Mount Anak Krakatau status escalated to Alert Level III

Indonesia has elevated the alert status of Mount Anak Krakatau to Level III (Alert) following a comprehensive analysis of its recent activity. Lana Saria, Acting Head of the Geological Agency, announced the change, which became effective on July 2, 2026, moving from Level II (Caution).

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Based on a comprehensive analysis and evaluation, the activity level of the Anak Krakatau volcano has been raised from Level II (Caution) to Level III (Alert), effective from July 2, 2026, at 4:30 PM WIB.

A strict hazard zone of 3 kilometers has been imposed around the active crater. The public, tourists, and climbers are forbidden from entering this area due to the risks posed by pyroclastic flows, lava, flying volcanic rocks, and heavy ashfall. Authorities urge heightened vigilance among those in surrounding areas.

Observations since June 1, 2026, using Sentinel Satellite data, revealed SO2 emissions and thermal anomalies. By June 10, active fire spots appeared within the crater, accompanied by high-intensity smoke emissions and a sharp rise in shallow volcanic earthquakes. Between June 18 and 19 alone, the number of emission, hybrid, and low-frequency earthquakes averaged over 50 per day.

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The public surrounding Mount Anak Krakatau, alongside visitors, tourists, and climbers, are strictly barred from entering or engaging in any activities within a 3-kilometer radius from the center of the mountain's activity, and they are urged to heighten vigilance against the threats of pyroclastic flows, lava, flying volcanic rocks, and heavy ashfall.

While tectonic earthquake activity remained stable, the surge in shallow volcanic seismic activity indicates magma movement close to the surface. Data from June 16 to July 2 recorded hundreds of various types of volcanic earthquakes. Tiltmeter data also showed fluctuating patterns, with some stations indicating a low-scale inflationary trend. On June 26, increased emission earthquakes were noted, along with volcanic ash plumes drifting westward.

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While this was not accompanied by an increase in tectonic-volcanic earthquakes (Volcanic A and Volcanic B) or deformation tremors, the surge in shallow volcanic seismic activity indicates magma dynamics near the surface of the Anak Krakatau volcano.