A study conducted by the Philippine Institute of Volcanology and Seismology (Phivolcs) has projected that a magnitude 7.2 earthquake along the West Valley Fault could cause the collapse of at least 168,000 buildings and result in the deaths of over 33,000 people in Metro Manila and surrounding provinces.
The West Valley Fault is an approximately 100-kilometer-long active fault line that traverses portions of the provinces of Bulacan, Rizal, Laguna, Cavite, and the areas of Quezon City, Pasig City, Marikina City, Taguig City, and Muntinlupa City.
In an interview, Phivolcs Senior Science Research Specialist Bhenz Rodriguez said that the agency is closely monitoring all active fault lines in the country.
“Based on our last earthquake record, the most recent earthquake that occurred close to the West Valley Fault is a magnitude 1.5 earthquake that occurred in Dona Remedios Trinidad in Bulacan last March 14.”
However, Rodriguez clarified that the minor earthquake occurred near the West Valley Fault, but it was not the fault itself that generated the quake.
The last recorded major earthquake by the West Valley Fault was in 1658, and it is forecasted by experts to generate major earthquakes every 200 to 400 years.
With the recent magnitude 7.7 earthquake in Myanmar and magnitude 7.1 earthquake in Tonga, the Phivolcs research specialist clarified that these earthquakes are “not directly related” to the Philippines.
“The Philippines is within the Pacific Ring of Fire, so earthquakes are unavoidable, and from time to time, we might experience these. The earthquakes normally occurring in the Philippines,” Rodriguez said.
He further explained the potential impact of strong earthquakes, noting that a magnitude 7.2 quake could reach Intensity 8, causing severe ground shaking that would make it difficult for people to stand and result in buildings and debris falling.
"Other earthquake-related hazards include liquefaction, ground ruptures, landslides, and tsunamis," Rodriguez added.
Office of the Civil Defense Undersecretary Ariel Nepomuceno emphasized in a radio interview the importance of infrastructural integrity amidst the threat of a strong earthquake.
“We need to catch up especially on engineering solutions. The buildings, infrastructures, and bridges should be strong enough to hold on in times of a strong earthquake,” Nepomuceno stressed.
With various earthquake drills and evacuation plans, is the country ready for The Big One?
“It’s a tough question. We should be ready, especially in Metro Manila. In case the West Valley Fault moves, that’s why we’re conducting drills to visualize what our best response could be in case of a major earthquake,” the Phivolcs official emphasized.