Geomorphic characterization of fault creep in the San Francisco Bay Area, California
Hannah Martin, Christie D. Rowe, & Rich D. KoehlerSubmitted September 7, 2025, SCEC Contribution #14383, 2025 SCEC Annual Meeting Poster #TBD
Creep has been observed along many seismogenic faults globally but is particularly common in the San Francisco Bay Area where the San Andreas Fault System distributes slip across several sup-parallel fault strands. Identification and characterization of creeping faults is a critical component of earthquake hazard assessment as creep can influence fault loading and stress transfer. Geomorphic evidence of creep in the landscape can be difficult to distinguish from seismogenic rupture. Observations of fault creep typically require long-term measurements through geodetic and satellite data and local deformation features, such as the opening of cracks and deformation of anthropogenic structures.
We focus on the Calaveras Fault in the San Francisco Bay Area which is both rapidly creeping and known to produce large (≥M6) earthquakes in the last century, providing the ideal natural laboratory to distinguish between active creep and seismogenic deformation in the landscape. Geomorphic fault mapping has not been updated in public databases since the availability of new lidar-based DEMs in Northern California. We aim to create a geomorphic framework for recognizing and delineating the subtle surface expression of slow or transiently creeping faults that can be used as a template for future creep characterization. Using high-resolution lidar data augmented with field observations along the Calaveras Fault, we refine fault stand locations in the actively creeping Morgan Hill section of the fault and document geomorphic indicators of faulting.
Citation
Martin, H., Rowe, C. D., & Koehler, R. D. (2025, 09). Geomorphic characterization of fault creep in the San Francisco Bay Area, California. Poster Presentation at 2025 SCEC Annual Meeting.
Related Projects & Working Groups
Earthquake Geology
