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Poster Abstracts
and Northridge Hills faults. Integration of these subsurface seismic data with an analysis of tectonic geomorphology suggests
that these three faults are continuous and represent a larger fault system. The new source model also added the Mission Hills
and Santa Susana East faults as new sources, both of which define geomorphically expressed range fronts. These relatively
short faults have not been included in recent regional source models (e.g., UCERF2) due to their relatively small dimensions.
However, including these smaller faults is critical to the site hazard as they represent moderate magnitude, single-fault
ruptures, as well as fill in gaps of potentially larger, multi-fault seismic sources. In an effort to capture a greater uncertainty in
segmentation and fault behavior, the model allows for multi-fault ruptures for several sources, including the Santa Susana-
Sierra Madre-Cucamonga fault system.
DOES THE TEAR FAULT MATTER? (A-078)
Q. Liu, R.J. Archuleta, and R.B. Smith
Faults are not planar; the geometry of the fault has introduced extra dimension of complexity into the earthquake physics
problem. (Scholz, 1998; Wesnousky 2006) Dynamic triggering between adjacent faults could lead to cascading earthquakes
thus changing the seismic hazard estimation dramatically. Previous work has address the multi-fault dynamic rupture
problem in terms of piece-wise planar fault system (e.g. Harris and Day, 1993; Magistrale and Day, 1999). We are trying to
study a similar but more realistic case with the Wasatch Fault. The Salt Lake City segment of the Wasatch Fault (SLCWF) is a
curved normal fault, which poses a serious threat to the surrounding communities due to the potential of a Mw 7+ earthquake.
In the middle of the segment there is a potential tear fault that would separate the northern and southern segments. We want
to answer the following question: to what extent does the possible tear fault impact the dynamic rupture process. This
problem needs a careful investigation about not only the rupture dynamic on a non-planar fault, but also several ingredients
in dynamic rupture problems, such as hypocenter location, initial stress distribution, etc. We use a finite element method (Ma
& Liu, 2006) to simulate the dynamics of a propagating rupture on SLCWF both with and without the tear fault.
NEW DEVELOPMENTS AND FUTURE APPLICATIONS OF THE COLLABORATORY FOR THE STUDY OF
EARTHQUAKE PREDICTABILITY (CSEP) TESTING FRAMEWORK (B-118)
M. Liukis, D. Schorlemmer, J. Yu, P. Maechling, J. Zechar, T.H. Jordan, and he CSEP Working Group
Southern California Earthquake Center (SCEC) began development of the Collaboratory for the Study of Earthquake
Predictability (CSEP) in January of 2006 with funding provided by the W. M. Keck Foundation. Since that time, scientists and
software engineers have applied the scientific and computational principles of CSEP to develop several operational testing
centers. The W. M. Keck Foundation Testing Center at SCEC, designed to conduct computational earthquake forecast
experiments in California, began operations on September 1, 2007 and has been improved, optimized, and extended over the
past four years. The implementation of the SCEC Testing Center has been guided by four design goals proposed by the
Regional Earthquake Likelihood Models (RELM) working group: (1) Controlled Environment, (2) Transparency, (3)
Comparability, and (4) Reproducibility. By meeting these goals, the CSEP testing framework can provide clear descriptions of
how all registered earthquake forecasts are produced and evaluated. As of August 2011, there are four testing centers
established around the globe, with 224 models under test. CSEP software is also available for personal use by scientists to
perform independent study and evaluation of their model prior submitting it to the Testing Center
(http://northridge.usc.edu/trac/csep/wiki/MiniCSEP). The SCEC Testing Center hosts intermediate-term and short-term alarmbased
and rate-based forecasts for California, the Western Pacific, and a global testing region. We describe how the CSEP
Testing Center at SCEC has been constructed to meet the design goals; we also present recent developments of the Testing
Center and share our experiences operating the center since its inception. Additionally, we discuss how the CSEP
infrastructure will be applied to geodetic transient detection, earthquake early warning and ground motion prediction
experiments.
THE CLARK CO. PARCEL MAP AND IMPLICATIONS FOR EARTHQUAKE HAZARD DEFINITION IN
SOUTHERN NEVADA (A-033)
J.N. Louie, W. Savran, B. Flinchum, G. Plank, S.K. Pullammanappallil, A. Pancha, and W.K. Hellmer
Clark County, Nevada has completed the nation's very first effort to map earthquake hazard class systematically through an
entire urban area. The Parcel Map contains measurements of geotechnical shear velocity to 30 m depth obtained using
SeisOpt® ReMi (© Optim, 2011) at over 10,000 separate sites in urban and urbanizing Clark County and the City of
Henderson. These municipalities use the Parcel Map to assure compliance with the NEHRP provisions of the International
Building Code. Leveraging the unprecedented detail of the Parcel Map, our multi-institutional collaboration is developing
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