2022/06/23 by Élyse Gaudreau, James Hollingsworth, Edwin Nissen +1 · 1 citation
Earth and Planetary Sciences · Computer Science · #Seismic Waves and Analysis #earthquake and tectonic studies #Seismology and Earthquake Studies #Geology #Seismology #Deformation (meteorology) #Preprint #Computer science #World Wide Web
paper · doi:10.1002/essoar.10511699.1
openalex publication_date 2022/06/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The shallow 1971 Mw 6.6 San Fernando, California earthquake involved a complex rupture process on an immature thrust fault with a non-planar geometry, and is notable for having a higher component of left-lateral surface slip than expected from seismic models. We extract its 3-D coseismic surface displacement field from aerial stereo photographs and document the amount and width of the vertical and strike-parallel components of distributed deformation along strike. The results confirm the significant left-lateral surface offsets, suggesting a slip vector rotation at shallow depths. Comparing our offsets against field measurements of fault slip, we observe that most of the offset was accommodated in the damage zone, with off-fault deformation averaging 68% in both the strike-parallel and vertical components. However, the magnitude and width of off-fault deformation behave differently between the vertical and strike-parallel components, which, along with the rotation in rake near the surface, can be explained by dynamic rupture effects.