Geophysical Research Letters
Recent investigations have provided new and significantly revised constraints on the subsurface structure of the Ventura-Pitas Point fault system in southern California; however, few data directly constrain fault surfaces below ~6 km depth. Here, we use geometrically complex three-dimensional mechanical models driven by current geodetic strain rates to test two proposed subsurface models of the fault system. We find that the model that incorporates a ramp geometry for the Ventura-Pitas Point fault better reproduces both the regional long term geologic slip rate data and interseismic GPS observations of uplift in the Santa Ynez Mountains. The model-calculated average reverse slip rate for the Ventura-Pitas Point fault is 3.5 ± 0.3 mm/yr, although slip rates are spatially variable on the fault surface with > 8 mm/yr predicted on portions of the lower ramp section at depth.
Licensed to Smith College and distributed CC-BY under the Smith College Faculty Open Access Policy.
Marshall, Scott T.; Funning, Gareth J.; Kreuger, Hannah E.; Owen, Susan E.; and Loveless, John P., "Mechanical Models Favor a Ramp Geometry for the Ventura-Pitas Point Fault, California" (2017). Faculty Publications. 3.