The Hindu , 05 February 2006

Indian system will rule out false tsunami alarms

HYDERABAD: The Indian Early Tsunami Warning System will ensure that no false alerts are generated, unlike the Pacific arrangement in which 70 per cent of the warnings are false.

"We want to remove it (false alarms) totally," Harsh K. Gupta, former Secretary, Department of Ocean Development, said speaking to reporters and while delivering the key-note address on "Science and Disaster Management" at the plenary of the 93rd Indian Science Congress here on Wednesday.

In the Pacific system, the warning was given only on the basis of the location and magnitude of the earthquake. Such advisories were not suitable for India in view of its large coastal population. The science of issuing warnings was being improved.

The key elements of the Rs.125-crore Indian system would be in place by March this year and the full-fledged mechanism operational by September 2007. The key elements include establishing connectivity among seismic stations and installing one or two bottom pressure sensors.

Pointing out that 13 per cent of world's cyclones occurred in the seas around the country, Dr. Gupta said the Indian system incorporated storm surge forecast also.

The system based on the end-to-end principle encompasses near-real time determination of earthquake parameters in the two known tsunamigenic zones of the Indian Ocean (the Indonesian seismic belt and the Makran area), using land-based seismic stations and establishing a comprehensive, real time ocean observational network comprising bottom pressure recorders, tide gauges and radar-based coastal monitoring stations.

Dr. Gupta, who is a Raja Ramanna Fellow at the National Geophysical Research Institute (NGRI) here, said the Indian Ocean was unique with more than 50 nations around with more than a 1.5-billion population.

The coastline was more than 66,500 km.

The December 26, 2004, earthquake released energy equivalent to 20,000 atomic bombs, he said.

"Draw another risk map"

V.P. Dimri, NGRI director, said India's biggest risk factor included earthquakes, which affected 56 per cent of the landmass.

It was time to prepare another risk map, including seismicity and ground acceleration information.

D.K. Sinha, former professor of Calcutta University; B. N. Goswamy, professor, Centre for Atmospheric & Oceanic Sciences, Indian Institute of Science, Bangalore; P. C. Kesavan, distinguished fellow, M. S. Swaminathan Research Foundation, and A. K. Parida, Director-General, Marri Channa Reddy Human Resource Development Institute, spoke.