On June 8, 2026, at 07:37:40 PhST (23:37:40 UTC on June 7), a 7.8 earthquake struck offshore southern Mindanao in the Philippines. The United States Geological Survey located the epicenter approximately southwest of Kablalan at a depth of about , while the Philippine Institute of Volcanology and Seismology located it south of Maasim, Sarangani, at a depth of . PHIVOLCS attributed the earthquake to subduction associated with the Cotabato Trench.

At least 106 people died, over 1,300 were injured and 7 were reported missing in Mindanao. The earthquake was among the most destructive in the country in five decades. The city of General Santos, and the provinces of Sarangani and South Cotabato in Soccsksargen and Davao Occidental in Davao, were the worst affected. Across Mindanao, over 138,500 homes were damaged or destroyed, along with numerous buildings and facilities; the towns of Sarangani, Jose Abad Santos, Glan and Malapatan had the highest percentage of homes affected, while more than 30% of homes were damaged in General Santos. The earthquake also caused severe damage, one death and several injuries on the Sangihe and Talaud Islands of North Sulawesi, Indonesia.

Tectonic setting

Mindanao lies across the convergent boundary between the Sunda plate and the Philippine Sea plate. Part of the oblique convergence between these plates is taken up by subduction along the Cotabato Trench. The strike-slip component of the convergence is accommodated partly by the Philippine fault system and partly by the Cotabato fault system, a network of NW-SE trending sinistral (left-lateral) strike-slip faults that form the boundary between the Cotabato Arc and the Central Mindanao volcanic belt. In 1976, a magnitude 8.0 earthquake and tsunami along the same trench killed 8,000 people.

The Cotabato Trench lies off the southwestern coast of Mindanao where oceanic crust of the Sunda Plate beneath the Celebes Sea subducts beneath the Philippines Mobile Belt. It forms part of a linked set of trenches along the western side of the Philippines formed over east-dipping subduction zones, including the Manila Trench and the Negros Trench. At its northern end the rate of convergence across this boundary is about per year. It is a relatively young structure, forming during the late Miocene to Pliocene; this age is consistent with the estimated age of the sedimentary rocks in the accretionary wedge associated with the trench and the age of adakitic arc rocks on Mindanao thought to date the onset of subduction. Major earthquakes in 1918 and 1976 were associated with ruptures on its southern and northern sections, respectively. The latter event involved a long, northwest-striking, rupture of the subduction zone beneath the Moro Gulf.

Earthquake

The Philippine Institute of Volcanology and Seismology initially reported a magnitude of , before revising the magnitude up to 7.8. The United States Geological Survey and European-Mediterranean Seismological Centre put the magnitude at and recorded a depth of and , respectively. The Meteorology, Climatology, and Geophysical Agency of Indonesia placed the moment magnitude at 7.7, along with a depth of . Shaking was estimated to have lasted for around 30seconds.

The earthquake was caused by thrust faulting on a north-south-striking, west-dipping fault or a north-northwest-striking, east-northeast-dipping fault. It occurred near the southern tip of Mindanao, close to where the northwest trending Cotabato Trench joins the north-south trending Sangihe Trench. The earthquake likely occurred because of a rupture along the northern Sangihe Trench or southern Cotabato Trench, or a combination of both scenarios. The entire rupture process was complete in about 70 seconds, releasing a seismic moment equivalent to 6.14×10 N⋅m.

