A magnitude 7.4 earthquake struck the eastern seaboards off Davao Oriental on Friday morning, making it the third tremor to hit the Philippines since Sept. 30.

The epicenter of the offshore quake that was first recorded at magnitude 7.6 was monitored at 43 km northeast of Manay, Davao Oriental around 9:43 am.

At 7:12 pm, an aftershock with magnitude 6.9, later revised to 6.8 struck in Manay. The town recorded the highest intensity of six. Officials raised a tsunami warning in Surigao del Norte, Surigao del Sur and Davao Oriental.

In the morning quake, children were herded by teachers from their schools to open spaces, people teemed out of buildings and government offices. The shaking, according to news reports, lasted at an average of 30 seconds.

The highest reading, Intensity V, was felt even as far as Surigao del Norte. A tsunami warning was issued but lifted at 1:43 pm.

President Ferdinand Marcos Jr ordered government agencies to respond swiftly to the emergency.

In a radio interview, Philippine Institute of Volcanology and Seismology (Phivolcs) Director Teresito Bacolcol said the tremor that has a depth of 23 km was probably due to the movement of the Philippine trench.

Phivolcs said Intensity V was felt in "Compostela, Maco, Mawab, Monkayo, Montevista, Nabunturan, and Pantukan, Davao De Oro; Asuncion, Braulio E. Dujali, Carmen, New Corella, City Of Panabo, Island Garden City of Samal, Santo Tomas, and City of Tagum, Davao Del Norte; City of Davao; Jose Abad Santos, Davao Occidental; Cateel, and City of Mati, Davao Oriental; City of Kidapawan, Cotabato; Alabel, Glan, and Malungon, Sarangani; City of Koronadal, Tampakan, and Tupi, South Cotabato; City of General Santos; City of Butuan; Claver, Gigaquit, and Mainit, Surigao Del Norte."

Intensity IV was also reported over the "City of Tacloban; Don Carlos, and San Fernando, Bukidnon; Bansalan, City of Digos, Hagonoy, Kiblawan, Magsaysay, Malalag, Padada, Santa Cruz, and Sulop, Davao Del Sur; Don Marcelino, and Santa Maria, Davao Occidental; Antipas, Banisilan, Kabacan, Magpet, Pigkawayan, President Roxas, and Tulunan, Cotabato; Kiamba, Maitum, and Malapatan, Sarangani; Banga, Polomolok, And Tantangan, South Cotabato; General Luna, Malimono, Placer, and City of Surigao, Surigao Del Norte; City of Cotabato, City Of Cotabato."

Intensity III was felt in the "City of Iloilo; Arteche, Balangiga, City of Borongan, Can-Avid, Giporlos, Guiuan, Hernani, Lawaan, Llorente, Mercedes, Salcedo, San Julian, San Policarpo, and Sulat, Eastern Samar; Abuyog, Alangalang, Albuera, Babatngon, City Of Baybay, Burauen, Calubian, Capoocan, Carigara, Dagami, Dulag, Hilongos, Isabel, Jaro, Javier, Kananga, Leyte, Macarthur, Mahaplag, Matag-Ob, Mayorga, Merida, Palo, Palompon, Pastrana, San Isidro, Santa Fe, Tanauan, Tolosa, Tunga, and Villaba, Leyte; Ormoc City, Ormoc City; Bobon, Mapanas, and Palapag, Northern Samar; Basey, City of Catbalogan, Gandara, Marabut, San Jorge, and Villareal, Samar; Anahawan, Bontoc, Hinunangan, Hinundayan, Libagon, Liloan, Limasawa, City of Maasin, Macrohon, Malitbog, Padre Burgos, Pintuyan, Saint Bernard, San Francisco, San Juan, San Ricardo, Silago, Sogod, And Tomas Oppus, Southern Leyte; City of Malaybalay, and Manolo Fortich, Bukidnon; City of Iligan; City of Cagayan De Oro; Sarangani, Davao Occidental; Matalam, And Pikit, Cotabato; Maasim, Sarangani; Norala, Santo Nino, Surallah, and T'boli, South Cotabato; Bagumbayan, Kalamansig, Lebak, and City of Tacurong, Sultan Kudarat."

