The Philippine Institute of Volcanology and Seismology (Phivolcs) has identified 18 cities and municipalities in Cebu that lie along fault lines.

These faults, collectively known as the Central Cebu Fault System, have the potential to generate strong to major earthquakes ranging from magnitude 6.4 to 7.1, with the epicenter possibly occurring within Metro Cebu.

Metro Cebu stretches from Cebu City to Danao City in the north, and from Cebu City to Carcar City in the south.

The Central Cebu Fault System cuts across several localities including Danao City, Compostela, Cebu City, Talisay City, Minglanilla, the City of Naga, Balamban and Toledo City.

Phivolcs has identified four major fault segments within the Central Cebu Fault System based on their length and historical fault activity.

The Balamban Fault and the Central Highway Fault can each generate earthquakes with magnitudes ranging from 6.4 to 6.9.

The Uling-Masaba Fault, the longest among the four at 50 kilometers, has the potential to produce a magnitude 7.1 earthquake — comparable to the 2013 Bohol earthquake.

Meanwhile, the Lutac-Jaclupan Fault, measuring 36 kilometers long, can also produce strong earthquakes with magnitudes between 6.4 and 6.9.

It extends northeast to Sirao in Cebu City and marks the contact point between the Mananga Group in Talisay City and the Bulacao Andesite and Malubog Formation in Cebu City.

Metro Cebu has previously experienced strong earthquakes from nearby faults. These include the magnitude 6.7 Negros quake on 6 February 2012; the magnitude 7.2 Bohol quake on 15 October 2013, which resulted in 15 deaths in Metro Cebu; and the most recent magnitude 6.9 Cebu quake on 30 September.

The Central Cebu Fault System transects numerous barangays. In the City of Naga, these include Patag, Balirong, Lutac, Cogon, Tagjagumit and Uling. In Toledo City, the affected barangays are Cantabaco, Camp 8, Pagamihan and Tungkay. In Minglanilla, the barangays include Guindarohan, Candulawan, Vito, Manduang, Cuanos, Camp 7 and Camp 8. In Talisay City, the affected areas are Tapul and Jaclupan. In Cebu City, the barangays impacted are Toong, Buhisan, Sapangdaku, Budlaan, San Jose, Pulangbato, Binaliw, Asungot, Mabini and Paril. In Balamban, the fault passes through Gaas, Sunog and Cabasiangan. In Compostela, it affects Barangay Mulao, while in Danao City, it crosses Barangays Licos, Ibo, Togonon and Baliang.

Beyond Central Cebu, other fault systems have been identified. The South Cebu Fault passes through Barangays Nangka and San Antonio in Boljoon; Nug-as in Alcoy; Lepanto, Guadalupe, Valencia, and Compostela in Alegria; and various barangays in Dalaguete, including Catolohan, Langkas, Caliongan, Obo, Dumalan, Babayongan, Bulak, Mantalongon, Maloray and Tabon. In Badian, the affected barangays are Candiis, Basiao, Patong, Basak, Talayong, Tiguib, Santicon, Tigbao and Busay. In Argao, the fault affects Canbantug, Butong, Tulang, Alambijud and Mompeller. In Sibonga, it includes Bae, Can-aga, Manatad, Papan, Libo and Sayo. In Carcar City, the affected areas are Guadalupe and Valencia.

The Bogo Fault affects Barangays La Paz, Anunang Norte, Malingin, Cayang, and Don Pedro Rodriguez in Bogo City, and extends to Barangays Argawanon, Hagnaya and Punta in San Remigio.

Meanwhile, the Daanbantayan Lineament passes through Barangays Bateria, Malbago, Tinubdan, Dalingding and Bitoon in Daanbantayan.

Phivolcs emphasized that this information is not intended to cause panic but to promote public awareness and disaster preparedness.