Plotting earthquakes in California for the “big one” is difficult due to the lack of historical data prior to 1857. From that point forward, the frequency appears to line up with the 8.6-year pi cycle insofar as the three major events — 1857, 1906, and 1989 — follow about 43-year (half-8.6) cycle. This is time period will now start to rise (March 2016), which is 43 years from a cluster of quakes that appeared in 1970-1973. We would have to run the current data through the system to determine a target in time and magnitude. We will look to update the short-term data when possible.
