Static friction → dynamic weakening → propagating rupture front
Static Friction μₛ0.6
Dynamic Friction μd0.2
Loading Rate1.0
Rupture Speed0.7 Vs
— Moment Magnitude
— Stress Drop (MPa)
— Avg Slip (m)
— Rupture Velocity
0 Aftershocks
Faults accumulate elastic stress through tectonic loading (Reid's elastic rebound theory). When shear stress exceeds the static friction threshold (Byerlee's law: μ ≈ 0.6–0.85), rupture nucleates and propagates at up to ~0.9× shear wave speed. Dynamic weakening mechanisms (flash heating, acoustic fluidization) drop friction sharply during slip. The Omori-Utsu law describes aftershock decay: n(t) = K / (t + c)^p, with p ≈ 1. Gutenberg-Richter: log N = a − bM, b ≈ 1.