Predictability of ground displacement and velocity near an earthquake fault: An example: The Parkfield Earthquake of 1966

Using the discrete wave number representation method (Bouchon and Aki, 1977; Bouchon, 1979), we model the Parkfield earthquake of 1966 as a Haskell-type dislocation source embedded in a layered medium. We show that the displacement and velocity recorded near the source (station 2 of the Cholame-Shandon array) can be fully accounted for by the propagation of the rupture on the branch of the fault closest to the station. The slip and slip velocity inferred are about 40 cm and 130 cm/s, respectively. The ground motion at the accelerograph site and in the region close to the source was very strongly amplifield by the sedimentary layer. The rupture, after being initiated at depth, stayed buried well under the sediments on the main segment of the fault. The dislocation then jumped across Cholame Valley and became quite shallow. On this southeast branch of the fault the rupture most likely penetrated the sediments. The results obtained constitute an encouraging step toward predicting the strong ground motion at a given site for a potential earthquake fault.

[1]  D. E. Hudson,et al.  An analysis of seismoscope data from the Parkfield earthquake of June 27, 1966 , 1967 .

[2]  M. Wyss,et al.  Seismic and aseismic slip on the San Andreas Fault , 1969 .

[3]  James N. Brune,et al.  Earthquake modeling in a homogeneous half-space , 1978, Bulletin of the Seismological Society of America.

[4]  K. Aki.  Seismic displacements near a fault , 1968 .

[5]  Virgilio Perez,et al.  Accelerograms—Parkfield earthquake , 1967 .

[6]  U. S. Coast.  United States Earthquakes, 1938 , 1933 .

[7]  J. E. Wolfe,et al.  Parkfield Earthquakes June 28–29, 1966 , 1966 .

[8]  Keiiti Aki,et al.  Discrete wave-number representation of seismic-source wave fields , 1977, Bulletin of the Seismological Society of America.

[9]  M. Bouchon.  Discrete wave number representation of elastic wave fields in three-space dimensions , 1979 .

[10]  F. E. Udwadia,et al.  Parkfield, California, earthquake of June 27, 1966: A three-dimensional moving dislocation , 1974, Bulletin of the Seismological Society of America.

[11]  N. A. Haskell.  Elastic displacements in the near-field of a propagating fault , 1969 .

[12]  I. Kawasaki.  On the dynamical process of the Parkfield earthquake of June 28, 1966. , 1975 .

[13]  Source, path and site effects on strong motion records from the Kern County, Borrego Mountain and San Fernando earthquakes , 1977 .

[14]  Mihailo D. Trifunac,et al.  Analysis of accelerograms—Parkfield earthquake , 1967 .

[15]  M. E. O'neill,et al.  Aftershocks of the 1966 Parkfield-Cholame, California, earthquake: A detailed study , 1970 .

[16]  T. Dibblee,et al.  Gravity, magnetics, and geology of the San Andreas Fault area near Cholame, California , 1972 .

[17]  W. Bakun.  Focal depths of the 1966 Parkfield, California, earthquakes , 1972 .

[18]  John G. Anderson.  A dislocation model for the Parkfield earthquake , 1974, Bulletin of the Seismological Society of America.

[19]  United States earthquakes, 1966 , 1968 .

[20]  M. Wyss,et al.  DISPLACEMENT ON THE SAN ANDREAS FAULT SUBSEQUENT TO THE 1966 PARKFIELD EARTHQUAKE , 1968 .

[21]  I. Yamashita.  ON THE DYNAMICAL PROCESS OF THE PARKFIELD EARTHQUAKE OF JUNE 28, 1966 , 1975 .

[22]  C. R. Allen.  The tectonic environments of seismically active and inactive areas along the San Andreas fault system , 1968 .

[23]  W. Bakun,et al.  The Parkfield, California, earthquakes of 1966 , 1967 .

[24]  A. Mal,et al.  Calculation of ground motion in a three-dimensional model of the 1966 Parkfield earthquake , 1976, Bulletin of the Seismological Society of America.