TOPICS: Tsunami alert systems working — too well

A tsunami alert, last week, sent thousands of Sri Lankans living along the coasts of this island nation fleeing inland, but authorities were exultant that the early warning systems installed after the disastrous Dec. 26, 2004 Indian Ocean tsunami were working. “The early warning systems worked perfectly,” said Dhammika Wijeyasooriya, deputy director (emergency operations) at the National Disaster Management Centre (DMC). Minutes after Colombo was alerted of the quake in Sumatra, Indonesia, the Meteorological Department and the DMC were in touch with disaster warning centres and alerting the public in vulnerable areas.

But there is now a niggling feeling that the alert systems worked a tad too well. Experts here have been raising questions as to whether the Sept. 12 quake, measuring 8.4 on the Richter scale, and followed by a series of aftershocks the next day, merited a full-scale tsunami alert. “Scientists have determined that there appears to be no immediate threat of an ocean-wide tsunami on this segment because such great earthquakes are typically at least 400 years apart,” argued Duleep Jayawardene, a retired geologist with the UN. Jayawardene says there are no officials who can read seismic data. He has urged the government to take immediate action to train seismologists and geophysicists in interpreting seismic data to ensure that an accurate assessment is made before residents are warned to leave their homes.

The government, he said, should review its decision to designate the meteorology department as the focal point for tsunami and earthquake warnings as the subject is complex and needs effective coordination and scientific input. Unlike Sri Lanka, the Thai National Disaster Warning Centre (NDWC) did not issue a tsunami alert. News reports from Thailand said that the NDWC, instead, made a broadcast three hours later telling people there was no cause for alarm. NDWC chairman S Dharmasarojana was quoted as saying that the delay was based on a thorough analysis of the situation.

Wijeyasooriya said plans were afoot to install 50 ‘early’ warning towers across the island where now only two exist. He said the towers are lamp post-like structures with loudspeakers fixed at the top facing different directions. These towers can be operated from the DMC’s central operations desk in Colombo. “I can send a message or make an announcement directly from Colombo,” he said. Authorities were also meeting on the weekend to review the early warning systems and look at lessons learnt from the latest experience. Wijeyasooriya agreed that there is a need for a central system but said that, in time, the DMC, set up after the 2004 tsunami, would be the central body handling alerts, disasters and evacuation procedures. He said the intensity of Wednesday’s quake was one-tenth of the 2004 quake, but believed that it was better to have alerted the people in the absence of enough skills to assess the seismic data than take a risk. “We need to be safe rather than sorry.” — IPS