HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nadeau, R. Articles by McEvilly, T. V. Search for Related Content GeoRef GeoRef Citation

Seismological studies at Parkfield III: Microearthquake clusters in the study of fault-zone dynamics

Lawrence Berkeley Laboratory Earth Sciences Division, MS 50E University of California, Berkeley, California 94720

Abstract

More than half of the microearthquakes that occur near Parkfield, California, when located with high-resolution methods, are seen to define some 80 small clusters of 2 to 12 similar events. Each cluster occupies a patch typically 100 to 200 m in length within the fault zone. Cluster members have nearly identical waveforms (correlation coefficient of 0.9 or greater) to frequencies of 50 to 100 Hz, as recorded by the borehole-installed seismographic network. The clusters are distributed throughout the fault zone around the presumed nucleation region, in the locked section to the SE and in the creeping part of the NW of the previous M 6 hypocenter. They are also found in the Salinian block several kilometers SW of the fault zone. The total area occupied by all of the clusters constitutes only a small fraction (1 to 2%) of the fault zone approaching failure at Parkfield. Such clusters provide insight into the dynamics of the failure process through their spatial-temporal characteristics and their mechanisms. They also serve as highly repetitive sources distributed throughout the fault zone suitable for monitoring the nucleation zone for possible precursory changes in physical properties that affect wave propagation. In this article we demonstrate these applications with a detailed analysis of selected clusters.

This article has been cited by other articles:

				W. Yang and Y. Ben-Zion An Algorithm for Detecting Clipped Waveforms and Suggested Correction Procedures Seismological Research Letters, January 1, 2010; 81(1): 53 - 62. [Full Text] [PDF]

				C.-P. Lee and Y.-B. Tsai Variations of P-Wave Travel-Time Residuals before and after the 1999 Chi-Chi, Taiwan, Earthquake Bulletin of the Seismological Society of America, December 1, 2004; 94(6): 2348 - 2365. [Abstract] [Full Text] [PDF]

				M. Wyss, C. G. Sammis, R. M. Nadeau, and S. Wiemer Fractal Dimension and b-Value on Creeping and Locked Patches of the San Andreas Fault near Parkfield, California Bulletin of the Seismological Society of America, April 1, 2004; 94(2): 410 - 421. [Abstract] [Full Text] [PDF]

				Double-Difference Tomography: The Method and Its Application to the Hayward Fault, California Bulletin of the Seismological Society of America, October 1, 2003; 93(5): 1875 - 1889.

				Seismological Studies at Parkfield IX: Fault-Zone Imaging Using Guided Wave Attenuation Bulletin of the Seismological Society of America, August 1, 2003; 93(4): 1415 - 1426.

				Asperity Models for Earthquakes Bulletin of the Seismological Society of America, August 1, 2003; 93(4): 1792 - 1802.

				Is Background Seismicity Produced at a Stationary Poissonian Rate? Bulletin of the Seismological Society of America, October 1, 2000; 90(5): 1174 - 1187.

				Precise Microearthquake Locations and Fluid Flow in the Geothermal Reservoir at Soultz-sous-Forets, France Bulletin of the Seismological Society of America, February 1, 2000; 90(1): 212 - 228.

				J. M. Lees Multiplet analysis at Coso geothermal Bulletin of the Seismological Society of America, October 1, 1998; 88(5): 1127 - 1143. [Abstract] [PDF]

				R. M. Nadeau and L. R. Johnson Seismological studies at Parkfield VI: Moment release rates and estimates of source parameters for small repeating earthquakes Bulletin of the Seismological Society of America, June 1, 1998; 88(3): 790 - 814. [Abstract] [PDF]

				R. M. Nadeau and T. V. McEvilly Seimological studies at Parkfield V: Characteristic microearthquake sequences as fault-zone drilling targets Bulletin of the Seismological Society of America, December 1, 1997; 87(6): 1463 - 1472. [Abstract] [PDF]

				M. Cattaneo, P. Augliera, D. Spallarossa, and C. Eva Reconstruction of seismogenetic structures by multiplet analysis: An example of Western Liguria, Italy Bulletin of the Seismological Society of America, August 1, 1997; 87(4): 971 - 986. [Abstract] [PDF]

				Y.-G. Li, W. L. Ellsworth, C. H. Thurber, P. E. Malin, and K. Aki Fault-zone guided waves from explosions in the San Andreas fault at Parkfield and Cienega Valley, California Bulletin of the Seismological Society of America, February 1, 1997; 87(1): 210 - 221. [Abstract] [PDF]

				M. Antolik, R. M. Nadeau, R. C. Aster, and T. V. McEvilly Differential analysis of coda Q using similar microearthquakes in seismic gaps. Part 2: Application to seismograms recorded by the Parkfield High Resolution Seismic Network Bulletin of the Seismological Society of America, June 1, 1996; 86(3): 890 - 910. [Abstract] [PDF]

				R. M. Nadeau, R. M. Nadeau, W. Foxall, and T. V. McEvilly Clustering and Periodic Recurrence of Microearthquakes on the San Andreas Fault at Parkfield, California Science, January 27, 1995; 267(5197): 503 - 507. [Abstract] [PDF]