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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 7 Sep, 10:18 am IST 2 developments 2 min read Latest ↓

Satellite view of Anak Krakatau on 12 May 2023; file image, not the September 2026 eruption — Image: Pierre Markuse / Wikimedia Commons · modified Copernicus Sentinel data (2023), 12 May 2023 · CC BY 2.0

Where it stands

Anak Krakatau's eruption has disrupted flights through Jakarta. In a 7 September 2026 update, AirAsia said all its Jakarta flights were cancelled or rescheduled after Soekarno-Hatta airport's temporary closure. Indonesia's Geological Agency said the long eruption episode had ended, but smaller eruptions continued. The volcano remains at Level III, with a 3 km exclusion radius around the active centre. Ending a continuous eruption does not remove ash already in the atmosphere. Reopening airports depends on changing aviation conditions, not only the volcano's visible activity.

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

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 Resources US Geological Survey ANTARA
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 Resources Indonesia Ministry of Energy and Mineral Resources
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 Survey AirAsia

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 (5)

Indonesia Ministry of Energy and Mineral Resources · official · Anak Krakatau: Level III remains after the long eruption ended (6 September 2026)7 Sep, 10:06 am
US Geological Survey · official · Volcanic ash: effects on aircraft7 Sep, 10:06 am
ANTARA · PVMBG continues monitoring Anak Krakatau after eruption ends7 Sep, 10:06 am
Indonesia Ministry of Energy and Mineral Resources · official · Anak Krakatau: monitoring continues after the continuous eruption (7 September 2026)7 Sep, 10:06 am
AirAsia · Jakarta flight disruption: updated 7 September 2026, 11:45 am GMT+87 Sep, 10:06 am

Anak Krakatau ash disrupts Jakarta flights; volcano remains on alert

Where it stands

Background

How it developed

Continuous eruption lasts about 25 hours; alert level remains unchanged

7 September monitoring records further smaller eruptions

AirAsia confirms continuing disruption to Jakarta services

Why it matters for UPSC

Key terms