A 4.2-magnitude earthquake shook Ilocos Sur at around 10:26 a.m., Friday, March 18, said the Philippine Institute of Volcanology and Seismology (Phivolcs).
Phivolcs traced the epicenter of the earthquake at 18 kilometers (km) southwest of San Esteban, Ilocos Sur. It was shallow at a depth of 23 km.
It said the quake was “slightly weak” at Intensity II in Sinait, Ilocos Sur.
Phivolcs’ instruments also measured the earthquake at Intensity III in Vigan City; Intensity II in Sinait, Ilocos Sur; and Intensity I in Pasuquin, Ilocos Norte.
Meanwhile, Phivolcs said the earthquake was tectonic in origin, which means it was caused by the movement of an active fault near the area.
However, it does not expect damage or aftershocks due to this earthquake.