DESTROYED: A crane shifts through the rubble of the damaged Our Lady of Assumption Parish church following a 7.2-magnitude earthquake, at Dauis in Bohol, central Philippines, on Tuesday. The tremor collapsed buildings, cracked roads and toppled the bell tower of the Philippines’ oldest church Tuesday morning, causing multiple deaths across the central region and sending terrified residents into deadly stampedes. —Photo: AP
A shake-up to wake up!
LAST Friday’s earthquake of a magnitude 6.4 was a reminder that Trinidad and Tobago lies in a seismically hot zone—an area prone to earthquakes. While the tremor which seemed to last forever left many feeling uneasy and worried with anticipation of aftershocks, it’s worth mentioning that we were actually very lucky.
Had the earthquake with the same magnitude but shallower depth occurred, then today we may have been discussing the considerable damage that was inflicted. As it turns out, the depth of last week’s quake was 60 km.
“That sort of magnitude actually could cause significant damage,” said research fellow (instrumentation) at the Seismic Research Centre Lloyd Lynch.
Lynch cited examples of past earthquakes in Algeria and Argentina which were around the same magnitude as the quake we experienced last Friday. However those earthquakes were of a more shallow depth and resulted in deaths, injuries and collapsed or seriously damaged buildings.
The University of the West Indies Seismic Research Centre has all the answers for those curious about seismic hazards that threaten Trinidad and Tobago and the wider Caribbean region. In celebration of its 60th anniversary the centre has been hosting an Open House on the last Thursday of every month during which all seismic related questions are answered.
For instance, what creates that loud roar or rumbling sound that sometimes precedes an earthquake?
“Earthquakes occur when faults rupture, the faults in this case were 60 km or so deep but the waves actually radiate out from the zone of rupture and upon reaching the surface some of that strained energy or elastic energy actually gets converted into sound energy and this is what you hear,” Lynch replied.
Since earthquakes don’t come announced, it’s best to be prepared, this includes having a carefully thought-out family plan and knowing what to do in the event of an earthquake, it also involves having a well stocked emergency kit.
It’s important to remember that earthquakes don’t kill people, buildings do. Time and time again, Lynch has stressed in interviews that it is necessary to have strong buildings that can withstand earthquakes when you are located in a seismically active zone (as we are).
“To have strong buildings you need to have good building standards, preferably a building code which is enforced and once you have that in place, you find that the buildings that are built over time will have the capability to not only stand up to the intensity of the shaking alone but also certainly save lives. Once you have a system in place that allows you to build strong buildings then you’re likely to come out better during earthquakes,”’said Lynch.
He added that strong building codes and good planning and development go hand in hand when it comes to preparing for earthquakes.
“You need to have good planning and development regimes. Earthquakes usually occur along certain zones. In Trinidad we have a number of well-defined areas where earthquakes frequent, the waves themselves tend to be amplified by the type of soil in which they pass so one can over time delineate the areas that are more susceptible to the damaging effects of an earthquake and once this is done you can actually choose the areas more suitable for development. In particular you can choose where your critical facilities go. You wouldn’t put them in areas more susceptible to the damaging effects of earthquakes,”said Lynch.
What is unfortunate, said Lynch, is that here in Trinidad we do not have a building code that is enforceable by law, per se. And our planning system is not optimised to identify the areas susceptible to the effects of strong earthquakes.
In an interview with the Express in May, Lynch warned that a massive earthquake with a maganitide of 7.0 could be triggered along the Central Range Fault line—a fault that in recent times has been engaging the attention of scientists at home and abroad.
In the event of an earthquake of such a magnitude, ground rupture, fires, landslides and inundation of coastlines are also likely to occur. Lynch said this country has not developed any sort of resilience adding that buildings are poorly constructed. Lynch said even though our engineers are said to be rated among the best, we do not have a highly effective system that allows for good quality assurance.
Lynch added that only 15-20 per cent of buildings in Trinidad are insured and often those that are, are also grossly under-insured, in that case, Lynch said the financial and property losses will be huge in the event of a large earthquake. He added that planning for such an event should include the establishment of a ‘catastrophe fund’.
He also questioned whether this country has the capacity (enough fire appliances and trained search and rescue workers) to deal with such an emergency.
Lynch also called for diasaster management legislation to be updated.
Currently the Disaster Management Act is almost 40 years old and is geared at quelling riots rather than managing disasters, observed Lynch.
To find out more about earthquakes and how you and your family can be prepared, reserve your seat at the next Open House at the Seismic Research Centre on October 31. To make bookings call 662-4659 or e-mail them at firstname.lastname@example.org.