Earthquakes Can Happen
Published 14th December 2009, 12:35pm
December 14th, marks the five anniversary of the 6.8 magnitude earthquake that occurred 20 miles South of George Town in 2004. Up until that event, many people were not even aware that the Cayman Islands are vulnerable to the earthquake hazard, however Cayman is located close to a fault boundary and earthquakes do occur.
To mark the anniversary, Hazard Management Cayman Islands (HMCI) has been raising the awareness in the schools and many civil servants will soon take part in an earthquake drill at the Glass House. HMCI believes it is beneficial to inform the public about the potential threat, and provide strategies for minimizing the risk to life and property associated with this hazard.
The Cayman Islands is located near to the southern boundary of the North American tectonic plate and below us is the Caribbean plate. The North American Plate is moving westward with respect to the adjacent Caribbean plate at a rate of motion of 0.24 to 0.43 inches per year. This may sound like a small amount, but tremendous force and friction builds up when these plates grind past one another, and with no warning the friction can suddenly release, resulting in an earthquake.
Since 1990 there have been four earthquakes that were magnitude six or more in the general area of the Cayman Islands. A recent vulnerability analysis conducted by Natural Disasters Assessment Consulting Group (published in June, 2009) for Grand Cayman shows that the estimated return period of a destructive earthquake ranging in magnitude from 7.2 to 7.5 on the Richter scale is 180 to 500 years, so while the possibility of a damaging earthquake occurring in Cayman in anyone year is small, there is still a risk and the public should prepare for the possibility.
The Cayman Islands has the ability to measure (regional) earthquake activity and we also receive information about earthquakes from the network of seismographs located in countries around the world, for example when a significant earthquake occurred off the Island of Roatan earlier in the year, the event was detected at the Frank Sound ‘seismograph.’ Additional local seismographs are due to become operational in Cayman Brac and Little Cayman.
So what can you do to make yourself safer from this threat? Earthquakes are not like hurricanes where you can see them on satellite images and you can anticipate the effects, but there are things you can do to protect yourself. During the sensitization sessions in the schools, Deputy Director of Hazard Management Cayman Islands, Mr. Omar Afflick demonstrates the response currently recommended by the Federal Emergency Management Agency (FEMA) which advocates the ‘duck, cover and hold’ procedure.
“Basically when you feel shaking, stay calm, move away from glass windows and duck under a heavy piece of furniture such as a desk or table. If there is nothing available for you to duck under you should cover your head with your arms. Do not run for the door and head outside, but if you are outdoors already you should move to an area which is open, where there are no trees, buildings or light poles that can potentially fall on you. If you are in a car pull over to the side of the road.” Mr. Afflick added that “once the tremors stop, you should head outside to an open area and if the earthquake was a strong event it is highly recommended that you have an expert check the structural integrity of your building before going back inside. Sometimes earthquakes can be associated with broken gas lines and fires have been known to occur so clearly you want to be aware of your surrounding, stay away from downed power lines and if you smell gas move away from the area.”
Omar Afflick highly recommends that people reduce the hazards in their own homes by ensuring that heavy objects, like bookcases, that can fall are anchored to the wall with screws. “Check that your televisions sets are secure as well. We have information on our website that will help you identify potential hazards so you can reduce the risks”
If you are interested in learning more about how you can construct or retrofit your building so it is more resilient to an earthquake there is information available on the Cayman Prepared website , there are also ‘hazard hunts’ that are fun activities for children and there are earthquake brochures that are available and can be picked up from the Hazard Management Office in the Corporate Centre on Hospital Road.