CaltechAUTHORS
Published March 28, 2019 | Version Published
Journal Article Open

A geodesy- and seismicity-based local earthquake likelihood model for central Los Angeles

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Michigan State University

Abstract

We estimate time‐independent earthquake likelihoods in central Los Angeles using a model of interseismic strain accumulation and the 1932–2017 seismic catalog. We assume that on the long‐term average, earthquakes and aseismic deformation collectively release seismic moment at a rate balancing interseismic loading, mainshocks obey the Gutenberg‐Richter law (a log linear magnitude‐frequency distribution [MFD]) up to a maximum magnitude and a Poisson process, and aftershock sequences obey the Gutenberg‐Richter and "Båth" laws. We model a comprehensive suite of these long‐term systems, assess how likely each system would be to have produced the MFD of the instrumental catalog, and use these likelihoods to probabilistically estimate the long‐term MFD. We estimate M_(max) = 6.8 + 1.05/−0.4 (every ~300 years) or M_(max) = 7.05 + 0.95/−0.4 assuming a truncated or tapered Gutenberg‐Richter MFD, respectively. Our results imply that, for example, the (median) likelihood of one or more M_w ≥ 6.5 mainshocks is 0.2% in 1 year, 2% in 10 years, and 18–21% in 100 years.

Additional Information

© 2019 American Geophysical Union. Received 10 OCT 2018; Accepted 21 FEB 2019; Accepted article online 27 FEB 2019; Published online 21 MAR 2019. C. Rollins was supported by a NASA Earth and Space Science Fellowship for most of this work. The authors are grateful to Tom Parsons and an anonymous reviewer for suggestions that greatly improved the manuscript, as well as numerous colleagues around the community for helpful input and guidance. The authors declare no competing financial interests. The GPS data used to constrain the moment deficit buildup rate in Rollins et al. (2018) and plotted in Figure 1 can be found in Argus et al. (2005, Table 3); the SCEDC seismic catalog is available at http://service.scedc.caltech.edu/ftp/catalogs/SCEC_DC/.

Attached Files

Published - Rollins_et_al-2019-Geophysical_Research_Letters.pdf

Files

Rollins_et_al-2019-Geophysical_Research_Letters.pdf

Files (32.6 MB)

Additional details

Identifiers

Eprint ID
93576
Resolver ID
CaltechAUTHORS:20190306-110635099

Funding

NASA Earth and Space Science Fellowship

Dates

Created
2019-03-06
Created from EPrint's datestamp field
Updated
2022-11-15
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Center for Geomechanics and Mitigation of Geohazards (GMG), Division of Geological and Planetary Sciences (GPS), Seismological Laboratory