Anak Krakatau shows renewed activity, alert raised to Level III

JAKARTA: Indonesia's Anak Krakatau volcano has shown renewed activity, recording at least 13 eruptions on Friday and prompting authorities to raise its alert status to Level III, the second-highest level in the country's four-tier volcanic alert system.

The Geological Agency said the alert was raised from Level II effective 9 pm local time on Friday, following an assessment of volcanic activity since early this month.

"Signs of increased activity on a low scale began to emerge in early October 2026," the agency said in its assessment dated Oct 9.

It noted however, that seismic monitoring had not indicated a significant overall increase in volcanic earthquakes.

Anak Krakatau, located in the Sunda Strait between Java and Sumatra, was downgraded to Level II on Sept 21 following a reduction in volcanic activity, after remaining at Level III since early September.

The latest activity follows a series of major eruptions in early September that sent volcanic ash into the atmosphere, forcing temporary airport closures.

The event disrupted 2,961 flights and affected about 341,000 passengers.

According to eruption reports published on the Volcanology and Geological Hazard Mitigation Centre's (PVMBG) website, Friday's documented eruptions included one at 4.17pm that sent an ash column 250 metres above the summit, followed by another at 4.30pm with a 150-metre column.

Eleven further eruptions were recorded between 6.28spm and 9.20pm, although their ash columns could not be observed. PVMBG's full-day seismic monitoring recorded 26 eruption earthquakes.

Apart from Friday's 13 individually reported eruptions, Anak Krakatau recorded at least five others earlier this month — four on Oct 5 and one on Oct 8 — bringing the documented minimum to 18 since the beginning of October.

The Geological Agency said satellite monitoring detected sulphur dioxide emissions ranging from 71 to 237.5 tonnes per day between Sept 21 and Oct 9, while incandescence had been observed at the volcano since Oct 6.

Meanwhile, according to an advisory issued by Australia's Darwin Volcanic Ash Advisory Centre (VAAC), volcanic ash reached an altitude of about 1.8 kilometres above sea level at 10.50pm on Friday, drifting westward over the Sunda Strait towards the Indian Ocean at approximately nine kilometres per hour, before being forecast to dissipate within six to 12 hours.

The Geological Agency warned residents, visitors, and tourists of volcanic rocks, heavy ashfall, lava flows, and secondary eruptions, and prohibited all from entering a five-kilometre radius of the eruption centre and areas within one kilometre of two newly formed islands northwest and southeast of Anak Krakatau.

It also urged coastal communities in Banten and Lampung provinces to remain calm, avoid spreading unverified tsunami claims, and follow official safety instructions. — BERNAMA