Shallow earthquakes and active tectonics in eastern Afghanistan

Brief studies of microearthquakes in four separate parts of eastern Afghanistan reveal a high level of seismicity over a broad area. In general, the activity is not concentrated on well‐defined faults, nor does it define new faults, but seismicity on or close to the Chaman and Sarubi faults attests to their activity. First motions of P waves are consistent with left‐ and right‐lateral strike‐slip motion, respectively, on these two faults. Fault plane solutions and composite solutions of events in different areas throughout the region differ from one another, but in general, the P axes are parallel to the north‐northwest direction of relative motion between India and Eurasia. Several earthquakes beneath Kabul and its immediate surroundings emphasize a need for further study of its seismic hazard. The appendix is available with entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C. 20009. Document J80‐001; $1.00. Payment must accompany order.