Poster #063, Seismology
Detailed seismic imaging of the Mw7.1 Ridgecrest earthquake rupture zone from data recorded by dense linear arrays
Poster Image:
Poster Presentation
2020 SCEC Annual Meeting, Poster #063, SCEC Contribution #10186 VIEW PDF
low-velocity fault damage zones are identified beneath each array. These low-velocity zones contain more intensely damaged inner cores (0.5-1.5 km wide) that produce additional 0.01-0.05 s delay in local P-wave arrival times. The damage zone at arrays B2 and B4 generate both fault-zone head and trapped waves. An automated detector based on peak ground velocities and durations of high amplitude waves identifies candidate fault zone trapped waves (FZTW) in a localized zone (300-400 m wide) for ~500 earthquakes. Synthetic waveform modeling of averaged FZTW generated by ~20 events with high-quality signals indicate that the trapping structure at array B4 has a width of ∼300 m, depth of ∼4 km, S-wave velocity reduction of ∼20% with respect to the surrounding rock, Q-value of ∼30, and S-wave velocity contrast of ~4% across the fault (faster on the northeast side). The results show complex fault zone structures that vary along fault strike, in general agreement with the surface geology in the area (alternating playa and igneous rocks). Combining the observations with additional seismological results should provide a detailed multi-scale model of the rupture and surrounding area.
SHOW MORE
SHOW MORE