SCEC Award Number 20190 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title Delivering the preliminary CRM and CTM: Websites, manuscripts and modeling
Investigator(s)
Name Organization
Elizabeth Hearn Capstone Geophysics
Other Participants Wayne R. Thatcher
SCEC Priorities 1c, 1b, 1e SCEC Groups CXM, SDOT, Geodesy
Report Due Date 03/15/2021 Date Report Submitted 03/15/2021
Project Abstract
 Most of my SCEC research this past year was devoted to seeing that initial versions of the CRM and the CTM were “out the door” in time for the 2020 SCEC Annual Meeting. The first version of the CTM is v20.8, it is available for download at the CTM website, and its DOI is https://doi.org/10.5281/zenodo.4010834. I developed a Google Colab notebook for querying, smoothing, and plotting the CTM. It is available in the CTM download package and through the scecpedia CTM page, and was used by SCEC IT to populate the GFM/CTM Viewer. The initial version of the CRM (v. 20.9) provides ductile rheologies for low-strain rocks. It is available for download from the CRM webpage, and its DOI is https://doi.org/10.5281/zenodo.4579627. Between the SCEC Annual Meeting and the end of the grant period, I developed tools for calculating CRM effective viscosities and importing them into PyLith finite-element models, and began comparing CRM effective viscosities to values inferred from postseismic deformation and surface loading models.
Intellectual Merit The CTM and the CRM are at the center of various SCEC research endeavors, most obviously, those relating to static deformation, fault mechanics, and interseismic stress transfer between fault systems in the lithosphere. CTM and CRM temperatures and rheologies may also factor into rupture propagation and SEAS-type models.
Broader Impacts The SCEC community models provide freely accessible knowledge infrastructure that enables cutting-edge representation of Earth properties in models of static and dynamic deformation. This improves our understanding of fault slip rates, rupture propagation, off-fault deformation, and other factors governing seismic hazard in the region.
Exemplary Figure Figure 2 (not recommended for Meeting Proceedings volume cover until we update it)

Figure 2. (top) CTM and CRM slices at 24 km depth. (bottom) CTM and CRM slices at 42 km depth. Values were computed for points on a grid with 8 km lateral spacing in the center of the region, and the unsmoothed CTM was assumed. Pink and red lines show borders of CTM heat flow regions (HFRs) and CRM Geologic Framework (GF) provinces. CRM effective viscosities assume a strain rate of 5 x 10-15 /s (10-15 /s in the Sierra Nevada, Basin and Range, and Pacific Ocean GF provinces. We are (2021) making adjustments to some CTM HFR boundaries, and adding a new CTM HFR representing the borderland provinces offshore. Note elongate artifacts (arrows) where CTM and GF boundaries do not coincide. We are currently looking at strategies to deal with these artifacts (e.g. recommending use of a smoothed CTM when computing viscosities, and reconciling GF province and CTM HFR boundaries in some places). W = SouthernWalker Lane, M = Mojave, PR = Peninsular Ranges, SS = Salton Sea (Rift and Rifted Margin), BR = Basin and Range, PO = Pacific Ocean, SN = Sierra Nevada.