Intensity A maximum Mercalli intensity of IX (Violent) was estimated by the USGS. According to the USGS Prompt Assessment of Global Earthquakes for Response service, approximately 10,000 people were within the zone of intensity IX in parts of Sarangani, including areas of Glan. An additional 1.405 million people were within the zone of intensity VIII (Severe), including the cities of General Santos, Polomolok, and other areas of Glan, while 2.91 million others were exposed to intensity VII (Very strong) shaking across Soccsksargen, Davao and Bangsamoro, as far away as the cities of Digos and Davao City. At least 5.93 million people were exposed to intensity VI (Strong) shaking across southern and central Mindanao, including Tagum and Cotabato City. On the PHIVOLCS earthquake intensity scale, a maximum intensity of VIII (Very destructive) was recorded at Malapatan, Sarangani. Tremors were felt as far as Abuyog and Dulag, Leyte at PEIS II (Slightly felt). In Indonesia, the earthquake was felt with an intensity of VI (Strong) at Miangas and Melonguane, V (Moderate) at Siau, Tagulandang and Sangihe Islands, IV (Light) in Morotai, Tolitoli and North Halmahera Regency and III (Weak) at Batang Dua Islands, Ternate, West Halmahera, Gorontalo, South Halmahera, East Halmahera, Parigi Moutong, Manado, Minahasa, Palu, Bitung, East Bolaang Mongondow, and Central Halmahera. Tremors were also felt in Tawau, Semporna and other parts of Sabah in Malaysia. A maximum peak ground acceleration of 173.4 gal (0.177 g) was recorded by a BMKG seismic station at Melonguane.

+PEIS reported intensitiesIntensity ScalesLocationVIIIGlan, Kiamba, Malapatan, and Malungon, Sarangani; General SantosVIIDon Marcelino and Jose Abad Santos, Davao Occidental; Alabel, Maasim, and Maitum, Sarangani; Koronadal and Tupi, South CotabatoVILake Sebu, Polomolok, T'Boli, Tampakan, and Tantangan, South Cotabato; Lutayan and Palimbang, Sultan KudaratVSibuco and Siocon, Zamboanga del Norte; Buug, Zamboanga Sibugay; Mabini, Maco, and Pantukan, Davao de Oro; Bansalan, Digos, Hagonoy, Kiblawan, Magsaysay, Malalag, Matanao, Padada, Santa Cruz and Sulop, Davao del Sur; Davao City; Banaybanay, Boston, and Governor Generoso, Davao Oriental; Arakan, Carmen, Matalam, and President Roxas, Cotabato; Banga, Norala, Santo Niño and Surallah, South Cotabato; Bagumbayan, Esperanza, Kalamansig, Lambayong, Lebak, President Quirino and Tacurong, Sultan Kudarat; Upi, Maguindanao del Norte; Cotabato CityIVZamboanga City; Kibawe, Kitaotao, Quezon, and Valencia, Bukidnon; Tagum, Davao del Norte; Caraga, Cateel, Lupon, Manay, Mati, and Tarragona, Davao Oriental; Banisilan, Kidapawan, M'lang, and Magpet, Cotabato; Isulan, Sultan Kudarat; Isabela, BasilanIIIBaybay, Leyte; Dapitan, Zamboanga del Norte; Kumalarang and Vincenzo A. Sagun, Zamboanga del Sur; Baungon, Damulog, Dangcagan, Don Carlos, Impasugong, Kadingilan, Kalilangan, Lantapan, and Malaybalay, Bukidnon; Sultan Naga Dimaporo, Lanao del Norte; Iligan; Balingasag and Jasaan, Misamis Oriental; Cagayan de Oro; New Bataan, Davao de Oro; Baganga, Davao Oriental; Alamada, Cotabato; Columbio, Sultan Kudarat; Butuan; Mainit, Surigao del Norte; Madrid, Surigao del Sur; Bongao, Tawi-TawiIIAbuyog, Dulag, Javier, and Palo, Leyte; Hinundayan, Libagon, Saint Bernard, San Francisco, and San Juan, Southern Leyte; Dipolog, Labason, Liloy,President Manuel A. Roxas, and Salug, Zamboanga del Norte; Molave, Zamboanga del Sur; Alicia, Ipil, Mabuhay, Olutanga, and Siay, Zamboanga Sibugay; Libona, Bukidnon; Tubod, Lanao del Norte; Oroquieta and Plaridel, Misamis Occidental; Magsaysay, Misamis Oriental; Laak, Davao de OroICarcar, Cebu; Panaon, Misamis Occidental

