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Caribbean Vulnerable To Killer Tsunamis U.S., Caribbean Seek To Develop Early-Warning Systems
Caribbean Vulnerable To Killer Tsunamis
By FRANK GRIFFITHS
20 January 2005
SAN JUAN, Puerto Rico (AP) - Scientists predict killer tsunamis could strike the Caribbean, which lacks a warning system even though its seabed is gouged by some of the world's deepest trenches, where the giant waves can be generated by tectonic activity, and its low-lying islands are heavily populated along their coastlines.
The last tsunami struck the Caribbean in 1946, before island populations skyrocketed, major construction dotted shorelines and the region developed into a prized tourist destination attracting 17 million visitors last year.
"The Caribbean is a very dangerous place for tsunamis," said Uri ten Brink, a U.S. Geological Survey geologist in Woods Hole, Mass., and co-author of an article on the threat in the Journal of Geophysical Research. "The Caribbean needs a tsunami warning system."
The article was published two days before a Dec. 26 earthquake under the Indian Ocean generated a tsunami that killed at least 157,000 people in 11 nations. The quake occurred along the long north-south fault in the Earth's crust where the edge of the Indian tectonic plate dives below the Burma plate, forming the Sunda Trench.
That trench is about 25,000 feet deep.
The Puerto Rico Trench -- one of the deepest in the world at 27,355 feet -- is a 560-mile-long underwater canyon and fault line running parallel to this U.S. island territory and east of the Lesser Antilles islands.
Seismic tensions in the Puerto Rico, Hispaniola and Cayman trenches ringing the Caribbean force tectonic plates to sink under one another as they collide, producing earthquakes, underwater landslides or tsunamis.
A tsunami is a series of waves formed by a disturbance in sea level over a short period of time, such as an earthquake, underwater volcanic eruption or coastal landslide.
In the deep and open ocean, the waves can travel at up to 600 mph but be no more than 2 feet high, making them imperceptible to the human eye.
The last fatal tsunami here occurred in 1946 when an 8.1-magnitude earthquake in the Hispaniola Trench triggered waves that killed an estimated 1,700 people in the Dominican Republic and Haiti, ten Brink said.
Major earthquakes erupt about every 50 years in the Caribbean, a region where even minor natural disasters can kill thousands because of environmental degradation, shoddy construction and the many people who live in coastal areas or on low-lying islands.
The Caribbean has an effective hurricane warning system and a number of tidal gauges to measure sea height. But it lacks a centralized system to alert all islands to a tsunami.
The United States uses a system called Deep-ocean Assessment and Reporting of Tsunamis, or DART, with pressure recorders anchored to the sea floor detecting tsunamis of less than a half-inch in height. A link transmits data to a buoy that relays information to alert centers via satellite.
There are only six DART buoys in the world and they are all in the northeast Pacific Ocean, Brink said. Last week, the U.S. government announced a $37.5 million plan to put 32 DART buoys in the Pacific and Atlantic oceans by mid-2007.
From 1900 to 2001, there were 796 tsunamis observed or recorded in the Pacific, according to the Pacific Tsunami Warning Center.
"There is a real risk from tsunamis in the Caribbean, but the risk is small when compared to other earthquake hazards over history such as buildings collapsing and fires," said Lloyd Lynch, a seismological engineer at the Seismic Research Unit in Trinidad. "But that could change. We're more vulnerable now because of recent coastal development."
One reason the Asian tsunami proved so deadly was that a 750-mile plate lifted as the pressure built, producing a magnitude 9.0 quake. Because the Caribbean trenches are shorter, they would be unlikely to produce such a strong eruption, ten Brink said.
Still, because of development and population growth, an 8.1-magnitude earthquake followed by a tsunami could be much deadlier than the 1946 wave, he said.
Members of the Caribbean Disaster Emergency Response Agency will meet in May with scientists and disaster coordinators to discuss the need for an early warning system, said Terry Ally, a spokesman for the Barbados-based agency.
"It's a matter of time before a tsunami happens in the Caribbean," said Christa von Hillebrandt, director of the Puerto Rico Seismic Network. "All the ingredients are there."
Tsunami Warning System To Cover Florida, Caribbean
The East Coast, including Florida, and the Caribbean will benefit from a broader tsunami detection system by 2007, U.S. officials said.
BY MARTIN MERZER
15 January 2005
Provoked by the disaster in Southeast Asia and eastern Africa, U.S. officials announced Friday that they will rapidly deploy a tsunami warning system for Floridians, others on the East Coast and residents of the Caribbean islands.
The system involves the placement of about 30 deep-water detection buoys and other sensors in the Atlantic, Caribbean and Pacific. It will complement an existing warning system along the West Coast, giving the United States nearly 100 percent coverage, officials said. And it will contribute to a global program being discussed by dozens of nations.
Though planned years ago, deployment in the Atlantic and Caribbean was accelerated by last month's mammoth disaster in and around the Indian Ocean. The expanded system -- which also will better protect residents of Central and South America -- will cost about $37.5 million and could be in place by mid-2007.
''The world's attention has been focused on people who live near the edge of oceans, and we have a responsibility to respond to their needs,'' John H. Marburger III, science advisor to President Bush, said during a news conference in Washington, D.C.
Scientists say tsunamis -- particularly those caused by an earthquake as powerful as the one that triggered the one last month off Indonesia -- do not pose a great risk to South Florida and the rest of the U.S. East Coast.
