Waves of the future

Local company helps build tsunami early warning system

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A tsunami warning buoy built by San Diego-based Science Applications International Corp. was lowered into the Tasman Sea near Australia. (SAIC)

Just minutes after the seafloor north of the Indonesian island of Sumatra buckled on Dec. 26, 2004 – the result of a 9.3-magnitude earthquake, the second strongest ever recorded by a seismograph – analysts in Alaska and elsewhere knew a massive tsunami would likely follow.

Warnings were immediately issued. Phone calls were made. But the effort was too little, too late. The quake happened early on a Sunday morning. Most government offices were closed. Word was appallingly slow to reach small, isolated villages along the coasts of Thailand, Indonesia, Sri Lanka and India. In many places, residents never knew what hit them.

When the first tsunami waves hit land 40 minutes after the quake, whole communities on the Sumatran coast disappeared beneath successive towering walls of seawater, each quickly clogged with debris and bodies. The tsunami spread, striking the Thai resort town of Phuket an hour or so later. Waves sped across the Bay of Bengal at speeds exceeding 500 miles per hour to hit India and Sri Lanka a few hours later.

And yet, few alarms sounded. In the end, more than 225,000 people in 11 countries died, with millions more displaced. Economic damage exceeded $10 billion, a huge amount in this mostly impoverished region.

The rest of the world watched in anguished awe, realizing that what happened in the Indian Ocean could – and would – happen again. And it was painfully clear that almost no one was truly prepared. The best early warning system – a string of six high-tech buoys deployed along the West Coast by the National Oceanic and Atmospheric Administration (NOAA) – seemed suddenly inadequate. Indeed, when the 2004 tsunami struck, three of the six NOAA buoys had been out of commission for months due to a lack of funding.

If a tsunami were to strike today, however, chances are much better that people in imperiled areas could be warned in time. Major elements of a global tsunami early warning system have been put in place, though some regions of the world remain uncovered.

In early 2005, the Bush administration announced a $37.5 million program to build an expanded, second-generation tsunami warning system called Deep-Ocean Assessment and Reporting, or DART2.

Closer to home, Science Applications International Corp. (SAIC), a multibillon-dollar technology company and defense contractor based in San Diego, saw an opportunity both to help and to become a player in a new market.

“After the 2004 tsunami, a lot of countries began to seriously look at early warning systems,” said Robert Lawson, vice president of ocean and atmospheric programs at SAIC. “Only NOAA had any real experience, and it was not set up to provide buoys to the rest of the world. This was something we thought we could do.”

Working closely with NOAA engineers, SAIC developed its own prototype buoy in 2006, testing it for four months in deep water 200 miles west of San Diego. After its buoys met standards set by the NOAA for its DART2 system, SAIC began marketing the devices.

Early this year, SAIC officials dispatched two completed buoys to Australia, part of that country's evolving tsunami warning system. On March 10, officials announced a contract to provide two buoys to China for deployment in the South China Sea.

Last year, NOAA deployed the final two buoys of its DART2 system – a network of 39 buoys that now stretches across portions of the Pacific and Atlantic oceans, the Caribbean sea and the Gulf of Mexico.

“Completing the U.S. Tsunami Warning System is truly a monumental triumph,” said retired Navy Vice Admiral and former NOAA administrator Conrad Lautenbacher. “As a young scientist who researched tsunamis and built early models of their effects, I never imagined that we could come so far in our ability to understand, to detect, to model and to warn on such a scale as we have just achieved.”

Undersea eyes

Both the SAIC and the DART2 buoys employ the same basic technologies and principles. Each device consists of two basic components.

The first is a bottom pressure recorder, an electronic device that measures water-pressure changes as ocean waves pass by. It is extremely sensitive, capable of detecting minute pressure alterations, but also able to filter out routine fluctuations caused by tides and currents.

The recorder, encased in a waterproof compartment, is attached (along with supporting batteries and other electronic components) to a heavy metal platform that anchors it to the seafloor.

Lawson said the recorders work best in deep water, preferably between 6,000 and 19,000 feet.

The second component is the buoy, which in the SAIC version is a highly visible yellow cylinder 7 feet in diameter and 13 feet tall. The buoy is tethered to a couple of surplus railroad car wheels weighing a combined 7,200 pounds. These anchor-wheels are deposited not far from the bottom pressure recorder.

