JOIN USStrong 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.
Australia's Qantas said all flights in and out of the southern island of Tasmania and to New Zealand were grounded today.
Three Qantas international services to Buenos Aires and Los Angeles were also cancelled, the airline said, but flights in and out of Melbourne had now resumed.
A total of 110 Qantas flights were cancelled on yesterday and today, delaying at least 20,000 Qantas travellers and a further 12,000 passengers on Qantas's offshoot Jetstar.
"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.
Aviation authorities and airlines are closely monitoring the plume, with Virgin Australia saying today 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.