PHIVOLCS warns of possible strong aftershocks to follow Cotabato quake

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) is not discounting the possibility of stronger earthquakes that may rock Mindanao after Tuesday's magnitude 6.6 tremblor.

"Kung ang fault ay kumilos nang malakihan, tiyak po na magkakaroon ng aftershocks," PHIVOLCS Director Renato Solidum said on GMA News TV program Balitanghali.

"Dahil 'yung faults dyan ay may kakayahan na mas malaki sa [magnitude] 6.3 na pwede ipakawala, hindi po natin inaalis 'yung posibilidad na may sumunod na mas malaki," he added, while also noting that aftershocks were typically weaker in magnitude than the preceding major quake.

A magnitude 6.1 aftershock was recorded by PHIVOLCS at 10:42 a.m. on Tuesday, Solidum said.

Further, he explained that there could be different motions felt depending on the distance from the earthquake's epicenter.

"'Yung vertical [motion] initial lang po 'yun, mas matagal po 'yung horizontal. Kung malayo naman po sa episentro, hindi na nararamdaman 'yung vertical, 'yung horizontal po ang nararamdaman. 'Yun po 'yung damaging," Solidum said.

"Pagdating sa ating building code, ang kinokonsidera po sa design ay 'yung horizontal shaking," he added.

According to the National Disaster Risk Reduction and Management Council, a 66-year-old man died while 43 others were injured in the magnitude 6.6 earthquake.

Almost two weeks ago, a magnitude 6.3 tremor claimed seven lives and injured dozens in different parts of Mindanao. — Dona Magsino/DVM, GMA News