Feasibility Study of Earthquake Prediction through a Study of b-Value Precursor (Case study: Silakhor Earthquake, Iran)

Document Type : Applied Article


Associate Professor, Institute of Geophysics, University of Tehran, Iran


The purpose of the present study is to compare the changes in b-value parameter using frequency-magnitude distribution for the data before and after the Silakhor earthquake by Gutenberg-Richter relation. The variations of b-values are investigated using Broadband Iranian National Seismic Network Center (BIN). Besides, spatial and time variations of the parameters were analyzed. The spatial variation of b-value parameter in the epicentral area showed anomalies before the event. Therefore, some important information was estimated about the changes in stress by reducing b-value in the region. On the other hand, anomalies were seen in b-value parameter in aftershocks sequences, representing a reduction in stress in the region. Generally, the results of this study indicate that the b-value parameter had a decreasing trend prior to the March 31, 2006 event in Silakhor, and an increasing trend after that. The increase and decrease of this parameter is associated with the increase and decrease of stress in active faults and a change in slip rate in the region. These anomalies in b-value parameters in the region suggest that b-value changes can be offered as a precursor for estimating the time and location of earthquakes along segments of the faults in the region. Therefore, proper data recording in different regions and permanent monitoring of this parameter can be an important step toward the long-term or medium-term prediction, and especially toward the identification of the approximate location of future events in the active seismic zones.


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