A series of offshore earthquakes near Santa Catalina in Ilocos Sur has been linked to the Manila Trench, raising the possibility of a magnitude 8.4 earthquake and a subsequent tsunami, according to a GMA News report citing the Philippine Institute of Volcanology and Seismology (PHIVOLCS).
Since the morning of December 17, PHIVOLCS has recorded 49 tremors in the area, with magnitudes ranging from 1.8 to 5.0. These movements are attributed to the Manila Trench, an ocean trench west of the Philippines reaching depths of 5,400 meters. In a worst-case scenario, this geological activity could trigger a tsunami with waves between three to 15 meters high.
PHIVOLCS’ tsunami simulation divided the trench into four segments to evaluate risks. The simulation revealed that a tsunami caused by a high-magnitude earthquake could reach the shores of Zambales, Pangasinan, La Union, Ilocos Sur, Ilocos Norte, and Cagayan within two to 15 minutes. Palauig, Zambales, could experience the earliest impact in just two minutes, while Vigan, Ilocos Sur, might see the highest waves at nearly 15 meters.
While PHIVOLCS highlighted that earthquakes and tsunamis remain unpredictable, the agency urged coastal communities to stay alert for warning signs, including strong ground shaking, abrupt sea level changes, or unusual noises from the sea.
