The magnitude-7.2 earthquake spawned more than 100 aftershocks in about 24 hours, including a sharp jolt felt in Davao Oriental and neighboring provinces Saturday afternoon.
According to Philippine Institute of Volcanology and Seismology science research assistant Gienela Pondevida, 141 aftershocks with magnitudes from 2.1 to 5.6 have so far been recorded as of 10 a.m. yesterday.
Only one, which is the magnitude-5.6 tremor last Saturday afternoon, was felt, Pondevida said.
The magnitude-5.6 earthquake, recorded at around 5:13 p.m., was felt at Intensity 2 in Manay, Davao Oriental and Intensity 1 in Gingoog City in Misamis Oriental, Kiamba and Alabel in Sarangani, Tupi in South Cotabato, and General Santos City.
Pondevida said aftershocks may continue in the next few days but will not be as strong as the magnitude-7.2 tremor.
She also noted that the earthquake was likely generated by the Philippine Trench.
Phivolcs noted that Eastern Mindanao is one of the most seismically active areas in the country because of the Philippine Fault and Philippine Trench, which are the main earthquake generators that can affect the area.
Likewise, there are other local faults, which can be sources of small- to large-magnitude earthquakes.
An average of 20 earthquakesare recorded by Phivolcs all over the country daily. Earthquakes are frequent in the Philippines because of several active faults surrounding or crisscrossing the country.
Phivolcs record earthquakes almost every day but some of them are too weak to be felt. (Ellalyn V. Ruiz)