Determination of the Fault Plane of the 2017 Iranian Sefidsang Earthquake, Mw 6.0, by Seismic Moment Tensor Inversion Method

Document Type : Research Article


1 Ph. D. Candidate, Institute of Geophysics, University of Tehran, Tehran, Iran

2 Assistant Professor, Institute of Geophysics, University of Tehran, Tehran, Iran

3 Ph.D. Candidate, Institute of Geophysics, University of Tehran, Tehran, Iran


Essentially, assuming a simple fault model, the hypocenter and centroid should be located on the same plane. This approximation can help to distinguish the fault plane from the auxiliary plane of an earthquake in many situations. On April 5, 2017, the Sefidsang earthquake Mw 6 occurred in north-eastern Iran. It was not possible to relate a fault to the earthquake according to the reports of the Iranian seismological center (IRSC) and the International Institute of earthquake engineering and seismology (IIEES) of Iran. The association of the earthquake to the western part of the Fariman fault or to the southern end of the Kashfroud fault is not possible. In this study, data from the stations of the aforementioned agencies was used to model the earthquake waveforms, and an effort was made to find the focal mechanism of this earthquake, investigate it, and also to eliminate the ambiguities that exist in determining the fault plane of the earthquakes using the Hypocenter-Centroid (H-C) method, due to the higher accuracy in simulating the waveforms and finding the centroid point of earthquakes in local and regional distances. we obtain the fault plane with a strike of 324 and dip of 44 degrees, which indicates the northwest-southeast trend, parallel to the trend of the Kashfroud fault. This has good agreement with the results of other researchers.


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