Reservoir Induced Microearthquakes Around Tarbela Dam, Pakistan Himalaya

The Tarbela reservoir is situated on the lndus river in the Pakistan Himalaya. A telemetred seismic network has been in operation around the reservoir site since 1973, about a year prior to its initial impoundment. Recently, a detailed statistical investigation of post-impoundment seismicity around this rcservoir for a period of seven years has been reported in the literature. Evidence has been presented there for relatively high probability of increased microearthquake activity at shallow depths in the crust beneath the Tarbela reservoir during periods of low water levels. We argue that, although this is important evidence on the question of whether reservoir induced seismicity can occur in the Himalaya, there is need for further detailed seismicity observations around the present and future reservoir sites in these mountains.