India’s tsunami warning facility is being established in Andaman and Nicobar Islands. A network of 35 motion accelerometers and GNSS (Global Navigation Satellite System) receivers is being set up on the island. It will vastly improve the tsunami-warning services under the Indian Tsunami Early Warning Centre (ITEWC), based in Hyderabad under the Indian National Centre for Ocean Information Systems (INCOIS).
On December 26, 2004, one of the deadliest earthquakes (9.3 magnitude), epicentred off the West coast of Sumatra, Indonesia, triggered a tsunami that killed over 2.3 lakh people across 14 countries, including 11,000 in India.
Since then, India has made rapid strides in establishing an early warning system with the help of various organisations, and partnered with international agencies involved in the study of earthquakes, tsunami and other ocean-related natural disasters.
The tsunami warning system in Andaman is expected to help assess the rupture, area and direction of an earthquake, enabling a quick estimation of a potential tsunami. Already, a national network of near-real-time seismic and GNSS stations is in place.
The ITEWC is also tapping new geospatial technologies such as 3D GIS to map coastal areas. This information can be used to improve the accuracy of coastal inundation modelling.
To test the efficiency of the existing facilities, the ITEWC had conducted a tsunami mock drill on September 7-8. It examined the communication links, and the readiness of the disaster management system and the local community to handle emergency situations.
For the first time, around 40,000 people participated from about 350 villages from 33 coastal districts of eight States/UTs.
The country now has a 24×7 early tsunami warning system that can issue tsunami bulletins in less than 10 minutes after any major earthquake in the Indian Ocean. This provides a response time of about 10-20 minutes to regions nearer to the epicentre and a few hours in the case of places farther away.
ITEWC comprises a real-time network of seismic stations, tsunami buoys and tide gauges. The centre analyses the collected data using high-power computational systems.
ITEWC has a network of seven tsunami buoy systems equipped with bottom-pressure recorders that transmit real-time data through satellite to INCOIS 24×7. The buoys are strategically placed at hypothetical tsunami sources of Andaman-Sumatra and Makran subduction zones (regions of the Earth’s crust where tectonic plates meet).
In addition, INCOIS has established a real-time network of 31 tide-gauge stations along the Indian coast, and receives real-time data from 300 international tide gauge stations across the world.