Hi John. I was just wondering if “preparatory phase” might be applied to the Parkfield M>6.0 quake. As you know nothing was seen on any of the data sites that gave a hint of an impending quake. At least to the point that a warning could have been issued. Do you have any thoughts about why this may be the case? Take Care…Don in creepy town

From: Earthquakes Not Influenced By Tides

“Vidale's research supports the theory that earthquakes are preceded by a "preparatory phase" that begins days in advance and accelerates substantially in the final few minutes or seconds before the actual earthquakes. This theory, developed by Jim Dieterich of the U.S. Geological Survey and others, gives some hope to those who think earthquakes can be predicted, although Vidale said that this "preparatory phase" is not well understood and may not be observable until just seconds before an earthquake, if at all. Even if this preparatory phase could be identified in advance, it would not necessarily indicate whether the approaching earthquake will be small, moderate or strong, he cautioned.”

• Quakes Not Caused By Tides