SCEC Award Number 24003 View PDF
Proposal Category Individual Research Project (Single Investigator / Institution)
Proposal Title High Resolution Catalogs of Template Earthquakes and Focal Mechanisms for Resolving Fine-Scale Fault Structures and Crustal Rheology
Investigator(s)
Name Organization
Egill Hauksson California Institute of Technology
SCEC Milestones A1-2, C1-1, D1-1 SCEC Groups Seismology, PBS, EFP
Report Due Date 03/15/2025 Date Report Submitted 03/17/2025
Project Abstract
 We have refined and updated the catalogs of earthquake hypocenters (Hauksson et al., 2012) and focal mechanisms (Yang et al., 2012) for southern California. The SCEC community will use the updated catalogs to address research problems, such as fine-scale fault structures, source studies, and crustal rheological properties, as well as applying template matching to generate high resolution catalogs.
SCEC Community Models Used Community Fault Model (CFM), Community Stress Model (CSM), Community Velocity Model (CVM)
Usage Description The data refined in our study, has been used to develop CFM/CSM/CVM community models.
Intellectual Merit This research continues to provide a more detailed understanding of earthquake source properties and their temporal variations. In addition it will contribute to the CFM, SCEC 3D velocity model, stress model, rheology model, and understanding of fault zone processes. In the case of a major earthquake, improved absolute and relative locations will provide rapid identification of the rupture planes. In addition, events in this catalog will be used as templates in machine learning algorithms to search for previously undetected smaller events, which could on average add up to a factor of 10 more events to the catalog (Ross et al., 2019).
Broader Impacts These catalogs have been and continue to be used for numerous SCEC studies such as: a) monitoring of temporal and spatial evolution of seismicity (Hauksson et al., 2022), b) mapping of the geophysical properties of fault zones (Plesch et al., 2020), c) 3D velocity model inversions (Tape et al., 2009), d) stress drop determinations, (Shearer et al, 2022), e) rheological properties of the crust, (Hauksson and Meier, 2018), f) earthquake statistics, Zaliapin and Ben-Zion (2021), g) identification and monitoring of anthropogenic seismicity.( Chen et al, 2011), h) aftershock studies (van der Elst and Shaw, 2015), and i) stress field determination (Yang and Hauksson, 2013).
Project Participants The PI did all the research. P. Shearer of UCSD has been involved as a partner to develop the methodology and software.
Exemplary Figure Figure 1. The HS catalog (1981 – 2024). Similar-event clusters that have been relocated by using waveform cross-correlation and GrowClust are shown in black. Uncorrelated events are not plotted. Events with M ≥ 5.5 are shown as red stars. Faults are from Jennings and Bryant (2010) with late Quaternary faults shown in magenta color. The blue dashed polygon delineates the SCSN reporting area.
Linked Publications

Add missing publication or edit citation shown. Enter the SCEC project ID to link publication.