Photo by Cristan Pago via Gov. Joey Salceda
The PHIVOLCS has warned the public on this as it advised local government units (LGUs) in Bicol to formulate contingency measures as what is being done in Metro Manila where officials are in a dash to come up with precautionary plans to minimize destruction should the long fault line underneath areas, where most parts of the metropolis sits on, cause a catastrophic scenario.
PHIVOLCs records show that the unnamed Sorsogon fault line moved in the morning of July 2, 1954, triggering an intensity 7 earthquake whose epicenter was traced somewhere between this city and the then town, now city, of Sorsogon, the provincial capital.
The same records say that based on the report of the Commission on Volcanology (COMVOL), PHIVOLCS’s forerunner, the quake was strong enough to be felt in as far the island of Iloilo down south and Camarines Norte up north.
The epicenter of that earthquake was located some 380 kilometers southeast of Manila and in the immediate vicinity of the towns of Sorsogon and Bacon (now combined as the Sorsogon City), said the PHIVOLCS records.
It was the strongest earthquake that hit Bicol Region so far, killing 13 persons—12 in Sorsogon and one, a construction worker who was thrown down by the quake from a tall building he was working on, in this city, according to the PHIVOLCS records.
It also injured over 100 other persons in Sorsogon while various public structures, one of them a Spanish-era bridge, crumbled to ruins while church belfries in the area collapsed, it said.
“It was the strongest quake I’ve ever experienced in my life. I was 16 years old and a high school student in Sorsogon when it happened at past 10:00 a.m., sending us in panic for almost a minute as the earth shook intensely, moving almost everything around in a trembling manner,” Rosalina Ortiz, a 70-year-old retired public school teacher here, recalled to the Philippines News Agency.
There were no tall buildings yet then, that was why not much damages to life and properties happened, she added.
That earthquake was tectonic in origin, described by then COMVOL chief Arturo Alcaraz in a report still being kept by the PHIVOLCs here, triggered by the sudden dislocation of the Earth’s crust along the plane of fracture that approximates the line joining the (then) towns of Bacon and Sorsogon.
Alcaraz, in the same report, drew such conclusion from facts that “the earthquake was felt over a large area and that earthquakes of volcanic origin are perceptible only in the vicinity of active volcanoes like Mayon in Albay and Bulusan in Sorsogon.
According to the PHIVOLCS, the still-unnamed fault line underneath Sorsogon might once more move to trigger an earthquake of similar or even stronger intensity, so that local authorities, particularly disaster risk reduction and management councils in Bicol provinces, cities, towns and barangays, more particularly in Albay and Sorsogon, are advised to come up with contingency or disaster mitigation plans.
The agency is more concerned over Sorsogon, which sits between two earthquake generators-- the Philippine Fault near the island of Masbate and the Philippine Trench in the Pacific Ocean.
Early this year, PHIVOLCS chief Renato Solidum warned that strong quakes may hit Bicol due to the region’s proximity to the Philippine Trench which is active and capable of triggering up to magnitude 8 earthquake.
Recently, a 4.2-magnitude temblor, whose epicenter was traced by the PHIVOLCS at 39 kilometers northeast of Prieto Diaz, Sorsogon, was felt at intensity 3 in some part of the province.
Wilfredo “Pecos” Intia, the city administrator and action officer of the City Disaster Risk Reduction and Management Council (CDRRMC) here, on Sunday said “we are now in the process of reviewing our existing contingency plan for the purpose of enhancing it against strong earthquakes.”
Initially, he said, the regular earthquake drills being done in schools and government offices will now be also conducted in crowded public structures around the city like transport terminals, hospitals, malls, hotels, restaurants, churches and movie houses, among others.
The conduct of tsunami drills will also be in regular basis in barangays along and near the shorelines of the city, according to Intia.
“We are also considering the inspection by the City Engineering Office of both commercial and government buildings to determine their structural integrity while for those that are ongoing construction, monitoring would be made to ensure that the building standards for safety and resistance to earthquakes are followed,” he said.
While they city is said to be not directly above the fault line, Intia said, getting ready for any related eventuality remains a concern in a 24/7 fashion insofar as the local government and the CDRRMC are concerned.
“Earthquakes, like any other forms of disaster-causing natural occurrences, do not give precursors and the best way to mitigate its possible impacts is preparedness—the way we do in the city,” he added. (By Danny O. Calleja, PNA)