JAKARTA—A large earthquake off the west coast of Indonesia has exposed major flaws in the multimillion-dollar warning system installed after the deadly 2004 Indian Ocean tsunami, raising questions about whether the country would be able to prevent a similar disaster.
None of the country’s 22 warning buoys were working at the time of the earthquake, Indonesia’s disaster agency said Thursday. An official separately blamed the malfunctions on vandalism by fishermen and inadequate maintenance.
Indonesia straddles the Indian and Pacific oceans in one of the world’s most seismically active areas. On Wednesday evening, a shallow 7.8-magnitude quake struck about 500 miles from Padang in West Sumatra province, stirring panic and sending residents scurrying for higher ground. No killer wave materialized and no damage or deaths were reported.
Authorities issued a tsunami warning, but struggled to acquire the data needed to rescind it quickly, waiting nearly three hours until it was clear that massive waves hadn’t formed.
A police officer stands on the roof of a tsunami evacuation center in Indonesia. PHOTO: REUTERS
Sutopo Purwo Nugroho, a spokesman for the National Disaster Management Agency, said all of the 22 buoys in the area operated by Indonesia needed to be replaced. Five other buoys operated by India, Thailand, the U.S. and Australia were working, he said. However, those are much further from the Sumatra coastline than the Indonesian-operated buoys.
After the 2004 earthquake and tsunami, which killed an estimated 228,000 around the Indian Ocean, regional tsunami-warning centers were set up in Indonesia, India and Australia. These centers use a series of seismic sensors that sit on the seafloor and floating buoys that relay information to land using satellites.
Knowing how big a wave is and being able to estimate when it will arrive onshore is crucial to determining how much flooding will result and creating more targeted evacuations, said Costas Synolakis, director the Tsunami Research Center at the University of Southern California.
“This is not a trivial matter,’’ Mr. Synolakis said. “False warnings diminish the credibility of the system, people become cynical and complacent.”
Djoko Hartoyo, a spokesman for the Coordinating Ministry of Maritime Affairs who worked as a project manager on the buoy warning system from 2007 to 2011, blamed the malfunctioning on ``vandalism,’’ saying that fishermen have tampered with the buoys by removing their antennas, preventing them from sending data to the main tsunami warning center in Jakarta.
An interactive map provided by the U.S. Geological Survey shows the location of Wednesday’s quake off Sumatra. PHOTO: US GEOLOGICAL SURVEY
