|Australia and New Zealand are bracing for further disruptions as the ash cloud circles the Earth for a second time [AFP]
Tens of thousands of air passengers in Australia are still facing cancellations and disruptions caused by an ash cloud from a Chilean volcano, although some grounded flights have started to resume.
The ash cloud, which has circled the southern hemisphere to disrupt Australian air travel for a second time, will reach New Zealand to the east later on Wednesday, threatening airline services there.
Qantas, Australia's flag carrier, cancelled flights to and from Australia's biggest airports on Tuesday and Wednesday, including some international services, and Virgin Australia cancelled some domestic flights.
But as the ash cloud slowly moved offshore on Wednesday, Qantas said it had restarted some services, with the main terminals at Melbourne and Sydney to resume services by the afternoon.
"The good news is that the busy ports of Sydney and Melbourne will once again be operating, so we will be able to clear the backlog and get people moving," Olivia Wirth, a Qantas spokeswoman, said.
Virgin Australia, Jetstar and Tiger Airlines were all also gradually resuming flights as the ash cloud cleared.
The majority of international carriers continued flights to and from Australia on Wednesday, with airlines including Singapore, Thai, Etihad and Emirates landing in Sydney.
Air New Zealand domestic flights were operating as scheduled on Wednesday, but the cloud was expected to cover the country by afternoon, potentially bringing disruptions.
Iceland's most active volcano at Grimsvotn sent a thick plume of ash and smoke 25 kilometres into the sky last month, disrupting air travel in northern Europe and Britain.
The eruption of another Icelandic volcano in April 2010, Eyjafjallajokull, led to 100,000 cancelled flights, affecting 10 million people at a cost of $1.7 billion.
|Ash from Puyehue-Cordon Caulle volcano is expected to cover New Zealand by Wednesday afternoon [AFP]
Australia's Transport Minister Anthony Albanese said the disruptions would impact the economy, already hit by natural disasters that cut 1.7 per cent from growth during the first three months of this year, the biggest decline in 20 years.
"Having that disruption to international services means lower revenue in terms of tourism and in a country such as ours, where we rely on aviation to connect each other and to the world, there is a bigger economic cost," he said.
Ash from avolcano in Chile's Puyehue-Cordon Caulle chain that erupted on June 4 after decades lying dormant has forced the sporadic cancellation of hundreds of flights, because of the potential for ash particles to damage jet engines.
Andrew Tupper from the Australian Bureau of Meteorology's Volcanic Ash Advisory Centre, said the ash cloud had already circuited the world twice, but would be unlikely to make a third journey round the globe.
"The volcano is still erupting but not at the same levels," he said. "It is very unusual for ash clouds to do two circuits."
Tupper said the cloud had been expected to pass south of Australian and New Zealand airspace until the unexpected arrival of cold weather from Antarctic regions dumped heavy snow falls across Australia's east.