Seismicity and Tectonic Investigation of Afghanistan

Afghanistan's location at the collision zone between the Indian and Eurasian plates makes it one of the world's most seismically active regions. This study investigates the country's seismo-tectonic provinces using gravity data, Moho depth variations, active faults, and earthquake distribution. Gravity data reveals a northeast-southwest trend of anomalies, suggesting northward thickening of the fold belt due to Indian plate convergence. Crustal thickness, obtained from CRUST۱.۰ model, increases from west to east, with the eastern Hindu Kush reaching depths of ۵۵ kilometers. Active faults were identified based on their deformation of recent landforms. Earthquake distribution is highest in northeastern Afghanistan due to active faults and the Indian plate's movement. Five seismo-tectonic provinces were defined based on geological, geophysical, and earthquake data: Central Afghanistan (low seismicity despite active faults), Helmand Block (seismically stable), North-Afghan Block (low seismicity with higher magnitude events), Chaman Block (history of tectonic activity), and the Hindu Kush (highly seismically active). This comprehensive analysis provides valuable insights into Afghanistan's tectonic framework and seismic hazards, crucial for risk assessments and mitigation strategies.

کلیدواژه ها:

Afghanistan ، seismo-tectonic ، Active Fault ، Crustal Thickness ، Gravity