Shallow Volcanic and Tectonic Quakes Dominate Mount Lokon Activity

The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) recorded that shallow volcanic and tectonic earthquakes dominated the activity of Mount Lokon in Tomohon, North Sulawesi, during the period of 16-31 May 2026. Mount Lokon is currently closed to climbers, and communities, especially those in areas around rivers originating from the volcano, are urged to remain vigilant. “Also recorded were 36 emission earthquakes, 11 deep volcanic earthquakes, two felt earthquakes at scale III MMI, and 89 distant tectonic earthquakes,” said Acting Head of the Geological Agency, Lana Saria. Based on visual observations of Mount Lokon’s activity, thin white smoke emissions were observed with a maximum height of approximately 50 metres above the crater, and a flame was visible at the base of the crater on 29 May 2026. The seismicity of Mount Lokon is dominated by shallow volcanic earthquakes (VB), while deep volcanic earthquakes (VA) are rarely recorded. Meanwhile, volcanic activity based on visual and seismic data has not yet shown any increase. The current potential hazard from Mount Lokon’s activity is the possibility of toxic gases that could escape from the crater at any time. Additionally, phreatic eruptions, or eruptions caused by the contact of hot magmatic steam with hydrothermal water, can occur suddenly. Communities residing along river channels originating from the summit of Mount Lokon are advised to be alert for lahar floods during the rainy season or when heavy rain falls at the summit for extended periods. Based on a comprehensive analysis and evaluation up to 31 May 2026, the activity level of Mount Lokon remains at Level II (Alert), with recommendations adjusted to the current potential hazards. The public, visitors, tourists, and climbers are prohibited from conducting activities and approaching the area within a 1.5-kilometre radius of Tompaluan Crater. In the event of an eruption and ashfall, residents are advised to stay indoors, and if outdoors, to use protection for the nose, mouth (mask), and eyes (glasses).