The Philippine Institute of Volcanology (Phivolcs) cited the specific areas that will be affected by the estimated 7.2-magnitude earthquake upon the movement of the West Valley Fault.
In a 2024 Handa Pilipinas forum titled, “Maghanda: Communicating Hazards, Risks, and Early Warning Forum for Policymakers,” Phivolcs Geologist Jeffrey Perez said the West Valley Fault is located at a very long scope that can traverse many areas in the country, particularly in Metro Manila.
Perez said the fault passes through Bulacan, particularly in Doña Remedios Trinidad, Norzagaray, and San Jose Del Monte; Rodriguez, Rizal; areas in Metro Manila including Quezon City, Marikina City, Pasig City, Taguig City, and Muntinlupa; the province of Laguna with included areas such as San Pedro City, Biñan, Sta. Rosa, Cabuyao, and Calamba; and Cavite including Carmona, General Mariano Alvarez, and Silang.
“Magsisimula siya sa Angat reservoir, hindi niya tatamaan iyong Angat Dam, ang tatamaan niya iyong ipunan ng tubig (It will begin at Angat reservoir, it will not affect Angat Dam, what will be struck down is the reservoir),” said Perez.
Moreover, Perez said it will also transect major roads including C5, Ortigas, and Marcos Highway, as well as the South Luzon Express Way (SLEX).
Meanwhile, Perez said the West Valley Fault moves four times in 1,400 years with intervals of 400 to 600 years. The last earthquake from the West Valley Fault was in 1658.
“Tandaan, approximately, pwedeng iyang 400 ay maging 367, pwede namang 601, ang gusto nating sabihin dito is that posibleng magkaroon ng malakas na lindol in our generation or posible namang sa next generation that is why everybody must prepare (Remember, approximately, 400 years can be 367, it can also be 601 years, what we wanted to say is that it is possible to have a strong earthquake in our generation or in the next generation, so everybody must prepare),” he said.
Impacts
In Metro Manila, around 30,000 to 33,000 fatalities may arise, if the 7.2-magnitude quake occurs with also approximately 113,000 to 500,000 injuries.
Around 1,741,514 structural damages may be recorded in Greater Metro Manila, while 50,124 buildings may collapse, which amounts to P882,530 million economic loss, said Phivolcs.
In Region III (Central Luzon), 68,388 injuries and 3,033 deaths may be recorded, while Region IV-A may have 202,267 injuries and 10,053 casualties based on the 2010 PSA data, said Phivolcs.
Phivolcs advises the public to avoid the effects of ground rupture by refraining from constructing on top of an active fault, and that the houses and buildings should be at least five meters away from the trace of the fault.
Phivolcs also recommended tools that can be maximized in preparing oneself to be safe against tremors.
They included the REDAS (Rapid Earthquake Damage Assessment Software), which can simulate hazards including ground-shaking liquefaction, landslides, and tsunamis; the How Safe is My House, which is a self-check website to assess the safety of the homes; and the HazardHunter PH, which is used to provide reports on potential hazards based on the user's designated location particularly for the property owners and developers who require quick access to information and assessments on hazards.