There are no Earthquake Cycles
Thomas H. HeatonSubmitted August 30, 2026, SCEC Contribution #15337, 2026 SCEC Annual Meeting Poster #215
There is extensive evidence that the effective coefficient of friction is in the range of 0.5 to 0.7 for shallow crustal faults. It is also clear that a coefficient of dynamic friction of more than 0.05 causes extensive melting that is not observed in exhumed faults. Although these two views of friction appear contradictory, there are examples where sliding suddenly transitions between high friction and low friction. For example, deep seated landslides have been observed to have sudden transitions between high low-speed friction and very low high-speed friction. This is very different from Dieterich-Ruina friction (aka, rate-state friction). I suggest that acoustic fluidization is a strong candidate to explain earthquake friction. This type of friction produces slip pulses. Dynamic chaos always accompanies slip pulses, and fractal spatial distributions of slip and stress are ubiquitous. The concept of earthquake cycles does not apply to systems that experience slip-pulses failures.
Citation
Heaton, T. H. (2026, 08). There are no Earthquake Cycles. Poster Presentation at 2026 SCEC Annual Meeting.
Related Projects & Working Groups
Earthquake Forecasting and Predictability (EFP)
