Study on active faults in Bukidnon needed

MALAYBALAY CITY (MindaNews/28 November) — There is a need to conduct a geologic study in Bukidnon to confirm if there is an active fault cutting through it following the 5.2 magnitude earthquake in Valencia City and the rest of the province this month, Desiderio Cabanlit, officer in charge of the Philippine Institute of Volcanology and Seismology (Phivolcs) in Davao said.

Cabanlit told the Sangguniang Panlalawigan last week the damage they found in the post-quake evaluation showed that it was caused by a possibly even stronger intensity. But he said it should be subjected to a more in-depth analysis.

He stressed that the recent quake was tectonic in nature. “The quakes were not caused by any activity of the Calayo volcano.”

Calayo is the old name of Musuan Peak, a volcano that sits within the campus of Central Mindanao University in Musuan, Maramag town.

Cabanlit said the probable fault lines such as the Cabanglasan and the Central Mindanao faults are far from the identified epicenter of the quake.

He said only a study can confirm is there is indeed an active fault line in Bukidnon, adding they will also dig in areas reported to have cracks for carbon dating to check some indicators.

The official stressed the importance of the study especially to land use zoning. He said it can map out other hazards such as ground rupture, liquefaction, and landslide.

He cited a study they made in Agusan del Sur where they discovered a fault line on which the local government had planned to build a structure.

Provincial board members welcomed the suggestion to conduct a study.

Cabanlit asked the provincial board to formalize the request to their national office.

Vice Gov.  Jose Ma. R. Zubiri Jr. vowed to pass a resolution supporting the study proposed by the Phivolcs official.

But Cabanlit said he could not determine how long the study would take.

“Our previous study on active faults in Caraga and Southern Mindanao, it lasted for months to a year before result was published. Carbon dating takes time, if there are samples to be dated,” he added.

In response to a query by board member Ranulfo Pepito on land depressions along the Sayre Highway, Cabanlit clarified that not all depressions are signs of active fault lines and quakes.

Pepito said many Valencia City-based businessmen sold properties in the past over fears the volcano in Musuan would erupt after tremors occurred.

“That is why this has to be clarified to possibly avoid the repeat of that,” he added.

Musuan Peak, or Mount Calayo, was recorded to have a mild eruption in 1896.

Cabanlit said that while they cited that the epicenter was 25 kilometers southwest of Malaybalay City, the city was mentioned only because their monitoring software uses it as reference. (Walter I. Balane/MindaNews)