Slip on the San Andreas Fault at Parkfield, California, over Two Earthquake Cycles, and the Implications for Seismic Hazard

2006/09/01 by J. R. Murray · 1 voice · 11 citations
Earth and Planetary Sciences · #Earthquake Detection and Analysis #Geological and Geochemical Analysis #earthquake and tectonic studies

paper · doi:10.1785/0120050820

openalex publication_date 2006/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22

Abstract

Parkfield, California, which experienced M 6.0 earthquakes in 1934, 1966, and 2004, is one of the few locales for which geodetic observations span multiple earthquake cycles. We undertake a comprehensive study of deformation over the most recent earthquake cycle and explore the results in the context of geodetic data collected prior to the 1966 event. Through joint inversion of the variety of Parkfield geodetic measurements (trilateration, two-color laser, and Global Positioning System), including previously unpublished two-color data, we estimate the spatial distribution of slip and slip rate along the San Andreas using a fault geometry based on precisely relocated seismicity. Although the three most recent Parkfield earthquakes appear complementary in their along-strike distributions of slip, they do not produce uniform strain release along strike over multiple seismic cycles. Since the 1934 earthquake, more than 1 m of slip deficit has accumulated on portions of the fault that slipped in the 1966 and 2004 earthquakes, and an average of 2 m of slip deficit exists on the 33 km of the fault southeast of Gold Hill to be released in a future, perhaps larger, earthquake. It appears that the fault is capable of partially releasing stored strain in moderate earthquakes, maintaining a disequilibrium through multiple earthquake cycles. This complicates the application of simple earthquake recurrence models that assume only the strain accumulated since the most recent event is relevant to the size or timing of an upcoming earthquake. Our findings further emphasize that accumulated slip deficit is not sufficient for earthquake nucleation. Online material : Model fault geometry, fit to the data for the inversions, and model resolution.

Citations

• Coseismic and Initial Postseismic Deformation from the 2004 Parkfield, California, Earthquake, Observed by Global Positioning System, Electronic Distance Meter, Creepmeters, and Borehole Strainmeters
• Inverting for Slip on Three-Dimensional Fault Surfaces Using Angular Dislocations
• Surface Fault Slip Associated with the 2004 Parkfield, California, Earthquake
• Surface deformation due to shear and tensile faults in a half-space
• Surface Slip Associated with the 2004 Parkfield, California, Earthquake Measured on Alinement Arrays
• Three-Dimensional Compressional Wavespeed Model, Earthquake Relocations, and Focal Mechanisms for the Parkfield, California, Region

Cited by

• Three-Dimensional Compressional Wavespeed Model, Earthquake Relocations, and Focal Mechanisms for the Parkfield, California, Region
• Coseismic and Postseismic Slip of the 2004 Parkfield Earthquake from Space-Geodetic Data
• Coseismic and Initial Postseismic Deformation from the 2004 Parkfield, California, Earthquake, Observed by Global Positioning System, Electronic Distance Meter, Creepmeters, and Borehole Strainmeters
• The 2004 Parkfield Earthquake, the 1985 Prediction, and Characteristic Earthquakes: Lessons for the Future
• Kinematic Inversion of the 2004 M 6.0 Parkfield Earthquake Including an Approximation to Site Effects
• Surface Fault Slip Associated with the 2004 Parkfield, California, Earthquake
• Surface Slip Associated with the 2004 Parkfield, California, Earthquake Measured on Alinement Arrays
• San Andreas Fault Geometry in the Parkfield, California, Region
• Reassessment of a Slip Budget along the Parkfield Segment of the San Andreas Fault
• Continuous Borehole Strain and Pore Pressure in the Near Field of the 28 September 2004 M 6.0 Parkfield, California, Earthquake: Implications for Nucleation, Fault Response, Earthquake Prediction, and Tremor
• Highly Systematic Response of Seismic Rupture Patterns to Background Loading Rate: Insights From Repeating Earthquakes

Discussions

• ⭐️Slip on the San Andreas Fault at Parkfield, California, over Two Earthquake Cycles, and the Implications for Seismic Hazard, J. Murray; J. Langbein (2006), doi.org/10.1785/0120... Available until Se [bsky, 2 points, 1 comments]

Related

• Surface Fault Slip Associated with the 2004 Parkfield, California, Earthquake
• Surface Slip Associated with the 2004 Parkfield, California, Earthquake Measured on Alinement Arrays
• Reassessment of a Slip Budget along the Parkfield Segment of the San Andreas Fault
• San Andreas Fault Geometry in the Parkfield, California, Region
• Frictional Properties on the San Andreas Fault near Parkfield, California, Inferred from Models of Afterslip following the 2004 Earthquake