Anak Krakatau After 11 September 2026: How to Check Official Updates and Spot Hoaxes

The clearest answer is this: as of the latest dated official evaluation verified for this article, Anak Krakatau remained at Level III (Siaga), with a 3-kilometre exclusion zone around its active centre. The Geological Agency’s 11 September 2026 bulletin also said eruption probability remained high, but it did not establish a new October status. Readers should therefore treat any post claiming a fresh October change as unverified until it is matched with a dated notice from an authorised agency.

This article was prepared on 14 October 2026. Searches of official Geological Agency and related government pages found September bulletins, including the 11 September evaluation, but no newer October 2026 Anak Krakatau status notice that could be independently verified here. That boundary matters: the absence of a bulletin in this review is not proof that activity has stopped or that the level has changed.

What did the official 11 September update actually say?

The report from the Geological Agency’s Centre for Volcanology and Geological Hazard Mitigation (PVMBG) evaluated observations through 06.00 WIB on 11 September. It recorded one eruption earthquake, 21 low-frequency earthquakes, 13 hybrid or multi-phase earthquakes, continuous tremor, 28 shallow volcanic earthquakes and 18 deep volcanic earthquakes during 10–11 September. The report said the continuous eruption episode that began at 23.07 WIB on 4 September ended at 00.04 WIB on 6 September after about 25 hours. By 11 September, 14 Strombolian eruptions had occurred after that episode.

PVMBG said the volcanic system was still being monitored and evaluated. It described the probability of another eruption in the following periods as still high. The hazards named in the notice were incandescent-rock ejecta, heavy ashfall and, if continuous eruption returned, lava flows. The official recommendation was to keep people, tourists, climbers and boats out of the 3-kilometre radius from the activity centre.

Does Level III mean that every viral warning is true?

No. Level III, or Siaga, is an official activity level; it is not confirmation of every photograph, video, evacuation message or tsunami prediction circulating online. It must be read together with the date, the agency’s observations and its current recommendations. PVMBG’s 11 September notice specifically told coastal communities in Banten and Lampung to stay calm and not believe claims that an Anak Krakatau eruption would automatically cause a tsunami.

BMKG’s role is different but complementary. In its 7 September release, BMKG reported ash detected up to 15,000 feet in the latest SIGMET period and described higher-altitude ash extending toward the Indian Ocean. It also said eight airports were temporarily closed as a flight-safety measure. BMKG reported that 20 tsunami gauges around the Sunda Strait detected no sea-level anomaly indicating a tsunami at the time of its monitoring, while its HF radar assessment placed tsunami probability in the low category, below 50 percent. Those were time-specific observations, not a permanent guarantee about future conditions.

How can readers separate official information from a hoax?

Check the issuing agency first. Look for a dated release on PVMBG or the Geological Agency website, MAGMA Indonesia, BMKG, BNPB, BPBD or the relevant local government. A screenshot without a source link is not an official bulletin.
Match the claim to the agency’s job. PVMBG evaluates volcanic activity and exclusion zones. BMKG publishes weather, volcanic-ash aviation information and geophysical monitoring. A social-media account cannot replace either agency.
Check the date and time. A real video from July, September or an earlier eruption can be reposted as if it happened today. The Geological Agency’s 4 July hoax report said a boat video was not a recording of the current Anak Krakatau eruption and warned against sharing unverified footage.
Reverse-search unusual images or video. AFP Fact Check found that the widely shared boat video had appeared online in November 2025, carried an AI warning label and showed visual inconsistencies. That verification is a reminder to inspect the original upload, not just the caption.
Do not confuse a recommendation with an evacuation order. The verified PVMBG notices cited here set a 3-kilometre exclusion zone. Posts claiming a different distance must show a newer official notice before they are trusted.

What do we know, and what remains unclear?

What we know: the latest dated evaluation verified for this report, issued on 11 September, kept Anak Krakatau at Level III (Siaga), described continuing volcanic dynamics and retained the 3-kilometre restriction. September government communications also documented ash impacts, aviation precautions and ongoing multi-agency monitoring. Banten’s provincial government urged residents in ash-affected areas to use respiratory protection and follow BPBD guidance.

What remains unclear: this review does not establish a verified October 2026 change in alert level, exclusion radius, eruption frequency or coastal conditions. Those details can change after a new evaluation. Until a newer notice appears, readers should not infer a downgrade, escalation, tsunami, airport closure or evacuation from a viral post alone.

Where should the public check the next update?

Start with the Geological Agency and PVMBG at geologi.esdm.go.id, PVMBG’s MAGMA Indonesia, and BMKG at bmkg.go.id. For local instructions, check Banten BPBD and the relevant district or city government. The Geological Agency’s 11 September notice also listed the Pasauran observation post and PVMBG contact channels. Share the link and publication time with a warning; do not forward a cropped image as if it were the latest official decision.