Hi EQF. Along the San Andreas Fault, the segment considered most likely to rupture is near Parkfield CA. Earlier this century it produced a series of identical earthquakes (about M 6.0) at fairly regular time intervals. USGS scientists are monitoring Parkfield for a wide variety of possible precursory effects. Using a set of assumptions about fault mechanics and the rate of stress accumulation, the USGS made a more precise Parkfield prediction - of an M 6.0 earthquake between 1988 and 1992. Though that prediction was not fulfilled, an M 6.0 earthquake is still expected at Parkfield.

The segment of the San Andreas fault that broke in the 1989 M 7.1 Loma Prieta earthquake had been identified by the USGS as one of the more likely segments of the San Andreas to rupture. Magnitude 5+ earthquakes 2 and 15 months before the damaging earthquake were treated as possible foreshocks, and the USGS issued 5-day Public Advisories through the California Office of Emergency Services.

Hours before the Hector Mine quake there was a small swarm of earthquakes. Just about everyone saw them. Was there anything there that said a major quake was on the way in a matter of hours? We have the same kind of swarm here in the Hollister area from time to time, but no major quake has followed.

Even in areas where foreshocks are fairly common, there is no way of distinguishing a foreshock from an independent earthquake. In the Pacific Northwest, there is no evidence of foreshock activity for most historic earthquakes.

How do you propose to monitor a fault that no one knows is there such as the one that caused the Northridge quake? There were no immediate foreshocks. No systematic change in strain above the background noise occurred during the hours to milliseconds before the event.

Most seismologists don’t believe in ear tones, the angle of the sun and moon, the number of missing animals and so forth. The biggest reason being that no one has proved it. It can’t be scientifically proven that a quake won’t occur and there is always the chance that it could occur on the specified date.

The Kobe quake claimed 6,400 lives and caused $120 billion in damage. The last time a quake struck directly beneath Tokyo was in 1855 and an estimated 10,000 people were killed. An even stronger 8.3 magnitude quake hit the coast southwest of Tokyo in 1923, killing more than 140,000 people. Destruction ranged from far up into the Hakone mountains, to the busy shipping lanes of Yokohama Bay, north to metropolitan Tokyo. Seismologists predict another powerful quake, registering at least 8 on the Richter scale, will rock the coast west of Tokyo, but first a smaller, yet lethal temblor is expected to jolt the city.

If a country such as Japan who have poured millions of dollars into earthquake prediction can’t predict a quake in their own country how will anyone be able to predict a quake that is remotely removed?

The cost of setting up and maintaining monitors for active faults worldwide would be astronomical not to mention the equipment needed to record and store that data. The money would be better spent on insuring that construction of buildings and the infrastructure be more earthquake resistant.

Just my personal opinion. Take Care…Don in creepy town