CITY OF SAN FERNANDO – Filipinos should always be prepared for strong earthquakes as these are always a possibility in the country, the chief of the Philippine Institute of Volcanology and Seismology said here Wednesday.

“Strong earthquakes are, by nature, events that do not occur regularly but people must not lay down their guard when it comes to earthquake preparedness because for the past 400 years, we already suffered from 90 destructive earthquakes,” Dr. Renato Solidum, Phivolcs director, told the Inquirer at the sideline of a workshop on hazards and impact reduction here.

Possibility
The Department of Public Works and Highways’ task force on building inspection held the whole-day workshop for some 200 building officials of local governments in Central Luzon. DPWH works on this together with the Phivolcs and the Association of Structural Engineers in the Philippines.

With the regularity of destructive earthquakes and with so many faults and trenches that generate earthquakes in the country, “strong earthquakes happening in the future are a possibility,” Solidum said.

“That is why the government is preparing for it,” he added.

An average of 20 earthquakes happens daily and around 200 are felt yearly, Phivolcs data showed.

There was nothing unusual in the more than 100 earthquakes that have been recorded since January this year, Solidum said.

A strong one, at magnitude 6, took place in Batanes but it did not affect communities as it happened offshore, he said.

Tremor record

The last destructive quakes occurred on April 1, 1955 with epicenter in Lanao (magnitude 7, 291 dead, 713 hurt); Aug. 2, 1968, in Casiguran, Aurora (magnitude 7.3, 270 dead, 600 hurt); April 7, 1970, in Baler, Aurora (magnitude 7.3, 15 dead, 200 hurt); Aug. 17, 1976, on Moro Gulf (3,739 dead, 8,000 hurt); July 16, 1990, in Luzon (magnitude 7.8, 1,283 dead, 2,786 hurt); and Nov. 15, 1994, in Mindoro (magnitude 7.1, 78 dead).

Solidum said strong earthquakes in other countries should not be viewed as precursors.

“We have our own earthquake generators. We have our own hazards to worry about. We should not look at earthquake events in other countries as a possible trigger of strong earthquake in the country. These are not related,” he said.

“A strong earthquake happening in the country is a possibility. What we can learn from other countries would be how the earthquake affected their structures and how we can improve our own structures,” he added.

Japan lessons

He said after a strong earthquake shook Kobe, Japan, in 1995, DPWH strengthened the flyovers along Edsa in Metro Manila. China, which recently reeled from a devastating tremor, has shared lessons in construction.

Solidum said disaster mitigation is “an interagency effort as it is a multidisciplinary undertaking.”

Citing the recommendations of the 2002-2004 impact reduction study by the Japan Bank for International Cooperation, Metropolitan Manila Development Authority and Phivolcs, Solidum said building officials should make regulation at the top of the list.

“Building safety is very important,” he said.

That study showed that 38 percent of residential buildings in the country’s capital could sustain slight to heavy damage. On the other hand, 30 percent of public buildings could be affected. No similar study has been done in other regions.