Saeed Zarei

The western Herat Fault system is one of Afghanistan's most seismotectonically active regions, having experienced four Mw >6 earthquakes in 2023. Given the significance of this region and the occurrence of successive seismic events, this study investigated the seismotectonic dynamics of the area through seismicity parameters and fractal analysis. Here, changes in the seismicity rate were analyzed based on variations in the seismic parameter (b-value) and the fractal dimension of fracturing and seismicity (D-value) using available seismic data. The study area was divided into nine primary zones, with each zone's parameters calculated. The largest fault fractal dimensions were identified in the southeastern, central, and northwestern zones, while the highest seismic fractal dimension was associated with the central and northwestern regions. The calculated b-values in the center of the study area, coinciding with the Herat Fault, indicate elevated stress accumulation, potentially signaling future large earthquakes. The seismic moment rate, representing the rate of energy change released through seismic activity, was estimated at 1.18 × 10¹⁸ Nm/yr for the entire study area. Combined fractal analysis and seismic moment calculations suggest that the Zendeh-Jan, Injil, Ghurian, and Kushan districts are potential candidates for future earthquakes. These results reinforce the interpretation that western Afghanistan, as an evolving deformation zone, remains highly susceptible to seismic events.