Anak Krakatau Sends Ash Up to 50,000 Feet, Disrupting 209 Flights at Jakarta’s Main Airport

Anak Krakatau’s latest eruption did not send residents fleeing, but it reached one of Southeast Asia’s busiest aviation hubs in a different way: through the sky.

Volcanic ash spreading across western Indonesia forced a temporary shutdown at Jakarta’s Soekarno-Hatta International Airport early Sunday, September 6, disrupting 209 flight movements and roughly 22,800 passengers. The ash was detected in two distinct clouds, one climbing as high as 50,000 feet—well above the cruising altitude of many commercial flights.

No casualties were reported, no evacuation order was issued, and Indonesian disaster officials said there was no imminent tsunami threat. But the scale of the aviation interruption, extending across domestic and international routes, showed how a remote volcanic island can quickly affect travel across a much larger region.

209 flights and about 22,800 passengers affected

Indonesia’s transportation authorities extended the temporary suspension at Soekarno-Hatta through 9:30 a.m. local time as safety teams tracked the ash. According to the Associated Press, the closure affected 209 flight movements and approximately 22,800 passengers.

Singapore was the international destination with the largest number of disrupted flights. Cancellations, delays or rescheduled service also affected routes involving Hong Kong, Sydney, Amsterdam, Seoul, Doha and Kuala Lumpur. Domestic service to destinations including Makassar, Lampung, Bali and Surabaya was also disrupted.

“Safety remains our top priority in every operational decision,” Lukman F. Laisa, Indonesia’s director general of civil aviation, said in a statement quoted by AP.

Authorities said 170 aircraft that had remained overnight at Soekarno-Hatta were secure on airport aprons. They also warned that the morning shutdown could create cascading problems for aircraft rotations, fleet availability and terminal capacity even after operations begin recovering. Travelers were urged to confirm current flight information directly with their airlines before heading to the airport.

Two ash clouds moved in opposite directions

Indonesia’s Meteorology, Climatology and Geophysics Agency, known as BMKG, said satellite analysis identified two major ash clusters. In a September 6 statement, the agency said one cloud reached 20,000 feet and moved generally eastward, affecting parts of Jakarta, Banten, West Java and nearby waters.

The second climbed to 50,000 feet and spread westward and northwestward across areas including Banten, Lampung and Bengkulu, as well as the southern Sunda Strait and parts of the Indian Ocean west of Sumatra.

BMKG said it had issued 50 significant meteorological advisories for aviation after the initial eruption late Friday. Temporary restrictions affected not only Soekarno-Hatta but also Halim Perdanakusuma, Radin Inten II and Budiarto airports at different times, with operational decisions subject to changing ash conditions.

Reuters reported that school activities and fishing trips were also halted in some communities, while residents experienced eye irritation from falling ash. Indonesia’s disaster agency advised people in affected areas to wear masks and eye protection, limit outdoor activity, cover water sources and drive cautiously because ash can reduce visibility.

The volcano was still producing new eruptive signals Sunday

Anak Krakatau sits in the Sunda Strait between Java and Sumatra. Indonesia’s Geological Agency said the volcano had shown increased activity since Friday before an eruption at 3:53 a.m. Sunday that lasted about 30 seconds.

The government’s MAGMA Indonesia eruption log recorded another event at 7:10 a.m. local time, measuring a maximum seismic amplitude of 50 millimeters and lasting 16 seconds. Officials maintained a three-kilometer exclusion zone around the active crater. The nearest settlement is more than 16 kilometers away, according to AP.

The volcano’s alert level remained the second-highest on Indonesia’s four-step scale. That status calls for vigilance, but it is not the same as an evacuation order.

Why Anak Krakatau’s history commands attention

Anak Krakatau—“Child of Krakatau”—emerged from the caldera left by the catastrophic 1883 eruption of Krakatau. That earlier disaster killed more than 36,000 people, largely through tsunamis.

More recently, a 2018 eruption destabilized part of Anak Krakatau’s slope. The resulting collapse displaced seawater and triggered a tsunami that killed at least 430 people along the coasts of Java and Sumatra.

That history makes any renewed activity especially alarming. For Sunday’s eruption, however, Indonesian authorities emphasized that there was no immediate tsunami threat. The direct, verified impact was instead above the volcano: a high, wide ash field that briefly closed key airports and scrambled travel plans for tens of thousands of people.

Conditions can change quickly during an eruption. Passengers with travel through Jakarta or other affected western Indonesian airports should rely on their airline and official airport notices for the latest operational status.