The Salton Trough was formed by past and current relative motions of the Pacific and North American tectonic plates. In its northern edge, the right-lateral transform boundary of the San Andreas Fault system turns into the divergent motion of the East Pacific Rise, which continues south through the Gulf of California. The Salton Trough is highly active: it exhibits a high rate of seismicity; contains major active faults; and geothermal activity is evident on the surface. Faults within the Salton Trough region accommodate together about 80% of the 5 cm/yr of relative Pacific–North American motion. Because the rift is buried beneath a thick pile of Colorado River sediments, surprisingly little is currently known about the total volume of intrusion into the crust and the magma distribution within and beyond the rift margins. This study will lead to a better understanding of magmatic dominated rifts as well as about extensional tectonics in general.
In January 2011, students and faculty from Stanford University have deployed a network of 40 seismometers across southernmost California from the Pacific Ocean to the Colorado River. These seismometers recorded earthquakes from around the world for a period of 2 years. The data collected over that two year period will be used to construct an image of the deep structure beneath the region, learning about the location of faults, the distribution of magma, and the thickness of the crust in the area. This will allow us to understand more about the tectonic plate boundary, and how that affects earthquakes and volcanism.
Related Departments: Geophysics
Related Faculty: Simon Klemperer
2016 Barak, S., and Klemperer, S.L. Rapid variation in upper-mantle rheology across the San Andreas fault system and Salton Trough, southernmost California, USA. Geology, v. 44, #7, doi: 10 .1130 /G37847 .1
2015 Barak, S., S. L. Klemperer, and J. F. Lawrence, San Andreas Fault dip, Peninsular Ranges mafic lower crust and partial melt in the Salton Trough, Southern California, from ambient-noise tomography, Geochem. Geophys. Geosyst., v. 16, doi:10.1002/2015GC005970.
2014 Barak, S., Klemperer, S.L. & Lawrence, J., “Ambient Noise Tomography of Southern California Images Dipping San Andreas-Parallel Structure and Low-Velocity Salton Trough Mantle”, (abstract, poster), AGU 2014 Fall meeting, T31B-4583.
2013 Poletti, M., Barak, S., Barrett, S.A., Klemperer, S.L. & Beroza, G.C., Temporal and spatial evolution of the Aug.-Sept. 2012 Brawley Earthquake Swarm, (abstract, talk), AGU Fall Meeting, S13C-07.
2012 Kinsella, A., Barak, S., Klemperer, S.L., “Rapid lateral variation of seismic anisotropy across the Salton Trough, Southern California”, (abstract, poster presentation), AGU 2012 Fall meeting, T51B-2576.
2011 Barak, S., Klemperer, S.L., Lawrence, J., Castro, R.R, Passive seismic study of a magma-dominated rift: the Salton Trough, AGU Fall Meeting 2011, (Abstract, Poster session) T33G-2496.