3-D Geologic and Seismic Velocity Models of the San Francisco Bay Region Documentation
Velocity Model Releases
- Switched from Olsen et al model for Qp and Qs to Brocher (2008) model for Qp and Qs that is based on Graves's model.
- Reduced Vp and Vs in granites, Francsican, gabrro, lower crust, and upper mantle.
- Increased Vp and Vs by 10% in the La Honda basin. More work is still needed to constrain the seismic velocities in this basin.
This release of the USGS Bay Area Velocity Model includes both a detailed model and an extended (regional) model. The extended model extends the velocity model to approximately 650 km x 330 km x 45 km. Note that the extended model contains much less detail than the detailed model, hence the names. Additionally, the detailed model has been extended down to a depth of 45 km.
Initial release of the USGS Bay Area Velocity Model. It fills the volume covered by the detailed 3-D geologic model.