After the recent devastating loss of life from the December
Indonesian tsunami, geophysicists are searching for other
areas where the same kind of disaster may be lurking due to
potential underwater earthquake activity. Now they say
there's a real danger that the Caribbean will be next.
Scientists say that several natural phenomena could trigger
giant tsunamis, with effects felt in the islands of the
Greater and Lesser Antilles and along the east and Gulf
coasts of the United States. These areas, which were
relatively sparsely populated when the last waves hit, now
have large populations.
Nancy Grindlay and Meghan Hearne of the University of North
Carolina Wilmington and Paul Mann of the University of Texas
at Austin focus on one major source of past tsunamis in the
region: movement along the boundary between the North
American and Caribbean tectonic plates.
Writing in the March 22 issue of Eos, the newspaper of the
American Geophysical Union, they say that at least 10
significant tsunamis have been documented in the northern
Caribbean since 1492, six of which are known to have
resulted in loss of life. All 10 were triggered by movement
along this plate boundary, which lies along the north coast
of Hispaniola (Haiti and the Dominican Republic) and extends
some 3,200 kilometers [2,000 miles] from Central America to
the Lesser Antilles.
Previous tsunamis destroyed Port Royal, Jamaica, in 1692,
killed at least 10 Jamaicans on the island's south coast in
1780, and ravaged the north coast of Hispaniola and the
Virgin Islands in 1842. The most recent of the destructive
northern Caribbean tsunami occurred in 1946 and was
triggered by a magnitude 8.1 earthquake in the Dominican
Republic. It killed around 1,800 people.
The researchers estimate that with increased populations,
especially in coastal areas, some 35.5 million people are
now at risk should another strong tsunami hit the northern
Caribbean. They note that in addition to their own studies
of fault lines along the North American and Caribbean plate
boundary, other researchers have studied the risk to the
northern Caribbean from submarine landslides, both in the
region and as far away as the Canary Islands. In the
pre-1492 period, tsunamis greater than any in the past 500
years may have occurred, the scientists say, based on their
study of underwater landslides off the north coast of Puerto
Rico.
Grindlay and her colleagues are planning to visit the region
later this month to investigate possible linkages between
groundwater flow from Puerto Rico and underwater seeps in
areas where land has subsided. Such flows, or fluxes, could
contribute to small landslides that might trigger tsunamis.
In the future, they hope to drill into the ocean bed to
determine when and how often land had collapsed in the
prehistoric era.
"The recent devastating tsunami in the Indian Ocean has
raised public awareness of tsunami hazard and the need for
early warning systems in high risk areas such as the
Caribbean," Grindlay said in a statement. "An Intra Americas
Sea Tsunami Warning Project proposal has been approved by
the Intergovernmental Oceanographic Commission, and meetings
to plan implementation are scheduled for this spring and
summer."
The research was funded by the National Science Foundation
and the University of Puerto Rico SeaGrant program.
Art Credit: http://www.freeimages.co.uk
When bad weather strikes, people have always turned to
Treasures
from Heaven, the religious icons that author Steven Sora
says still have power today!
