Determining seismotectonic provinces based on seismicity coefficients in Iran

چکیده مقاله

Various seismotectonic province maps were made in Iran by different researchers having different perspectives long ago. The difference in these perspectives has led to differences among the maps in numbers and forms of the seismotectonic provinces.

As a primary hypothesis, seismicity coefficients such as a and b values in the Gutenberg-Richter equation must be separately constant in a seismotectonic province. The main objective of this research is to prepare a seismotectonic province map based on seismicity coefficients. Therefore, the areas containing constant seismicity coefficients are placed in one province after determining the seismicity coefficients in interconnected networks in Iran. As a matter of fact, the province borderlines are determined based on the numerical values of the seismicity coefficients.

The seismicity coefficients include values a and b in the Gutenberg-Richter equation, and also other parameters include rate of earthquakes per year (λ), largest (Mmax) and smallest (Mmin) earthquakes in the area, and density of faults and earthquakes.

In other words, the borderlines of the seismotectonic provinces are calculated based on the numbers and magnitudes of the earthquakes in specific ranges of location and time. A comprehensive map is developed for the seismotectonic provinces in Iran according to the mentioned parameters as well. Based on this map, the region is divided into eleven major seismotectonic provinces and three subzones. The position of each seismotectonic province demonstrates a good compatibility with the geologic and tectonic situation of the region.