Water

Country Water Action: Sri Lanka
Tsunami Alert Systems Working Too Well
October 2007

Still plagued by the stigma of the 2004 Asian tsunami, people at Sri Lanka’s coastal areas rushed to higher grounds when the government and the media sent out a tsunami alert in September, right after an earthquake hit Indonesia. But no tsunami came. What measures are being taken by the government of Sri Lanka to perfect their early disaster warning system?

Contents Alert System Works False Tsunami Alarm People and Media Response More than Two Towers

In mid-September, a tsunami alert sent thousands of people living along the coasts of Sri Lanka fleeing inland, but no tsunami arrived. Authorities, however, were exultant that the early warning systems installed after the 2004 Indian Ocean earthquake triggered the now infamous Asian tsunami were working.

“The early warning systems worked perfectly,” said Dhammika Wijeyasooriya, Deputy Director for emergency operations at the National Disaster Management Center (DMC), which was set up after the 2004 tsunami. The tsunami alert was made just minutes after Colombo was alerted of an earthquake across the Indian Ocean in Sumatra, Indonesia. The Meteorological Department, which acts as the tsunami hazard information center, and the DMC were immediately in touch with disaster warning centers and alerted the public in vulnerable areas.

Various forms of communication were used to alert residents—TV, radio, three-wheeler scooter taxis carrying loudspeakers, police riding jeeps and motorcycles, and even residents going door-to-door.

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Some, however, think that the alert systems worked too well. Experts have been raising questions as to whether the quake that hit Sumatra on 12 September, 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,” said Duleep Jayawardene, a retired United Nations geologist.

Jayawardene said there are no officials who can read seismic data. He 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.

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While people were told the quake was not bigger than the one in 2004, they did not take chances. Most of those living close to the coastline fled to higher grounds with just the clothes on their back. This reaction was understandable. More than 30,000 people died and a million people were affected by the 2004 tsunami that devastated coastal Sri Lanka. Reconstruction work has still to be completed in some areas even after nearly three years and for many affected residents the 2004 tsunami is still fresh in their minds.

Prof. Rohan Samarajiva, executive director of LIRNEasia, a nongovernment organization involved in disaster and hazard management research, said initial reports indicated that the meteorological department received numerous phone calls from journalists when word got out about the Indonesian earthquake.

“In many cases, senior officers who should have been communicating the scientific evidence to key decision makers at the DMC and the ministry were being called directly,” Samarajiva said, adding that this created a problem as time these officers spent on the phone was time not spent on analyzing or communicating the evidence to the relevant authorities in the quickest possible time.

Samarajiva said the unstructured format of a journalist-initiated phone call can lead to misunderstanding. “For example, some journalists may not know the difference between an alert and a warning. This format also does not leave a record in case there is a need to review it at a later time,” he said, noting that this does not mean officials should not talk to the media.

Furthermore, Samarajiva said the best way is to develop a reliable and faster method of communicating tsunami alert to journalists in all three official languages of the country. Messages should be sent to designated numbers and e-mail addresses, preferably using automated procedures.

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Wijeyasooriya said plans were afoot to install 50 “early warning towers” across the island country’s coasts where only two exist now. He said the towers are lamp post-like structures with loudspeakers fixed at the top facing different directions, and can be operated from the DMC’s central operations desk.

“I can send a message or make an announcement directly from Colombo,’” Wijeyasooriya said. Authorities were also meeting to review the early warning systems and look at lessons learned from the latest experience.

Wijeyasooriya agreed that there is a need for a central system but said that, in time, the DMC would be the central body handling alerts and evacuation procedures. He said the intensity of the September 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 risk people’s lives. “We need to be safe rather than sorry,” Wijeyasooriya said.