Convener: Cliff Thurber

WORKSHOP SUMMARY: A SCEC workshop was held in October 2018 on future development of SCEC Community Velocity Models (CVMs). The goals of that workshop were as follows: (1) assess the current status of the CVMs for California; (2) define key information needed to improve and/or develop CVMs; (3) propose viable workflow strategies for CVM development; (4) identify approaches for assessing CVM uncertainties. An essential next step is the formation of a Technical Activity Group (TAG) tasked with further developing and collectively carrying out a coordinated set of activities to improve and validate the CVMs. The mission of this Technical Activity Group (TAG) is to promote and coordinate efforts to improve SCEC Community Velocity Models (CVMs). This TAG will help galvanize efforts to develop and apply an open framework for the assessment, validation, and improvement of CVMs. This full-day workshop, to be held in conjunction with the September 2019 SCEC Annual Meeting, will be the first meeting of the CVM TAG.

WORKSHOP GOALS: A substantial effort has gone into the development of the two "standard" SCEC CVMs for Southern California, currently CVM-H version 15.1.0 (Shaw et al., 2015) and CVM-S version 4.26 (Lee et al., 2014). Incremental improvements are being made to CVM-H over time, but CVM-S model is essentially frozen at the current version. SCEC has also developed a Central California Area CVM, current version CCA-06. SCEC's Unified CVM framework (Small et al., 2017) provides access to these models as well as other models covering different regions of California, including the San Francisco Bay Area and the entire state. To make further progress on these CVMs, open-source workflows are needed to evaluate and/or update these models, methods need to be developed to merge new high-resolution localized models into the existing models, strategies to integrate constraints from other geophysical, geotechnical, and geological sources are required, and methods for assessing model uncertainty must be developed. This TAG will facilitate research initiatives at the intersection of seismology, ground motion, and computational science.

The proposed goals for the CVM TAG are:

• Develop open methods for improving SCEC CVMs;
• Develop methods for CVM assessment and validation, including providing uncertainty estimates;
• Expand the participation of SCEC researchers in work related to improving and utilizing the CVMs.

The tasks for the workshop are (1) to reach final consensus on the mission and goals statement of the TAG (a draft of which will be circulated in advance of the workshop), (2) to refine and prioritize the identified action items, and (3) to coordinate plans for submission of related SCEC 2020 proposals as well as future proposals to other funding agencies. The primary outcomes expected from the workshop are a completed mission and goals statement for the CVM TAG, including prioritized action items, and plans for submission of coordinated and collaborative proposals in response to the 2020 SCEC Science Collaboration Plan and other funding opportunities.

To promote discussion and due to logistics, the workshop is limited to 30 participants. Interested participants should contact the workshop convener to inquire about space availability.

Presentation slides may be downloaded by clicking the links following the title. PLEASE NOTE: Files are the author’s property. They may contain unpublished or preliminary information and should only be used while viewing the talk.

SATURDAY, SEPTEMBER 7, 2019

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PARTICIPANTS

This workshop is held prior to the 2019 SCEC Annual Meeting.