Tsunami is a series of traveling waves of extremely long wavelength generated primarily by earthquake occurring below and near the ocean floor. Underwater volcanic eruptions and landslides can also generate tsunami. Though the return period of tsunami is infrequent, the destruction done by tsunami is widespread, in terms of life and property. The most devastating tsunami occurred in December, 2004 affected the coastal countries of the entire Indian Ocean. It became necessary to set up a system in India to monitor seismic activity and sea level to evaluate potentially tsunamigenic waves and disseminate tsunami alert or warning.