has started its activities since 1973 in the organizational framework of the planning organization. In 1981 the strong motion network was transferred to Building and Housing Research center and a new stage of its activities was corresponding born.
The network is started its operation in 1973 and since then gradually extended.At present it consists of 1160 digital strong motion accelerographs. Most of the accelerograph units are concentrated in seismically active or in densely populated and industrialized areas. Since the installation of the first station, our strong motion network has recorded about 10000 accelerograms. Among these, the maximum peak acceleration of 1g is related to 1994 Zanjiran earthquake with the magnitude of mb 6.1 and recorded at Zanjiran station.