Two earthquakes hit Mindanao, aftershocks rattle region

By: Aianna Xyril Monsod
December 03, 2023

Two earthquakes strike Mindanao early morning with strong intensities, causing widespread damage. Photo courtesy of VOA News.

Two earthquakes struck Mindanao, triggering tsunami alerts on Saturday night, December 2. The first earthquake had a magnitude of 7.4, while the second one happened not too long after at 6.1 as reported by the Philippine Institute of Volcanology and Seismology (PHIVOLCS).

PHIVOLCS described the initial quake that occurred off the coast of Hinatuan, Surigao del Sur on Saturday, 10:37 p.m. at a depth of 32 kilometers.

The Pacific Tsunami Warning Center, citing the temblor's size and depth, anticipated a tsunami impact. PHIVOLCS issued a corresponding alert. 

Meanwhile, residents of Surigao del Sur and Davao Oriental coastal areas were urged to evacuate to higher ground.

On Sunday midnight at 3:23 a.m. PHIVOLCS withdrew the tsunami alert. The data indicating that the highest waves generated by the seismic activity were minimal, reaching only 0.64 meters (25 inches) on Mawes Island which led the agency to conclude that the tsunami threat had subsided.

Super Radyo dzBB Davao’s casualty report states a woman in Tagum City, Davao del Norte, passed away after a collapsed house wall fell on her due to the magnitude 7.4 earthquake. She was taken to a hospital but was declared dead upon arrival.

Over 500 aftershocks were recorded, prompting PHIVOLCS to advise caution as individuals went back to their regular occupations. 

“Yung aftershocks would last for several days to several weeks. Habang tumatagal, lumiliit 'yung number ng aftershocks and magnitude," PHIVOLCS director Dr. Teresito Bacolcol said in an interview on Super Radyo dzBB.


The Big One

The Philippines is situated on the Pacific Ring of Fire, an arc of seismic faults encircling the ocean, making it vulnerable to natural calamities like earthquakes. An average of 20 earthquakes per day are reported by the PHIVOLCS, with approximately 100–150 of them being felt each year. 

Mindanao is surrounded by several major fault lines putting the region in a perilous location provoking earthquakes.

The "Big One" describes the worst-case scenario in the event that the West Valley Fault, which passes through the capital region, moves and causes an earthquake of magnitude 7.2.

“The damaging effects of earthquakes can be minimized if we prepare ourselves for the event. Because a large-magnitude earthquake, either from active faults in Luzon of the Manila Trench… it is always prudent to prepare for such eventuality.” PHIVOLCS advises.