A combined total of 569 aftershocks have so far been recorded after the magnitude 7.4 and 6.8 ‘doublet earthquake’ hit Davao Oriental, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Friday.
According to Phivolcs, the aftershocks recorded as of 11 p.m., range from magnitude 1.2 to 6.8. Phivolcs director Teresito Bacolcol earlier said that these aftershocks could take up to several weeks.
The first of the doublet earthquake, the magnitude 7.4 earthquake, occurred at 9:43 a.m. with its epicenter located 62 kilometers southeast of Manay, Davao Oriental.
Afterward, the magnitude 6.8 temblor that hit less than 10 hours later at 7:12 p.m. was traced 36 kilometers southeast of the same town.
A doublet earthquake, according to Phivolcs, refers to distinct or different earthquakes that occurred in almost the same area ‘with two (or more) main shocks that have slight difference in magnitude.’
Both earthquakes were generated by the Philippine Trench.