Abstract:
This paper finds that there exist 11-year cycle and multi-11-year cycle in Parkfield seismicity of USA. The 22-year cycle found by USA scientists is just one example among them. Analysis shows that the 2004 Parkfield earthquake can not be predicted with 11-year cycle or 22-year cycle theory, so the prediction of Parkfield earthquake failed. The reason is that a new regulation-Golden Ratio law appeared, namely 11-year×0.618=6.8 years. With this law the 2004 Parkfield earthquake can be predicted accurately. Based on these new findings, it is predicted that the next Parkfield earthquake will occur around 2032.