Where Are the Major Fault Lines in the Philippines?
Where Are the Major Fault Lines in the Philippines?
Earthquakes always happen somewhere, but this doesn’t mean you should be unconcerned when discussing such occurrences Experts revealed that magnitude 2 and smaller earthquakes happen over a hundred times daily. But what about higher-intensity earthquakes?
In the Philippines, the most destructive quake happened in 1968. An intensity eight earthquake jolted the town of Casiguran, Aurora, and severely impacted Metro Manila, where major buildings sustained varying levels of damage. It was also estimated that the overall property damage cost several million dollars.
Hence, one cannot dismiss the danger of living near earthquake fault lines. Such lines are located in places where two tectonic plates meet and where earthquakes could wreak much havoc
To determine if your current or future property stands in an earthquake-prone area, check out the Philippine fault line map below:
Where Are the Major Fault Lines in the Philippines?
Philippine Fault Zone
One explanation for why we experience several destructive quakes is the existence of the Philippine Fault Zone (PFZ), a 1,200-kilometer (km) tectonic feature that runs across the country. The Philippine fault zone starts from northwestern Luzon and ends in southeastern Mindanao, traversing the following areas:
Where Are the Major Fault Lines in the Philippines?
● Ilocos Region
● Nueva Ecija
● Quezon Province
● Masbate
● Leyte
● CARAGA Region
● Davao Gulf
● Davao Oriental
The PFZ has been the source of massive earthquakes in recent years, including the magnitude 7.7 Luzon quake (1990) and magnitude 6.2 Masbate earthquake (2003).
Most Notable Fault Lines in the Philippines
Guinayangan Fault
According to the 2020 data from the Philippine Institute of Volcanology and Seismology (PHIVOLCS), the Guinayangan Fault is an active fault traversing Quezon Province’s central portion, and is also a part of the PFZ.
The Guinayangan Fault can generate high-intensity quakes and was the cause of the magnitude 7 Ragay Gulf Earthquake During this event, intensity eight ground shaking was recorded in the areas of Guinayangan, Calauag, and Lopez in Quezon
Important to note: Magnitude and intensity measure different characteristics of an earthquake The former measures the energy released at the earthquake’s source The latter tells the strength of the ground shaking, determined by the quake’s effects on people and structures
Masbate Fault
Masbate is considered a seismically active region in the country, which explains the frequent quakes in the area Like the Guinayangan Fault, Masbate Fault is also a
Where Are the Major Fault Lines in the Philippines?
segment of the PFZ. There are also other potentially active faults in Masbate, including the Uson Fault and Southern Masbate Fault.
The movement of the PFZ caused the magnitude 6 6 earthquake that struck the province in August 2022 Nearby provinces impacted include Aklan, Albay, Biliran, Capiz, Leyte, and Negros Occidental
Vigan-Aggao Fault
Located in the westernmost part of the fault line in the Philippines, in northern Luzon, is the 140-km Vigan-Aggao Fault A study published in 2020 showed that the fault has four segments: Santa-Sinait, San Juan-Vintar, Bacarra-Burgos, and Pagudpud
Besides the Vigan-Aggao Fault, Ilocos Region could also be severely affected by the West Valley Fault, should the “Big One” or the worst-case scenario of an earthquake happen.
Where Are the Major Fault Lines in the Philippines?
Marikina Valley Fault System
Finally, we have the Marikina Valley Fault System, one of the most well-known and feared fault lines in the Philippines. It runs from Doña Remedios Trinidad in Bulacan and ends in Canlubang in Laguna. The active Philippine fault line system also traverses six cities in Metro Manila and the nearby provinces of Rizal and Laguna.
Where Are the Major Fault Lines in the Philippines?
There are several recognized faults within the Marikina Valley Fault System, but the most well-known are these two segments:
East Valley Fault
The East Valley Fault is around 10 km long and traverses the areas of Rodriguez and San Mateo in Rizal Province The fault reportedly moves roughly every 400 years and could generate a magnitude 7 2 quake and a casualty of over 30,000 people
West Valley Fault
Meanwhile, the West Valley Fault is 100 kilometers long and runs through the portions of Quezon City, Pasig, Marikina, Makati, Taguig, and Muntinlupa in Metro Manila and nearby provinces. The fault could trigger the “Big One” and be followed by a tsunami, according to PHIVOLCS.
Knowing these major and active Philippine fault lines, it becomes clear why earthquakes frequent different parts of the country. If you live in a high-risk area or near a fault line in the Philippines, go beyond doing the duck, cover, and hold. Retrofit your house, create a disaster plan, and put together an emergency kit.
For those who plan to acquire real estate in the Philippines, go for a quake-proof property or choose a location away from the hazardous areas on map of the fault lines in the Philippines
Sources: PHIVOLCS, eFOI, MDPI Open Access Journals, PNA
