Saturday 18 November, 2017

UWI Seismic Research Centre: T&T at risk for the 'big one'

People clear rubble after an earthquake hit Mexico City, Mexico, Sep. 19, 2017. Photo: Reuters.

People clear rubble after an earthquake hit Mexico City, Mexico, Sep. 19, 2017. Photo: Reuters.

Trinidad and Tobago citizens are being warned to prepare for the ‘big one’.

Catastrophic earthquakes which devastated countries like Mexico, Japan, Nepal and New Zealand could also happen in Trinidad and Tobago, said Director of the UWI Seismic Research Centre, Dr Joan Latchman.

Dr Latchman said that globally, scientists have been observing an increase in seismic activity, and the country is not prepared for a natural disaster of that nature at this time.

Speaking to LoopTT, Dr Latchman said it is critical for the region to start implementing proper building codes and safe practices to help mitigate any effects of a strong earthquake.

We have had major earthquakes before…people come away with the idea that it isn’t a risk but that is not true.”

“There have been big earthquakes before in Trinidad and Tobago, and some of them have been catastrophic.”

“We are seeing a build-up of activity, this is a global phenomenon….and our analysis is that bigger earthquakes, that is greater than magnitude six, may occur in future.”

(Photo: The Eastern border of the Caribbean plate, courtesy the UWI Seismic Research Centre)

Dr Latchman said that the Centre is also recording more seismic activity in new areas within the region.

“We are seeing earthquakes in areas that we have not seen since we (the Centre) began recording.”

“The fact is that we are in a seismically active area of plate boundaries. We have experienced earthquakes regularly and we are speaking as a region because if an event occurs within the Caribbean, we would be impacted by that event.”

“So far we have been blessed in that the big earthquakes have been giving us time to prepare, but we have not been doing that,” she said.

Dr Latchman said that earthquake building codes in the region and in Trinidad and Tobago must be developed and incorporated into law, in order to ensure that developers and homeowners are compliant.

“We have to be prepared for earthquakes, we have to dispense with the idea that big earthquakes won’t affect us.”

“The bigger earthquakes that have occurred, fortunately, have occurred offshore, at significant depths, so that the impact has been minimal. But the measures we need to put in place are not for those earthquakes. We need to prepare for the big earthquakes,” she said.

Historically Trinidad and Tobago has already experienced strong and even catastrophic earthquakes, such as the 1766 earthquake which destroyed the country’s first capital, San Jose (St Joseph), and the more recent 6.1 earthquake in Tobago in 1997 which caused millions of dollars in damages.

According to reports, after the 1766 earthquake, more than 60 percent of dwellings and religious buildings collapsed or suffered heavy damage. Some reports allege that the face of the island completely changed.

In 1968 a 7.0 earthquake caused significant damage in Venezuela and was strong enough to also cause damage to Port of Spain.

In 2007 a powerful 7.3 earthquake rocked the region, causing damage in Martinique, St Lucia, St Vincent and Barbados.

 

The Caribbean Plate

The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America.

The Caribbean Plate borders the North American Plate, the South American Plate, the Nazca Plate and the Cocos Plate. These borders are regions of intense seismic activity, including frequent earthquakes, occasional tsunamis, and volcanic eruptions.

 

The Caribbean Plate's northern boundary with the North American plate is a transform or strike-slip boundary which runs from the border area of Belize, Guatemala (Motagua Fault), and Honduras in Central America, eastward through the Cayman trough on south of the southeast coast of Cuba, and just north of Hispaniola, Puerto Rico, and the Virgin Islands.

The eastern boundary is a subduction zone, the Lesser Antilles subduction zone, where oceanic crust of the South American Plate is being subducted under the Caribbean Plate.

Subduction forms the volcanic islands of the Lesser Antilles Volcanic Arc from the Virgin Islands in the north to the islands off the coast of Venezuela in the south.

This boundary contains seventeen active volcanoes, most notably Soufriere Hills on Montserrat;, Mount Pelée on Martinique; La Grande Soufrière on Guadeloupe; Soufrière Saint Vincent on Saint Vincent; and the submarine volcano Kick-’em-Jenny which lies about 10 km north of Grenada.

Large historical earthquakes in 1839 and 1843 in this region are possibly megathrust earthquakes.


For more information on earthquakes visit the UWI Seismic Research Centre at www.uwiseismic.com