Monday, September 3, 2012

Lagmay: Quake preparedness should be a way of life

Lagmay: Quake preparedness should be a way of life


 - Every year, earthquakes of varying degrees are recorded across the globe, especially in earthquake-prone areas like the Pacific Ring of Fire.

"The earth is alive, it’s not static," UP professor Mahar Lagmay of the National Institute of Geological Studies told ANC.

Lagmay said at least one Magnitude 8 quake strikes per year, compared to 15 Magnitude 7 to 7.9 quakes, and more than 30 with a magnitude of 6 to 6.9.

Strategically located in a quake-prone zone, Lagmay said the Philippines is surrounded by fault lines including the Philippine trench, the Manila trench and the Marikina fault line, which is capable of generating a 7.2 magnitude earthquake.

"The Philippine fault goes all the way from Aparri to Quezon, Leyte, Davao until the Southern Philippines. It is 1,200 to 1,400 kilometers long, comparable to the most dangerous faults in the world, when it moves they move in segments…,” he explained.

A segment of the Philippine trench triggered Friday's magnitude 7.6 earthquake off the coast of Eastern Samar. The tremble was felt as far north as the Bicol region, and in Mindanao.

It claimed one life, destroyed homes and bridges, disrupted power and caused panic among locals. On Monday, the Philippine Institute of Volcanology and Seismology said more than 370 aftershocks have been recorded since Friday.

Damage to infrastructure is now estimated at P40 million.

Experts said the scenario would have been dire had the quake's epicenter been closer to land.



Hazards



Lagmay likened it to the strongest earthquakes the country experienced in the past, including the 7.9 magnitude quake that struck the Moro Gulf in 1976 and the July 1990 quake that struck Northern Luzon.

"Because it happened offshore more than 100 kilometers, the impact in terms of intensity and ground shaking was less on land...The depth of the quake was about 34 kilometers. Had it happened on land, the force or impact of the earthquake would've been very devastating,” he said.

Lagmay noted it is not the quakes themselves that kill, but the hazards associated with them.

"Earthquakes per se do not kill. It's the hazards that kill. Many hazards associated with it, such as landslides, fire, tsunamis, ground shaking, liquefaction, ground subsidence...Structures are affected, they fall and might kill people,” he said.

"The more populated an area is, the more urbanized an area is, the more vulnerable people are to hazards. Disasters only happen when people are affected. If we plan accordingly and put in place mitigation measures we can lessen the losses and casualties that would be the impact of the quake,” he added.



Preparedness

Lagmay said earthquake risks can be minimized through proper compliance with strict building standards and by making earthquake preparedness a way of life.

"Because we have all these hazards we should make it a way of life, we are always prepared and alert,” he said. "If there's a strong ground shaking: hold, duck and cover. If you're outside, go to a safe place."

He also said developers should be able to adapt to such kinds of hazards.

"In Metro Manila, we have this rule that you cannot build any structure five meters away from the official trace of the faultline...When you make a project in Metro Manila, you go through a process called the geological hazards assessment,” he said.

He said it is possible to do long-term earthquake predictions, especially in earthquake-prone zones.

Short-term predictions are a different matter, however, he said.

Despite the unpredictability of earthquakes, Lagmay said the chances of a big quake striking is a sure thing.

"It's for sure than an earthquake will happen in the Philippines or a strong one...We just don't know when and where it will take place next."

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