Hi Don:

Thanks for the insight into my interpretation of my observations. You brought up several items which I hadn't even considered.

I assume that these instruments only measure creep/strain at the surface. So, whould it be safe to say that if one sees eqs at depth, but not at the surface for a given area, that the upper levels are locked and the lowers levels are not locked? In that case, I suppose one could say that the surface portion of the fault has strain building as the depths slide past each other? Of course that brings up another question ... do we know the depths of many/any of these faults here in California?

Assuming we only measure creep/stree at the surface, and if no deep quakes are occuring, then we have no idea if the deep portion of the fault is moving or locked, right? I think thats what I'm reading into your comments....

And, since we see two stations creeping and the 5 in between not moving, we have two portions of the fault moving and one that is not moving in the Parkfield area, right? So do we know what is happening at depth on these three segments? ANd of course, I guess we could figure that out if we knew the depth of the fault at this point and compare that to recent eq history of these segments .....

Michael