Given the recent spate of strong earthquakes in northern and central Luzon, central Visayas and eastern Mindanao, the provincial government’s directive to the 11 towns to develop and implement comprehensive contingency plans for seismic events, including tsunamis, is timely and appropriate.
Located less than 100 kilometers from the Philippine trench that generates earthquakes of magnitudes 7.0 and above, Catanduanes is vulnerable to temblors as two of the so-called “major fault splays” cross the island or pass beside its western coast.
According to a graphic recently posted on social media, the Hilawan Fault stretches from underneath the sea north of Camarines Sur, passes through the San Andres barangay for which it is named, and crosses over to Virac until somewhere in Bote, Bato.
On the other hand, the Minas Fault begins in Camarines Norte and goes in a similar southeast direction, with its last part under the sea along the coast of San Andres and Virac.
These two faults were presumably mapped based on the study done by a group headed by Dr. Mahar Lagmay, a professor at the UP National Institute of Geological Sciences and executive director of Project NOAH (Nationwide Operational Assessment of Hazards).
Former UP-NIGS Director Carlo Arcilla of Virac, who now heads the Philippine Nuclear Research Institute (PNRI), once tried to bring his students to Catanduanes on a summer break in the early 90s to locate and map local faults but was unable cooperation from local authorities.
By identifying the approximate location of the faults in the island, local government units can be guided on the construction of earthquake-resilient buildings and pinpoint specific “no build” zones.
Late last year, the Philippine Institute of Volcanology and Seismology (Phivolcs) unveiled the Seismic Hazard Atlas containing maps and other resources developed by the Department of Science and Technology (DOST) in the past years.
According to Phivolcs, the atlas includes “high-quality seismic hazard ground motion maps that will serve as a critical tool for structural design and urban planning in earthquake-prone areas.”
These maps show areas in the country that have active fault lines and identify possible hazards in the construction of buildings.
Unfortunately, a check of the atlas in the agency’s website shows no available seismic hazard map for the province of Catanduanes.
The importance of such a map cannot be discounted, considering that at least two earthquakes of 7.0 magnitude or greater have struck near Catanduanes in 1982 and 1988.
While the conduct of quarterly earthquake drills serves to remind the people on what to do during an earthquake, particularly the “Duck, Cover and Hold” strategy as the best way to survive such an event, the drills are largely limited to public buildings such as schools, offices and hospitals.
The public should likewise be continuously educated on what to do in specific situations: whether indoors, lying in bed, in a high-rise building, inside a theater, stadium or a supermarket, outdoors, near the shore, or below a dam like Solong, San Miguel or Obi, Caramoran.
In a recent advisory, the Department of the Interior and Local Government (DILG) ordered local chief executives to strictly enforce critical earthquake and tsunami preparedness measures following the recent strong earthquakes that struck northern Cebu and eastern Mindanao.
Among others, it reminded LGUs to prioritize structural assessments of public and private buildings, especially critical infrastructure, and prohibit reoccupation of damaged structures unless declared safe.
Gov. Azanza’s instruction to the Provincial Engineering Office (PEO) to assess the integrity of buildings and maintain an updated inventory of the structures is proper.
But given the limited number of engineers at the PEO who would certainly focus on province-owned structures, there has to be a coordinated effort in this structural assessment among the PEO, DPWH, the CatSU College of Engineering, and municipal engineering offices.
Even technical personnel of contractors and retired civil engineers should be tapped to help carry the burden of checking every public building as well as thousands of private homes whose owners may not be fully aware of the hazards they face.
Nothing less than collaboration and teamwork will accomplish the job of limiting casualties in an inevitable earthquake event in the near future.