Bobbing on the ocean surface, the buoy serves as a communications relay station. When the bottom pressure recorder detects a notable change in water pressure, it sends that information to the buoy, where onboard electronics relay the data to a satellite that in turn transmits it to a warning center in either Hawaii or Alaska.

Lawson declined to reveal how much the buoys cost, saying only that the price was well under $1 million each.

The buoys are typically located in seismically active regions where undersea earthquakes may generate dangerous tsunamis. At greatest risk are coastal countries encircling the Pacific Ocean's “ring of fire,” a 25,000-mile horseshoe-shaped belt riven with fault lines and dotted by more than 75 percent of the world's active and dormant volcanoes.

The U.S. West Coast lies on the western arm of the ring, making it potentially vulnerable to tsunamis. A 2005 study by the U.S. Geological Survey identified two places where colliding tectonic plates could cause a major tsunami affecting the U.S.: the 680-mile Cascadia subduction fault, which runs 50 miles off the Pacific Northwest, from Cape Mendocino in California to Vancouver Island in British Columbia, and the Prince William Sound fault in Alaska.

In 1964, a 9.2-magnitude quake occurred on the Prince William Sound fault, generating a tsunami that swept all of the way down to California. More than 100 people were killed, mostly in Alaska. The tsunami actually reached San Diego, though by then the waves were only a few feet high.

While San Diego is not as vulnerable to deadly tsunamis as other parts of the West Coast, experts say it is not entirely immune, particularly if the waves are generated by a rupturing fault just off the coast.

And any significant tsunami could be disastrous. A 2005 University of Southern California analysis estimated $7 billion to $42 billion in potential economic damage, with unknown lives lost.

Rough waters

Installing a tsunami warning system is one thing; keeping it functional is another.

“The ocean is a tough place to keep sensitive electronic gear working,” said Lawson.

Generally speaking, the buoys must be rotated and refitted once a year, the bottom pressure recorder array every two years. Engineers retrieve the pressure recorder by transmitting a signal for the device to release itself from the heavy anchor plate. Attached floats then pull the recorder to the surface.

Lawson said the biggest maintenance headache is biofouling. The buoys provide a welcome home for clinging barnacles, worms, plants and other sea life.

“This stuff doesn't really affect the buoy's functioning,” said Lawson, “but after a while, all of that accumulating growth starts to pull down on the buoy and make it unstable.”

Lawson said the buoys also occasionally suffer damage from local fishermen. “The mooring lines beneath the buoys tend to attract fish, which the fishermen know,” he said. “So they'll hook onto a buoy and pull it back, stringing a net where the buoy had been. Then they release the buoy, which snaps back into position, driving the fish into the net. Obviously, this isn't good for the mooring system.”

Buoys have also been snagged and dragged by trawlers' nets, damaging the buoys and, in the case of an Indonesian buoy in 2007, actually severing a jacketed steel wire mooring line.

Pirates are a problem, too: “In that part of the world, unfortunately, if someone sees a buoy loaded with electronics and batteries just floating there, they're probably going to take and sell parts of it,” Lawson said.

As soon as multiple buoys begin reporting anomalous water pressure changes and indicating wave direction, scientists can start to determine if a tsunami is coming – and if so, how bad it might be.

“Combined with all of the seismic sensors in the ocean and other data sources, not to mention newer and better computer models, scientists have gotten pretty good at assessing tsunami threats,” said Lawson.


That response may be a warning to any at-risk country that a tsunami is heading its way. Conversely, it may be an all-clear, a message that there is no significant danger. That is important, too. In 2003, NOAA scientists determined that a potentially catastrophic tsunami was not, in fact, a threat to Hawaii, where officials were preparing to evacuate thousands of residents and tourists from an imperiled coastline. The tsunami warning was canceled; the state saved an estimated $68 million in lost productivity.

However, it is the real danger of real tsunamis that drives people like Lawson. Expanding buoy warning systems will help prevent future catastrophes, but Lawson said it was also critical that at-risk countries build reliable communications systems to make sure warnings are heard and effective evacuation programs are run by trained professionals who know what to do.

That requires not just wealth, but political and social will.

“It can be decades between really big tsunamis,” Lawson said. “You can't just build systems and then forget about them.”