Addressing the risk of tsunami in the Indian Ocean

Abstract

Identification and forecasting of tsunamis require detection of a tsunamigenic earthquake and its parameters, generation of model scenarios to estimate travel time and run-up height, monitoring of sea level, a decision support system, a standard operating procedure and mechanisms for timely delivery of information. India has successfully set up the First Tsunami Warning Centre in the Indian Ocean in record time, which has been operational from October 15, 2007. The Indian Tsunami Early Warning System comprises a real-time network of seismic stations, Bottom Pressure Recorders (BPR) and tide gauges to detect tsunamigenic earthquakes and to monitor tsunamis. Tunami N2 model has been used for the purpose of predicting surges for different scenarios of earthquakes. For operational early warning, a large spatial database (about 8 Terabytes) of pre-run numerical simulations has been created, which can be accessed at the time of an earthquake event to generate forecast of tsunami travel time and run up estimates for different parts of the coastline of the Indian Ocean. A state-of-the-art early warning centre has been established at the Indian National Centre for Ocean Information Services (INCOIS) with all the necessary computational and communication infrastructure that enables reception of real-time data from all the sensors, analysis of the data, generation and dissemination of tsunami advisories following a standard operating procedure. The end-to-end performance of the system was validated against the earthquake and tsunami event of September 12, 2007. It was observed that the system performed extremely well, enabling reception, display and analysis of the real-time and model data sets as well as generation and dissemination of timely and accurate advisories following the standard operating procedure. The instrumentation of the Indian System capable of detecting tsunamis originating from both known tsunamigenic sources in the Indian Ocean. India has begun providing regional tsunami watch services from its national system for the Indian Ocean region. At present, it provides earthquake source information to assess potential tsunami threat and travel time.