TEMPO.CO, Jakarta - Mount Lewotobi Laki-laki's alert status has been raised from Level III (Siaga) to the highest Level IV (Awas) today, September 6, 2025, at 10:00 local time. This action was taken by the Center for Volcanology and Geological Hazard Mitigation (PVMBG) due to increased volcanic activity, reversing a status downgrade from August 23.
The head of the Geological Agency, Muhammad Wafid, attributed the recent status change to the escalating volcanic activity of the volcano, which is located in East Flores, East Nusa Tenggara. Wafid noted that seismic data from the volcano over the past week showed a significant increase in harmonic tremors and volcanic earthquakes.
"This indicates the presence of a new magma supply at depth and the migration of magma from the shallow zone toward the surface, although the movement is relatively slow," Wafid stated in his official release on Saturday, September 6, 2025.
The volcano, which stands at 1,584 meters above sea level, has recently experienced various seismic events, including one avalanche earthquake, seven emission earthquakes, and three harmonic tremor earthquakes. Additionally, there were 131 non-harmonic tremor earthquakes, 20 low-frequency earthquakes, 53 deep volcanic earthquakes, seven local tectonic earthquakes, and 31 distant tectonic earthquakes.
"Continuous tremors on September 6, 2025, indicate that magma is approaching the surface and has the potential for an explosive eruption," he added.
Visual observations from the Mount Lewotobi Laki-Laki volcano monitoring team showed that the summit was partially obscured by medium-intensity mist. The main crater was seen emitting thin to thick white smoke, which rose 50 to 1,000 meters above the volcano's surface.
"The air temperature is around 17.1-40.0 degrees Celsius. There were avalanches, but visually, the distance and direction of the flow were not observed," he reported.
Despite the heightened seismic activity, Mount Lewotobi Laki-Laki has not erupted in the past week. According to Wafid, this suggests that the magma conduit is currently blocked, which leads to increased seismic activity without the release of energy through an eruption.
Furthermore, on September 5, 2025, a shallow volcanic earthquake was recorded, an event that is uncommon for Mount Lewotobi Laki-Laki. "Because Mount Lewotobi Laki-Laki is an 'open system,' materials from inside can move to the surface without barriers," Wafid explained.
Wafid also noted that the volcano's body is showing signs of slow swelling, as indicated by deformation monitoring using a tiltmeter. This condition requires close attention due to its potential to trigger an eruption. "GNSS data actually shows a deflation tendency, indicating that volcanic activity is more dominant at shallow depths," he said.
In response to the elevated risk, Wafid urged the public to avoid all activities within a six-kilometer radius of the eruption center, with an extended exclusion zone of seven kilometers in the southwest-southeast sector.
Residents in disaster-prone areas are also advised to be vigilant for potential lahar flows in the event of heavy rainfall, particularly in river basins originating from the peak of Mount Lewotobi Laki-Laki, such as those in Nawakote, Dulipali, Nobo, Hokeng Jaya, and Nurabelen.