MANILA – Researchers from the University of the Philippines have identified four previously unmapped fault zones beneath the seabed west of Luzon, a discovery that could improve scientists’ understanding of earthquake hazards and strengthen disaster preparedness in the country.
The findings were published in a peer-reviewed study conducted by researchers from the University of the Philippines Diliman in collaboration with National Central University in Taiwan. The research was also highlighted by the University of the Philippines Office of the Vice President for Academic Affairs (OVPAA), which said the newly mapped offshore structures appear to branch from the northern segment of the Philippine Fault Zone (PFZ).
According to the researchers, the discovery offers new insights into how the Philippine Fault Zone extends beneath the sea and interacts with the Manila Trench, one of the country’s major offshore tectonic features capable of generating powerful earthquakes and tsunamis.
Using high-resolution seafloor bathymetry, seismic reflection profiles, and other advanced geophysical imaging techniques, the research team mapped four offshore fault zones that had not previously been identified. The study noted that the full offshore extent of the Philippine Fault Zone, particularly toward northwestern Luzon, has long remained uncertain.
One of the newly identified fault branches appears to connect the Philippine Fault Zone to the Manila Trench. Researchers said the structure may even divide the trench into two segments, providing new evidence of the region’s complex tectonic processes.
The study also found that the Manila Trench changes direction by approximately 35 degrees toward the south. Beneath this area, seismic data revealed signs of a tear within the Earth’s crust. According to the researchers, this deformation may result from two major tectonic interactions occurring simultaneously: the collision of the Palawan Microcontinental Block from the southwest and the influence of the Philippine Rise from the northeast.
The researchers emphasized that the discovery does not indicate that a major earthquake is imminent. Instead, the newly mapped fault zones provide scientists with a better understanding of where stress may accumulate beneath the Earth’s surface, helping improve seismic hazard assessments and future earthquake risk studies.
“These newly mapped faults and the tearing of the Earth’s crust can help explain how and where large earthquakes may happen in the future,” the researchers said in the UP OVPAA release. “By identifying these geologic structures, we can better understand the complex forces shaping Luzon and improve hazard assessments and earthquake preparedness.”
The Philippine Fault Zone is one of the country’s largest active fault systems, stretching for more than 1,200 kilometers from northern Luzon to eastern Mindanao. Together with the Manila Trench and the Philippine Trench, it forms part of the complex network of active faults and subduction zones created by the interaction of the Philippine Sea Plate and the Eurasian Plate.
The Philippines lies along the Pacific Ring of Fire, making it one of the world’s most earthquake-prone countries. Thousands of earthquakes are recorded annually, although most are too weak to be felt. Geological studies such as the latest UP-led research play a critical role in refining hazard maps, supporting infrastructure planning, and strengthening disaster risk reduction efforts.
The findings underscore the importance of continued investment in geologic research and seismic monitoring as government agencies and scientists work to improve the country’s resilience against future earthquakes and other tectonic hazards.
Sources: University of the Philippines Office of the Vice President for Academic Affairs; peer-reviewed research by the University of the Philippines Diliman and National Central University (Taiwan); Philippine Institute of Volcanology and Seismology (PHIVOLCS).
Si Venus L Peñaflor ay naging editor-in-chief ng Newsworld, isang lokal na pahayagan ng Laguna. Publisher din siya ng Daystar Gazette at Tutubi News Magazine. Siya ay isa ring pintor at doll face designer ng Ninay Dolls, ang unang Manikang Pilipino. Kasali siya sa DesignCrowd sa rank na #305 sa 640,000 graphic designers sa buong daigdig. Kasama din siya sa unang Local TV Broadcast sa Laguna na Beyond Manila. Aktibong kasapi siya ng San Pablo Jaycees Senate bilang isang JCI Senator.
- Venus L Peñaflor
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- Venus L Peñaflor
- Venus L Peñaflor
