By Ellalyn De Vera-Ruiz
A joint team of Taiwanese and Filipino researchers has identified four previously unknown fault zones branching from the Philippine Fault Zone beneath the sea off western Luzon.
The discovery, published in the Journal of Asian Earth Sciences on July 3, raises concerns about heightened earthquake and tsunami hazards in the region.
The analysis revealed that one of the fault branches appears to connect directly to the Manila Trench, a major undersea feature known to generate powerful earthquakes and tsunamis.
Seismic data also showed that the trench bends by about 35 degrees southward, aligning with the Philippine Fault Zone in central Luzon.
Researchers noted that the Earth’s crust beneath this area is tearing at depth, with the northern slab dipping gently and the southern slab dipping steeply.
This deformation is linked to simultaneous tectonic processes: the southeastward collision of the Palawan Microcontinental Block and the northwestward docking of Benham Rise.
The effects of these fault zones could be significant:
- Increased risk of major earthquakes along western Luzon.
- Potential for tsunami generation if ruptures occur near the Manila Trench.
- Greater complexity in predicting seismic activity due to overlapping tectonic forces.
Researchers stressed that identifying these structures is crucial for improving hazard assessments and strengthening earthquake preparedness for communities living near these zones.
