Abram Katz, Register Science Editor
New Haven Register
The shocks of the Indian Ocean tsunami and Hurricane Katrina have faded, along with any palpable sense of urgency to take better precautions against such coastal disasters.
Photo: Southern Connecticut State University Associate Professor James Tait will be teaching a graduate course on the effects of hurricanes and tsunamis, and the need for warning and preparedness. Peter Casolino/Register photo illustration
A generation of New Englanders cannot remember the devastating hurricane of 1938, nor do many people recall any North American tsunamis.
Many meteorologists and geologists predicted the Katrina catastrophe years before it happened, yet little was done, noted James Tait, associate professor of science education and environmental studies at Southern Connecticut State University. Many victims of the Southeast Asia’s massive tsunami could have had several hours to evacuate — if they had been warned, Tait said.
Nothing can prevent or moderate hurricanes or tsunamis, so preparedness is paramount, Tait said.
Preparing for a disaster raises a sea of questions, which is why Tait is going to be teaching a special graduate-level course called "Hurricanes and Tsunamis: Process, Impacts, and Preparedness."
The Atlantic seems to be entering a busier than normal hurricane cycle, meaning greater coastal impacts, Tait said. The United States does not face any imminent tsunami threats, but certain parts of the country are potentially vulnerable, he said.
For instance, a powerful earthquake in Alaska on March 27, 1964, brought the coast of California a wall of water. Perhaps the worst damage was sustained by Crescent City, which was practically scraped off the face of the Earth by 21-foot waves, leaving 11 people dead.
Tsunamis race across the open ocean at hundreds of miles an hour, undetected, Tait said. Hardly noticeable in deep water, the wavelength shortens as it approaches shore, making the wave taller. The faster-moving wave farther from shore catches up, and the tsunami crashing on the shore produces a turbulent onrush of water.
The next crests of the tsunami arrive every 10 to 20 minutes. One cubic yard of water weighs about one ton, meaning that the wave easily sweeps away almost anything in its path, Tait said.
Crescent City had built a breakwater out of four-ton pieces of concrete shaped like jacks. The tsunami picked one up and dumped it in the center of town, where it remains today.
Tsunamis are usually associated with subduction zones, where the ocean floor sinks under continents, producing trenches. Pressure builds up until the ocean floor or continent shift. The displacement of water streams away as a tsunami.
Water in the sinking plate lowers the melting point of continental rock, which rises as magma to create volcanoes.
On Dec. 26, 2004, a large section of plate shifted in the Java trench, creating an enormous tsunami that killed about 200,000 people from Indonesia to Africa.
Seismologists in the United States registered the earthquake immediately and calculated the size of the impending tsunami, Tait said. But there was no one to call. Had scientists been able to reach capital cities, how would the warnings have been transmitted to the countrysides?
"The high death toll was very much an effect of the lack of a public warning system. Hilton hotels called other Hilton hotels. That was the only kind of alert system," Tait said.
Governments are now installing tide gauges and tsunami meters around the Indian Ocean. However, questions of preparedness remain unanswered, he said.
In the United States, Hawaii seems to be at the highest risk of a tsunami, he said. It is surrounded by the Aleutian trench, the Chile trench, and the Japan trench. The Aleutian trench also continues to threaten the West Coast.
The Caribbean trench seems to be quiescent, though it has produced chains of volcanic islands.
The East Coast faces island landslides off the coast of Africa. A major landslide at the Madeiras Islands, for example, could send a tsunami shooting toward the Eastern Seaboard.
The continental shelf off the East Coast is showing cracks, Tait said. If part of that massive ledge breaks off, it could generate a tsunami capable of inundating Florida to Nova Scotia.
Since practically everyone in the United States owns a television, a timely warning could be issued, Tait said. There’s no good plan for moving millions of people inland in a few hours, however.
Hurricane planning faces the same problem, Tait said.
"For Katrina and Rita, it seems like a lot of disaster planning was hoping it wasn’t going to happen," he said. Preparing an area below sea level for a hurricane requires significant resources.
The Dutch, for instance, have a complex and well-maintained system of dikes, tidal gates, and other systems to keep the North Sea out.
In the United States, the primary hurricane danger now is property damage, not loss of life, Tait said.
The shoreline has been so built up that a repeat of the 1938 hurricane would result in billions of dollars in smashed expensive development. Meanwhile, evacuation plans have apparently not been well thought out, Tait said.
No one knows where they should go or what services would be available, he said. Many shore dwellers might refuse to leave, despite an approaching category 4 hurricane.
"You need to start leaving early, in an orderly fashion. You need pre-planning, where help will be, what it will be," Tait said.
However, hurricane tracks are almost impossible to predict and damage depends to a considerable extent on the tidal cycle. The tide combines with geography to create a standing wave in Long Island Sound, he said. The New York City end is higher and the difference between high and low tide is minimal. The Connecticut shore at the eastern end of Long Island has a tidal difference of about 7 feet.
The storm track, intensity, storm surge and tidal stage are all crucial. If the hurricane’s forward winds rake the Connecticut coast at high tide, there would be significant damage.
Hurricane Gloria arrived at low tide in 1985, lessening the amount of damage it caused. Had it arrived six hours later, at high tide, the result might have been much worse, Tait said.
A difference of a few hours, or a few miles, can create different storms.
Connecticut has a high percentage of coastal development, is low-lying, and has many rivers that could channel the storm surge, or flood with rain.
"We’re nicely set up for another costly hurricane," Tait said.
Some sections of Texas are refusing to let owners rebuild if their homes are more than 50 percent damaged. This seems like the only practical way to gradually move the population away from the shore.
For a similar plan to work in Connecticut, a destructive hurricane has to come along, Tait said.
Contact Abram Katz at akatz@nhregister.com or 789-5719.
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