skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Southern California Earthquake Center - SCEC1: Final Report Summary Alternative Earthquake Source Characterization for the Los Angeles Region

Abstract

The objective my research has been to synthesize current understanding of the tectonics and faults of the Los Angeles Basin and surrounding region to quantify uncertainty in the characterization of earthquake sources used for geologically- and geodetically-based regional earthquake likelihood models. This work has focused on capturing epistemic uncertainty; i.e. uncertainty stemming from ignorance of the true characteristics of the active faults in the region and of the tectonic forces that drive them. In the present context, epistemic uncertainty has two components: First, the uncertainty in source geometrical and occurrence rate parameters deduced from the limited geological, geophysical and geodetic observations available; and second. uncertainties that result from fundamentally different interpretations of regional tectonic deformation and faulting. Characterization of the large number of active and potentially active faults that need to be included in estimating earthquake occurrence likelihoods for the Los Angeles region requires synthesis and evaluation of large amounts of data and numerous interpretations. This was accomplished primarily through a series of carefully facilitated workshops, smaller meetings involving key researchers, and email groups. The workshops and meetings were made possible by the unique logistical and financial resources available through SCEC, and proved to be extremely effective forums for themore » exchange and critical debate of data and interpretations that are essential in constructing fully representative source models. The main products from this work are a complete source model that characterizes all know or potentially active faults in the greater Los Angeles region. which includes the continental borderland as far south as San Diego, the Ventura Basin, and the Santa Barbara Channel. The model constitutes a series of maps and representative cross-sections that define alternative fault geometries, a table containing rault geometrical and slip-rate parameters, including full uncertainty distributions, and a set of logic trees that define alternative source characterizations, particularly for sets of fault systems having inter-dependent geometries and kinematics resulting from potential intersection and interaction in the sub-surface. All of these products exist in a form suitable for input to earthquake likelihood and seismic hazard analyses. In addition, moment-balanced Poissonian earthquake rates for the alternative multi-segment characterizations of each fault system have been estimated. Finally, this work has served an important integrative function in that the exchange and debate of data, results and ideas that it has engendered has helped to focus SCEC research over the past six years on to key issues in tectonic deformation and faulting.« less

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
15004050
Report Number(s):
UCRL-ID-151950
TRN: US201015%%288
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
58; CALIFORNIA; CROSS SECTIONS; DEFORMATION; EARTHQUAKES; EVALUATION; LOS ANGELES; SANTA BARBARA CHANNEL; SYNTHESIS; TECTONICS; TREES

Citation Formats

Foxall, B. Southern California Earthquake Center - SCEC1: Final Report Summary Alternative Earthquake Source Characterization for the Los Angeles Region. United States: N. p., 2003. Web. doi:10.2172/15004050.
Foxall, B. Southern California Earthquake Center - SCEC1: Final Report Summary Alternative Earthquake Source Characterization for the Los Angeles Region. United States. doi:10.2172/15004050.
Foxall, B. Wed . "Southern California Earthquake Center - SCEC1: Final Report Summary Alternative Earthquake Source Characterization for the Los Angeles Region". United States. doi:10.2172/15004050. https://www.osti.gov/servlets/purl/15004050.
@article{osti_15004050,
title = {Southern California Earthquake Center - SCEC1: Final Report Summary Alternative Earthquake Source Characterization for the Los Angeles Region},
author = {Foxall, B},
abstractNote = {The objective my research has been to synthesize current understanding of the tectonics and faults of the Los Angeles Basin and surrounding region to quantify uncertainty in the characterization of earthquake sources used for geologically- and geodetically-based regional earthquake likelihood models. This work has focused on capturing epistemic uncertainty; i.e. uncertainty stemming from ignorance of the true characteristics of the active faults in the region and of the tectonic forces that drive them. In the present context, epistemic uncertainty has two components: First, the uncertainty in source geometrical and occurrence rate parameters deduced from the limited geological, geophysical and geodetic observations available; and second. uncertainties that result from fundamentally different interpretations of regional tectonic deformation and faulting. Characterization of the large number of active and potentially active faults that need to be included in estimating earthquake occurrence likelihoods for the Los Angeles region requires synthesis and evaluation of large amounts of data and numerous interpretations. This was accomplished primarily through a series of carefully facilitated workshops, smaller meetings involving key researchers, and email groups. The workshops and meetings were made possible by the unique logistical and financial resources available through SCEC, and proved to be extremely effective forums for the exchange and critical debate of data and interpretations that are essential in constructing fully representative source models. The main products from this work are a complete source model that characterizes all know or potentially active faults in the greater Los Angeles region. which includes the continental borderland as far south as San Diego, the Ventura Basin, and the Santa Barbara Channel. The model constitutes a series of maps and representative cross-sections that define alternative fault geometries, a table containing rault geometrical and slip-rate parameters, including full uncertainty distributions, and a set of logic trees that define alternative source characterizations, particularly for sets of fault systems having inter-dependent geometries and kinematics resulting from potential intersection and interaction in the sub-surface. All of these products exist in a form suitable for input to earthquake likelihood and seismic hazard analyses. In addition, moment-balanced Poissonian earthquake rates for the alternative multi-segment characterizations of each fault system have been estimated. Finally, this work has served an important integrative function in that the exchange and debate of data, results and ideas that it has engendered has helped to focus SCEC research over the past six years on to key issues in tectonic deformation and faulting.},
doi = {10.2172/15004050},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Feb 26 00:00:00 EST 2003},
month = {Wed Feb 26 00:00:00 EST 2003}
}

Technical Report:

Save / Share: