by Lauren McMah
ALL flights between Australia and Bali have been cancelled and Denpasar international airport has been closed as the Mount Agung volcano continues to spew dangerous volcanic ash and steam more than 9km into the sky above the holiday island.
The closure of Denpasar airport has ruined summer holiday plans and left thousands of Australians stranded in Bali.
In a statement, the airport said 445 flights - including 196 international flights - have been cancelled on Monday.
That affects about 59,000 passengers, the airport said.
The Bureau of Meteorology, which is monitoring the situation from its Volcanic Ash Advisory Centre in Darwin, said height of the eruption was "steadily increasing".
"Ash is currently observed to a height of 30,000 feet (or 9144 metres) and a small amount of ash has fallen at Denpasar Airport and across Bali's south east," the centre said.
"Eruptions and ash falls are likely to continue for at least the next 24 hours."
Geologist Mark Tingay, an associate professor from the University of Adelaide's Australian School of Petroleum, said the eruption had moved on to a more severe phase.
"The volcanic eruption has now moved on to the next, more severe, magmatic eruption phase, where highly viscous lava can trap gasses under pressure, potentially leading to an explosion," he said.
"From my own eyewitness experience, the situation on Bali is very calm, and life is mostly continuing as normal outside of the 8 to 10km exclusion zone. People have been evacuated from the exclusion zone for several months.
"The local authorities are extremely experienced in managing volcanic eruptions, and have the situation extremely well in-hand."
ALL FLIGHTS CANCELLED
Jetstar confirmed due to worsening conditions all Monday's flights have been cancelled.
"While these disruptions are frustrating, we will always put safety before schedule. We appreciate our customers' patience," the airline on Monday morning.
"We are doing everything we can to get customers moving as quickly as possible. Our senior pilots will make an assessment with the latest information and forecasts from the Volcanic Ash Advisory Centre."
Virgin Australia has also confirmed all its flights in and out of Bali have been cancelled.
"Due to the significant volcanic ash and current weather conditions, Denpasar Airport is now closed and we have cancelled today's flights to and from Bali," the airline said.
"The safety of our guests and crew is our highest priority and our team of meteorologists continue to monitor the situation in consultation with the Volcanic Ash Advisory Centre."
AirAsia and AirAsia X flights in and out of Bali have been cancelled, the airline said, as well as flights in and out of Lombok.
Qantas has said its one flight that operates daily between Sydney and Bali was also cancelled.
Airlines are urging travellers to check their websites for updated flight status information on Monday. Travellers are also advised to check in with their insurance company to see if they will be covered for volcano-related activity.
Indonesia's National Disaster Mitigation Agency said authorities would consider reopening Denpasar airport on Tuesday after evaluating the situation.
Volcanic ash also forced the closure of the small international airport on the neighbouring island of Lombok on Sunday.
Authorities have now raised the alert for the erupting volcano to its highest level and are ordering anyone within 10 kilometres of Mount Agung to leave.
An exclusion zone has been in place around the volcano since it started showing signs of a possible eruption in September. More than 140,000 people fled their homes inside the exclusion zone.
Ash from the volcano has covered nearby roads, cars and buildings as activity enters the "magmatic eruption" phrase, said Gede Suantika, an official at the Volcanology and Geological Disaster Mitigation Centre.
"It is still spewing ash at the moment but we need to monitor and be cautious over the possibility of a strong, explosive eruption," he said.
The Department of Foreign Affairs and Trade is telling Australians in Bali to "plan for the possibility that you won't be able to depart Bali on your scheduled flight".
"Ensure you have ongoing access to accommodation, funds and other necessities beyond your original date of departure from Bali," the department said.
"Hotels in Bali are making a range of preparatory arrangements in anticipation of an eruption. Confirm details with your accommodation provider."
The department said Australians in Bali should stay clear of the volcano exclusion zone and follow the instructions of authorities and expect delays and disruptions to transport and tourism services.
Mount Agung last erupted in 1963, killing more than 1000 people and destroying several villages.
Associate Professor Oliver Nebel from the School of Earth Atmosphere and Environment at Monash University said Mount Agung was part of the part of the Pacific Ring of Fire, made up of active volcanoes and others that have been dormant for decades or centuries that could still be revived.
"[These] volcanoes have a high volatile content (water, CO2, SO2), which, when close to the surface, are released from the melt - pretty much as bubbles out of a champagne bottle," he said.
"This causes molten rock to burst into tiny fragments - so-called defragmentation - which will be carried at high velocity into the sky. We call this a volcanic ash plume.
"Dependent on weather conditions, this ash will remain in the atmosphere and can be carried with winds. If a plane flies through the ash, it will cause abrasive damage to the windscreen and more importantly, when heated up in turbine engines, can be melted again.
"When melt droplets chill against ambient temperature, a fine layer of volcanic glass then stalls the engine. Hence the danger to aviation services."
Prof Nebel said the energy of the eruption could not be accurately predicted, which was why airlines were taking precautions.
"However, once the volcano has erupted, it is unlikely that a more violent eruption is following straight away, so that the local geological survey apparently sees no need to raise the danger level," he said.