Strong tremor shakes Cebu

CEBU CITY, PHILIPPINES — In the stillness of the early hours of Monday, around 1:06 a.m., residents of northern Cebu were jolted awake when a magnitude 5.8-tremor struck Bogo City, with shocks spreading southward across Cebu island and eastward across Leyte and Bohol islands.

The Philippine Institute of Volcanology and Seismology (Phivolcs) immediately posted a public advisory that the tremor was tectonic in origin and occurred at a depth of 10 kilometers, about 14 kilometers southwest of Bogo City.

Phivolcs said the quake was initially recorded as magnitude 6.0, but was later downgraded to 5.8 after a more detailed analysis. But the agency followed it up with a declaration that it was, after all, an aftershock only.

Phivolcs Director Teresito Bacolcol clarified that the event was an aftershock of the magnitude 6.9 earthquake that devastated northern Cebu on September 30, killing at least 75 people and injuring hundreds.

The Office of Civil Defense (OCD) echoed the Phivolcs findings to the public, saying that the magnitude-5.8 tremor that jolted northern Cebu yesterday (October 13) is not a doublet, but a strong aftershock of the magnitude-6.9 offshore earthquake, a month ago.

OCD Deputy Administrator, Asec. Rafaelito Alejandro IV, clarified this yesterday: “This is an aftershock of the September 30 earthquake po…as per Phivolcs,” Alejandro said. “Malakas ang shaking kahit aftershock siya…tuloy-tuloy pa rin ito.”

With this, OCD reminded everyone to stay alert. “Ang abiso namin, stay alert po muna, dahil malakas po ang iniaasahaang aftershocks dahil sa Sept. 30 earthquake,” he added.

In Cebu Province, even if the mag-5.8 tremor was an aftershock, local authorities immediately mobilized response teams to check on residents and assess possible damage.

Governor Pamela Baricuatro has ordered all department heads and local engineers to conduct a comprehensive assessment of public infrastructure, including roads, bridges, and hospitals, to ensure that they remain structurally sound.

Provincial authorities immediately raised the alert status to Red, mobilizing local disaster teams to conduct assessments across affected areas.

Cebu Provincial Public Information Officer Ainjeliz dela Torre-Orong said no new fatalities have been recorded as of yesterday morning. “Thankfully wala may recorded additional fatalities,” said Orong.

The Cebu Provincial Disaster Risk Reduction and Management Office (PDRRMO) reported that while the quake caused no fatalities, at least 14 individuals were injured and several infrastructures sustained additional damage. In San Remigio, two people were reported injured.

In Bogo City, seven individuals sustained various injuries—three suffered from chest pains, three had lacerations, one experienced an asthma attack, while another was reported for an accident. Meanwhile, Daanbantayan recorded four cases of minor injuries.

Orong added that the Bogo Provincial Hospital, which has recently resumed full operations after the September 30 quake, had to temporarily evacuate patients following yesterday’s aftershock. She said that some of the patients were still traumatized by the previous quake.

Water and power status

In Daanbantayan, PDRRMO reported a temporary water supply interruption due to damaged pipelines caused by the aftershock. Assessment and repair operations are ongoing. No power interruptions were reported in the affected LGUs.

Meanwhile, telecommunication services across Cebu remain stable, with no reported disruptions in mobile and internet connectivity.

However, the Hagnaya Port in San Remigio sustained structural damage, limiting operations pending further inspection by engineers.

Roads from Cebu City to Bogo City remain passable, while the Department of Public Works and Highways (DPWH) has standby clearing teams in Sogod to address potential road obstructions.

Classes and work suspensions

Monday’s strong aftershock prompted widespread class suspensions across Cebu. Municipalities and cities including Carmen, Sogod, Daanbantayan, Bantayan, Bogo, Medellin, Tuburan, Borbon, Catmon, San Remigio, Toledo, Naga, and Carcar, among others, suspended classes in all levels until further notice.

In Sibonga, classes were officially suspended from October 13 to 17, while Minglanilla and Consolacion suspended classes from October 13 to 14. The Municipality of San Fernando opted for a shift to remote learning, suspending all face-to-face classes.

In Moalboal, three schools—San Juan High School, Moalboal National High School, and Moalboal Elementary School—halted classes temporarily. Meanwhile, in Oslob, the suspension applied only to Oslob National High School and Saint Mary’s Academy.

