Still on Alert! Latest Update on the Mount Anak Krakatau Eruption, 7 September
Jakarta, CNBC Indonesia — The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) has issued the latest update on the development of the eruption of Mount Anak Krakatau in Lampung Province, as of 7 September 2026 at 06.00 WIB.
In visual observations during the period of 6–7 September 2026, the volcano was clearly visible at times and covered in mist at others. “The weather was clear to overcast, with weak to moderate winds blowing towards the north and north-west. Air temperature was around 26–31°C. Visual and CCTV observations showed Strombolian eruptions occurring, with black eruption columns whose height could not be observed,” the Geological Agency explained on Monday (7/9/2026).
In instrumental observations during the period of 6–7 September 2026, 3 eruption earthquakes, 9 blowing earthquakes, 93 low-frequency earthquakes, 98 hybrid/multiphase earthquakes, 4 continuous tremor earthquakes and 1 shallow volcanic earthquake were recorded. The volcanic activity energy, as reflected by the averaged RSAM (Real-time Seismic Amplitude Measurement) value, increased on 5 September 2026 but decreased again on 6 September 2026.
“Tiltmeter data from the Tanjung station showed a tendency towards inflation in early August 2026, while the Lava93 tiltmeter station showed a flat pattern, indicating a constant condition with neither increase nor decrease,” the Geological Agency said.
Evaluation
One continuous eruption episode that began on 4 September 2026 at 23.07 WIB ended on 6 September 2026 at 00.04 WIB after lasting 25 hours. Three Strombolian eruptions occurred after the continuous eruption episode ended. The return of Strombolian eruptions — the current characteristic of Mount Anak Krakatau’s activity — is for the time being interpreted as the end of the rather long continuous eruption episode. Nevertheless, the development of the volcano’s dynamics continues to be monitored and evaluated.
The probability of an eruption occurring in the coming periods remains high. The hazards posed by the eruption come from incandescent rock ejections accompanied by heavy ash rain. Other potential hazards come from lava flows should a continuous eruption occur again.
“Based on the results of a comprehensive analysis and evaluation up to 7 September 2026, the activity level of Mount Anak Krakatau remains at Level III (Siaga/Alert),” the Geological Agency affirmed.
Accordingly, the Geological Agency recommends:
Communities around Mount Anak Krakatau and visitors/tourists/climbers are not permitted to enter or conduct activities within a 3 km radius of the centre of the volcano’s activity, and must heighten their vigilance against the hazards of pyroclastic clouds, lava, incandescent rock ejections and heavy ash rain.
Communities affected by volcanic ash from the eruption of Mount Anak Krakatau are advised to reduce outdoor activities or wear masks whilst active, in order to avoid respiratory problems.
Communities in the coastal areas of Banten and Lampung provinces are asked to remain calm and not to believe rumours that the eruption of Mount Anak Krakatau will cause a tsunami; they may carry out their activities as usual whilst continuing to follow the directions of the local disaster management agency (BPBD).
For further information, the public may contact the Centre for Volcanology and Geological Hazard Mitigation, Geological Agency, on (022) 7272606 in Bandung (West Java Province), or the Krakatau Volcano Observation Post on (0254) 651449 or 085846324506 in Pasauran (Banten Province). Communities, regional governments and relevant agencies can monitor the development of the volcano’s activity and recommendations through the Centre for Volcanology and Geological Hazard Mitigation’s application/website (www.vsi.esdm.go.id), Magma Indonesia (https://magma.esdm.go.id), the Geological Agency’s social media (Facebook, X and Instagram), and the Geological Agency’s website (www.geologi.esdm.go.id).
The activity level of Mount Anak Krakatau will be reassessed periodically or if there is a significant change in activity. The activity level and recommendations for Mount Anak Krakatau at Level III (Siaga) remain in force until the next evaluation letter/report is issued.