1 minute read
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?
Advertisement
● 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 segment of the PFZ. There are also other potentially active faults in Masbate, including the Uson Fault and Southern Masbate Fault.
Where Are the Major Fault Lines in the Philippines?
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?
