Is it safe to fly to Bali? Flights resume after volcanic eruption causes cancellations and delays

Flights were cancelled in Indonesia earlier this week after a volcano erupted, releasing a massive cloud of ash.

All flights to and from the resort island of Bali have now resumed following the disruption.

An eruption from Mount Lewotobi Laki Laki on Tuesday afternoon sent a thick grey plume up 11km into the sky, creating a mushroom-shaped ash cloud visible as far as 150 kilometres away. Several more eruptions on Tuesday evening sent ash up 5km into the sky.

It erupted again on Wednesday morning, belching a 1km high ash cloud, according to Indonesia’s volcanology institute, which has raised the alert to the highest level. The danger zone where people are recommended to leave has been expanded to 8 kilometres from the crater.

But, ash and debris fell in a number of places outside of the danger zone, including the villages of Boru, Hewa and Watobuku. Some residents from Nurabelen village in Ile Bura subdistrict fled to evacuation sites in Konga to avoid the impact of the eruption, the National Disaster Management Agency said in a statement.

Indonesia eruption leads to flight cancellations

The eruption of Mount Lewotobi Laki-laki led to a number of cancellations and delays on Wednesday.

A total of 87 flights to and from Bali were affected on 18 June, according to the airport operator. That included 66 international flights connecting the resort island to Australia, Singapore and Vietnam and 21 domestic flights.

By Thursday morning, the ash cloud had cleared and all flights from Bali to locations in Australia, Vietnam, Singapore, Malaysia and China, Gede Eka Sandi Asmadi were operating on schedule.

Arrivals and departures from airlines including Qantas, JetStar, Singapore Airlines and Virgin Australia now appear to be running smoothly.

Two airports in the East Nusa Tenggara province also reopened on Thursday after being closed due to the eruption.

The closure of Fransiskus Xaverius Seda airport in Maumere has been extended until Friday as authorities are still concerned about some volcanic ash in the air posing a risk to aircraft, the airport's operator said in a post on social media.

Why is volcanic ash dangerous for planes?

Volcanic ash clouds pose a risk to planes because they can cause severe damage to aircraft engines and affect flight controls.

When ash enters a plane engine, the glass inside it melts, which then sticks to various other engine parts. Sensors can fail, and the ash can block the thousands of tiny holes that direct air through the turbine blades to keep the engine cool.

Flying through an ash cloud is also a bit like sandblasting the outside of the plane and can reduce visibility for pilots by damaging the glass in the cockpit.

Why is Indonesia an eruption hotspot?

There are around 130 active volcanoes in Indonesia. The archipelago sits between the most seismically active region of the world, the Pacific Ring of Fire, and the Alpide Belt, an area where there are a large number of eruptions and earthquakes.

Mount Lewotobi Laki Laki last erupted in May and also in March. Indonesia's volcanology agency says it has erupted a total of 427 times this year.

Though people who live close to the volcano have learned to live with it, seismic activity can still be very dangerous. An eruption last November killed nine people and injured dozens more.