Causes of M 7.7 Earthquake in Philippines Trigger Tsunami Warnings in Indonesia

The BMKG has revealed that the southern coast of Mindanao, Philippines, was struck by a tectonic earthquake, with the magnitude updated to M 7.7. The agency disclosed that the earthquake triggered tsunami early warnings in several regions across Indonesia.

“Considering the location of the epicentre and the depth of the hypocentre, the earthquake is a shallow-depth event resulting from tectonic plate subduction activity,” stated Wijayanto, Director of Earthquakes and Tsunamis at BMKG, on Monday (08/06/2026).

Analysis of the source mechanism indicates a thrust fault movement. This earthquake carries the potential for a tsunami, with several regions placed under ‘SIAGA’ (Alert) status. The areas potentially affected by the tsunami include Minahasa, Bolaangmongondow, Manado, North Minahasa, South Minahasa, Buol, Sangihe Islands, Gorontalo, Talaud Islands, Minahasa Islands, Toli-toli, Palu, Donggala, Ternate, and Bitung. Additionally, a ‘WASPADA’ (Warning) status has been issued for Tidore, Bulungan, Nunukan, Halmahera, Tarakan, North Halmahera, East Kutai, South Minahasa, Bontang, and Berau.

As of 07:00 WIB, BMKG recorded one aftershock with a maximum magnitude of M 6.7.

Via its X account, BMKG released the following list of regions under tsunami alert:

• ALERT (SIAGA): North Sulawesi, Sangihe Islands, Manado, North Minahasa (North/South), Minahasa Islands, South Minahasa (North/South), North Bolaangmongondow, Gorontalo (North), Buol, and Toli-toli.

• WARNING (WASPADA): Talaud Islands, Bitung, Halmahera, North Donggala, Ternate, East Kutai, Tidore, Bulungan, Nunukan, and North Halmahera.