How Amateur Video Is Helping Us Understand Deadly Tsunamis

Back in the lab at Georgia Tech, Fritz could superimpose the real-life scan onto the original video to figure out how high the water got and how quickly it traveled. The team could even isolate a piece of debris to determine its speed and interpret the tsunami’s pattern of flow. At Kesennuma Bay, he found that the tsunami moved at speeds of up to 11 meters per second. “You’d need to be a sprinter like Usain Bolt” to outrun it, he says.

Video, Synolakis says, can also help save lives. With the images, scientists can confirm the accuracy of the computer models that predict when a tsunami will hit. “I can’t see how else we could benchmark our computer models,” he says. “If you hear a tsunami warning, you want to know how much time you have.”

As Fritz and Synolakis were focusing on videos, other scientists, like Eddie Bernard, director of the Pacific Marine Environmental Laboratory in Seattle at the time, were rushing to fortify the global tsunami detection and warning system. In the aftermath of the Indian Ocean tsunami, the US earmarked $55 million for tsunami research and preparedness, setting aside more than $20 million per year in additional funding through 2011. The lab used the money to deploy dozens of DART buoys; other countries did the same. Today there are about 60 ringing the world’s oceans.

Parallel improvement in earthquake modeling means warning centers quickly receive more accurate estimates of the magnitude of a quake. Staff sizes at some warning centers have doubled, and thousands of researchers around the world now study the natural disaster.

If today’s system had existed in 2004, “maybe 15,000 people didn’t have to die in Sri Lanka. Thousands of people didn’t have to die in India,” explains Stuart Weinstein, who serves as deputy director of the Pacific Tsunami Warning Center near Honolulu. “If something like that happened again, it would not be killing people thousands of miles away.”

The data from the DART buoys and seismometers, along with information from survivor videos, has proved to be a powerful combination. “Before 2004, everybody was under the impression that the earthquake could tell you about the tsunami,” Bernard says. “That was the crude way we did it. It was so crude that 75 percent of our warnings were considered false alarms.” Now, Weinstein says, “we have the tools in place to generate a tsunami forecast within about 20 minutes.”

Scientists at the Pacific Marine Environmental Laboratory are trying to build better forecasts for water inundation—similar to hurricane storm-surge predictions—based on the models that Fritz and Synolakis have perfected. “This is the next frontier,” Synolakis says. If, for instance, they detected that 3 meters of water were displaced in a certain place in the middle of the ocean, the researchers could, pretty quickly, get an estimate of where that water might go and how fast it would get there.

Such detailed forecasts are crucial for evacuation planners and civil engineers. If people in the path of a tsunami don’t have enough time to head to higher ground, they need another option. After the Indian Ocean tsunami, engineers in Japan pushed to expand the number of vertical evacuation structures along the country’s coasts. Shaped like skeletal parking garages with large platforms at the top, 37 of these provided a last-minute refuge from the 2011 tsunami, saving around 5,000 people. In addition, a vertical evacuation building designed to hold more than 500 people rises from the Banda Aceh neighborhood that Fritz visited in 2005. “The site was selected,” he says, “because there were enough videos of people surviving there to instill confidence.”

Fritz is now 47. Clean shaven with dark hair, he has circled back to studying his first interest: uncommon triggers for destructive waves. When he’s not teaching at Georgia Tech, he can often be found at Oregon State University, in the O. H. Hinsdale Wave Research Laboratory, located 40 miles inland in Corvallis.

In July 2018, I visited him at the wave lab. We stood at the edge of a shallow artificial wave basin, measuring 160 by 87 feet, inside a dark, cavernous arena. In the recent past, he had used the pool to study how landslides create tsunamis. That work made him well known around campus as the guy who dumped 3,000 pounds of gravel into the pool. Undergrad laborers armed with shovels and brooms were tasked with wading into the water to clean up the debris, over and over again.

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