Indonesia’s Anak Krakatau volcano has erupted with renewed intensity, producing dramatic scenes as volcanic ash and material were blasted high into the atmosphere and major disruption spread across the country’s aviation network.

The volcano, located in the Sunda Strait between Java and Sumatra, entered a period of heightened activity that affected large parts of western Indonesia. Volcanic ash spread across the region, airports were temporarily closed and hundreds of thousands of passengers faced cancellations and delays.

Dramatic videos emerging from the area show powerful explosions from the crater and a towering column of ash rising above Anak Krakatau.

Volcanic ash reached around 15 kilometres

One of the most significant aspects of the eruption was the altitude reached by the volcanic ash.

During the strongest phase of the activity, ash clouds were reported at altitudes approaching 50,000 feet — roughly 15 kilometres above sea level.

At such altitudes, volcanic ash represents a serious hazard to aviation. Fine volcanic particles can damage aircraft engines, reduce visibility and create dangerous conditions along flight routes.

The threat prompted Indonesian authorities to temporarily suspend operations at several airports, including Jakarta’s Soekarno-Hatta International Airport, the country’s largest and busiest aviation hub.

Nearly 3,000 flights affected

The eruption quickly developed into a major disruption for air travel across Indonesia.

According to the latest figures, approximately 2,961 flights were affected by cancellations, delays or operational changes, including hundreds of international services.

Around 341,000 passengers were caught up in the disruption.

As winds gradually carried much of the volcanic ash away from key aviation corridors, Soekarno-Hatta and four other airports were able to resume operations on Tuesday, September 8.

However, authorities continue to closely monitor the volcano, with further explosive activity still possible.

Dramatic videos capture the eruption

Videos recorded during the eruption show the extraordinary force of the volcano.

Huge quantities of volcanic material can be seen being thrown from the crater as a dense ash column expands rapidly into the atmosphere.

The eruption also caused ashfall in populated areas around the volcano, while authorities introduced restrictions to prevent residents and visitors from approaching the active crater.

The alert status for Anak Krakatau remains at Level III – Siaga, the second-highest level on Indonesia’s four-tier volcanic alert system.

The “Child of Krakatoa”

Anak Krakatau literally means “Child of Krakatoa.”

The volcano emerged from the sea inside the enormous caldera left behind by the catastrophic 1883 eruption of Krakatoa, one of the most destructive volcanic events in recorded history.

The 1883 eruption generated devastating tsunamis across the Sunda Strait and killed more than 36,000 people, with coastal communities across Java and Sumatra suffering catastrophic destruction.

Anak Krakatau subsequently began emerging from the sea during the 20th century and has remained highly active.

Its history has already demonstrated how dangerous the volcano can become.

In December 2018, part of Anak Krakatau’s flank collapsed into the sea following an eruption. The collapse generated a tsunami that struck the coasts surrounding the Sunda Strait, killing more than 400 people.

Indonesia remains on alert

Although several airports have now reopened and the immediate disruption caused by the ash cloud has eased, Anak Krakatau remains under close surveillance.

Further eruptions cannot be ruled out while the volcano continues to show elevated activity.

Indonesia sits along the Pacific Ring of Fire, one of the most geologically active regions on Earth, where several major tectonic plates interact.

The country is home to more than 100 active volcanoes and experiences frequent earthquakes and volcanic eruptions.

For communities surrounding the Sunda Strait, Anak Krakatau is therefore much more than an extraordinary natural spectacle. Its violent history means every new period of unrest is watched closely — both by Indonesian authorities and volcanologists around the world.