The source of the October 1987 Whittier Narrows earthquake was determined to be the Puente Hills thrust system ( unknown at the time ) and could be identified by the fault-plane solution of the mainshock and aftershocks , fault-plane reflections ( up to 8 km deep ) , and by high resolution seismic profiles at shallower depths
1987 Whittier Narrows earthquake
1987 Whittier Narrows earthquake
Puente Hills Fault