Still, tsunamis occur from time to time in the Atlantic basin, which includes the Caribbean and the Gulf of Mexico, and virtually all coastal residents are at least theoretically vulnerable to the series of giant waves that can mark a tsunami.
Most at risk in this part of the world are the Caribbean islands, which sit atop or near an earthquake zone.
Tsunamis -- smaller than last month's but deadly nevertheless -- struck the Virgin Islands in 1867, Puerto Rico in 1918 and the Dominican Republic in 1946. A tsunami battered several eastern Caribbean islands with 20-foot waves in 1755.
In response, a tsunami warning system already is in place at a university in Puerto Rico, but its scope is limited, focused mostly on Puerto Rico and the Virgin Islands.
South Florida experts are unaware of any tsunamis in the region in the recent past, though several longtime residents cite an unexplained event during the early 1960s that left several Miami Beach hotels swamped by unusual tidal waves.
Some South Floridians have expressed concern over reports that a mega-tsunami, one that dwarfs the Southeast Asia disaster, could be triggered by the partial destruction of a volcano in the Canary Islands.
Experts say the so-called Cumbre Vieja event could propel a 60-foot tsunami to South Florida and many other regions of North, Central and South America.
But they cannot pinpoint the timing, saying that the disaster is likely to occur at some point during the next 5,000 years.
''I wouldn't worry about this at all,'' said Steven Ward, a research geophysicist at the University of California at Santa Cruz and coauthor of a Cumbre Vieja study.
At the same time, some experts expressed reservations about the system announced Friday.
Tim Dixon, a professor of geology and geophysics at the University of Miami, welcomed the project, but said he wished it went further -- including sensors that could gather other data and help forecast hurricanes, among other things.
''If you're going to spend that much money, I would try to get more out of it than just tsunamis,'' he said. ``Why not put a bunch of other gauges on it as well -- things that could measure water quality, atmospheric quality, ocean chemistry?''
Government officials said that the system will include tsunami risk-assessment studies and, particularly important, improvements in warning and response systems.
''We've been very busy since the 25th and 26th of December, when this terrible tragedy struck the Indian Ocean,'' said retired Navy Vice Adm. Conrad C. Lautenbacher Jr., administrator of the National Oceanic and Administrative Administration. ``It is very important to provide a sense of security to people who live along our coasts.''
Caribbean Seeks To Develop Tsunami Early-Warning System
28 December 2004
BBC Monitoring Americas
(c) 2004 The British Broadcasting Corporation. All Rights Reserved. No material may be reproduced except with the express permission of The British Broadcasting Corporation.
Text of report by Caribbean Media Corporation (CMC) news agency on 28 December
Bridgetown, Barbados: The Barbados-based Caribbean Disaster Emergency Response Agency (CDERA) said [on] Tuesday [28 December] that it was working towards establishing an early tsunami warning system for the Caribbean in light of the tragic events that led to the death of more than 23,000 people from Thailand to Somalia over the weekend.
CDERA said it is holding discussions with a number of partners, including the Pacific Tsunami Warning Centre, the University of Puerto Rico Seismic Network, the University of the United States Virgin Islands and the Seismic Research Unit at the University of the West Indies, regarding on the establishment of a tsunami early-warning system for the Caribbean.
The focus of the Intra-Americas Sea Tsunami Warning System (IAS TWS) was initially on Puerto Rico and the United States Virgin Islands but the system is now being widened to include the rest of the Caribbean, it said in a statement.
"There is already a basic framework that can be used for an early warning system in the Caribbean, which comprises equipment such as tidal gauges established by the Caribbean Planning for Adaptation to Climate Change (CPACC) and an early-warning system set up for the Kick 'em Jenny underwater volcano," the statement said.
It added that this network of tidal gauges is at the disposal of the region as part of the backbone for an early warning system.
But it noted that the availability of funding would determine how quickly such a system can be implemented.
"The events from the Indian Ocean underwater earthquake have again emphasized the vulnerability of the Small Island Developing States (SIDS) and should further justify the call for their special consideration in support of sustainable development interventions. It also highlights the importance of addressing critical threats to the region other than the hurricane hazard," said CDERA's coordinator Jeremy Collymore.
"The seismic events present their own set of challenges. The potential impact of these hazards can be quite devastating. CDERA has recognized the need for the region to accelerate its level of preparedness to deal with these events and is supporting this through strengthening of the agency's search-and-rescue capability and volcanic-contingency planning."
"CDERA joins with the international humanitarian community in expressing its sympathy to the governments and people of the countries hit by the Boxing Day earthquake in the Indian Ocean and stands ready to learn as many lessons as possible from this event to inform our support of the region's preparedness efforts," the statement added.
Tsunamis are triggered by underwater earthquakes, underwater volcanoes, landslides, land-based volcano eruptions and meteor strikes.
Disaster officials say the probability of one occurring in the Caribbean is low, although "there are two known potential sources that can generate tsunamis in the Caribbean".
They said these include "tectonic earthquakes and volcanoes such as the underwater volcano Kick 'em Jenny, located 8 km north of Grenada".
"The greatest known seismic threats to the Caribbean are from terrestrial volcanoes and earthquakes," the statement said as CDERA urged member countries "to familiarize themselves with volcano and earthquake preparedness measures so they would know how to safeguard themselves".
Source: Caribbean Media Corporation news agency, Bridgetown, in English.