Mandates are divided across various ministries to do different things. As a science ministry, it is our mandate to issue warning for Tsunami and inform those agencies who are supposed to take care of the mitigation. It is largely the Home Ministry which is responsible, through their large access to paramilitary forces and other organizations to organize evacuation. The district administration reports to them. There are other authorities, such as Disaster Management Authority, who are making sure that such capacity building mechanisms come up in the country. However, I am also aware that the country has good preparation which you can see when the recent cyclone struck two months ago. A massive exercise of shifting people was undertaken by these arms of the government, and was done very well. When it comes to evacuating people, the method is not different whether you have to relocate because of cyclone or tsunami.

For an event, particularly in the Indian Ocean which happens once every 60 years, you obviously cannot have a frequent real-time testing. But if you look at it as a science, you don’t need an earthquake or a tsunami of that magnitude to test the system. A system consists of various elements. In this case, we have sensors at the bottom of the ocean, various tide gauges, seismological equipment, and we are getting seismological data from across the world. Each of these individual systems is tested 24 hours. For example, we have placed the Bottom Pressure Recorders (BPR) at the depth of, say, 3km which gives a reading every hour. So we know whether the recorder is working or not. It is also highly accurate. We know how the variations take place with respect to the normal tides so we know exactly how the BPR is working because all these tides have a definite mathematical model. Similarly, the tide gauges are also tested. The seismological equipment is tested very frequently because there are so many earthquakes taking place at a low magnitude. When these work for low magnitude, they will also work for high magnitude. Most of the equipment is being tested and monitored by computers on a 24 hour basis.

The systems are planned with a sufficient amount of redundancy. We have established the system with six BPRs – four in the Bay of Bengal and two in the Arabian Sea. Our original configuration is actually for twelve BPRs to maintain very high level of redundancy. When it comes to the actual detection of the tsunami, one BPR on each side is sufficient. We have placed four. For data correlation, we will further multiply this redundancy.

The ocean is a very difficult environment. Maintaining the equipment is difficult, particularly when the sea is rough for about four months. Thus the complete chain of sensors has more than 100 per cent redundancy. Any one failure should not cause any problem with respect to the functioning of the system anywhere in the chain.