Mount Sinabung Eruption Could Be Followed by Larger Explosion
The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) stated that the eruption of Mount Sinabung in Karo Regency, North Sumatra, on Monday afternoon was an initial eruption, meaning there remains a possibility of a larger explosion.
“This eruption serves as an initial eruption, and the possibility of a larger eruption cannot be ruled out,” said the Head of the Geological Agency, Lana Saria, in Jakarta on Monday.
She confirmed that the development of Mount Sinabung’s volcanic activity will continue to be monitored, and activity levels will be evaluated periodically or whenever significant changes occur to serve as a basis for field preparedness actions.
Mount Sinabung was previously detected by the Geological Agency’s volcanology team to have erupted on 31 August 2026, at 10:17 WIB, with an eruption column reaching approximately 3,500 metres above the peak, or about 5,960 metres above sea level.
A thick, black ash column was observed leaning towards the east and southeast. The eruption was recorded on a seismogram with a maximum amplitude of 120 millimetres.
The Geological Agency recorded 85 volcanic earthquakes, one inflation earthquake, and one harmonic tremor recorded before the eruption at 10:17 WIB.
Based on the results of visual and instrumental monitoring, the Geological Agency raised Mount Sinabung’s activity level from Level II (Alert) to Level III (Standby) starting from 31 August 2026, at 12:30 WIB. Mount Sinabung had been at Level II since 17 May 2023.
At Level III (Standby) activity, the public, visitors, and tourists are requested not to engage in any activities in villages that have been relocated, and to remain outside a three-kilometre radius from the peak of Mount Sinabung and a sectoral radius of six kilometres towards the south-southeast.
Residents living near rivers that originate from Mount Sinabung are also advised to be wary of the potential danger of lahars.
Monitoring from 1–30 August 2026 showed that Mount Sinabung emitted white and grey smoke from the main crater with intensities ranging from thin to thick and heights of approximately 50–1,000 metres from the peak.
Additionally, vegetation on the eastern slopes was observed to be yellowing and drying up.
The Geological Agency has requested that the public remain calm, increase vigilance, and follow the directions of the North Sumatra Provincial BPBD and the Karo Regency BPBD.
Local governments are also requested to continue coordinating with the Sinabung Volcano Observation Post in Ndokum Siroga Village, while information regarding the development of volcanic activity can be accessed through the official PVMBG Geological Agency applications and channels.