Earthquake hazard analysis for East Anatolian Fault Zone, Turkey

Abstract

The aim of this study was to investigate the earthquake hazard of the East Anatolian Fault Zone by determining the a and b parameters in a Gutenberg–Richter magnitude–frequency relationship. For this purpose, the East Anatolian Fault Zone is divided into five different source zones based on their tectonic and seismotectonic regimes. We calculated the b value, which is the slope of the frequency–magnitude Gutenberg–Richter relationship, from the maximum likelihood method (ML). Also, we estimated the mean return periods, the most probable maximum magnitude in the time period of t years and the probability for an earthquake occurrence for an earthquake magnitude ≥M during a time span of t years. We then produced a and b value maps using the ML. We obtained the lowest b value in Region 1 covered Karliova triple junction. This conclusion is strongly supported from the probability value, which shows the largest value (90 %) for an earthquake with magnitude greater than or equal to 6.0. The mean return period for such a magnitude is the lowest in this region (43 years). The most probable magnitude in the next 100 years was calculated, and we determined the highest value around Karliova triple junction. According to these parameters, Region 1 covered the Karliova triple junction and is the most dangerous area around the East Anatolian Fault Zone.