US to expand tsunami warning system

The Bush administration announced yesterday that it plans to create a tsunami warning system in the Atlantic Ocean and Caribbean Sea and expand an existing network of sensors in the Pacific by mid-2007.

Deep-ocean water pressure sensors and surface tidal gauges, along with improved earthquake monitoring instruments, will give the United States nearly perfect ability to detect destructive tidal waves on both coasts and put out alerts within 15 minutes, government officials said at a news conference in Washington.

It's an ''end-to-end system. We're talking not only about detection devices in the water, but how to spread the word, communications, risk assessment, emergency plans, and an education system," said Conrad C. Lautenbacher Jr., undersecretary of commerce for oceans and atmosphere.

After the devastating Dec. 26 earthquake and tidal wave in the Indian Ocean, which had no warning system, tsunami specialists and politicians have been clamoring for a warning system not only there, but also in the Atlantic and the earthquake-prone Caribbean.

''The risk for the Caribbean is so real that we need to put [a detection system] in there right now," said Jian Lin, a marine geophysicist at the Woods Hole Oceanographic Institution. Two days before the massive tsunami, he published a paper warning that the Caribbean was at great risk for a major earthquake and possible tsunami over the next 50 years, after examining fault zones in the Dominican Republic and off the shore of Puerto Rico that could cause quakes.

The Pacific Ocean has a network of tidal gauges and six deep ocean sensors to alert the West Coast and other Pacific rim nations, but three of the six deep ocean sensors are out of order, Lautenbacher said yesterday.

The plan discussed yesterday calls for the National Oceanic and Atmospheric Administration to install 32 new deep ocean sensors: 25 will arranged along the volcanically active ''ring of fire" in the Pacific, and seven will be scattered through the Caribbean Sea and along the Atlantic shoreline. Additional tidal gauges also are planned, and seismic-wave measurement equipment will be updated in the Caribbean.

The system would initially cost $37.5 million, and it would cost around $19 million in annual maintenance once operational, according to NOAA spokesman Scott Smullen. The Office of Management and Budget has found the initial money for installation, Smullen said, so the plan does not require congressional approval.

Senator Joseph Lieberman, a Connecticut Democrat, who introduced legislation last week that would commit $30 million for purchasing sensors for an international warning system, praised the administration's plan.

''The announcement today of an expanded warning system to the Atlantic and the Caribbean is a big step in the right direction," he said in a statement, adding that his legislation would help expand the effort further to coordinate with other nations.

Scientists supported the move as a timely and necessary step, but some expressed concern about the allocation of resources.

''I'm cautiously optimistic," said George Maul, an oceanographer from the Florida Institute of Technology who has been lobbying for an East Coast monitoring system for 11 years. ''Since there is nothing in the Atlantic at the moment, that is a dramatic improvement." But the two sensors off the East Coast of the US look thin, he said, in comparison with the two-dozen that are to be planted around the Pacific. Maul estimated that about a dozen deep ocean sensors would be needed along the Atlantic coast.

Tsunamis typically occur after underwater earthquakes of magnitude 7.5 or larger, or when landslides occur under water.

The seismically volatile Pacific basin poses the greatest risk of tsunamis, with one occurring on average every 10 years. So researchers were supportive of the large increase in the number of deep ocean buoys, which cost $250,000 apiece and have high annual maintenance fees, in the region.

But many pointed out that the Caribbean is a little-known center of risk. There have been 88 tsunamis in the region over the last 500 years, according to William Schwab, team chief scientist at the United States Geological Survey Woods Hole Division. A large earthquake of magnitude 7.0 or greater occurs there about once every half-century, and a number of the Caribbean earthquakes have been greater than magnitude 7.5. In the last major quake, in 1946, the resultant tsunami killed at least 1,600 people on the island of Hispaniola, Lin said.

It is not a question of if a large earthquake might trigger another destructive wave, but when, he said.

''If we had a big quake north of Puerto Rico . . . then it's possible to create a tsunami in that part of the Atlantic Ocean," where it could travel across the open ocean all the way to Massachusetts, Lin said.

Even in the relatively seismically stable Atlantic basin, the risk exists.

In 1929, an earthquake south of Newfoundland caused a landslide under the sea, snapping telecommunication cables and causing a tsunami that killed 29 people when the wave slammed onto Newfoundland's coast.

Some scientists also believe that a large chunk of land could cleave off the volcanically active Canary Islands, off the coast of northern Africa, fall into the ocean, and send a wall of water moving as fast as a jet toward the east coast of the United States.

Once it is operational, the nationwide warning network will also be used to alert other nations at risk. It will be tied in with an international warning system that includes a coalition of 54 nations including Indonesia, India, and Thailand, which were hard-hit by the recent tsunami.

Officials said that plans for an international warning system, including the Indian Ocean, were underway.

Carolyn Johnson can be reached at cjohnson@globe.com.