Intensity II was also felt in areas of "Casiguran, and Juban, Sorsogon; City of Dumaguete, and Sibulan, Negros Oriental; Culaba, Biliran; Dimataling, Zamboanga Del Sur; City of Zamboanga; City of Tangub, Misamis Occidental; Aleosan, Cotabato; Lake Sebu, South Cotabato."

Aside from the reported intensities, Instrumental Intensity V was also recorded in "Hinunangan, Southern Leyte; City of Gingoog, Misamis Oriental; Nabunturan, Davao De Oro; City of Davao; Santa Maria, Davao Occidental; City of Kidapawan, Cotabato; Alabel, and Malungon, Sarangani; City of Koronadal, and Tupi, South Cotabato."

Instrumental Intensity IV in the "City of Cebu; Sulat, Eastern Samar; Abuyog, Alangalang, Dulag, Hilongos, and Javier, Leyte; Hinundayan, Silago, and Sogod, Southern Leyte; Molave, Zamboanga Del Sur; Kalilangan, City of Malaybalay, and San Fernando, Bukidnon; City of Cagayan De Oro; City of Digos, Magsaysay, and Matanao, Davao Del Sur; Banisilan, M'lang, and Magpet, Cotabato; Glan, Kiamba, Maitum, And Malapatan, Sarangani; Banga, Polomolok, and Tampakan, South Cotabato; City of General Santos; Columbio, and Palimbang, Sultan Kudarat; City of Cabadbaran, Agusan Del Norte; City of Surigao, Surigao Del Norte; City of Bislig, Surigao Del Sur."

Instrumental Intensity III in areas of "Argao, Cebu; City of Borongan, and Can-Avid, Eastern Samar; Carigara, Palo, And Villaba, Leyte; Ormoc City; Palapag, Northern Samar; City of Catbalogan, and Gandara, Samar; City of Maasin, Southern Leyte; Kadingilan, and Maramag, Bukidnon; Mambajao, Camiguin; Pikit, and President Roxas, Cotabato; Maasim, Sarangani; Norala, Santo Nino, Surallah, T'boli, and Tantangan, South Cotabato; Bagumbayan, Esperanza, Isulan, Kalamansig, Lambayong, and President Quirino, Sultan Kudarat."

Instrumental Intensity II in "Talibon, Bohol; Asturias, Danao City, San Fernando, San Francisco, And City of Talisay, Cebu; Isabel, Leyte; Mapanas, and Rosario, Northern Samar; San Jorge, And Villareal, Samar; Padre Burgos, Southern Leyte; Sindangan, Zamboanga Del Norte; Dumingag, Zamboanga Del Sur; City of Zamboanga; Initao, Misamis Oriental; Alamada, and Carmen, Cotabato; City of Tandag, Surigao Del Sur" and Instrumental Intensity I over "City of Sorsogon, Sorsogon; City of Roxas, And Tapaz, Capiz; City of Iloilo; Culaba, Biliran; Albuera, Leyte; City of Dipolog, Zamboanga Del Norte; Tubod, Lanao Del Norte."

Phivolcs noted that damage and aftershock are expected while a tsunami warning was also issued following the powerful earthquake.

Office of Civil Defense Deputy Administrator for Administration Assistant Secretary Bernardo Rafaelito Alejandro IV said based on the warning issued by Phivolcs, the first wave of tsunami as high as one meter is expected from 9:43 am to 11:43 am.

"A tsunami warning has been issued urging people in the coastal communities of the following provinces to immediately evacuate to higher grounds or move further inland, so Eastern Samar, Dinagat Island,Davao Oriental, Southern Leyte, Surigao del Norte, Leyte and Surigao del Sur," he said.

"Those in the coastal areas of those above-mentioned provinces should secure their boats and move away from the waterfront, boats already at sea during this period should stay offshore in deep waters until further notice," he added.

"Tandag, Surigao del Sur sea level monitoring station for tsunami detection has recorded a tsunami wave height of around 30 centimeters at 10:20 am," it stated

"With this, any effects due to the tsunami warning have largely passed and therefore (Department of Science and Technology) DOST-Phivolcs has now cancelled all tsunami warnings issued for this event," it stated. Robina Asido/DMS