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Anak Krakatau ash disrupts Jakarta flights; volcano remains on alert

English हिंदी ಕನ್ನಡ മലയാളം தமிழ் తెలుగు
First brief 7 Sep, 10:18 am IST Updated 8 Sep, 10:57 am IST 3 developments 2 min read Latest ↓
Anak Krakatau, satellite view (12 May 2023)
Pierre Markuse; modified Copernicus Sentinel data (2023) · CC BY 2.0

Where it stands

Jakarta’s main airports have reopened after disruption from Anak Krakatau’s volcanic ash. The airport operator reported cleaning and safety checks before flights resumed early on 8 September 2026, western Indonesian time. Soekarno-Hatta, Halim Perdanakusuma and Bandung’s Husein Sastranegara resumed operations. Indonesia’s transport ministry counted 2,961 disrupted services during 6–7 September. About 341,000 passengers were affected by cancellations, delays or diversions. The count does not mean 2,961 flights were all cancelled. Airport reopening does not establish that the eruption has ended.

Background

Anak Krakatau stands in the Sunda Strait between Java and Sumatra. Volcanic ash is made of tiny rock, mineral and glass fragments, not soft ash from a wood fire. Winds can carry these particles far beyond the volcano. Ash can scratch aircraft surfaces and damage instruments. Inside a hot jet engine, some ash can melt and later harden on cooler components. That can reduce thrust or cause engine failure.

How it developed

  1. 4 September 2026, 9:37 pm IST: episode began
    How it started

    Continuous eruption lasts about 25 hours; alert level remains unchanged

    Indonesia's volcano-monitoring agency recorded the continuous episode from 11:07 pm WIB on 4 September to 12:04 am WIB on 6 September. The episode lasted about 25 hours. A shorter eruption followed. Authorities retained Level III and warned people to stay outside a 3 km radius. The official statement did not declare the volcano safe or the wider ash hazard over.

    Indonesia Ministry of Energy and Mineral ResourcesUS Geological SurveyANTARA
  2. 7 September 2026: agency bulletin, time unstated
    New fact

    7 September monitoring records further smaller eruptions

    The Geological Agency reported 3 smaller eruptions after the long episode ended. Seismic activity remained high, and Level III stayed in force. Authorities kept the 3 km exclusion radius and continued monitoring.

    Indonesia Ministry of Energy and Mineral ResourcesIndonesia Ministry of Energy and Mineral Resources
  3. 7 September 2026, 9:15 am IST: airline update
    Consequence

    AirAsia confirms continuing disruption to Jakarta services

    AirAsia's advisory was updated at 11:45 am GMT+8 on 7 September, equivalent to 9:15 am IST. All AirAsia flights to and from Jakarta were cancelled or rescheduled following Soekarno-Hatta airport's temporary closure. Flight status remains changeable; this statement does not mean every Indonesian airport is closed.

    US Geological SurveyAirAsia
  4. 8 September 2026, western Indonesian time
    Consequence

    Jakarta airports reopen after ash removal and safety checks

    Jakarta’s main airports reopened early on 8 September 2026, western Indonesian time. The airport operator reported ash removal and runway checks. Soekarno-Hatta, Halim Perdanakusuma and Bandung’s Husein Sastranegara resumed operations. The transport ministry counted 2,961 disrupted flight services during 6–7 September. Disruptions included cancellations, delays and diversions. About 341,000 passengers were affected. Reopening the airports does not mean the volcanic eruption has ended.

    AntaraAntaraAssociated Press / Business Standard

Why it matters for UPSC

GS1 · Physical geographyGS3 · Disaster managementPrelims · Straits and volcanic hazards

For GS1, locate the Sunda Strait between Java and Sumatra; do not confuse it with the Strait of Malacca. For GS3, connect volcanic monitoring with aviation risk management. A volcano's alert level and an airport's operating status answer different safety questions.

Key terms

Volcanic ashSmall fragments of rock, minerals and volcanic glass blasted into the air. Ash is abrasive. Wind can spread an ash cloud across flight routes even after an eruption weakens.
Sunda StraitThe passage between the Indonesian islands of Sumatra and Java. Anak Krakatau lies in this strait. The Strait of Malacca is a different passage, between Sumatra and the Malay Peninsula.
Exclusion radiusA zone around a hazard where authorities restrict entry. The Indonesian agency maintains a 3 km exclusion radius around Anak Krakatau's active centre. Ash hazards can extend well beyond that local zone.
Strombolian eruptionAn eruption pattern involving intermittent bursts that can throw out hot fragments. The Indonesian agency observed smaller bursts after the long continuous episode ended. Smaller bursts do not mean the volcano is inactive.
Aviation ash hazardThe risk that airborne volcanic particles damage an aircraft. Visibility is only part of the problem. Ash can melt in hot engine sections and accumulate again on cooler parts, interfering with airflow and engine performance.
Sources (8)
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