Unforgettable Earthquake

Thursday, 29th 2007, started as an ordinary day until about 19 seconds after 3 p.m. local time when it turned into an extraordinary day for Vincentians and the people of the Eastern Caribbean. Many persons at home were taking their afternoon rest, school children were about to head for home and many workers were into their last hour at work when they were rocked and swayed by an earthquake of magnitude 7.4. (a figure refined many times by the United States Geological Survey website).{{more}} We have had small quakes before, mostly at night, but nothing to compare with this shaker. Luckily, we were spared some of the worst effects such as damage to our buildings and infrastructure.

I had gone to the supermarket to pick up a few items and was at the cash desk when the shake started. For the first few seconds persons around me appeared not to comprehend what was happening. When they realized that it was an earthquake there was a mad rush for the single door at the end of the building. Even while we were outside, the shaking continued, and we watched as the steel rods jutting out of an unfinished building nearby moved to and fro.

The experience has generated a great deal of interest in information about earthquakes. Some of our memories of earth tremors are associated with the volcanic eruptions in 1979. We have heard and seen on television some of the devastation and destruction that result from earthquakes. The Internet has been a good source of information on earthquakes, and even though my knowledge is limited, I would share some information that I have extracted from the Internet with you.

The Epicentre

Scientists give the location of the November 29th earthquake of 14.95 degrees North and 61.24 degree West, somewhere north of the island of Martinique. Scientists call this the epicentre. The earthquake sent shock waves form this epicentre to as far as Anguilla in the North and Guyana in the South. The US Geological Survey website gave a preliminary moment magnitude of 7.4 on the Richter scale. This figure 7.4 describes the magnitude of the earthquake. The magnitude is the measure of the amount of energy released during an earthquake. It is determined by using mathematical formulae. The measuring scale was developed by Dr. Charles Richter a seismologist at the California Institute of Technology in the 1930’s. The largest earthquake to have been recorded is 9.5. That earthquake occurred in Chile in 1960 followed by a 9.2 earthquake that occurred in Alaska in 1964.

Tsunami

The dangerous and frightening effect of earthquakes is the ability to trigger off a tsunami, that is a tidal wave. The earthquake which triggered off a tsunami in Indonesia on December 26th, 2005, measured 8. 2 on the Richter scale. We cannot forget the devastation and suffering that it caused.

Intermediate Depth Earthquakes

Many persons were amazed that an earthquake of magnitude 7.4 did not cause substantial damage. According to the US Geological Survey website, earthquakes between 70 and 300 km. in depth are commonly called ‘intermediate depth’ earthquakes and they typically cause less damage on the ground surface above their foci than is the case with similar magnitude shallow focus earthquake. The shallow focus earthquake can be felt at greater distances from their epicenter. The recent earthquake occurred at a depth of 146.2 km. or 90.8 miles according to the US Geological Survey website. Damage has been recorded in Martinique, northern Saint Lucia and southern Dominica, according to findings from the Caribbean Catastrophe Risk Insurance Facility (CCRIF)

For the Future

Our first response is to get out of buildings and into open space, away as much as possible from utility poles. If there is no hope of making it outside, then one could take refuge under tables or other structures inside. Some of our homes are so heavily padlocked against burglars that it could be difficult to get out. Nonetheless, plan your escape route beforehand.

Ada Johnson is a solicitor and barrister-at-law.

E-mail address is: exploringthelaw@yahoo.com