𝗡𝗘𝗪𝗦: “UP Researchers Discover Four New Fault Zones West of Luzon” by Ava Graciella Ainza
Layout by: Monique Baban
Published by: Rianna Isabel M. Tan
Date Published: July 7, 2026
Time Published: 1:02 PM
A multinational research team that included two geologists from the University of the Philippines Diliman, Leo T. Amarda and Carla B. Dimalanta, along with scientists from Taiwan, previously identified four unmapped fault zones beneath the sea west of Luzon.
The faults appeared to expand out from the main Philippine Fault Zone (PFZ), as per the study released by the UP office of the vice president for academic affairs (OVPAA), mentioned.
With the usage of high-resolution seafloor maps and seismic-reflection profiles, the researchers discovered four offshore fault zones that emerge from the northwestward extension of the Philippine Fault Zone.
It is explained that the southernmost branch may continue toward the Manila Trench, a known major offshore subduction zone west of Luzon, which can help clarify why the trench is divided into different segments.
Northern and southern sections descending beneath the region at different angles was found as evidence that the subducted slab central Luzon was ripped.
One of the faults’ branches appears to extend within the main fault to the Manila trench, a major undersea feature wherein the tsunamis and earthquakes can also come into existence.
Researchers said that the tearing may be caused by the two major geologic collisions happening at the same time, one from Palawan Microcontinental Block pushing from the southwest, and another from the Philippine Rise pushing from the northeast.
They also mentioned that it is important to understand how PFZ works as it is essential for earthquake risk reduction within the country.
The researchers added; by knowing geologic structures, a person can understand much more about the complex forces shaping Luzon, which can be the guide of improving hazard assessments and earthquake preparedness.
REFERENCES:
Cariso, B (2026, July 02). 4 new fault zones discovered in Luzon. Philstar Global.
https://www.philstar.com/nation/2026/07/04/2539653/4-new-fault-zones-discovered-luzon
Office of the Vice President of Academic Affairs (2026, July 02). Researchers have discovered four new fault zones beneath the sea west of Luzon, branching out from the main Philippine Fault Zone
OVPAA education ph.
https://ovpaa.up.edu.ph/research/researchers-have-discovered-four-new-fault-zones-beneath-the-sea-west-of-luzon-branching-out-from-the
-main-philippine-fault-zone/?fbclid=






