SCEC Award Number 19155 View PDF
Proposal Category Collaborative Proposal (Data Gathering and Products)
Proposal Title Delivering and Assessing the Preliminary CRM: TAG Coordination and PyLith Deformation Modeling
Investigator(s)
Name Organization
Elizabeth Hearn Independent Contractor Charles Williams GNS Science (New Zealand)
Other Participants n/a
SCEC Priorities 1c, 1e, 3b SCEC Groups CXM, SDOT, Geodesy
Report Due Date 04/30/2020 Date Report Submitted 11/12/2020
Project Abstract
 The SCEC Community Rheology Model (CRM) TAG worked in 2019 to complete a Community Thermal Model (CTM), a Geologic Framework (GF), and a suite of ductile flow laws for GF rock types. This involved hosting the May 2019 CRM workshop; holding and documenting several conference calls; contacting the potential CRM user community at workshops and via individual calls and surveys; and other tasks. In collaboration with Charles Williams, I began to develop finite element models making use of the CRM. The southern California-wide modeling we proposed was sidetracked by the July 2019 Ridgecrest earthquake. Our preliminary models of this event demonstrate agreement between GAEA and PyLith computations of coseismic and early postseismic displacements. Far-field GPS velocities available during the grant period were inadequate to test hypotheses about effective viscosity of the southern California mantle.
Tasks described in the project report include:
• Planning and leading 2019 CRM workshop, and other CRM leadership tasks (Hearn)
• Coordinating CRM website and tool development with SCEC IT (Hearn)
• Southern California deformation modeling using PyLith (Hearn and Williams)
Intellectual Merit The work leads to development and testing of SCEC community models.
Broader Impacts SCEC community models (CXM's) provide research infrastructure in the form of a freely available and community-vetted repository of geophysical characterizations of the southern California lithosphere (seismic velocities, rock types, temperatures, fault geometries, etc.). The CXM's facilitate increasingly realistic representations of this region in computational models, enhancing both scientific hypothesis and knowledge compatibility testing.
Exemplary Figure Figure 1. (a) Coseismic InSAR range change for the Ridgecrest earthquake sequence (from Xu et al., 2019). (b) PyLith modeled coseismic range change. (c) residual. (d) assignment of GFM provinces to the coarse version of the Ridgecrest FE mesh, now awaiting CRM and CTM input. Dots are shown at model element centers, and their colors represent different GFM provinces.