A volcanic eruption in Indonesia has sent ash clouds towards Australia, shutting down Darwin airport and disrupting travel around the country.
Up, up, up and now coming Down Under ... Mount Sangeang Api spews smoke and ash in this shot taken from the window of a passing commercial flight by professional photographer Sofyan Efendi. The volcano is one of 129 active volcanoes in Indonesia. Picture: Barcroft Media/Splash News Source: Supplied
FLIGHTS around Australia this weekend have been disrupted after a major volcanic eruption in Indonesia sent an ash cloud barreling into our skies.
The impact could last for days, Deputy Prime Minister Warren Truss has warned, and could hit other airports beyond Darwin, which is already closed.
The cloud is spreading south towards Alice Springs.
"Depending on wind and other weather conditions, the ash has the potential to affect flights to and from other airports, including Brisbane, during coming days. This is currently being fully assessed," Mr Truss said.
The cloud has come from Mount Sangeang Api, a volcano off the northeast coast of the Indonesian island of Sumbawa, which blew late Friday and is continuing to discharge debris with further eruptions.
"The volcano is continuously erupting," Tim Birch from the Bureau of Meteorology's Volcanic Ash Advisory Centre in Darwin told AFP.
Birch said one plume was affecting northern Australia and impacting Darwin and was expected to linger for at least the next 18 hours.
Another was located over central Australia which could cause problems for overland flights, while a third was about 100 kilometres (60 miles) from Denpasar airport on Indonesia's Bali.
"All of the plumes will be affecting aviation," he said.
Surono, an Indonesian government volcanologist who goes by one name, said that Sangeang Api was spewing columns of ash up to 2,500 metres (8,200 feet) into the air on Saturday.
Towering inferno ... an aerial shot by photographer Sofyan Efendi shows the terrifing majesty of the ash cloud. Picture: Barcroft Media/Splash News Source: Supplied
Airservices Australia, the nation's air navigation authority, the Civil Aviation Safety Authority and the Bureau of Meteorology are all investigating the cloud, Mr Truss said.
"Passengers are advised to check with their airlines for further information."
While early indications were that Sydney and Brisbane would not be badly affected, experts warned that could change as the volcano has not yet finished erupting.
Airservices Australia has begun diverting international flights around the ash cloud.
WHEN WILL FLIGHTS RESUME?
It depends on whether further volcanic eruptions in Indonesia amplify an already huge intercontinental plume of ash, an expert says.
Sangeang Api, a volcano off the Indonesian island of Sumbawa, has erupted three times since Friday afternoon.
The volcano is about 300km east of the eastern tip of Java and about 1200km west-northwest of Darwin.
The manager of the Volcanic Ash Advisory Centre at the Bureau of Meteorology in Darwin, Emile Jansons, said the cloud was dispersing as it spread south but the situation could change at any time. He said there was a "pretty clear" stream of ash from the volcano across the Timor Sea, flowing west of Darwin and southeast to Alice Springs.
"If there is a big eruption in the next six to 12 hours, longer effect is more likely across Australia," he told AAP.
Strong winds within a narrow jet stream had carried the ash at up to 150km/h towards central Australia but the ash was dissipating, he said.
"The ash that is west of Darwin will affect Darwin for the next 18 hours, so it looks likely to hang around for a day or so. "Regional aviation to places like Kununurra and even Derby (in Western Australia) may be affected but in terms of larger international airports only Darwin is affected." The jet stream will move east over the 24 hours, changing wind direction and helping to further dissipate the ash, unless another large eruption spews more into the air.
The ash near Darwin is in a band between 10km and 15km in the air - the cruising altitude for commercial jet aircraft.
WHY IS VOLCANIC DUST DANGEROUS?
Volcanic ash can affect all aircraft with piston or jet engines at all flight levels, CASA warned. Fine particles of pulverised rock consisting mainly of silica contained in volcanic ash clouds can be highly abrasive and damage aircraft engines, structures and windows.
