News Column

Tsunami Alerts Not at Risk Despite $1 Million Cut, Experts Say

March 12, 2012

Jim Borg

Despite proposed spending cuts of $4.6 million to U.S. tsunami-warning programs, geophysicists say they have never been better prepared to alert the public if another quake of 9.0 magnitude -- or bigger -- rattles the Pacific Rim.

The cuts proposed by the Obama administration include $1 million for maintaining a system of 39 buoys used to track the progress of seismic sea waves generated by an earthquake. The maintenance budget is now about $11 million.

Gerard Fryer, a geophysicist at the Pacific Tsunami Warning Center in Ewa Beach, says a tsunami warning would go out well before any wave hits the DART buoys. DART stands for Deep-Ocean Assessment and Reporting of Tsunamis, a program under the National Oceanic and Atmospheric Administration.

"Our warnings initially are based purely on what we know about the earthquake," he said in an interview at the center Friday. "We make our warnings from seismology and those warnings -- we're pretty proud of our recent record. Those warnings are darn good. Our false-alarm rate is way lower than it used to be. In fact, there has been no recent event for which the DARTs actually were needed. There were no events for which the DART data changed our decision."

Broadband instrumentation allows the warning center staff to measure the quake at critical low frequencies in a way that wasn't possible 20 years ago, he said.

"As the earthquake gets bigger and bigger, it speaks with a deeper voice," he said.

In fact, if the current technology had been in place in 1986, when a tsunami warning led to gridlock on Honolulu's freeways during the afternoon rush hour, there would have been no need to alarm the public, Fryer said.

"If '86 happened today, there would be no (need for a) warning," he said. "And the other one was 1994. If that happened today, there would be no warning. Our procedures are way better now. We are much more up to date."

The DART buoys first proved their worth in November 2003, when a magnitude 7.7 quake shook a section of the Aleutians. A tsunami warning was canceled because buoy data showed the waves would not be destructive.

That avoided an evacuation order in Hawaii, which saved the state an estimated $68 million in lost productivity, according to the state Department of Business, Economic Development and Tourism.

The evacuation in 1986, when only small waves hit Hawaii's shores, cost the state about $40 million, according to a department study. The 1994 evacuation, which led to morning rush-hour gridlock, cost $50 million, the department estimated.

The buoy system also could come in handy when there is another quake like the March 11, 2011, Tohoku megaquake off Honshu, Fryer said.

"The Japan earthquake is slightly of concern because there was a huge amount of very shallow slip," he said. "That is part of why the tsunami was so large -- the tsunami that hit Japan. And it was much, much larger than anything anyone expected.

"Up near the trench, one side of the fault moved t-770 meters (230 feet), and the previous record was about 35. So what that can do, if conditions are right, that can put a spike, a big high peak, in the tsunami, and we wouldn't know that just from the seismology. So in an instance like that, it would be nice to have a DART."

With the proposed budget reduction, about 70 percent of the buoys will be in working order at any given time, he said.

"My understanding is that is just they're going to back off on maintenance, that when things break, they won't be in such a hurry to go out and fix them," Fryer said. "And things always break. It's a big, complicated system, the ocean is an unfriendly environment, so things fail."

Ultimately, any warning system relies on the common sense of individuals, he emphasized.

"The problem with a tsunami is the wavelength is so huge," he said. "If the front of it is at your feet, the top of it is over the horizon. You don't know how high it's going to get. And I saw one YouTube video of some kid on the sea wall at Kailua-Kona, saying, 'Oh, now I'm surrounded by water.' Well, he had no way of knowing how high that water was going to get. It took away his slippers, and it sort of got up to his knees, but he could easily have been swept off his feet."

Source: (c)2012 The Honolulu Star-Advertiser

Story Tools Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters