Showing posts with label Earthquake. Show all posts
Showing posts with label Earthquake. Show all posts

Wednesday 14 January 2015

Is Jamaica Prepared For A Major Earthquake?

Tuesday January 12, 2015, marked the 5 Th anniversary of the 2010 Haiti. The intensity was measured a remarkable 7.0. M on the Moment Magnitude Scale (MMS), a scale designated to measure the intensity of earthquakes. The MMS scale is preferred to the somewhat antiquated, Richter scale, that is said to underestimate higher magnitude earthquakes. However, the Richter scale is said to be a better measure of lower end earthquakes.

A fact to note is, to the eastern and southern end of the Island, Jamaica share the Enriquillo fault zone with Hispaniola. The Enriquillo fault zone is responsible for numerous earthquakes within the past 400 years. Including the aforementioned Haiti earthquake, the 1907 Kingston earthquake and the destructive 1692 earthquake that destroyed Port Royal. To the north and western end of Jamaica, lies the Walton fault zone. Both Walton and Enriquillo fault zones, separates the Gonave microplate from the Caribbean plate.

 Gonave And Caribbean plates. Source of images: UWI earthquake unit 

The 1907 Kingston earthquake was measured at 6.5. M on the Moment Magnitude Scale, not dissimilar to the 2010 Haiti earthquake. In technical terms, the 1907 earthquake was three times smaller in comparison to the 2010 Haitian earthquake, and released fewer than six times the energy of the 2010 Haitian earthquake. However, it is estimated that 1000 individuals were killed, with approximately 10 000 individuals left homeless.

The big daddy of the aforementioned earthquakes to affect Jamaica, was the disreputable 1692 Port Royal earthquake. It had an intensity of 7.5. M, a local tsunami was also triggered. It is estimated that 2000 individuals were killed. Additionally, approximately 66% of the Port Royal archipelago sank, destroying virtually everything. There were also numerous reports of landslides across Jamaica.

Is Jamaica Prepared For the Inevitable?

The Office of Disaster Preparedness and Emergency Management (ODPEM) designates the month of January as earthquake awareness month. Quoting from the earthquake unit at the University of the West Indies (UWI) "About 200 earthquakes are located in and around Jamaica per year most of which are minor, having magnitudes less than 4.0.". However, are we prepared for the next major earthquake?

A February 7, 2014 story in the Jamaica Gleaner, suggests that approximately 70% of designed buildings, are done without the input of building professionals. See the Jamaica Gleaner story for additional information: Jamaica's New Building Code Imminent.


Giddy House in Port Royal, Kingston. A region that is prone to liquefaction. Source of Image: Clarmo

A worrying statistic. But a study commissioned by NEM insurance company, implies that Jamaica should fare better Haiti, in the event of a 7.0. M earthquake. The study was carried out by the Mona Geoinformatics Institute and the earthquake unit at the University of the West Indies (UWI). The study suggests that eastern parishes should fare the worst. This attributable to the geology of the area, an area that is prone to landslides and liquefaction.

Despite being relatively prepared for a major earthquake, steps should be taken to improve our preparation for the inevitable. This includes proclamation of a new building code, providing required funding to the essential services and educating the public on what should be done in the event of a major earthquake. We cannot prevent earthquakes, but the aforementioned steps should go a far way in reducing property loss and loss of life.


References:

http://earthquake.usgs.gov/learn/topics/calculator.php

http://www.jamaicaobserver.com/news/Jamaica-will-fare-better-than-Haiti-if-hit-by-a-7-0-quake--say-scientists_8573231

http://earthquake.usgs.gov/earthquakes/world/events/1692_06_07.php

http://www.mona.uwi.edu/earthquake/jaequake.php