SCEC Award Number 21134 View PDF
Proposal Category Collaborative Proposal (Data Gathering and Products)
Proposal Title Dating prior earthquakes along faults of the 2019 Ridgecrest sequence
Investigator(s)
Name Organization
Ramon Arrowsmith Arizona State University
Other Participants Rich Koehler (UNR), Ian Pierce (UNR), Alana Williams (ASU)
SCEC Priorities 5b, 3e, 1a SCEC Groups Geology, SAFS, SDOT
Report Due Date 03/15/2022 Date Report Submitted 02/27/2024
Project Abstract
 This project was an effort to secure 14C and optically stimulated luminescence (OSL) ages for target sedimentary units exposed in trenches across faults activated in the 2019 Ridgecrest earthquake sequence. We dated several shells which produced anomalously old ages and then twelve samples for OSL with the University of Nevada Reno laboratory. These data are still in process.
Intellectual Merit Results from this project will refine earthquake dates, enabling us to compute the recurrence interval and determine a short-term slip rate for faults ruptured in the Ridgecrest earthquakes of 2019. A more complete chronological model of event history in this region is vital to advance our understanding earthquake recurrence within the Eastern California Shear Zone (ECSZ) and beyond. Results from this study will inform fault-based deformation models and contribute to regional earthquake hazard models for southern California. Additionally, ages of the penultimate rupture along both faults that ruptured in 2019 will help assess whether the faults have ruptured together in the past potentially contributing to a better understanding of multi-fault ruptures.
Broader Impacts Support for woman graduate student to learn new skills in geochronology. The project also addresses earthquake hazards.
Exemplary Figure Figure 2 shows nicely the event record.