The North Bohol Fault (NBF), which was created by the 7.2 magnitude earthquake on October 15, 2013, has an offshore extension that runs from Manga to Bool along the Tagbilaran coastline, towards Cebu. The eastern part of the NBF forms the Tagbilaran Bay.
This was explained by Geologist Kilven A. Matuod, one of the speakers at the 2nd Environmental Forum of Tagbilaran Baywatch on February 19 at the Holy Name University (HNU) High School Multi-Media Center. The other speaker was Dr. Noelyn S. Dano, Ph.D., an environmental specialist, researcher, and urban/environmental planner.
The forum revolved around the theme, “Bridging the gap between environmental policy and sustainable practice.”
The forum was attended by City Vice Mayor Adam Relson Jala and other officials from the provincial government, including Atty. Abeleon Damalerio, who represented First District Congress Representative Edgar M. Chatto, and the civil society.
Student and youth leaders, including student government presidents from all public high schools in the city, were also present. They were given permission to attend by DepEd City Division Superintendent Wilfreda D. Bongalos.
Geologist Matuod further revealed that the Philippine Institute of Volcanology and Seismology (PHIVOLCS) conducted a study to delineate the extent of the fault, which was 40 kms inland. They found that it had an offshore extension that reached the Bohol Sea seafloor, as shown in the PHIVOLCS map. The NBF is a reverse fault, or a kind of fault where there was vertical movement going up. The eastern part of the NBF created an uplifted block or thrust block that led to the upliftment of the Maribojoc shoreline, extending to the sinkholes in the coastal areas of Tagbilaran City, including Taloto District, along Burgos St., and even in the neighboring town of Baclayon.
The PHIVOLCS map also shows that there are epicenters surrounding the NBF, including the part of the fault that extended to the Bohol Sea.
The Karst topography of Bohol contributed to the creation of sinkholes not only in the land area but also in the seabed of the Bohol Sea and Tagbilaran Bay. Based on history, the formation of Bohol was submarine, meaning Bohol used to be submerged in the sea. Therefore, Bohol is underlain by limestone.
Karst is a type of landscape where the dissolving of the bedrock has created sinkholes, sinking streams, caves, springs, and other characteristic features. It is associated with soluble rock types such as limestone.
Matuod, therefore, reminded policy makers to consider the impact or the effect of the existing North Bohol Fault in future developments, not only on the loss of marine life and the ecosystem, but also on the loss of human lives. Consultation has to be made with a lot of experts – hydrogeologists, marine biologists, terrestrial studies and the ecosystem, even before the Environmental Impact Assessment. These studies by the experts should already be included in the proposal.
“The North Bohol Fault is not just something that they have learned. It happened in 2013, they should have considered it already. In the proposal, they should have mentioned the geologic hazards or the structural impacts of the NBF,” Matuod emphasized.
On the other hand, environmental specialist, researcher, and urban/environmental planner Dr. Noelyn Dano, Ph.D. highlighted, among others, the need to connect the action or implementation by policy makers to the city and province’s Vision, Mission, Goals.
“The disconnect that I have noticed is not a disconnect between a policy and a particular project. It’s a general disconnect. No one size fits all. We expect you to think independently as our officials here, as our representatives, because the message of Kilven was very clear that there are so many things to consider, really serious matters to take into account before making a decision or even promoting it (reclamation) as a project. That is why people are complaining why you are not looking at this or that. People also do research on things. Not all legal is legitimate. Just because it is being allowed by the national government, the fact that there are those who raise their opposition, that is something that should make us pause. Probably, those who are opposing it have seen things using their different lenses. Maybe, they look at things more from the social, environmental perspective. I would really hope that the city government would instead acknowledge that there is some kind of a need for some technical aspect, an institutionalized response to this issue, like having an office with a clear mandate, clear thrusts, a budgeted office, with expertise that is really fit for the job. That is one of the things I can propose on this matter, especially if we are really conscious and mindful of the climate change. So, the more that we are cautious. The economic argument so far is really weak compared to the many, many losses that we’ll have – the ecosystem functions and services which are often non-monetized, that is why we don’t see the economic value there. But actually, they have economic value. We just don’t monetize them. And the value of whatever promise of jobs and all is nothing compared to these ecosystem functions and services because our survival depends on them, probably because we see things from a different light. There is a good reason to have a dialogue or conversation to clarify what the development trajectory or pathway is of Tagbilaran,” Dano explained.
The forum had a ripple effect, as, immediately after the activity, which was also shown live on Facebook, a civic organization offered to co-host or co-sponsor the 3rd environmental forum of Tagbilaran Baywatch.