Editor’s Note: An 8.9 magnitude earthquake struck Japan last Friday, March 12, triggering a tsunami that killed thousands of people, as well as renewing talk here in the Philippines on disaster prevention and management.
by Cherrie Anne Ongteco
published July 2009, Tinig ng Plaridel
“I accidentally elbowed a pregnant woman while rushing out of the canteen.”
This was the kind of panic Dr. Alfredo Lagmay, a volcanology expert, had to experience to save his life during the 1990 earthquake.
Also a professor at the National Institute of Geological Sciences (NIGS), Lagmay recalled feeling the ground shake like hell and hearing the violent clanging of metal pipes.
With thousands of people dead and millions of properties destroyed, the 1990 quake would forever haunt Metro Manila as it celebrates its nineteenth anniversary on July 16. Coincidentally, in the past few weeks, news has been circulating that another “Big Quake” will soon strike the city again.
All that thanks to Metro Manila’s geological vulnerability. The place is practically surrounded by several earthquake generators such as the Manila trench, the Philippine fault, the East Valley fault and the West Valley fault (Marikina fault).
With these facts at hand, is the news about the occurrence of the “Big Quake” a rumor or a fact?
“This statement is true today, will be true tomorrow, and has been true in the past,” NIGS professor Emoy Rodolfo said in an interview last July 7.
News about the nearing earthquake is also based on a study on seismic hazards assessment of Metro Manila by Dr. Raymundo Punongbayan, former director of the Philippine Institute of Volcanology and Seismology and other geological experts.
Findings show that the recurrent interval of the seismic activity along the Marikina fault is between 200-400 years.
“The last one happened a little more than 200 years ago, so if the recurrence interval is anytime from 200-400 years, then it’s roughly about time to expect a big earthquake happening,” Lagmay said.
The predicted magnitude of the “Big Quake” is 6.0-7.0, based on the length of the Marikina fault. A magnitude of 6.0-7.0 is already strong enough to damage buildings and destroy lives.
In the face of the uncertainty and perils of an earthquake, “It is imperative for us to prepare for it the best way we can. We prepare for it so as to mitigate the consequences of the hazards,” Lagmay said.
Safe infrastructures and hospitals, secure supply of potable water, stand-by evacuation centers and properly designed buildings are just some of the ways we can prepare for the earthquake. If an earthquake as strong as that which happened in 1990 strikes anytime soon, the number of damaged property and more importantly, the loss of lives may be reduced.
According to a Philippine Daily Inquirer article, the 1990 earthquake killed an estimated 1,621 people with most fatalities located in Central Luzon and the Cordillera Region.
On that day, the magnitude here in Quezon City was around 4-5. There were no reported structural damages in the University of the Philippines Diliman, Lagmay said.
Dr. Lagmay and his colleagues were able to identify quake faults in the UP community. One starts from UP Village, one to the northwest of the National Institute for Science and Mathematics Educational Development (NISMED); another fault along C.P. Garcia Avenue continuous to the Marine Science Institute and the back of Kamia Residence Hall, to the Balara exits.
With reporting by Nikki Careen Palacios