In Carcar City, local authorities declared a half-day suspension of work for government employees, citing the need to inspect facilities and ensure worker safety before full operations resume.

Hagnaya Port declared safe 

Following an assessment of the Port of Hagnaya, which sustained damage from the September 30 earthquake that struck northern Cebu, the Cebu Port Authority (CPA) has declared the port generally safe for continued operations.

However, the CPA emphasized that port activities will proceed under strict safety measures. Among the temporary conditions to be implemented are:

1. Alternate use of the remaining berths by Island Shipping Corporation and Asian Marine Transport Corporation (Shuttle Ferry) because one berthing area remains unusable;

2. Only the rightmost ramp will be used during high tide for the safe loading and unloading of rolling cargoes and passengers;

3. Vehicles must be loaded and unloaded directly, with no parking or standby allowed within port premises; and

4. Periodic structural inspections will be conducted, and operations may be suspended depending on findings.

CPA said that port operations continue as normal during low tide, while only three trips at 1:00 a.m., 2:00 a.m., and 3:00 a.m. are affected during extreme high tide.

Earlier, CPA officials led by General Manager Kit Comendador met with the local government unit of San Remigio and shipping lines to discuss operational adjustments and safety protocols.

The coordination meeting was also attended by Municipal Engineer Alex O. Caayon and Fhaye Mondigo of the IDP Evacuation Camp Site on behalf of San Remegio Mayor Mariano R. Martinez.

CPA assured the public that these measures are aimed at ensuring uninterrupted and safe maritime transport services at Hagnaya Port while structural repairs and monitoring are ongoing.

October 13 tremor not doublet 

A doublet is defined as a two distinct, strong earthquakes occurring close in time and location. Alejandro emphasized that this is not the same scenario as in Davao Oriental.

The Davao Oriental doublet experienced a magnitude-7.4 quake at 9:43 a.m. on October 10, followed by a magnitude-6.8 quake at 7:12 p.m. that same day. Phivolcs classified both events as separate mainshocks.

In Cebu, the October 13 aftershock registered Intensity V in Bogo City, Daanbantayan, Medellin, San Remigio, Tabogon, Daanbantayan, and Tabuelan.

Intensity IV was felt in the cities of Cebu, Lapu-Lapu, Mandaue, Danao, Talisay, and Toledo, and the towns of Asturias, Balamban, Bantayan, Carmen, Catmon, Compostela, Consolacion, Liloan, Pinamungajan, Sogod, and Tuburan.

The quake was also strongly felt in Villaba, Leyte, Escalante, Negros Occidental, Iriga City and as far as Camarines Sur in the Bicol region, confirming its wide reach.

Alejandro reported that the shaking caused blackouts in Bantayan, Madridejos, and Sta. Fe, and that many residents remain outside their homes.

“Marami pa pong lumabas sa mga bahay nila, marami pang mga kababayan din na natutulog pa rin sa labas,” he said, adding that Phivolcs has recorded nearly 11,000 aftershocks since September 30. The previous strongest aftershock in Bogo was magnitude 5.1, recorded on October 3.

As of press time, 75 deaths and over 600 injuries have been reported out of the Bogo earthquake. A minor rockfall was cleared along the national highway in Sogod, and damage assessments are ongoing.

Meanwhile, Phivolcs also recorded earthquakes in other parts of the country yesterday, including San Felipe in Zambales, Loreto and Dinagat Island, Puerto Galera in Oriental Mindoro, Tingloy and Calatagan in Batangas, Cadiz City and Sibulan in Negros Occidental, San Jose in Romblon, Fuga Island and Aparri in Cagayan, Paluan in Occidental Mindoro, and Vigan in Ilocos Sur.

This underscores the widespread seismic activity across the archipelago. The past few weeks also had numerous earthquakes, occurring in different parts of the country.

The earlier Davao Oriental earthquake also caused ground movement in parts of Cebu, further highlighting the region’s vulnerability within the Pacific Ring of Fire.

“We are in the Pacific Ring of Fire…Talagang inaasahan itong mga ganito … Nakakalungkot lang po na medyo ramdam ang lindol,” added Alejandro.

Phivolcs has temporarily taken its FaultFinder tool offline due to system security concerns. The public is advised to use HazardHunterPH (https://hazardhunter.georisk.gov.ph/map) for updated geohazard assessments.

The OCD and the NDRRMC remain on red alert, with all agencies mobilized for round-the-clock monitoring and coordination.