A magnitude 5.6 earthquake was felt by some residents in this northern part of Luzon at 5:19 p.m. on Sunday, state seismologists said.
Located at 18 km. northeast of Maconacon in Isabela province, the earthquake was tectonic in origin with a depth of 55 km., according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
Some residents also felt Intensity V in Penablanca; Intensity IV in Gonzaga, Cagayan; Intensity III in Ilagan, Isabela; and Intensity II in Casiguran, Aurora, as well as in the cities of Laoag, Batac, and Pasuquin town in Ilocos Norte, Santiago City in Isabela, Tabuk City in Kalinga, and Madella in Quirino province.
Intensity 1 was logged in Bangued in Abra, Baler and Diapaculao in Aurora, Vigan City and Sinait in Ilocos Sur, and Bayombong in Nueva Vizcaya.
While expecting no damage, residents in these areas were advised to take precautionary measures as aftershocks are expected, authorities said.
Reported intensity is the traditional way of knowing the intensity based on reports of people who felt the earthquake.
Instrumental intensity, on the other hand, is measured using an intensity meter that measures ground acceleration.
CURRENTPH NEWS SERVICE