Don:

Good questions -

1. The signature of the last multiple impulse burst of the ULF was of the type of signature that fits "silent quakes". It was not of the type that is the standard quake that you and I immediately think of

2. Your understanding is basically correct, that a silent quake is too low in frequency to be detected by our typical broadband. Maybe the accelerometers such as the Kinemetrics might have picked it up, but perhaps that is doubtful too. What I tried to emphasize was the effects of the silent quake, and that would show up as rather unusual activity such as the current 39.2 km depth quake near Calexico this morning around 9 and the swarm activity at Trona. I fully expect more anomalous behavior to show up, since we're still in the time window.

We need to break out of our stereotypical thinking about quakes and realize that they can happen at any speed up to about maximum which was a couple in China and India which threw the people up in the air against gravity.

Finally, I am not too concerned about the quake as I am about the effects at Coso.