The ongoing eruption of Mount Anak Krakatau has forced six Indonesian airports to suspend flight operations, with Jakarta's main international hub among those affected, stranding hundreds of passengers and disrupting more than 300 flights — including dozens of international services — on Sunday.
Soekarno-Hatta International Airport posted on Instagram that it had halted operations until 1:30pm local time (4:30pm AEST) after volcanic ash from the eruption blanketed the area. Airport operator Angkasa Pura confirmed the suspension had affected 301 flights in total, including 58 international services. At least one major international carrier cancelled all its flights to and from Jakarta for the remainder of the day.
Eruption Ongoing Since Friday, Ash Reaching 15,000 Metres
Anak Krakatau, situated roughly halfway between the Indonesian islands of Java and Sumatra, began erupting late on Friday. Volcanic ash was detected at Soekarno-Hatta early on Sunday morning, prompting Indonesia's transport ministry to extend what had initially been a shorter operational halt.
Indonesia's meteorological agency reported that ash columns reached as high as 15,000 metres on the Sumatra side of the strait and across parts of Banten province on Java. The dispersal of ash has disrupted daily life across both islands, with Lampung province in Sumatra and Banten province among the worst-affected regions.
This is the fifth eruption event at Anak Krakatau since 2020, though authorities stress none have approached the destructive scale of the catastrophic 2018 event. Indonesia's disaster mitigation agency, BNPB, confirmed on Saturday that there was no imminent risk of a tsunami from the current activity.
Communities Urged to Stay Calm as Ash Blankets the Region
BNPB spokesperson Berton Panjaitan urged the public to remain calm while taking sensible precautions in ash-affected areas.
"BNPB urges the public to remain calm while increasing vigilance. In the event of ashfall, people are advised to wear masks and eye protection, reduce outdoor activities, cover water sources and exercise caution when driving, as volcanic ash can reduce visibility," Panjaitan said.
The human impact was already being felt before Sunday's aviation disruptions. Several schools cancelled activities on Saturday after students and residents reported eye irritation from falling ash. Local fishermen also abandoned their planned trips to sea as a result of the eruption.
Haunted by 2018: The Eruption That Reshaped Krakatau
The name Anak Krakatau carries significant weight in Indonesia. In December 2018, a major eruption caused the volcano's southwestern flank to collapse into the sea, dramatically reducing the volcano's size and triggering a deadly tsunami that struck the coastlines of Java and Sumatra without warning. More than 400 people were killed and tens of thousands were left injured in what became one of the country's worst recent natural disasters.
The volcano has erupted multiple times since then, and while the current episode has brought considerable disruption, officials have been careful to reassure the public that conditions remain very different from those that preceded the 2018 collapse. Indonesia sits on the Pacific Ring of Fire, a zone of intense seismic and volcanic activity that makes eruptions a recurring feature of life across the archipelago.
Second Volcano Erupts Hundreds of Kilometres Away
Adding to the country's volcanic activity on Sunday, Mount Semeru in East Java — located approximately 850 kilometres from Anak Krakatau — also erupted, sending an ash column one kilometre above its summit. Indonesia's volcano monitoring agency, PVMBG, advised residents to maintain a distance of at least five kilometres from the crater and warned of the potential for hot ash clouds and lava flows reaching up to 17 kilometres from the summit.
The simultaneous eruptions across two of Indonesia's active volcanoes highlight the country's exceptional geological instability as a nation straddling multiple tectonic plate boundaries.
What Travellers and Residents Need to Know
Passengers with flights in or out of Jakarta should expect continued disruption and are advised to check with their airlines directly. The situation has been evolving rapidly since Friday, with operational suspensions progressively extended as ash dispersal continued.
For those on the ground in affected provinces, authorities are urging people to cover water sources, wear respiratory protection when outdoors, and avoid unnecessary travel where ash has reduced road visibility. The BNPB continues to monitor conditions across both islands.
Indonesia's tourism and aviation sectors — an area of significant growth for the country, given its appeal as a rising destination for regional travellers — are likely to feel the short-term effects of Sunday's disruptions, though authorities have not indicated any expectation of prolonged closures beyond the immediate ash event.
