Hi All. Most of you know I follow the data very close. Just recently I posted about the Bay Area creep appearing to slow down. Still not sure if it’s returning too normal, or if there is some strain building somewhere that is not showing up on the data.

I have noted something on the Chabot tilt that at first I didn’t think all that much about until a thought came to mind. What if the strain was already near max when the data collectors were put into place? Would we really see an increase in dilational stress, or tensor stress? What I’m seeing with tilt is that it is contracting. In other words it, or what has caused the tilt is now moving away, or shrinking.

As the rock that causes the fault to stop moving starts to break, or shear, cracks start to form. This in turn causes the rock to expand, which in turn causes tilt that is measured near the surface. As the rock starts to give either through brute force or water being forced into the cracks it starts to give there by causing the tilt to decrease. When the shearing is complete we have an earthquake. The magnitude of the quake depends upon how much force was required to shear the rock. Something to think about and to rethink about. Take Care…Don in creepy town.