Huge tsunami spurred progress, revealed needs
The catastrophic tsunami that struck Indonesia and East Asia almost a year ago has done much to heighten the interest, research programs and preparations in the United States for events of this type, but experts say there are areas that need more attention and challenges yet to be met.
Dec. 26 will mark the first anniversary of the tsunami that claimed the lives of about 275,000 people and struck with waves up to 100 feet high, one of the deadliest disasters in modern history.
Since that time, Congress has worked on legislation that would enable the National Oceanic and Atmospheric Administration to spend $35 million per year for a major expansion and improvement of warning systems in the United States, and support other smaller research or disaster planning initiatives around the nation in a U.S. Tsunami Warning Network.
But scientists at Oregon State University, which operates one of the worlds leading tsunami research facilities, say more studies are necessary on expected wave behavior at specific coastal locations, the probable impact on structures and measures that could be taken to reduce casualties and damage.
"The significant support to NOAA is a good sign that the risks of tsunamis are finally being taken more seriously," said Harry Yeh, the Edwards Professor of Ocean Engineering at OSU and a leading international expert on tsunamis. "The majority of that will be focused on early detection systems in the Pacific Ocean and Caribbean Sea to improve warnings about tsunamis originating from distant locations."
However, according to Yeh and Dan Cox, an associate professor and director of the Hinsdale Wave Research Laboratory at OSU (http://wave.oregonstate.edu/), there are still pressing educational, research and planning needs. They have special urgency in the Pacific Northwest – the North American location most vulnerable to a tsunami that would strike with little forewarning -- from the nearby Cascadia Subduction Zone.
"Much of our current approach to tsunami preparation is about warning systems and getting people out of the way," Cox said. "In some cases, thats appropriate. But there are also serious questions about how practical it will be to evacuate large numbers of people in towns that are accessible by a two-lane road. We will have only a very short time – 20 to 30 minutes, not hours – in the case of the Cascadia Subduction Zone tsunami."
"So we should consider other approaches to protect public safety like designing hotels or parking garages that would be strong enough and high enough to provide a local haven for people who would not be able to reach higher ground," he said. "The emphasis on warning systems also does little to help the personnel responding to the disaster. For example, will debris make some roads inaccessible?"
Studies addressing those topics are conducted at OSU in its Tsunami Wave Basin, a sophisticated, $4.8-million facility in which scientists can simulate, in miniature, the forces and behavior of waves as they approach a coastline with various features and types of undersea topography. Researchers all over the world use the facility, the largest of its type in the world, for advanced tsunami research.
And last year, both Yeh and OSU civil engineering professor Solomon Yim did field research in East Asia on the behavior and impacts of the tsunami there.
"One big change we need is better interdisciplinary research in this field," Yeh said. "We have to get seismologists and marine geologists talking to civil engineers, so we can get better tsunami-source information to propagation models for prediction of coastal effects. We need to have social scientists working with disaster planners so that evacuation plans are realistic and actually work in the short time frame we may have available. We soon plan to begin research on the social dynamics of this problem."
In Oregon, Yeh said, theres also an inadequate analysis of the specific marine terrain at various coastal towns and the implications that would have for a tsunami wave run-up. Much more work also needs to be done on the impacts of large, heavy debris sloshing back and forth in repeated tsunami waves – a problem vividly illustrated in the enormous structural damage caused by the East Asian tsunami.
With more research, it might be possible to construct at least some future buildings with methods that would better resist damage or destruction by tsunami waves, the OSU researchers say. The Oregon Sea Grant Program has provided a two-year, $170,000 grant to support fundamental research in this area.
"The number of fatalities from earthquakes in the U.S. is actually very low, because a long time ago we realized the dangers they pose and changed our building codes to start planning for them," Cox said. "But we dont have comparable building codes for tsunami-resistant structures."
The major tsunami of last year has also caused a surge of student interest in study and research on this field, the OSU experts said, that could be tapped to better prepare the scientists of the future who will continue to deal with the threats posed by these catastrophic events.
Some experts say there is a 10-14 percent chance that there could be a massive earthquake and tsunami on the Cascadia Subduction Zone within 50 years. The last such event is believed to have happened in 1700, and 23 major earthquakes have been recorded on this fault zone, which runs from northern California to Vancouver Island, in the past 10,000 years.
Dan Cox | EurekAlert!