Ear to the ground

A few minutes later,the alarm goes off againa powerful aftershock off the East Coast of Honshu in Japan. Nothing,not even a minor tremor anywhere in the world,goes unnoticed here and it is Kumars job to send out tsunami warnings not just to those living along the Indian coast,but to 28 other nations in the Indian Ocean. The centre records five or six earthquakeswhat they call eventsevery day,but the past one week has been busy. They have recorded more than 200 aftershocks after the Japan earthquake on March 11.

Except for the occasional alarms that go off,the room is all quiet. Below the giant screen,people sit in two rows watching and analysing the data that streams into their individual monitors. The centre is monitored by three members of the staff round-the-clock and when Kumar is not inside,his cellphone is hooked to the system. When an alarm goes off here,the system sends a text message to my mobile phone,the director,as well as other key people linked to this centre. It gives details of the quake,location and magnitude,based on which we can decide what action to take, he says.

From 9:30 a.m. to 7 p.m.,Kumar sits at his desk,his eyes darting from his monitor to the giant screen. The screen is divided into six sub-screens where numbers,graphs,colour-coded images and maps keep changing every minute. The earthquake data is coming in from over 300 seismic stations across the globe. The graphs indicate tide levels and pressure. The data comes directly from 38 tide gauges located along the Indian coast and from those located in the Andaman and Nicobar islands,Indonesia and other countries in Southeast Asia. From the depths of the oceans,Bottom Pressure Recorders and tsunami buoys relay information about water level changes once every six hours. If there is a threat of a tsunami,we trigger them into tsunami mode and they send information every minute, says Kumar.

Any quake thats above 6.5 on the Richter scale could trigger a tsunami and when that happens,Kumar gets anything between a few seconds to a few minutes to react,depending on the location of the quake. Based on the magnitude and location of the event,I have to decide whether a tsunami will occur or not. It has to be quick work because if its a tsunami,it could strike the nearest habitation within a few seconds. We cant help people there but we can warn the others who are a couple of hours away from the approaching tsunami. In the case of the March 11 earthquake on the East Coast of Honshu,Japan,we were able to generate a tsunami report within seven minutes of the event. Our model showed that there was no threat of a tsunami in the Indian Ocean but it would hit the Japanese coast within minutes, Srinivasa says,showing a simulated map of the quake and tsunami that hit Japan.

After the December 26,2004,tsunami,the Government of India invested heavily in putting together state-of-the-art infrastructure,information technology and resources to set up this Early Warning Centre. In a room next to the Early Warning Centre,servers that are 10 feet tall process,analyse and store terrabytes of information.

INCOIS was established in 2001 and Kumar was one of the first few scientists to join. After joining INCOIS,I got involved with setting up the Early Warning Centre right after the 2004 tsunami, says Kumar,who has done his Masters in marine sciences and has a PhD in Remote Sensing and GIS from Berhampur University,Orissa.

Our system of collecting information,our simulated models for predicting tsunamis and our information dissemination process make this the worlds best tsunami Early Warning Centre. While alerts issued by other such centres are 30 per cent accurate,we are 70 per cent accurate, he says.

INCOIS Director Dr Satheesh C Shenoi says the efficiency of the early warning system was proven when an under-sea earthquake of 8.4 magnitude occurred on September 12,2007,in the Indian Ocean. We are now graduating into a Regional Tsunami Watch Provider in the Indian Ocean, says Shenoi.

Taking early warning to the next step,INCOIS has mapped the coastal area of Nagapattinam in Tamil Nadu which was one of the worst affected during the 2004 tsunami. We have created a map of inundation that may occur in case of a tsunami. We now have the complete data of the houses and buildings in the area,how many people may be present in each house at any given time during the day or night,which are the multi-storeyed houses that may be safe during an inundation etc. In case of a tsunami warning,we can give accurate information to the coastal commanders or the district collectors on the areas that have to be evacuated first. It will save a lot of lives, he says. Efforts are underway to map vulnerable areas all along the Indian Coast.