JAKARTA — AirNav Indonesia closed airspace around Soekarno-Hatta and Halim Perdanakusuma airports in Jakarta, as well as Radin Inten II Airport in Lampung and three other airports. Soekarno-Hatta International Airport suspended flight operations from 5:30 a.m. to 1:30 p.m. local time on Sunday due to volcanic ash. By mid-afternoon on Sunday, the airspace closures had affected 516 flight movements. The disruptions affected approximately 22,800 passengers.

Lukman F. Laisa, Director General of Civil Aviation, stated, "Safety remains our top priority in every operational decision." He warned that flight schedules could face cascading disruptions affecting aircraft rotations, fleet availability, and terminal capacity.

Indonesia's volcanology agency and the Darwin Volcanic Ash Advisory Centre identified two ash clouds using satellite imagery. One ash plume rose to an altitude of 20,000 feet (6,100 meters) and drifted northeast. A second ash cloud reached 50,000 feet (15,200 meters) and moved westward and northwestward. According to kompas.id, BMKG reported that two clusters of volcanic ash distribution from Mount Anak Krakatau were identified, with one plume reaching an altitude of 20,000 feet and moving towards the southeast-south, covering parts of Banten and West Java as well as the surrounding waters, while the second plume reached 50,000 feet and moved towards the southwest-northwest, covering parts of Banten, Lampung, Bengkulu, West Sumatra, the southern Sunda Strait, and the Indian Ocean to the west of Lampung and Banten.

Authorities warned residents to stay at least 2 miles (3 kilometers) clear of the crater. The nearest settlement to the volcano is more than 10 miles (16 kilometers) away. Berton Panjaitan, spokesperson for Indonesia's disaster mitigation agency BNPB, advised people to wear masks and eye protection, reduce outdoor activities, cover water sources, and exercise caution when driving due to ashfall. The Health Minister urged residents in affected areas to stay indoors and wear face masks to protect against respiratory, eye, and skin risks.

Indonesia's disaster mitigation agency stated there was no imminent risk of a tsunami from the volcano. Lana Saria, head of Indonesia’s Geological Agency, said activity at Anak Krakatau has intensified since July. Lana Saria stated, "We continue to evaluate the volcano’s development based on all monitoring data, not solely on the number of eruptions or the height of the ash column." The volcano showed signs of activity starting Friday before erupting Sunday.

Anak Krakatau is located in the Sunda Strait between the islands of Java and Sumatra. Anak Krakatau means "Child of Krakatau." Anak Krakatau emerged from the sea in the 1920s in the caldera left by the 1883 eruption of Krakatoa. The 1883 eruption of Krakatoa killed more than 36,000 people.

A 2018 eruption of Anak Krakatau triggered a tsunami that killed at least 430 people in Sumatra and Java. Scientists said Anak Krakatau island was reduced to about a quarter of its original size after the 2018 eruption.

Why It Matters

The eruption of Mount Anak Krakatau disrupted air travel for thousands of passengers and closed multiple airports. The formation of two distinct ash plumes reaching up to 50,000 feet required coordinated monitoring by Indonesian authorities and the Darwin Volcanic Ash Advisory Centre to manage aviation safety.

Historical precedent includes a 2018 eruption that triggered a deadly tsunami and reduced the island's size. While authorities confirmed no imminent tsunami risk from the current event, the dispersal of ash across several provinces necessitated public health advisories and precautionary measures for residents in affected areas.

Timeline

The volcano showed signs of activity starting Friday before erupting Sunday on September 5, 2026. Singapore Airlines canceled two flights to and from Jakarta on Saturday and delayed two more into Sunday on September 6, 2026. Several schools canceled activities on Saturday due to the eruption on September 6, 2026. Volcanic ash from the eruption drifted across western Indonesia, affecting parts of Jakarta, Lampung, Banten, West Java, and Bengkulu provinces on September 7, 2026.

What's New

Later reporting indicated that BMKG reported that two clusters of volcanic ash distribution from Mount Anak Krakatau were identified, with one plume reaching an altitude of 20,000 feet and moving towards the southeast-south, covering parts of Banten and West Java as well as the surrounding waters, while the second plume reached 5.

Additional context noted that submarine landslide megablocks show half of Anak Krakatau island failed on December 22nd, 2018. Research titled Media Dissemination “The Threat of Tsunami Unleashed from the Eruption of Mount Anak Krakatau” Through Documentary Movie was published in 2015 in JAS (Journal of ASEAN Studies). Research titled "Volcano-Stratigraphy of Anak Krakatau Volcanic Complex (Indonesia) and Comparison Between the 2018 Anak Krakatau Eruption and the 1883 Krakatau Eruption" was published in 2023 in Advances in Science, Technology & Innovation. A study titled Monitoring Anak Krakatau Volcano in Indonesia was published in 2006 in Eos. A study titled Satellite Geodesy Uncovers 15 m of Slip on a Detachment Fault Prior to the 2018 Collapse at Anak Krakatau, Indonesia was published in 2024 in Geophysical Research Letters.