TECTONIC INVESTIGATION OF EARTHQUAKE REGIONAL ACCUMULATIONS IN AFGHANISTAN

Subsurface and surface studies show that the Afghan region is affected by three main faults and their deformational zones. The right lateral Hari rod fault zone oriented W-E in the middle of Afghanistan and the left lateral Chaman and Badakhsan fault zones oriented NNE-SSW in the eastern boundary of Afghanistan. The seismotectonic maps shows two main accumulation of earthquakes in Afghan region that are different at depth and focal mechanism. one of them located in Hindu Kush area (A region) and another one is located in the Southern part of Transpressional Plate Boundary (B region). The folds have Type 1 and 2 of interference patterns in B.The A region with the mantel seismicity is clash zone of three plates, where the Arabian and Indian plates subduct beneath the Eurasian plate, and also one of the largest triangular edges of Indian plate boundary is located in the south of this region. Therefore, earthquakes with dip-slip focal mechanism and mantle seismicity at depths occur in A because of stress accumulation. While the B region is located in the boundary between the Arabian and Indian plates that both of them are moves northward with different rate but the Z shape curvature of Indian plate boundary in the B causes to accumulation of stress and occurrence of earthquakes with left lateral strike-slip focal mechanism and crustal seismicity at depths

Keywords:

Earthquake Accumulation , Seismotectonic , Badakhsan Fault , Chaman Fault , Afghanistan