Workshop Report: Earthquake Rupture and Creep in Shallow Earth Materials

William A. Griffith, Katherine M. Scharer, & Alexis K. Ault

Published February 5, 2026, SCEC Contribution #15056

We led a two-day, in-person workshop with scientists from across the full spectrum of Statewide California Earthquake Center (SCEC) disciplines to explore earthquake rupture and creep in shallow earth materials, and to discuss technologies and strategies for studying these processes through future observations and implementing them in modeling efforts. The workshop included a one-day field trip to visit three sites along the Southern San Andreas Fault (SSAF) at the Salt Creek paleoseismic site, Ferrum, and the Mecca Hills, CA (Fig. 1), followed by one day of presentations and moderated discussions in Palm Springs, with emphasis placed on involvement of early career researchers.

Shallow on- and off-fault earth materials are part of the geotechnical layer that can influence deformation throughout the earthquake cycle and strong ground motion. Key workshop topics were (1) geodetic and geomorphic observations of shallow crustal deformation associated with earthquake rupture and interseismic creep, (2) geological processes associated with this deformation, (3) the properties of the geotechnical layer that cause uncertainties in modeling seismic site response and the interpretation of surface deformation observations, and (4) strategies for future instrumentation and observations needed to resolve uncertainties, as well as identifying key study areas outside of southern California in the statewide center.

Citation
Griffith, W. A., Scharer, K. M., & Ault, A. K. (2026). Workshop Report: Earthquake Rupture and Creep in Shallow Earth Materials. , : Statewide California Earthquake Center. https://www.scec.org/events/2025-scec-shallow-earth-workshop/