The Indian Tsunami Early Warning Centre (ITEWC) is established after the deadly Tsunami on 26 December, 2004 at Indian National Centre for Ocean Information Sciences (INCOIS – ESSO), autonomous body under Ministry of Earth Sciences, located at Hyderabad and is made fully functional to cover the entire Indian Ocean Region.
The Indian Tsunami Early Warning System comprises a real-time seismic monitoring network of 17 broadband seismic stations to detect tsunamigenic earthquakes, a network of real-time sea-level sensors with 4 Bottom Pressure Recorders (BPR) in the open ocean and 25 tide gauge stations at different coastal locations monitor tsunamis and a 24 X 7 operational tsunami warning centre to provide timely advisories to vulnerable community. It also receives earthquake data from all other global networks to detect earthquakes of M>6.5. The state-of-the-art early warning centre at INCOIS – ESSO is operational since October 15, 2007 with all the necessary computational and communication infrastructure that enables reception of real-time data from seismic & sea-level sensors, analysis of the data, tsunami modeling, and dissemination of tsunami advisories guided by a comprehensive standard operating procedure (SOP).
A host of all available communication technology options have been employed for timely dissemination of advisories to various designated authorities to deal with effective emergency response actions as appropriate. The centre is capable of detecting tsunamigenic earthquakes occurring in the whole of Indian Ocean region as well as in the Global Oceans within 10 minutes of their occurrence and disseminates the advisories to the concerned authorities within 20 minutes through various modes of communication like email, fax, SMS, GTS and website. Since its inception in October 2007 to till date, ITEWC has monitored 339 earthquakes of M > 6.5 out of which 63 are in the Indian Ocean region.
ITEWC in its capacity as National Tsunami Warning Centre (NTWC) for India disseminates tsunami bulletins to various national contacts like the Ministry of Home Affairs (MHA) control room, Ministry of Earth Sciences (MoES), National Disaster Management Authority (NDMA), Battalions of National Disaster Relief Force (NDRF), Coastal State disaster relief commissioners, Indian Navy, Administration of Nuclear Power plants in the coastal states, Disaster Management Administrators from Andaman & Nicobar Islands etc. ITEWC also acts as one of the Regional Tsunami advisory Service Provider (RTSP) along with Australia & Indonesia for the Indian Ocean region.
The tsunamis generated by the under-sea earthquakes in the two known subduction zones of Andaman-Sumatra and Makran in Indian Ocean, can potentially affect entire Indian coastal states and Island regions. The tsunami wave arrival time to different coastal locations depends upon the location of the under-sea earthquake. In general the tsunami reaction time will be around 2 hours for the Indian mainland if the earthquake has occurred in the above mentioned subduction zones. While for the Andaman & Nicobar Islands there is an exception where the reaction time will be less than half an hour if the earthquake occurs off the A & N Islands region.