By Ellalyn de Vera-Ruiz

A 4.6-magnitude shallow earthquake jolted Davao del Sur on Tuesday—an aftershock of the 6.9-magnitude earthquake last December 15.

The Philippine Institute of Volcanology and Seismology (Phivolcs) recorded the earthquake at around 2:07 p.m. and traced its epicenter at 6 kilometers southwest of Magsaysay, Davao del Sur.

It was felt as a “strong” tremor at Intensity V in Hagonoy, Davao del Sur, and “moderately strong” earthquake at Intensity IV in Davao City.

Kidapawan City felt the earthquake as a “weak” shaking at Intensity III.

The 4.6-magnitude earthquake is an aftershock of the destructive 6.9-magnitude temblor in Davao del Sur last Sunday.

Phivolcs said the 6.9-magnitude quake followed the recent earthquake events (5.9-magnitude on July 9, 6.3-magnitude October 16, 6.6-magnitude and 6.1-magnitude October 29, and 6.5-magnitude on October 31) in the area.

The shaking was felt as far as 300 kilometers away from the epicenter.

Davao Region in southern Mindanao is one of the seismically-active regions in the country because of the presence of several active faults that include the Tangbulan Fault, Central Digos Fault and Cotabato Fault System.

The Cotabato Fault System, which includes the Makilala-Malungon, Makilala, M’lang, North Columbio, South Columbio, and Balabag, triggered the recent destructive earthquakes in October.

Phivolcs is particularly looking into the Tangbulan Fault as the possible source of the 6.9-magnitude tremor.

There are other nearby local faults in Davao Region, some of which may be covered by recent deposits, that could be sources of small to strong magnitude earthquakes, it added.