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Heat Flow and the Seismogenic Zone in Southern California. Colin F. Williams USGS, Menlo Park, CA. U.S. Department of the Interior U.S. Geological Survey. Depth of seismicity in Southern California (after Nazareth and Hauksson, 2004). Heat Flow in California.
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Heat Flow and the Seismogenic Zone in Southern California Colin F. Williams USGS, Menlo Park, CA U.S. Department of the Interior U.S. Geological Survey
Depth of seismicity in Southern California (after Nazareth and Hauksson, 2004)
SHLK RDS
Observations • Observed pattern of seismicity depth cut-off consistent with variations in heat flow • Imperial Valley – Hi HF and Shallow Seismicity • Landers – Consistent Variations in HF, Seismicity and Rupture depth along strike • Ventura Basin – Lo HF and Deep Seismicity • San Gregorio Pass – No HF Constraint • Temperature for the seismic-aseismic transition is ~350 to 400 oC for most of southern California but is lower (~250-300 oC ??) in the Mojave, probably due to lithologic variations • Improved EQ catalogues key to quantitative evaluation