3D Shear-Wave Velocity Model for Southern California, from Ambient-Noise Surface-Wave Tomography
Abstract/Contents
- Abstract
- Our high-resolution 3D shear-velocity model of southern California generated from ambient-noise surface-wave tomography reveals new structure beneath the San Andreas Fault, Peninsular Ranges, southern Sierra Nevada and the Salton Trough. We use four years of data, 1997-1998, 2007, and 2011, recorded on 849 broadband stations, vastly more than previous studies, chosen to include, in addition to permanent stations, our own broadband Salton Seismic Imaging Project, a 40-station transect across the Salton Trough, as well as other campaign stations in both Mexico and the U.S.A.. Our final model has 0.05° x 0.05° lateral and 1-km vertical blocks. Across the San Andreas Fault, south of Palm Springs, we observe vertical to steeply-dipping lateral velocity contrasts that reach beneath the Moho. Beneath the Peninsular Ranges and westernmost southern Sierra Nevada, we observe high-velocities (Vs {$\geq$}3.8 km/s) in the lower-crust, that we interpret as a remnant of the Farallon plate. The Peninsular Ranges' high-velocity lower-crust wedges into the upper-mantle beneath the the San Gorgonio section of the SAF, and might be related to previously observed upper-mantle downwelling beneath the Transverse Ranges. Finally, beneath the Salton Trough, we image a shallow ({$\sim$}7 km depth) high-velocity body that we interpret as a shallow magmatic intrusion. We also observe zones of low shear-velocity in the lower-crust and upper-mantle, which suggest up to 4.5\% melt in the lower-crust and {$\leq$}2\% melt in the upper-mantle.
Description
| Type of resource | software, multimedia |
|---|---|
| Date created | April 2015 |
Creators/Contributors
| Author | Barak, Shahar |
|---|---|
| Primary advisor | Klemperer, Simon |
Subjects
| Subject | southern California |
|---|---|
| Subject | Geophysics |
| Subject | School of Earth Sciences |
| Subject | San Andreas Fault |
| Subject | Peninsular Ranges |
| Subject | Sierra Nevada |
| Subject | Salton Trough |
| Subject | SSIP |
| Genre | Dataset |
Bibliographic information
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- Use and reproduction
- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).
Preferred citation
- Preferred Citation
- Barak, Shahar and Klemperer, Simon. (2015). 3D Shear-Wave Velocity Model for Southern California, from Ambient-Noise Surface-Wave Tomography. Stanford Digital Repository. Available at: https://purl.stanford.edu/rj028qb2994
Collection
Stanford Research Data
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- Contact
- shaharb@stanford.edu
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