Refining the image of the San Andreas Fault near Parkfield, California using a finite difference travel time computation technique

2006 ◽  
Vol 426 (1-2) ◽  
pp. 189-205 ◽  
Author(s):  
S. Roecker ◽  
C. Thurber ◽  
K. Roberts ◽  
L. Powell
Keyword(s):  
Finite Difference ◽  
Travel Time ◽  
San Andreas Fault ◽  
San Andreas ◽  
Computation Technique

The July 2019 Ridgecrest, California, Earthquake Sequence Recorded by Creepmeters: Negligible Epicentral Afterslip and Prolonged Triggered Slip at Teleseismic Distances

2020 ◽  
Vol 91 (2A) ◽  
pp. 707-720 ◽  
Author(s):  
Roger Bilham ◽  
Bryan Castillo
Keyword(s):  
Surface Waves ◽  
Travel Time ◽  
San Andreas Fault ◽  
Surface Strain ◽  
Earthquake Sequence ◽  
Fault Creep ◽  
San Andreas ◽  
Garlock Fault ◽  
Growing Body ◽  
Epicentral Region

Abstract We report sequential triggered slip at 271–384 km distances on the San Andreas, Superstition Hills, and Imperial faults with an apparent travel-time speed of 2.2 ± 0.1  km/s, following the passage of surface waves from the 4 July 2019 (17:33:49 UTC) Mw 6.4 and 6 July 2019 (03:19:53 UTC) Mw 7.1 Ridgecrest earthquakes. Slip on remote faults was not triggered instantaneously but developed over several minutes, increasing in duration with distance. Maximum slip amplitudes varied from 10  μm to 5 mm within minutes of slip nucleation, but on the southernmost San Andreas fault slip continued for two months and was followed on 16 September 2019 by a swarm of microearthquakes (Mw≤3.8) near Bombay Beach. These observations add to a growing body of evidence that fault creep may result in delayed triggered seismicity. Displacements across surface faults in the southern epicentral region and on the Garlock fault in the months following the Ridgecrest earthquakes were negligible (<1.1  mm), and they are interpreted to characterize surface strain adjustments in the epicentral region, rather than to result from discrete slip on surface faults.

The San Andreas Fault

1993 ◽  
Author(s):  
Sandra S. Schulz ◽  
Robert E. Wallace
Keyword(s):  
San Andreas Fault ◽  
San Andreas
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