EARTHQUAKES AND TIDAL FORCES

More than 40 years ago, I coined the term, "Seismic Window" to specify an eight-day period, which contains heightened seismic potential. This interval is focused on the alignment of the Sun, Moon, and Earth twice each month at syzygy, especially at the time of the monthly closest approach of the Moon at perigee. From two to five times each year syzygy and perigee coincide within 25 hours. Such conditions prevailed on October 14, 1989, with a syzygy/perigee time separation of only five hours. This produced tidal forces not exceeded at any other time between December 1986 to December 1990. Based upon tides, and several other established clues, I publically predicted, with 85% confidence, that a Bay Area "World Series Quake" of 6.5-7.0M would strike locally between October 14-21, 1989. Most local residents could attest to what happened on the afternoon of October 17, 1989, when the 6.9-7.1M event produced widespread death and destruction. The previous +6.5M earthquake had hit south of San Jose on July 01, 1911, the day of a New Moon syzygy.

The subject of earthquake prediction has produced much controversy in the scientific world since my own courses in Geology at U.C. Berkeley in the late 1950's. It is ironic to examine the legal aspects of the 6.3M killer quake at L 'Aquila, Italy on April 06, 2009, when seismic evidence was ignored and local scientists were convicted of failing to warn the public. In my own case, my predictive success resulted in a 70-day suspension from my position as Santa Clara County Geologist. I was allowed to return to work only by promising to predict no more quakes "on County time." I immediately began printing my SYZYGY newsletter, which is now in its 26th successful year of publication.

Let me here make note of the only table of earthquakes in the 1975 publication of the National Academy of Sciences, "EARTHQUAKE PREDICTION AND PUBLIC POLICY." Therein can be found a listing of just five "representative U.S. earthquakes." I took it upon myself to add the syzygy data, which was ignored in the table as printed: (1933 Long Beach; (2) 1952 Fort Tejon; (3) 1959 Hebgen Lake; (4) 1964 So. Alaska; (5) 1971 San Fernando. All five of those "representative earthquakes" occurred on the day of syzygy, and the first and last were on the day of a lunar eclipse. A statistician assured me that the random chance against that correlation is 759,000 to one.