Phivolcs discovers new fault system in Bohol quake

MANILA, Philippines - State volcanologists who have been hunting for a hidden fault discovered a new fault system in Inabanga town that triggered the 7.2-magnitude earthquake that shook Bohol and killed hundreds.

The Philippine Institute of Volcanology and Seismology (Phivolcs) on Tuesday noticed ground rupture in Barangay Anunang, Inabanga in the devastated Bohol province that served as a surface representation of a fault underneath.

Phivolcs' started a survey last October 16, the day after the quake hit Central Visayas, to trace where it came from.

Phivolcs research analyst Nolan Evangelista said in a state news report that the ground rupture occurs only once in 100 years.

The new fault is manifested on the surface with the upliftment of the southern part of the ground rupture up to almost three meters, while the northern part remains lower, Evangelista said.

He explained that the layering of the rocks beneath the rupture break during an earthquake, creating a sound similar to an explosion.

Phivolcs Director Renato Solidum had said that the 7.2-magnitude ground shaking has an energy equivalent to around 32 Hiroshima atomic bombs.

As of posting time, over 190 people were discovered dead at the aftermath of the quake, mostly in Bohol  and others in Cebu. The quake also destroyed centuries-old national treasures estimated to cost over P100 million to rehabilitate.

Local residents, meanwhile, discovered sinkholes in several towns as ground surface caved in.

Mines and Geosciences Bureau acting directoR Leo Jasareño said that areas in Bohol, known to be lying on limestones, are likely to have sinkholes after an intense ground activity.

"Ang sinkhole (ay lumalabas kapag) nabubuo ang butas sa ilalim ng lupa dahil nandun ang limestone," he said in a television interview.