By Priam Nepomuceno

JOLT. Residents flock to the Provincial Health Office in Tandag City, Surigao del Sur after a magnitude 7.4 earthquake at 10:37 p.m. Saturday (Dec. 2, 2023). Aftershocks as strong as 6.2 were recorded past midnight Sunday (Dec. 3). (Photo courtesy of PIA-Caraga)

MANILA – A magnitude 7.4 earthquake struck Surigao del Sur on Saturday night, with a tsunami warning immediately issued by the Philippine Institute of Volcanology and Seismology (Phivolcs).

The epicenter was recorded east of Hinatuan at 10:37 p.m.

Phivolcs first recorded it at magnitude 6.9.

Intensity VII (Destructive) was felt in Tandag City; Intensity VI (Very Strong) in Bislig City; and Intensity V (Strong) in Cagayan de Oro City; Nabunturan, Davao de Oro; and Davao City.

By Sunday past midnight, strong aftershocks were recorded by Phivolcs at 12:03 a.m., magnitude 6.1, Lingig, Surigao del Sur; 12:19 a.m., magnitude 5.1, Hinatuan; and 12:53 a.m., magnitude 5.7, also in Hinatuan.

They were followed by magnitudes 6.2 at 1:40 a.m., 5.0 at 1:55 a.m., and 5.2 at 3:36 a.m. — all in Hinatuan.

In between, there were several aftershocks ranging from magnitudes 1.9 to 4.5.

Several videos posted on social media showed residents fleeing their communities and going to evacuation centers. 

Phivolcs urged residents in coastal areas of Surigao del Sur and Davao Oriental to immediately evacuate to higher ground or move farther inland amid the threat of a tsunami.

“Based on the local tsunami scenario database, it is expected to experience wave heights of more than one meter above the normal tides and may be higher on enclosed bays and straits. Destructive tsunami is expected with life-threatening wave heights,” the agency warned. 

Tsunami warning lifted

At 3.23 a.m. Sunday, Phivolcs reported that the last recorded tsunami wave arrival occurred at 2:52 a.m. at Hinatuan-Bislig Bay Station on Mawes Island.

“This means that the tsunami threat associated with this earthquake has now largely passed the Philippines,” the Phivolcs advisory said.

The local governments of threatened coastal areas were asked to assess the tsunami’s impact.  

Evacuation

Meanwhile, the powerful quake triggered thousands from different areas in the province to leave their houses when Phivolcs issued the tsunami warning.

Residents in coastal areas of Tandag and Bislig cities, and the municipalities of Carrascal and Cortes were advised to stay in the evacuation centers until the tsunami warning was lifted.

The tremor also damaged infrastructures in the different parts of the Caraga Region.

In the municipality of Hinatuan, Mayor Shem Garay formed a Damage Assessment and Needs Analysis team to check on government buildings, roads and bridges, schools and other establishments.

In Tagbina town, a landslide occured Saturday evening, rendering a portion of the Tagongon-Sta Maria-Sta Juana-Bislig Road impassable.

In Bislig City, a bridge in Barangay Mangcarogo was damaged and travelers have been advised to take extra precautions when crossing.

NDRRMC on ‘blue alert’

The National Disaster Risk Reduction and Management Council (NDRRMC) was placed on “blue alert” status as it monitors the effects of the powerful quake.

In a memorandum released Sunday morning, Assistant  Secretary Hernando Caraig Jr., Civil Defense Deputy Administrator for Operations, directed the Armed Forces of the Philippines, Bureau of Fire Protection, Philippine Coast Guard, and Philippine National Police to deploy personnel to render duty at the NDRRMC Operations Center to ensure seamless coordination.

Under the blue alert status, half of the agency’s officials must be on standby to ensure that there will be enough manpower in case of an emergency.

Meanwhile, the Office of Civil Defense in the Davao Region and Caraga is on “red alert” status to also closely monitor developments. (With reports from Alexander Lopez, Priam Nepomuceno/PNA)