The SCEC southern California reference three-dimensional seismic velocity model Version 2

We describe Version 2 of the three-dimensional (3D) seismic velocity model of southern California developed by the Southern California Earthquake Cent er and designed to serve as a reference model for multidisciplinary researc h activities in the area. The model consists of detailed, rule-based repres entations of the major southern California basins (Los Angeles basin, Ventu ra basin, San Gabriel Valley, San Fernando Valley, Chino basin, San Bernard ino Valley, and the Salton Trough), embedded in a 3D crust over a variable depth Moho. Outside of the basins, the model crust is based on regional tom ographic results. The model Moho is represented by a surface with the depth s determined by the receiver function technique. Shallow basin sediment vel ocities are constrained by geotechnical data. The model is implemented in a computer code that generates any specified 3D mesh of seismic velocity and density values. This parameterization is convenient to store, transfer, an d update as new information and verification results become available.