2002/12/01 by John H. Shaw · 119 citations
Earth and Planetary Sciences · Engineering · #earthquake and tectonic studies #Geological and Geochemical Analysis #High-pressure geophysics and materials #Geology #Thrust #Archaeology #Geography #Engineering #Aerospace engineering
paper · doi:10.1785/0120010291
published in Bulletin of the Seismological Society of America 92(8), 2946-2960 (Seismological Society of America)
openalex publication_date 2002/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We describe the three-dimensional geometry and Quaternary slip history of the Puente Hills blind-thrust system (PHT) using seismic reflection profiles, petroleum well data, and precisely located seismicity. The PHT generated the 1987 Whittier Narrows (moment magnitude [ M w] 6.0) earthquake and extends for more than 40 km along strike beneath the northern Los Angeles basin. The PHT comprises three, north-dipping ramp segments that are overlain by contractional fault-related folds. Based on an analysis of these folds, we produce Quaternary slip profiles along each ramp segment. The fault geometry and slip patterns indicate that segments of the PHT are related by soft-linkage boundaries, where the fault ramps are en echelon and displacements are gradually transferred from one segment to the next. Average Quaternary slip rates on the ramp segments range from 0.44 to 1.7 mm/yr, with preferred rates between 0.62 and 1.28 mm/yr. Using empirical relations among rupture area, magnitude, and coseismic displacement, we estimate the magnitude and frequency of single ( M w 6.5-6.6) and multisegment ( M w 7.1) rupture scenarios for the PHT. Manuscript received 16 November 2001.