ESDM Reports Increased Seismic Activity at Mount Karangetang

The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) has reported an increase in seismic activity at Mount Karangetang in the Sitaro Islands Regency, North Sulawesi. “During the period of 1-10 June 2026, two avalanche earthquakes, 44 emission earthquakes, 20 harmonic tremors, 47 non-harmonic tremors, and six hybrid/multi-phase earthquakes were recorded,” said Acting Head of the Geological Agency Lana Saria. The statement was made in a special report shared in the Info Gunung Api Sitaro chat group in Manado on Sunday. She added that 20 shallow volcanic earthquakes, 100 deep volcanic earthquakes, one local tectonic earthquake, nine felt earthquakes on the I-IV MMI scale, and 143 distant tectonic earthquakes were also recorded. The report noted that on 11 June 2026, volcanic activity at Mount Karangetang increased significantly, particularly deep volcanic earthquakes with 70 events recorded, while other types of earthquakes showed no increase. The following day, 12 June 2026, seismicity appeared to change, with 16 distant tectonic earthquakes, two local tectonic earthquakes, 15 deep volcanic earthquakes, eight shallow volcanic earthquakes, three emission earthquakes, 10 hybrid/multi-phase earthquakes, and one avalanche earthquake recorded. On 13 June 2026, data recorded 11 distant tectonic earthquakes, two felt earthquakes, four local tectonic earthquakes, 19 deep volcanic earthquakes, and six shallow volcanic earthquakes. The recordings also included 15 hybrid earthquakes, 10 avalanche earthquakes, seven emission earthquakes, 11 non-harmonic tremors, and one harmonic tremor. The increase in seismicity was not accompanied by visual anomalies, with the smoke column height remaining around 20 metres and other conditions not yet apparent. Based on the recorded seismic data, the volcanic activity at Mount Karangetang indicates an ongoing process of magma supply moving from the deep interior to the shallow subsurface. This is characterised by the recorded increase in shallow volcanic earthquakes and hybrid/multi-phase earthquakes, reflecting fluid movement at the surface that disrupts the equilibrium of the lava dome, resulting in avalanche earthquakes. The emergence of shallow volcanic, hybrid, and avalanche earthquakes following an increase in deep volcanic earthquakes indicates that the volcano is heading towards a lava dome formation phase or towards an eruption. This increase in seismicity warrants vigilance given the potential hazards of Mount Karangetang, which include magmatic eruptions and pyroclastic flows sliding towards valleys from the eruption centre of the north or south crater. The report also mentioned the potential for effusive eruptions, which are characteristic of Mount Karangetang, where lava domes or lava emerge and slide into valleys. With the increase in seismicity and occurrences of incandescent lava avalanches, the public is advised not to enter or conduct activities within a 1.5 kilometre radius of the north and south craters, and within 2.5 kilometres in the southwest and south sectors from the south crater. The public is urged to remain calm, comply with recommendations issued by the Geological Agency through the Centre for Volcanology and Geological Hazard Mitigation, and not be provoked by false or irresponsible news regarding Mount Karangetang’s activity.