Burridge-Knopoff Earthquake Model

Burridge-Knopoff (1967): a chain of blocks connected by springs, pulled over a rough surface. Friction is velocity-weakening (once sliding starts, friction drops), causing runaway slip.

This model produces self-organized criticality and reproduces the Gutenberg-Richter law: log₁₀(N) = a − b·M (b ≈ 1), meaning large earthquakes are exponentially rare.

Color = block velocity. Red = seismic slip. White = locked (stuck).