Reza Mansoori

Afghanistan’s complex tectonic setting within the Alpine-Himalayan belt results from the ongoing India-Eurasia collision. Through integrated analysis of seismic, geodetic, and gravity data, this study characterizes five distinct seismotectonic provinces. The Hindu Kush province exhibits extreme crustal thickness (65–80 km) and deep seismicity (B 300 km), with Bouguer anomalies reaching - 479 mGal, indicating active sub- duction processes. The Chaman fault system shows high left-lateral slip rates (5–35 mm/yr) with shallow seismicity. Northern Afghanistan exhibits moderate to shallow seismicity within thick sedimentary basins (up to 16 km), whereas central Afghanistan displays sparse seismicity despite its complex fault networks. The Helmand block remains stable with consistent crustal thickness (40–45 km). To understand Afghanistan’s seismotectonics within regional dynamics, the authors compared the findings with recent studies from the Himalayan and Northeast Indian regions. This study findings directly inform seismic hazard assessments, high- lighting the urgent need for updated building codes in Kabul and Kandahar, as well as prioritized infrastructure reinforcement along the Chaman fault system. This provincial classification provides a framework for targeted risk mitigation strategies across Afghanistan.