Source dynamics of the Dasht-e Bayāz earthquake of August 31, 1968
- 1 October 1969
- journal article
- Published by Seismological Society of America (SSA) in Bulletin of the Seismological Society of America
- Vol. 59 (5), 1843-1861
- https://doi.org/10.1785/bssa0590051843
Abstract
Radiation patterns of the P-wave first motion and S-wave polarization angle of the Dasht-e Bayāz earthquake of August 31, 1968, as well as its principal aftershock which occurred about 20 hours after the main shock are studied. The main shock data are consistent with the observed left-lateral strike-slip fault which accompanied it. The radiation pattern of the aftershock differs somewhat from that of the main shock and agrees with the directions of the secondary faulting in the area. Several lines of evidence pointing to a multiple source for the main shock are presented. They include complexity of the body phases, low value of the rupture speed as studied from the analysis of the surface wave spectra, reported long duration of shaking and complicated pattern of striations produced by faulting. Energy, moment and stress drop associated with the main shock are estimated. The resulting mean value of stress drop over the faulted surface has a range of 40-100 bars. Based on the age of some well-built structures in the area, it is proposed that no earthquake as severe as the recent one has occurred near the location of the August 31, 1968 earthquake during the last 800 years.Keywords
This publication has 18 references indexed in Scilit:
- Fault Rupture in the Iranian (Dasht-e-bayāz) Earthquake of August 1968Nature, 1968
- Estimation ofPKPtravel timesBulletin of the Seismological Society of America, 1968
- The earthquake sequence of November 1964 near Corralitos, CaliforniaBulletin of the Seismological Society of America, 1966
- A study of the aftershocks and focal mechanism of the Salinas-Watsonville earthquakes of August 31 and September 14, 1963Bulletin of the Seismological Society of America, 1965
- The Focal Mechanism of EarthquakesPublished by Elsevier ,1962
- Radiation of seismic surface-waves from finite moving sourcesBulletin of the Seismological Society of America, 1961
- The Revision of Earthquake Epicentres, Focal Depths and Origin-Times using a High-Speed ComputerGeophysical Journal International, 1960
- Study of earthquake mechanism by a method of phase equalization applied to Rayleigh and Love wavesPublished by American Geophysical Union (AGU) ,1960
- The nature of the first motion in the Chilean earthquake of November 11, 1922American Journal of Science, 1928
- The Montana earthquake of June 28, 1925, G.M.C.T.Bulletin of the Seismological Society of America, 1926