Tsunami! How to Catch a Wave Before It Kills

March 13, 2008 -- Just three years after the deadly Indian Ocean tsunami, the final two buoys are up and running in an unprecedented 39-buoy tsunami warning system designed to protect U.S. coastal communities from a similar fate, announced officials of the National Oceanic and Atmospheric Administration (NOAA) this week.

The buoy array is a dramatic improvement over the six-buoy system that existed before the 2004 disaster, which killed upwards of 350,000 people.

The Deep-Ocean Assessment and Reporting of Tsunami (DART) buoy system, plus seismometers and other instruments, collect and transmit tsunami vital signs in hazardous earthquake zones all around the Pacific Ocean, as well as in the North Atlantic, Caribbean and Gulf of Mexico.

The system is designed to incorporate what is known and accommodate what remains unknown about the planet's most powerful earthquakes and waves. And it appears to be already working.

Location, Location, Location

"It was a 25-year overnight success," quipped Eddie Bernard, director of NOAA's Pacific Marine Environmental Laboratory in Seattle. He and many of his colleagues had long wanted to build a system like this one, he said. The Indian Ocean disaster three years ago finally created the political will to do so.

The Indian Ocean tsunami didn't just provide the impetus to check-cutters inside the Beltway. It also offered valuable scientific lessons used in developing the DART system.

The Indian Ocean tsunami's driving force, the Great Sumatra-Andaman Earthquake, was created by a rupture in a subduction zone, a place where one plate of the Earth's crust is being shoved underneath another. The rupture, 800 miles (1,300 km) long, moved a block of earth as long as California about 30 feet, explained geophysicist Seth Stein of Northwestern University.

The tsunami created by the rare "mega-thrust" earthquake was of similarly impressive breadth. In order not to miss broad wave fronts of future tsunamis, the DART buoys in the Pacific Ocean were placed 400 to 600 miles (700 to 1,000 km) apart, Bernard explained.

"Those buoys were placed in a scientific way to maximize benefit to the U.S. public," agreed John McNulty, director of the National Weather Service's Office of Operations Systems. Those locations and actual data from the DART buoys can be viewed by the public anytime here. The small, regular waves seen in the online buoy data reflect the rise and fall of tides.