U.S. Set To Bolster Tsunami Warning Technology

The expansion is part of the Global Earth Observation Systerm of Systems (GEOSS), an international effort to develop a comprehensive Earth observation system, noted an OSTP announcement. The plan will cost $37.5 million over the next two years.

Under the expansion program, the National Oceanic and Atmospheric Administration (NOAA) will deploy 32 new "advanced technology Deep-ocean Assessment and Reporting of Tsunami (DART) buoys" to create a fully-operational tsunami warning system slated for completion in mid-2007, said OSTP.

A tsunami is actually a series of long, traveling ocean waves that are generated by disturbances primarily associated with earthquakes occurring below or near the ocean floor, according to the International Tsunami Information Center, based in Honolulu. Such waves can cross the ocean at speeds of more than 1,000 kilometers per hour (thats over 700 miles per hour).

"Its length from crest to crest may be a hundred kilometers or more," noted ITIC, with "its height from trough to crest only a few centimeters or meters. It cannot be felt aboard ships in deep water."

As the tsunami enters shallower waters near coastlines, however, the speed of the waves decreases while their height increases. "It is in these shallow waters that tsunamis become a threat to life and property, for they can crest to heights of more than 30-to-50 meters [98-to-164 feet] and strike with devastating force," the center added.

At present, the U.S. tsunami warning system includes six DART buoys, deployed primarily off the Pacific Ocean coasts of Alaska, Oregon and Hawaii, according to David Green, a representative for NOAAs National Weather Service, based in Silver Spring, Md.

"The buoys sit on top of the water, while a deep-water bottom-pressure sensor sits on the ocean floor well offshore," he explained. When a tsunami passes by, the device on the ocean floor senses a change in water pressure and sends an acoustic signal to the buoy nearby. The buoy, in turn, sends a signal to a satellite, which relays the information to NOAA centers.

There is no confirmation of a tsunami until the information is interpreted by NOAA experts, who check that information with other data gained from tide-gauge stations located closer to shorelines, which monitor the depth of the water, said Mr. Green. The U.S. maintains "a large network" of tide-gauge stations in the Atlantic and Pacific Oceans, and even in the Great Lakes, he added.

"Were expanding and strengthening [our existing] capability to have greater coverage of our coastlines," Mr. Green said. He suggested that future improvements might include two-way communication with the DART buoys, "so we can ask them for informationa different satellite network might allow that. In conjunction with the deployment, were developing a technology roadmap [that will include] insertion points for future technology."

The expansion will include seven additional DART buoys in the Atlantic Ocean, as well as "expanding the number and distribution of tide gauges," he noted. "The Indian Ocean did not have a buoy system when the recent tsunami struck. They do have tide gauges, but to my understanding they have not been implemented or used. They dont have the technology infrastructure in place."

John H. Marburger III, science advisor to the president and director of OSTP, said that "working through GEOSS and other international partners, the U.S. will continue to provide leadership in planning and implementing a global observation system and a global tsunami warning system, which will ultimately include the Indian Ocean."

"The new system will provide the United States with nearly 100 percent detection capability for a U.S. coastal tsunami, allowing response within minutes," said OSTP. "The new system will also expand monitoring capabilities throughout the entire Pacific and Caribbean basins, providing tsunami warning for regions bordering half the worlds oceans."

The two-year U.S. upgrading effort will also include "expansion of modeling capability to understand how a particular event will affect the coastline," said Mr. Green. "We want to turn that into an action plan for people to be tsunami-ready."

NOAA stresses that public education and awareness is a key component of the strategy. "We need to take technology and turn it into some kind of information that people can make decisions on," Mr. Green emphasized. "A lot of what were doing relies on the use of supercomputers and different capabilities enabled by technology."

He added that "we want to give people accurate and timely warnings, but its also important to understand false alarmshow to respond to them and how to minimize them. We have to have confidence in the warnings we deliver"especially when others will use the warnings and information to assess the degree of risk associated with an event.

"We provide guidance and as much information as possible," he explained. "Others decide how to use that information."

Reproduced from National Underwriter Edition, February 25, 2005. Copyright 2005 by The National Underwriter Company in the serial publication. All rights reserved.Copyright in this article as an independent work may be held by the author.