23 aftershocks felt after 6.0-magnitude Masbate quake

Plot of the 16 February 2023 Magnitude 6.0 Masbate earthquake and aftershocks as of 16 February 2023, 1:00 p.m.. (COURTESY OF PHIVOLCS)

The Philippine Institute of Volcanology and Seismology (Phivolcs) has so far recorded over 300 aftershocks following the magnitude 6.0 earthquake that struck Batuan, Masbate on Feb. 16.

As of 8 a.m., Friday, Feb. 17, Phivolcs had detected 329 aftershocks, with magnitudes ranging from 1.5 to 4.2.

Of the recorded earthquakes, 75 earthquakes have been plotted by three or more stations, while 23 tremors were felt.

“We can expect aftershocks to occur in the epicentral area, but occurrences of moderate aftershocks are not discounted. These may continue for several days to weeks, some of which may be felt,” Phivolcs said.

The 6.0-magnitude earthquake, which occurred at 2:10 a.m. on Feb. 16, has an epicenter located 11 kilometers southwest of Batuan, Masbate and an estimated depth of 10 kilometers.

“In case of another strongly felt earthquake, it is recommended that people protect themselves by doing the ‘drop, cover, and hold.’ In homes and offices, heavy furniture and appliances should be strapped to the walls, and hanging objects securely fastened to prevent these from causing injuries,” Phivolcs advised the public.

It also asked the public to be cautious of structures visibly weakened or showing signs of damage caused by the 6.0-magnitude earthquake, as these could be further damaged by subsequent earthquakes and injure building occupants.

Moreover, Phivolcs warned against sharing messages from “unconfirmed” and “unreliable” sources. It advised the public to rely only on information from Phivolcs and the respective Disaster Risk Reduction and Management Offices.

According to Phivolcs, earthquakes occur in Masbate because it is one of the seismically active regions in the country and has active faults that include the Masbate and Sibuyan Sea Segments of the Philippine Fault, and potentially active faults that include the Uson Fault and Southern Masbate Fault.

It added that there are other nearby local faults, some of which may be covered by recent deposits, and offshore active faults that could be sources of minor to strong earthquakes.