Active parasitic folds on the Elysian Park anticline: Implications for seismic hazard in central Los Angeles, California

We characterize the seismic hazard of the Elysian Park fault, a blind rever se fault beneath central Los Angeles, by analysis of the Elysian Park antic line, which overlies it, New shallow-subsurface geotechnical data, combined with other surficial stratigraphy and geomorphology, reveal that the Elysi an Park anticline is an active 20-km-long structure. From the style and rat es of deformation of parasitic folds on the southern limb of the anticline, we estimate a contraction rate of 0.6-1.1 mm/yr This rate provides a basis for estimating a rate of contraction of the entire Elysian Park anticline, which in turn allows us to estimate a 0.8-2.2 mm/yr time-averaged rate! of slip on the underlying fault. At this rate of slip, rupture of the Elysian Park fault could produce a nominal M-w 6.2 to 6.7 earthquake every 500 to 1300 gr, on average. Although this Elysian Park earthquake would recur infr equently, its size and recurrence interval may be similar to those estimate d for the sources of the destructive 1971 San Fernando and 1994 Northridge earthquakes.