there may even be a third if you show a listing with quakes from 1973 to present.

To have a quake in the center of the Pinnacles would be good call indeed. The Pinnacles is located in a block and is part of a volcano that erupted about 20M years ago down by the town of Lancaster, which is about 200 miles south maybe a little less of its present location. It was for the most part carried up here under the surface, but the further north it moved the more it moved towards the surface. Time and erosion did the rest. At least that is how it was told to me. Take Care…Don in creepy town.