"Commercial air operators and private pilots planning to fly in this area should conduct a safety risk assessment before any flights," a spokesman said.
"CASA recommends flights are not conducted into areas with visible volcanic ash clouds. Flights into areas with low levels of ash contamination should only be conducted after a safety risk assessment has been carried out."
However the decision whether or not to fly is a safety and economic decision that rests with individual airlines.
Ring of fire ... another of Indonesia's volcanoes, Mount Merapi, spews lava and ash in 2006. Source: AP
The manager of the Volcanic Ash Advisory Centre at the Bureau of Meteorology in Darwin, Emile Jansons, earlier said the cloud is dispersing as it spreads south.
"It is continuing to disperse but it is moving very rapidly — at 70 to 80 knots (130 to 150km/h) — towards Alice Springs," Mr Jansons said. "There is a very strong jet stream so the boundary (of the cloud) may come further south."
While it is a "fairly sizeable eruption", Mr Jansons told the Northern Territory News that the cloud here would be invisible to the naked eye.
"The volcano has been erupting to 15km in the air," he said. "It has moved across the Kimberley and western Top End. It's high in the atmosphere so there won't be any ashfall different to normal bushfire ashfall."
He said there should be negligable impact on the air quality and said adverse health effects were unlikely.
STRANDED OVERSEAS AS BALI AND SINGAPORE FLIGHTS HALTED
Qantas and Virgin Australia confirmed all their flights to and from Darwin have been cancelled, including some overseas.
"Because of the impact of the volcano we have cancelled all flights today on our schedule to and from Darwin," Virgin Australia spokeswoman Jacqui Abbott said.
"Our meteorologists are monitoring the situation and are consulting with the (volcanic ash) advisory centre in Darwin and we will renew normal operations as the situation allows."
Qantas Group spokeswoman Kira Reed said cancellations also affect all Qantas flights to and from Darwin on Saturday and Jetstar's Cairns-Darwin and Darwin-Cairns flights — plus its Darwin-Adelaide service and its Darwin-Bali, Bali-Darwin, Singapore-Darwin and Darwin-Singapore flights.
Flights from Melbourne were also affected by the plume of volcanic ash.
Holidaymakers scheduled to fly to Bali on Saturday afternoon were inconvenienced when their flight with Virgin Australia was cancelled.
Flights between Melbourne and Darwin were also cancelled by Virgin, Jetstar and Qantas on Saturday.
Virgin has also cancelled a flight from Denpasar due into Adelaide at 7.35am on Sunday.
The airlines said they were monitoring the situation closely to see if further flights would be affected.
The Northern Territory News reports that while there is no official announcement yet, word on the ground at Darwin Airport is most flights will be cancelled until Monday.
PICTURE SPECIAL: The stunning beauty of an erupting giant
Not the first time ... ash from this Chilean eruption in 2011 disrupted flights in Australia and elsewhere. Source: News Limited
Asked to look into his crystal ball to get an end date, Mr Jansons said: "It continues to erupt — it's still going up right now — but how long it'll go I don't know".
"They tend to stop after a day or two so it's unlikely to reach the east coast.
"It's almost reached Tennant Creek in the south. It won't get to Brisbane or Sydney."
Sangeang Api is 1373km northwest of Darwin, roughly halfway between Bali and Timor.
This is not the first time an exploding volcano overseas has disrupted air traffic Down Under.
One of the most memorable was the Chilean eruption in 2011 that caused chaos here and in other countries.
The Indonesian volcano causing the current problem is a regular menace.
It is believed to have erupted at least 17 times since 1512, with the last eruption recorded in 1999.
The island of Sangeang Api has no permanent residents after they vacated the area in 1985.
Volcanos are prevalent across Indonesia, as part of the Pacific's "Ring of Fire". A number of people were killed during an eruption in East Java in February.
