Seismic network in Pakistan
Muhammad Daud Shah, Muhammad Qaisar and Suhail Ahmed
Micro Seismic Studies Program, Ishfaq Ahmed Research Laboratories,
Pakistan Atomic Energy Commission, Islamabad, Pakistan
Seismic measurements started in 1954 when United States Geological Survey started installing World Wide Standard Seismographic Network (WWSSN) stations in Pakistan. Later in 1973 a nine station short period, VHF radio telemeterd seismic network, having a central recording system, was established by Water and Power Development Authority with the help of Lamont Doherty Geological Observatory of Columbia University, USA, to monitor seismicity around Tarbela Dam.
Micro Seismic Study Program of Pakistan Atomic Energy Commission started playing an important role in the field of seismic monitoring from 1975 by establishing its seismic network for the site selection/evaluation of Nuclear Power Plants and other critical structures. A seismic network of 30 stations was spread over 400x300 km area from north to south of Pakistan. In 2005 it was decided to upgrade the seismic network with broadband sensors, accelerometers, 24 bit analog to digital converters, radio and satellite digital telemetry. A high quality seismic network is now fully operational to monitor seismic data from 360 seconds to 50 Hz. The seismic noise characteristics of seismic stations sites indicate that these stations are capable of producing highly reliable seismic data from 360 sec to 50 Hz and have a large amplitude dynamic range due to 24 bit analog to digital converters. This data provides new opportunities to the seismologists for undertaking research activities in different fields of seismology and earthquake engineering. The Muzaffarabad earthquake of October 2005 and its aftershocks were successfully recorded by this network. Details of the seismic network with some important recordings from this earthquake are discussed. |
