Anak Krakatau Erupting Continuously Since July, Lava Fountains Reported
Another night of eruptions at Anak Krakatau has reinforced what Indonesia's Geological Agency has been tracking since early July: the Sunda Strait volcano is in a sustained period of heightened activity, and it shows no sign of stopping soon.
According to the Agency, the eruption was still ongoing as of 4:40 a.m. Western Indonesian Time on Saturday, 5 September 2026, with audible rumbling confirmed from the Krakatau Pasauran monitoring post. The bright red color of the eruption plume was clearly visible, even though the precise height of the ash column could not be measured.
A Night of Repeated Blasts
Seismograph data from the MAGMA Indonesia website shows the sequence began on the morning of Friday, 4 September, with a recorded maximum amplitude of 33 mm and a duration of 14 seconds at 4:11 a.m. Three further eruptions followed within the same morning hour, each with greater amplitude and slightly longer duration. After a period of relative quiet, a second cluster began at 10:03 p.m. that evening, with six eruptions recorded through to just after midnight.
The Geological Agency described the phenomenon as resembling a "lava fountain," one that produces actual lava flows. It also noted that multi-hour continuous eruptions are not unusual for this volcano.
Felt Across Three Provinces
The overnight activity was not confined to the strait. The Agency received public reports of booming sounds and ground vibrations from parts of West Java, Banten, and Lampung, occurring at the same time as the recorded eruptions. Officials consider these reports consistent with Anak Krakatau's activity.
The current elevated status dates to 2 July 2026, when the volcano was raised to Alert Level III. That is the third of four levels in Indonesia's volcanic alert system, and it has remained there continuously since.
No Tsunami Risk Assessed
For those aware of the December 2018 flank collapse that generated a deadly tsunami, the Geological Agency addressed the concern directly. It stated that the growth of Anak Krakatau's volcanic body since that event remains relatively small, and that there is no potential for a collapse on a scale that could trigger a tsunami.
Why It Matters for Hosts
Operators running guesthouses, dive resorts, or boat-tour businesses along the Banten and Lampung coastlines should keep a direct line to the MAGMA Indonesia website and the Geological Agency's official statements. Alert Level III carries a formal exclusion zone around the crater; any tour or transfer that brings guests near the island needs to be paused until the status changes. Beyond safety, proactive communication is key: guests arriving in the region may have heard about booming sounds or seen social media footage and will want reassurance or clear guidance. Maintaining updated cancellation and rebooking policies for volcano-related disruptions protects both guests and operators during extended activity periods like this one.
Details in this post were first reported by Tempo.co, based on statements from Indonesia's Geological Agency, published 5 September 2026.
First reported by en.tempo.co.