PHIVOLCS warns on quake due to East fault

A known earthquake generator in the province called as the “East Bohol Fault” is closely being monitored by the Philippine Institute of Volcanology and Seismology (PHIVOLCS)

This was the chilling statement issued by Dr. Renato U. Solidum Jr., PHIVOLCS Director on the occasion of the turn-over of the updated hazard maps to the Provincial Government of Bohol and the installation of two additional earthquake monitoring stations in Talibon and Garcia Hernandez.

But Solidum assured the residents of Bohol that “no more large earthquake would occur generated by the North Bohol Fault” even as three fault lines cuts across several towns in the province of Bohol including the South Offshore Fault.


The East Bohol Fault starts at Barangay Tayong, Loay and transects the hinterland of Lila, Dimiao, Valencia, Garcia Hernandez reaching up to the Sierra Bullones – Pilar area.

Also, the South Offshore Fault lies adjacent to the town of Anda affecting the southern coastal towns up to Maribojoc.

The North Bohol fault starting at Inabanga traverses southwest passing Loon including the offshore areas reaching Boljoon, Cebu while the Maribojoc fault also cuts across the mountains of Maribojoc up to Antequera

Evangelista told the Chronicle that the devastating 2013 Bohol earthquake which released an amount of energy equivalent to 30 Hiroshima atomic bombs can occur again on the same fault over a hundred years or more.

The reverse fault found and seen in Inabanga will remain quiet and will not pose imminent danger from earthquake hazards except for landslides and further aggravate weakened infrastructures triggered by aftershocks and strong rains, said Evangelista.


Solidum turned over to Anthony Damalerio, Provincial Disaster Risk Reduction and Mitigation (PDRRM) Officer hazard maps showing the active faults in Bohol, liquefaction, groundshaking, tsunami and earthquake induced landslides.

The updated maps were the result of the multi-hazard mapping and re-assessment and validation of previous maps in Bohol conducted by PHIVOLCS staff and PHIVOLCS-Bohol Officer in Charge Nolan Evangelista.

The hazard maps will be used by the Provincial Government in their disaster preparedness and rescue plans, according to Damalerio.

Meanwhile, two new solar powered broadband seismic stations were installed in President Garcia Ancestral Park in Sitiio Luy-a, Barangay San Agustin Talibon and Sitio West Ulbujan, Barangay West Cogon, Garcia Hernandez as part of the Philippine Seismic Network, according to Evangelista.


The new broadband seismic stations will significantly increase the “detectability of events and more accurate and timely determination of earthquake parameters of events generated by active earthquake sources in Bohol”, said Evangelista.

The new seismic stations installed in Bohol is equipped with different types of seismic instruments that can detect, monitor and record earthquakes locally or anywhere in the world.

It can accurately determine the magnitude, depth and epicenter of an earthquake and have the ability to communicate and share data via satellite with the data receiving center of the PHIVOLCS main office, explained Evangelista.

Bohol is considered one of the seismically active areas in the country but a higher magnitude earthquake related to the October 15, 2013 magnitude 7.2 is no longer expected to occur, according to Evangelista. (Chito M. Visarra)

Leave a Reply

Your email address will not be published. Required fields are marked *