Data describing the locations, slip rates, and lengths of Quaternary faults are the primary basis in this work for constructing maps that characterize seismic hazard in California. The expected seismic moment M^e₀ and the strength of ground shaking resulting from the entire rupture of each mapped fault (or fault segment) are estimated using empirical relations between seismic moment M₀, rupture length, source to site distance, and strong ground motions.