India’s Initiative in Mitigating Tsunami Hazard & Tsunami Potential in Northern Bay of Bengal (Invited)

Soon after the occurrence of the most devastating tsunami caused by the 26th December 2004 Sumatra earthquake, India took the initiative to set up an end-to-end system to mitigate tsunami and storm surge hazard. The system includes all the necessary elements: networking of seismic stations; deployment of ocean bottom pressure recorders; real time sea level monitoring stations; establishment of radar based monitoring stations for real time measurement of surface currents and waves; modeling for tsunamis and storm surges; generation of coastal inundation and vulnerability maps; operation of a tsunami and storm surges warning centre on 24×7 basis; capacity building and training of all the stakeholders and communication with the global community. This initiative was estimated to have a direct cost of US $30million and was to be operative by August 2007. This has been achieved. The Indian National Centre for Ocean Information and Services (INCOIS), belonging to the Ministry of Earth Sciences (MoES), Government of India, located at Hyderabad, is the nodal agency for this program. The system is functioning well. We also examine the tsunami potential in the northern Bay of Bengal, where a large population (about 100 million) in the coastal area makes the region very vulnerable if a large tsunami was to occur. It is observed that: i) oblique plate motion characterizes the region resulting in strike-slip dominated earthquakes with low tsunami generating potential; ii) in the northern Bay of Bengal, the deformation front associated with the plate boundary between India and Sunda plates is either landward or in the shallow water in the Arakan region and therefore a great earthquake will not displace large amounts of water causing a major tsunami; and iii) there is no evidence of the region been affected by a large tsunami in the past 2000 years. We therefore conclude that though a great earthquake could occur in the Arakan region, it would not generate a large tsunami in the northern Bay of Bengal.