SCEC Award Number 25139 View PDF
Proposal Category Community Workshop
Proposal Title Update and Re-evaluation of the Earthquake Hazards in the Santa Barbara-Ventura Area: Science Workshop & Field Trip in Commemoration of the 1925 Santa Barbara Earthquake
Investigator(s)
Name Organization
Craig Nicholson University of California, Santa Barbara Thomas Rockwell San Diego State University Chen Ji University of California, Santa Barbara
SCEC Milestones A1-1, A1-3, A2-2, A3-1, A3-5 SCEC Groups Seismology, Geology, CEM
Report Due Date 07/30/2025 Date Report Submitted 07/29/2025
Project Abstract
 The 29 June 1925 M6.5 Santa Barbara earthquake was a seminal event for the city of Santa Barbara and for the perception of earthquake hazards statewide in California. The 100th anniversary offered a unique and timely opportunity to re-evaluate and better understand the likely causative fault (or faults) for this and other major damaging earthquakes in the Santa Barbara-Ventura area, as well as important aspects of the active 3D fault geometry, the significance of variable uplift, fault slip and geodetic strain rates along the coast, and the more extensive earthquake and tsunami hazards for this important active earthquake region with large urban populations at risk. As a SCEC Special Fault Study Area (SFSA), numerous wide-ranging, multi-disciplinary studies were undertaken that resulted in major conflicting interpretations that have yet to be resolved. Since the last major Ventura SFSA review, nine years of important datasets, reports and publications have been developed that need to be properly integrated and reconciled if they are to provide critical insight, data validation, and discrimination between these competing alternative fault geometry and hazard models. This science workshop and field trip brought together many of these disparate groups in the areas of 1925 and more recent earthquake history, offshore geophysics, crustal structure, seismicity, geodesy, fault modeling, tectonic geomorphology, paleoseismology, sedimentology, and dynamic rupture modeling to enable review and evaluation of the important observations and their implications for updated earthquake rupture, crustal deformation, geodetic strain and earthquake hazard models for this region.
SCEC Community Models Used Community Fault Model (CFM), Community Geodetic Model (CGM), Community Stress Model (CSM), Community Velocity Model (CVM)
Usage Description Each of these Community Earth Models (CFM, CGM, CSM & CVM) were utilized by various workshop participants as part of their detailed studies and investigations, the results of which were incorporated into various talk and poster presentations given at the workshop.
Intellectual Merit This workshop contributed to SCEC’s goals by facilitating collaboration between SCEC scientists, students and consultants focused on a better understanding of the active fault systems and earthquake hazards in the Santa Barbara-Ventura area. Fundamental controversies related to the large anomalous uplift events at Pitas Point, their implications for earthquake hazard, alternative fault geometries, and important discrepancies and corroborations between various model predictions and observations were reviewed and discussed. This project was an excellent example of the strengths of SCEC in that people with different, disparate expertise and multi-disciplinary approaches were brought together to better understand these important fault systems.
Broader Impacts This workshop and field trip fostered communication and discussion between numerous SCEC researchers, students and stakeholders. Societal benefits include an increased awareness of the seismic hazard potential in the western Transverse Ranges, and specifically in the heavily urbanized coastal zone of the Santa Barbara-Ventura area affected by the active offshore North Channel-Pitas Point-Red Mountain and onshore Mission Ridge-More Ranch and San Cayetano fault systems. The broad-based participation of scientists and workers from various universities, government agencies, and the private hazard consultant community will help facilitate further dissemination of important workshop results, interpretations, and hazard implications to the broader public.
Project Participants Besides SCEC, sponsors for the workshop and field trip included UCSB College of Letters and Science, Department of Earth Science, and Marine Science Institute, who provided additional funding, equipment, facilities, and support personnel. In addition to the 3 convenors, workshop and field trip planning and development benefited from contributions and participation by Larry Gurrola, Sue Hough, Alex Simms, Marc Kamerling, and Sandy Seale. Santa Barbara City College published the field trip guidebook. Field trip participants numbered 28 and the hybrid workshop included 44 in-person and remote participants.
Exemplary Figure N/A, Results from 24 separate projects were presented at the workshop and it would be inappropriate to select just one of these as exemplary.
Linked Publications

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