Waving the Tsunami Warning Flag

Re-posted from the Wall Street Journal Asia:

This week’s twin disasters in Indonesia—the eruption of Mount Merapi and the 7.7-magnitude earthquake off west-central Sumatra—have again brought warning systems and emergency preparedness into the spotlight. The resulting view is far from flattering.

The tsunami struck at 9:42 p.m. local time on Oct. 25, only a few hours before the volcano erupted. The tsunami death toll is likely to climb beyond the 350 at which it currently stands, while the volcano killed 30.

Both nature and man worked against the victims. The undersea tremor that caused Monday’s deadly wave was a rare “tsunami earthquake,” a tremor that for some reason produces a tsunami far larger than is normal for an earthquake of that magnitude. Because of this, most people on shore did not feel the earthquake, so the first sign the wave was coming was the roar of it crashing ashore.

Yet those hundreds of deaths were far from inevitable. That the victims had no warning marks a failure of the German-Indonesian Tsunami Warning System (GITWS), inaugurated with great fanfare two years ago. The system, developed at a cost of $69 million, was supposed to avert another catastrophe like the 2004 Boxing Day tsunami that claimed 184,000 lives, 131,000 of those in Indonesia. It features a futuristic control room in Jakarta and a system of tsunamographs—devices to record sea levels in deep water, which relay data back to the control room via buoys on the ocean surface.

Those recorders were plagued by problems from the start. Sometimes deep ocean moorings would break off and the buoys would float off. Sometimes signals wouldn’t trigger or relay properly. Fishermen have been known to remove solar panels and use the buoys as anchors. Sharks occasionally bite off pieces of the mooring line.

Solutions exist. For more than a decade the U.S. National Atmospheric and Oceanic Administration has deployed a system that avoids these pitfalls, and their tsunamographs are better than 70% reliable. But Indonesia relied on untested technology and didn’t build in the redundancy—multiple sensors in high-risk areas—common to other systems.

Even if the GITWS system had worked, it’s still not clear the message would have gotten out to those who needed it. UNESCO’s Pacific Tsunami Warning Center in Hawaii issued a warning about eight minutes after the earthquake, but that message didn’t reach the public in time. Rapid warning dissemination remains key for effective civil protection.

It’s inexcusable that these problems persist today. On average, one earthquake capable of producing a tsunami shakes Sumatra every year. Southeast Asia is one of the most studied regions in the world in terms of tsunamis and seismic phenomena. So what has gone wrong?

To answer that, it is first important to understand what has gone right. Thanks to better public education, more people now know the most common warning signs for a tsunami and how to self-evacuate without an official order. Several research groups have developed evacuation maps for the region that would have helped people reach safety ahead of a tsunami a little bigger than the one that materialized in this case.

Yet further progress is constrained by the fact that emergency managers in Indonesia, as elsewhere, always plan for the last disaster instead of the next one. Bureaucrats by nature prefer specific checklists and the like. As a result, planning tends to be much more “event-specific”—developing detailed action plans for evacuating x number of people from y area ahead of a wave of z size. That scenario inevitably resembles the most recent disaster that planners encountered.

It would be better to focus on first principles: bolstering the ability to detect potential tsunamis and warn people as early as possible. For cases like this where people on the shore see no warning signs, the key is to focus on how authorities will know there’s a danger and get that message out. In this framework, the problems dogging GITWS transmitters should have been the top concern of disaster planners, not one of many issues on a long to-do list.

It has now been six years since the disaster that made “tsunami” a household word. Another four tsunamis in Indonesia have claimed more than 1,000 lives. Asia needs the best technology and the best minds working together. No country can be prepared for all natural disasters that might strike. But we can do far better, if we choose to learn from the experience of others.

Mr. Synolakis is director of the Tsunami Research Center at the Viterbi School of Engineering of the University of Southern California.

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