Analysis of the Williams, Arizona earthquake of November 4, 1971

abstract The frequency of occurrence of earthquakes in northern Arizona is low, and consequently the coverage of events when they do occur is generally poor. The station coverage of the November 4, 1971, Williams earthquake was unusually good and provided enough raw data to attempt a fault-plane solution. Hypocenter determinations in the past and in this study do not provide a clear association of the earthquake with any specific faults or fault trends. The focal mechanism plot shows reverse fault movement on a northwest trending, high-angle fault.