State seismologists continue to detect aftershocks following the powerful 6.4-magnitude earthquake that shook the provinces of northern Luzon on Oct. 25.
The Philippine Institute of Volcanology and Seismology (Phivolcs), in its latest count as of Thursday, Nov. 3, said a total of 1,203 aftershocks have already been recorded after the “very strong” Abra quake.
Of the 1,203 recorded quakes ranging from magnitudes 1.3 to 4.8, only 417 were plotted while 26 were felt. Plotted quakes, as disclosed by Phivolcs earlier, were detected by three or more stations. Recorded earthquakes, on the other hand, were logged by at least one seismic station.
Meanwhile, the epicenter of the said quake was traced 5 kilometers (km) northeast of Lagayan, Abra.
“The seismicity in Abra and vicinity can be attributed to the presence of several active faults in the region such as the Abra River Fault, West Ilocos Fault System, Bangui Fault, Naglibacan Fault, Manmanoc Fault, as well as the offshore presence of the Manila Trench, west of the province,” said Phivolcs in its earthquake primer issued on Oct. 26, 2022.