Building a Community Velocity Model for the Cascadia Region and Beyond
Multi-scale information on P-wave and S-wave velocities and density in a tectonically active region is fundamental to a deeper understanding of subsurface processes (e.g., mantle hydration, Moho topography, crustal lithology), as input to other science activities (e.g., seismicity relocation, Green’s function estimation), and, especially at shallow depths, to better quantify seismic hazard. The recently NSF-funded Cascadia Region Earthquake Science Center (CRESCENT) paves the way to build a multi-scale community velocity model (CVM) of the Cascadia region (https://cascadiaquakes.org/cvm/). This model will be a first-order product for other CRESCENT working groups’ science and will help make significant advances in our understanding of the Cascadia subduction zone structure and associated hazards.
The CRESCENT CVM working group will combine active and passive seismic data acquired onshore and offshore in a region spanning the entire Cascadia subduction zone, from the Juan de Fuca Plate to well into the backarc along the Idaho-Montana border and from the Mendocino triple junction (~38°N) to the Queen Charlotte fault (~52°N). We will start with low wavenumber data to resolve regional-scale structure into the upper mantle using Bayesian joint inversions of P-wave radial receiver functions and ambient noise-derived Rayleigh waves. Subsequently, upper crustal structure (lateral resolution of <5 km) will be incorporated using information from active source datasets, P- and S- wave travel times, and higher frequency ambient noise data from higher density networks including legacy and recent datasets. Later model generations will incorporate a geotechnical layer. Formal uncertainty analysis will be completed for each generation of the model and we will validate the final model against recorded waveforms (ideally up to >1 Hz) from regional and moderate-sized events. The various generations of the CVM will be available for CRESCENT-related science and community users in various formats. CVM building and validation is a Cascadia community-wide effort and mechanisms for contributing will be presented.
Session: Earth’s Structure from the Crust to the Core [Poster Session]
Type: Poster
Room: Exhibit Hall
Date: 5/2/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Emilie Hooft
Student Presenter: No
Additional Authors
Emilie Hooft Presenting Author Corresponding Author emilie@uoregon.edu University of Oregon |
Jonathan Delph jdelph@purdue.edu Purdue University |
Alex Grant agrant@usgs.gov U.S. Geological Survey |
Valerie Sahakian vjs@uoregon.edu University of Oregon |
Pieter-Ewald Share sharep@oregonstate.edu Oregon State University |
William Stephenson wstephens@usgs.gov U.S. Geological Survey |
Douglas Toomey drt@uoregon.edu University of Oregon |
Erin Wirth emoriarty@usgs.gov U.S. Geological Survey |
Ross Macguire rossrm@illinois.edu University of Illinois Urbana-Champaign |
Guoliang Li guolingl@usc.edu University of Southern California, Los Angeles, California, United States |
Building a Community Velocity Model for the Cascadia Region and Beyond
Category
Earth’s Structure from the Crust to the Core
Description