Supplementary Materials for: Large Holocene Ruptures on the Cañada David Low Angle Normal Fault, Baja California, Mexico; Implications for the Seismogenesis of Low-Angle Normal Faults
Description
This data set contains complete trench logs PDF format and plain image mosaics of the trench walls with no interpretation in JPG format. Image resolution is 2,950 pixels per meter of trench wall. We provide versions of the trench logs with and without interpretations so others can work with the raw data and evaluate our observations. This data set also includes a detailed description of the ground-penetrating radar surveys performed around and between trenches at the study area along the western flank of Sierra El Mayor. These data show evidence for at least six major surface ruptures during the past 17 ka on the Cañada David detachment, which is a low-angle normal fault in northern Baja California, Mexico. Recurrence intervals show little variability and range from 2.5 to 3 ka. These findings suggest that the seismogenesis and mechanical behavior of this severely misoriented fault are very similar to, if not indistinguishable from, other more optimally oriented faults with similar slip rates. This contrasts with the observation that large earthquakes demonstrably associated with such faults are exceedingly rare in catalogs of global seismicity and adds to the controversy surrounding our understanding of how fault geometry and orientation affects the conditions for failure.