Reported MMI intensities in IndonesiaIntensity ScalesLocationVIMiangas and Melonguane, North SulawesiVSiau, North Sulawesi; Tagulandang, Sangihe Islands Regency, North SulawesiIVMorotai Regency, North Maluku; North Halmahera, North Maluku; Manado, North Sulawesi

Ground effects Numerous landslides occurred in southern Mindanao. Of these, 70 caused damage, primarily in Glan and Jose Abad Santos. One landslide in Patulang, Jose Abad Santos measured 15 ha (37 acres), with some others in the town measuring 60 ha (150 acres). An unspecified barangay in southern Mindanao was also almost completely buried. The Philippine Space Agency (PhilSA) identified approximately 137.87 ha (340.68 acres) of land affected by landslides in Sarangani and Davao Occidental.

Along of coastline spanning the southern tip of Mindanao, primarily the towns of Glan in Sarangani and Jose Abad Santos in Davao Occidental, the earthquake raised the area's coastline by up to and moved it up to seawards, exposing coral reefs and other previously submerged areas, and affecting the local marine environment.

Tsunami PHIVOLCS issued a tsunami warning for the provinces of Sarangani, Davao Occidental, Tawi-Tawi, Sulu, Basilan, Zamboanga del Sur, Zamboanga Sibugay, Sultan Kudarat, and South Cotabato, which prompted the evacuation of all residents and businesses living in the coastline of the identified provinces. Around 10,000 families in Sarangani and Sultan Kudarat were evacuated. BMKG also issued a tsunami warning and evacuation of residents in Gorontalo, Maluku Islands, Sulawesi, Borneo and Sangihe Islands. In Malaysia, tsunami advisories were issued by the Malaysian Meteorological Department for four beaches in Sabah, which include Tawau, Semporna, Kunak, and Lahad Datu. The Pacific Tsunami Warning Center said parts of the Philippine coastline could experience waves while waves could hit the Indonesian and Malaysian coast. A tsunami advisory was also issued for the Pacific coast of western and eastern Japan, ranging from Ibaraki Prefecture to Okinawa Prefecture. The Japan Meteorological Agency warned of waves reaching in Miyako Island and the Yaeyama Islands.

Two people drowned while a third went missing in the Philippines when they were swept out into the sea off General Santos; four others were rescued. A subsequent survey revealed a maximum run-up height of and run-in distance at Lebak, Sultan Kudarat. The tsunami also travelled upstream via a nearby rivermouth. At Salaman, eyewitness account stated that the tsunami arrived about 20 to 25 minutes after the earthquake, the highest run-up was , and flowed inland. The tsunami damaged stilt homes and carried boats inland at Kalamansig; the survey recorded a inundation distance and wave height. On Balut Island, the tsunami carried large boulders and deposited them onto a reef flat. One boulder was displaced by the waves.

In Indonesia, tsunami waves were detected at Kedi in North Maluku province, Ulu Siau, and Melonguane, with the waves detected ranging from , with the highest recorded measurement at Talengan-Sulut at . PHIVOLCS reported tsunami waves along six areas in Mindanao's southern coast between 07:42 and 08:45PHT measuring . A tsunami was also recorded in two locations in Palau. In Japan, waves measuring were observed in the Ogasawara Islands and Kushimoto, Wakayama, while tsunami waves were also observed in Okinawa Prefecture.

+ Tsunami observations in the Philippines Location Tsunami height Kiamba, Sarangani Kalamansig, Sultan Kudarat Maasim, Sarangani Zamboanga City Mati, Davao Oriental Tandag, Surigao del Sur

+ Tsunami observations in Indonesia Location Tsunami height Talengen, North Sulawesi Paleleh, Central Sulawesi Melonguane and Tanjung Sidupa, North Sulawesi Tahuna, North Sulawesi Bitung, North Sulawesi Ulu Siau, North Sulawesi Ternate, North Maluku Loloda, North Maluku

Aftershocks PHIVOLCS recorded more than 8,500 aftershocks as of June 19, including three + events, the largest measuring 6.5.

Impact Philippines