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Creating an Updated Version of the Community Fault Model (CFM) for Use by Earthquake Simulators


Please contact the conveners if you are interested in participating in this workshop, or would like more information about the workshop.

Participants: 25 maximum

Date: September 10, 2017
Time: 1:00pm-5:00pm
Location: Hilton Palm Springs Resort

SCEC Award: 17254

Conveners: Terry Tullis, Michael Barall, Jim Dieterich, Ned Field, and Scott Marshall

SUMMARY: The SCEC Community Fault Model (CFM) is the most detailed description of the geometry of faults in California. As such it is the logical fault description to be used by future increasingly detailed simulations of long historic earthquake sequences. However, several problems arise in trying to use the CFM in Earthquake Simulators. The purpose of this workshop is to discuss these problems and potential solutions to them by a small and diverse group of specialists in order to define how and by whom the CFM can be made useful for Earthquake Simulators. An additional intent is to define a process by which future updates to the CFM can be easily made usable by Earthquake Simulators.

Among the problems to be solved are the following:

  • How best to create CFM versions that involve roughly equal-sized and equant-shaped elements and whether grids should be created having triangular elements, rectangular elements, or both.
  • The top edges of the faults in the CFM follow actual topography, but Earthquake Simulators require an upper planar surface on a half-space, so a version of the CFM needs to be created in which the topography is somehow flattened.
  • The CFM contains fault geometry, but does not have either slip rates or slip rakes, both of which are needed by Earthquake Simulators which currently are loaded by back slip. Some method is needed to assign slip rates and rakes for the many faults having no such data and also to reconcile the many instances where finding a simple correspondence between the faults included in the CFM and those included in UCERF3 for which slip-rate and slip-rake data do exist.

The hope is that from this workshop will emerge:

  • A consensus as to the best way to solve these problems
  • A team of individuals who will agree to do collaborate via one or more SCEC proposals to do the required work
  • An approach is developed so that once an initial CFM-EQSIM is created it can easily be updated as improvements are made to the CFM


13:00 - 13:10 Introduction and goals of workshop Terry Tullis
13:10 - 13:30 Brief Description of 2015 Attempt Michael Barall
13:30 - 13:45 Discussion of which shape elements to use and how to create them Terry Tullis
13:45 - 14:00 Remeshing the Community Fault Model for use in Boundary Element Method Models Scott Marshall
14:00 - 14:15 Discussion of best way to flatten topography All
14:15 - 14:30 Overview of efforts to determine slip rates and rakes in UCERF3 Ned Field
14:30 - 14:45 Discussion of what can be done to determine slip rates and rakes for faults in the CFM All
14:45 - 15:00 Break  
15:00 - 15:15 Current plans for ongoing improvements to the CFM Andreas Plesch
15:15 - 15:30 Discussion of how the CFM process could be augmented to include a version without topography and with slip-rate and slip-rake data All
15:30 - 16:00 Discussion of who is interested in being part of a collaborative proposal to create an initial CFM-EQSIM and what role they would play All
16:00 - 16:15 Discussion of how could future updates to the CFM lead to the same version of an updated CFM-EQSIM All
16:15 - 17:00 General discussion of issues that were short-changed All
17:00 Adjourn  


Michael Barall (Invisible Software Inc.)
Jean Beyer (U Mass)
Tim Dawson (CGS)
Jim Dieterich (UC Riverside)
Jacob Dorsett (Appalachian State)
Brittany Erickson (Portland State)
Ned Field (USGS)
Nadia Lapusta (CalTech)
Phil Maechling (SCEC)
Scott Marshall (Appalachian State)
Ossian O'Reilly (Stanford)
Andreas Plesch (Harvard)
Keith Richards-Dinger (UC Riverside)
John Rundle (UC Davis)
Bruce Shaw (Columbia)
John Shaw (Harvard)
Terry Tullis (Brown)