THE tsunami warnings issued by the Indonesian authority soon after the 7.8-scale earthquakes struck off West Sumatra on March 2 were cancelled a few hours after they were activated all over Sumatra by the Meteorology, Climatology and Geophysics Agency (BMKG).

Although the earthquakes were powerful enough to be felt in some parts of Singapore, they were determined to be less tsunamigenic than thought, as they occurred 650km off the Sumatran fault line. Still, there were noticeable gaps in the Indonesian tsunami warning system.

On Mentawai Island, the closest populated region located 650km from the epicentre, tsunami sirens were activated. In most of West Sumatra province, local communities reportedly moved to evacuation shelters and higher ground, as well as tall buildings. Traffic congestion resulted when people rushed towards higher places. Probably no authority in the world can eliminate the complexities of large-scale evacuations because of tsunamis and other natural hazards.

… The writer is a research fellow at the Centre for Non-Traditional Security Studies at the S. Rajaratnam School of International Studies, Nanyang Technological University, Singapore.