Fault slip rates, effects of elastic heterogeneity on geodetic data, and the strength of the lower crust in the Salton Trough region, southern California

2005 ◽  
Vol 110 (B9) ◽  
Author(s):  
Noah P. Fay ◽  
Eugene D. Humphreys
Keyword(s):  
Lower Crust ◽  
Southern California ◽  
Fault Slip ◽  
Geodetic Data ◽  
Slip Rates ◽  
Fault Slip Rates ◽  
Salton Trough

scholarly journals New geodetic constraints on southern San Andreas fault-slip rates, San Gorgonio Pass, California

Geosphere ◽  
2020 ◽  
Author(s):  
Katherine A. Guns ◽  
Richard A Bennett ◽  
Joshua C. Spinler ◽  
Sally F. McGill
Keyword(s):  
Velocity Field ◽  
Southern California ◽  
San Andreas Fault ◽  
Plate Boundary ◽  
Slip Rate ◽  
Fault Slip ◽  
Slip Rates ◽  
San Andreas ◽  
Fault Slip Rates ◽  
Gps Velocity Field

Assessing fault-slip rates in diffuse plate boundary systems such as the San Andreas fault in southern California is critical both to characterize seis­mic hazards and to understand how different fault strands work together to accommodate plate boundary motion. In places such as San Gorgonio Pass, the geometric complexity of numerous fault strands interacting in a small area adds an extra obstacle to understanding the rupture potential and behavior of each individual fault. To better understand partitioning of fault-slip rates in this region, we build a new set of elastic fault-block models that test 16 different model fault geometries for the area. These models build on previ­ous studies by incorporating updated campaign GPS measurements from the San Bernardino Mountains and Eastern Transverse Ranges into a newly calculated GPS velocity field that has been removed of long- and short-term postseismic displacements from 12 past large-magnitude earthquakes to estimate model fault-slip rates. Using this postseismic-reduced GPS velocity field produces a best- fitting model geometry that resolves the long-standing geologic-geodetic slip-rate discrepancy in the Eastern California shear zone when off-fault deformation is taken into account, yielding a summed slip rate of 7.2 ± 2.8 mm/yr. Our models indicate that two active strands of the San Andreas system in San Gorgonio Pass are needed to produce sufficiently low geodetic dextral slip rates to match geologic observations. Lastly, results suggest that postseismic deformation may have more of a role to play in affecting the loading of faults in southern California than previously thought.

scholarly journals Interseismic Ground Deformation and Fault Slip Rates in the Greater San Francisco Bay Area From Two Decades of Space Geodetic Data

2018 ◽  
Vol 123 (9) ◽  
pp. 8095-8109 ◽  
Author(s):  
Wenbin Xu ◽  
Songbo Wu ◽  
Kathryn Materna ◽  
Robert Nadeau ◽  
Michael Floyd ◽  
...  
Keyword(s):  
San Francisco ◽  
San Francisco Bay ◽  
Ground Deformation ◽  
San Francisco Bay Area ◽  
Fault Slip ◽  
Geodetic Data ◽  
Slip Rates ◽  
Bay Area ◽  
Fault Slip Rates
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