Hidden faults produce weaker quakes than exposed faults — PHIVOLCS

Hidden faults actually produce weaker quakes than exposed faults, PHIVOLCS Director Undersecretary Renato Solidum said.

“Ang mga ganyan po hindi ganun kalaking lindol ang napro-produce. Ang mga fault na malalaki na nagpro-produce ng major earthquakes ay bumibitak sa ibabaw,” Solidum said in an interview on Balitanghali on Wednesday.

Solidum made the clarification after the agency revealed that the magnitude-6.1 earthquake that shook parts of Luzon last month occurred along a hidden fault that had not been previously plotted.

“Para lang hindi maging takot yung ating mga kababayan,” Solidum said.

He added that any earthquake, whether caused by an exposed or a hidden fault, still requires the same level of preparedness from the public.

Solidum pointed out that the presence of a hidden fault under the surface of a location was also considered in formulating the national building code.

“[Isaalang-alang] yung kahandaan [ng estruktura] pagdating sa pag-uga ng lupa,  dahil po sa ganyang mga pangyayari  na may mga fault sa ilalim na hindi lumalabas, ay taken into account po 'yan sa ating national building code,” he said.

“Kaya lagi po nating sinasabi hindi lang kung saan ang fault ang kailangan nating pagtuunan ng pansin. Pangalawa 'yung pag-uga ng lupa, ang dapat hinahanda natin 'yung mga bahay,” he added.

He said that PHIVOLCS is expanding the number of its earthquake monitoring stations across the country to monitor faults better.

To monitor earthquakes from faults offshore, PHIVOLCS is using also echo sounding, which determines their location by transmitting sound pulses into the water. — Joviland Rita/BM, GMA News