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Distribution of aseismic deformation along the central San Andreas and Calaveras Faults from differencing repeat airborne lidar

October 26, 2020

Fault creep reduces seismic hazard and serves as a window into plate boundary processes; however, creep rates are typically constrained with sparse measurements. We use differential lidar topography (11–13 year time span) to measure a spatially dense surface deformation field along a 150 km section of the Central San Andreas and Calaveras faults. We use an optimized windowed‐iterative‐closest‐point approach to resolve independent creep rates every 400 m at 1–2 km apertures. Rates vary from <10 mm/year along the creeping fault ends to over 30 mm/year along much of the central 100 km of the fault. Creep rates are 3–8 mm/year higher than most rates from alignment arrays and creepmeters, likely due to the larger aperture of the topographic differencing. Creep is often focused along discrete fault traces, but strain is sometimes distributed in areas of complex fault geometry, such as Mustang Ridge. Our observations constrain shallow seismic moment accumulation and the location of the creeping fault trace.

Publication Year 2020
Title Distribution of aseismic deformation along the central San Andreas and Calaveras Faults from differencing repeat airborne lidar
DOI 10.1029/2020GL090628
Authors Chelsea P Scott, Stephen B. DeLong, J Ramon Arrosmith
Publication Type Article
Publication Subtype Journal Article
Series Title Geophysical Research Letters
Index ID 70217887
Record Source USGS Publications Warehouse
USGS Organization Earthquake Science Center