Steady‐state seismic slip – A precise recurrence model

Regularity of seismic slip along a 9 km segment of the Calaveras fault zone is believed to result from steady‐state loading of a creeping fault to generate stresses on an isolated stuck patch which moves in a stick‐slip event in the magnitude range 3 to 4 whenever a critical threshold is reached. The patch behavior can be described by a simple model similar to the spring‐driven frictional models used in laboratory simulations of stick‐slip. The (M ≥ 3) recurrence time for this model is directly proportional to the seismic slip (computed from magnitudes) since the last time the threshold was reached. If the model is correct, an (3 ≤ M ≤ 4) earthquake should occur at 37° 17′ ± 2′ N, 121° 39′ ± 2′ W within 48 days of January 1, 1977.