A radio-linked local seismological network around Tehri dam was deployed by the Department of Earthquake Engineering, Indian Institute of Technology Roorkee in July 1995 for the purpose of monitoring local seismicity of the region. Since then the network is continuously operating and recording the local earthquakes in the region. First expansion and upgradation of the network from 6 stations to 12 stations was done in Nov.- Dec. 2007.

In which all the equipment were replaced by the state-of-the-art 24-bits digital telemetry equipment. The second expansion and upgradation of the network from 12 stations to 18 stations has been made recently in July - August 2019. Presently, 18-station seismological network is under operation around Tehri dam reservoir. The locations of stations of the network are selected in such a way that they encompass the area of dam reservoir as well as the active seismic source zones in the region. Analysis and interpretation of local seismological data collected so far has provided valuable information regarding the seismological conditions prevailing in the region around Tehri dam prior, during and after reservoir impounding.

The study of long-term seismological data collected through the operation of local seismological network enable detecting and studying the seismicity changes if any associated with the reservoir impounding for the larger area.

Tehri dam with a height of 260.5 m is the fifth tallest dam in the world. It is located in the Garhwal Kumaon Himalaya of Uttarakhand state of India. It is built down on confluence of Bhagirathi River and Bhilangana River. It is of paramount importance to study the behaviour of dam body during occurrence of earthquake, if it occurs. This can be achieved by deploying the strong motion instrumentation network inside the dam body.

Records of such strong motion instruments installed inside Tehri dam during earthquake will be required for two important purposes: