A wake-up call
by Jon Joaquin
My family and I were having late lunch at a downtown Davao City restaurant on December 15 when my sister-in-law announced that there was an earthquake. I didn’t think too much of it at the time; after all, Southern Mindanao had been hit by three big earthquakes in October and I was sure this wouldn’t be so strong. But the initial weak shaking soon gave way to a strong tremor, and we realized were going through a big one. The ground was moving sideways and up and down, and we could see the cars outside shaking. It was a good thing the restaurant was only at ground level, and so we went out to the street where we felt it was safer. I don’t know what the official duration of the earthquake was, but it felt like it lasted for more than a minute.
The December 15 earthquake was only the second time I got truly scared during a tremor – the first being the July 16, 1990 Luzon temblor that measured 7.7 magnitude and felt at around intensity VII in Metro Manila where I was at the time. In both instances I actually feared the worst – the ground opening up, buildings falling down, and panic ensuing. When the December 15 tremor stopped I looked around and was relieved that the tall buildings within view were still standing. Slowly it became clear that Davao City was again spared much damage, but at the epicenter of the 6.9 magnitude earthquake in Padada, Davao del Sur, a grocery building had collapsed and buried a number of people.
Interestingly, on the very day of the earthquake I had come out with an article on what actually causes deaths during such incidents. Here are some portions:
Earthquakes don’t kill; poorly designed buildings do.
This, in essence, was what Ishmael Narag, Officer-in-Charge of Phivolcs’ Seismological Observation and Earthquake Prediction Division, said in a briefing with reporters in late October after a series of earthquakes left 21 people dead and more than 400 injured.
“Earthquakes, they don’t kill people… It’s the collapse of man-made structures, buildings, retaining walls that do,” Narag said.
This echoes what engineers and architects have been saying: earthquakes don’t kill but poorly designed buildings do. Most injuries and deaths during earthquakes occur not because of the tremor itself but due to collapsing structures.
According to scientists at the Philippine Institute of Volcanology and Seismology (Phivolcs), this was the first time in at least 20 years that such a series of strong earthquakes has happened.
On October 16, a 6.3-magnitude earthquake struck 23 kilometres off Tulunan, Cotabato at 7:37 p.m.; another quake occurred in the same area at 8:09 p.m.
Then on October 29, two more quakes struck. The first was at 9:04 a.m. at 6.6 magnitude and the next at 10:42 a.m. at magnitude 6.1. Both quakes occurred in the same general area off Tulunan, Cotabato.
Finally, on October 31, a 6.5 magnitude quake struck 28 kilometers off Tulunan, Cotabato at 9:11 a.m.
Scientists at Phivolcs have said the Cotabato region is seismically active because there are several faults underneath it: the M’lang Fault, Makilala-Malungon Fault, North Columbio Fault, and South Columbio Fault.
Besides these, there are also the western extension of the Mindanao Fault (Cotabato-Sindangan Fault) and the Cotabato Trench. Any one of these faults can trigger earthquakes in the area.
Update, organize, enforce building codes
According to Dr. Benito Pacheco, Project Leader of the UP National Engineering Center (UP-NEC) Team, the fact that thousands of homes, schools, and other structures in Cotabato were damaged means that most, if not all of them, were not built to be earthquake-resilient.
Earthquake-resilient structural design reduces damage to or even prevents outright collapse of buildings and houses during a very strong quake, Pacheco said. This is crucial in increasing the likelihood of residents’ survival during a quake.
Pacheco said the only way to make sure that our homes and other structures are earthquake-resistant is for builders and contractors to follow an updated set of building standards. This ensures that structures would be designed to be resilient not only against earthquakes but also to other hazards like typhoons, floods, and fires.
“We already have updated versions of our national building code all filed in Congress – all in five different bills,” Pacheco said. “One of these is the Philippine Building Act of 2018 (House Bill 7804). An updated set of national building standards is sorely needed considering that the current National Building Code in force today is 42 years old. Just think about that: our national building code is older than most Filipinos alive today.”
Pacheco said the proposed Philippine Building Act of 2019 not only updates the National Building Code but also seeks to integrate the different building codes being used in both the local and national levels.
“Yes, besides the National Building Code, there are also local building codes enforced by city and municipal governments. It’s a complicated, even confusing situation,” he added.
The UP-NEC team has created a Facebook page called Project Building Resilience PH (https://www.facebook.com/ProjectBuildingResilience/) that details how people can help. This website (https://bit.ly/35hPg6G) also gives further information on the Philippine Building Act.
The views and opinions expressed in this column are those of the original author, and do not necessarily represent those of the Pilipino Express publishers.
Jon Joaquin is the Editor-In- Chief of the Davao City-based Mindanao Daily Mirror. E-mail Jon at email@example.com.