Scientists at the Pacific Tsunami Warning Center acknowledged they were off as much as 50 percent in their tsunami wave-height estimates.

Despite technological strides, plotting the course of a tsunami is not an exact science and there were many lessons learned yesterday as Hawaii scientists tracked the 500-mph moving target.

“;Fifty percent off isn't so bad. That's OK, that's about the level of accuracy of this game,”; said Gerard Fryer, National Oceanic and Atmospheric Administration geophysicist.

Readings from tide gauges and more than 38 deep ocean dart buoys, installed throughout the Pacific, Atlantic and Indian Oceans after 2004 for about $30 million, combined with historical data contributed to the center's decision to upgrade its tsunami advisory to a warning early yesterday morning, Fryer said.

Based on the information available to them at the time, scientists expected Hilo and Kahului would sustain damage from the tsunami waves generated by a magnitude 8.8 earthquake off Chile. They also identified the harbor regions in Hanalei and Haleiwa as particularly vulnerable.

Six- to 11-foot surges were expected; however, in the end, the worst wave action of the day, in Kahului, reached just 3.2 feet.

Given the scientific equipment and expertise available, if the same events unfolded today, scientists would make similar decisions, Fryer said. But with every event, improvements are made, he said.

“;If this had happened next year, we might have made a different decision,”; he said. “;As we get more experience under our belts, we'll get better.”;

  Pacific Tsunami Warning Center

 

Though Hawaii already received the clear, the Pacific Tsunami Warning Center in Ewa Beach is still hard at work.

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NOAA oceanographer Nathan Becker said the tsunami gave Hawaii scientists a rare opportunity to learn.

“;Events like this allow us to better calibrate the models that we use,”; Becker said. “;It gives us a better feel for how our instruments measure in the ocean. These are rare events that don't happen too often. Our data is sparse.”;

While center officials prefer to err on the side of caution, their decision to evacuate based on the data they had available did not come lightly, Fryer said. The last time Hawaii evacuated isle shorelines was in 1994.

“;An evacuation isn't something that you call at the drop of a hat,”; he said. “;There are dangers, people can have accidents. And there are economic losses. We would never consider an evacuation unless it was absolutely necessary.”;

Hawaii residents and visitors have to remember that while the impacts were not as severe as anticipated, they “;went through a real tsunami”; yesterday, said NOAA geophysicist Barry Hishorn.

“;It wasn't a fake alarm,”; Hishorn said.

Still, the tsunami-related activity that occurred in Hawaii yesterday could prove to be a best-case scenario, Fryer said.

The tsunami was “;one that's big enough that everyone sees that something's happened, but not big enough to cause any damage,”; he said.