Sydney: Tens of thousands of travellers were left stranded on Monday after ash from Chile`s volcanic eruptions prompted Australian airlines to ground some domestic services and flights to New Zealand.
Strong winds have carried the ash more than half way around the world, over the southern Atlantic and southern Indian Oceans to Australia and New Zealand since Chile`s Puyehue volcano erupted more than a week ago.
Australian airline Qantas said all flights in and out of the southern island of Tasmania and to New Zealand were grounded on Monday, and that flights in and out of Melbourne would be suspended until at least 0300 GMT.
Three Qantas international services to Buenos Aires and Los Angeles have also been cancelled, the airline said.
The cancellations have delayed at least 10,000 Qantas travellers, and a further 12,000 passengers on Qantas` offshoot Jetstar are also affected.
"It`s down to our safety standards. Our Qantas group policy is that if there is any sign of ash cloud around we won`t operate," airline spokeswoman Olivia Wirth told state broadcaster ABC.
"The problem at the moment that we have is that we just don`t know the density of this ash cloud. There isn`t the technology here in Australia to determine that, so we don`t know whether it`s a thick ash cloud or one that `s quite thin.”
"So at this stage, if there`s any sign of ash we won`t be flying."
Aviation authorities and airlines are closely monitoring the plume, with Virgin Australia saying on Monday it believed it was safe to fly to Melbourne, Tasmania and New Zealand, adding its planes would fly around or under the ash.
"We decided to resume services based on information that we received from the Bureau of Meteorology and also the Volcanic Ash Advisory Centre," a spokeswoman said.
In New Zealand, the Civil Aviation Authority (CAA) said the cloud now covered most of the country and was likely remain for the next 24 hours.
Authority spokesman Bill Sommer said the CAA believed it was safe to fly under the cloud, but the decision on whether to fly rested with individual airlines.
"Air New Zealand is happy that they are remaining clear of the ash cloud, and at the moment we are happy that is safe for the passengers," he told TVNZ on Monday.
"We provide the volcanic ash information to the airlines and it`s up to airlines to make their own operational decisions about whether they are going to fly."
Australia`s Volcanic Ash Advisory Centre said a similar ash cloud had not been seen in two decades and this one was likely to continue to travel around the globe, after passing over Tasmania and New Zealand.
"It went over the south Atlantic, south of South Africa and into the southern Indian Ocean and around the south of Western Australia," said Graham Weston, volcanic ash forecaster at the Darwin centre.
"It`s almost circumnavigated the world."