Klao Bell, Staff Reporter
JAMAICA has been rattled by scores of minor earthquakes over the past year, according to seismologists, who are concerned that a major jolt could pose severe danger in the country's heavily populated areas.
Although only about 15 of the 178 quakes since January 2000 were likely felt by the public, and no one can say when another will jolt Jamaica, geologists are aware that sections of the island are highly vulnerable to widespread damage in the event of a major earthquake.
Norman Harris, director of applied research at the Mines and Geology Division of the Ministry of Mining and Energy, identified some areas across the island where there could be heavy casualties and destruction should a magnitude 7.6 earthquake occur. And although these fall within just five of Jamaica's 14 parishes, approximately half of Jamaica's population of 2.5 million people live in those crucial areas.
An earthquake measuring 7.6 is considered major. Last month, a quake of that magnitude rocked El Salvador killing 683, destroying 38,628 houses and damaging 84,682 others.
"Some areas one would expect to have severe damage would be the coastal areas, Palisadoes, Port Royal, Harbour View (in east Kingston), all along the coast going downtown along Marcus Garvey Drive - you tend to have soft soils in those areas...with this type of ground condition there would be increased ground motion, causing higher earthquake intensity," Mr. Harris said.
The foothills of Jack's Hill, New Kingston, sections of rural St. Andrew, Portmore, St. Catherine, Portland, and the coastline of Montego Bay were also listed. And although the full extent of the damage could not be specified, Mr. Harris outlined what can be expected.
"If a major earthquake occurs on land or near the shore we could expect to have debris slides and mud flows around the foothills of Jack's Hill and other hills around Kingston and St. Andrew," he explained.
The structures in New Kingston, a business centre for the island, are built on sturdy soil foundation. This, however, would cause intense shaking in that area if there was a major quake.
"New Kingston is built on good alluvial soil, but studies in other countries have shown that where there are thick alluvial soil there is greater amplification and more intense ground shaking," Mr. Harris said.
Falling buildings and landslides claim more lives in earthquakes than other repercussions.
Squatter settlements, often perched precariously along hillsides, are also at risk as they are sometimes located right in the path of a landslide proned area.
"More than 50 per cent of the people in MoBay live in areas that can be labelled squatter settlements, most are on the hills like the Canterbury and Flankers...their houses would be severely damaged or destroyed whether from landslides or because the houses are poorly constructed," Mr. Harris said.
Some parts of the island are naturally disadvantaged because of the rock composition and the terrain. Some of Portland's geological features are weak rocks and hilly terrain, which could create a death trap for communities in the event of major earthquakes.
"Portland is at risk because the area is prone to landslides and landslide dammes," Mr. Harris said. "Landslides can cause damming of the rivers and subsequent flooding of communities. Communities could be marooned, there could be real danger to life and property."
But while little can be done to change the soil composition on the island, building codes offer guidelines to withstand earthquakes of various intensities. Established codes are largely ignored, however.
"Building codes need to be followed to reduce the vulnerability of structures, it is currently not being followed," said Dr. Barbara Carby, director general of the Office of Disaster Preparedness and Emergency Management, responding through the ODPEM's public relations office.
