CANBERRA (Reuters) - Tens of thousands of air passengers faced more flight chaos in Australia on Wednesday caused by an ash cloud from a Chilean volcano, although grounded flights were starting to resume from some cities as the ash moved offshore.
The ash cloud, which has circled the earth twice to disrupt Australian airlines for a second time, will reach New Zealand to the east later on Wednesday, threatening airline services there.
Qantas canceled flights to and from Australia's biggest airports on Tuesday and Wednesday, including some international services, and Virgin Australia canceled some domestic flights.
But as the ash cloud slowly cleared 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," Qantas spokeswoman Olivia Wirth said.
Virgin Australia, Qantas low-cost subsidiary Jetstar and discount carrier 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.
Iceland's most active volcano at Grimsvotn sent a thick plume of ash and smoke 15.5 miles 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 canceled flights, affecting 10 million people at a cost of $1.7 billion.
Australia's Transport Minister Anthony Albanese said the disruptions would impact the economy, already hit by natural disasters that cut 1.7 percent 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 a volcano 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.
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.
New Zealand's Jetstar said on Tuesday it would cancel all New Zealand domestic flights until midday Wednesday, when it would review the situation.
Andrew Tupper from the Australian Bureau of Meteorology's Volcanic Ash Advisory Center, 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 well south of Australian and New Zealand airspace until the unexpected arrival of a blast of freezing weather from Antarctic regions which dumped heavy snow falls across Australia's east
(Reporting by Rob Taylor in CANBERRA and Michael Perry in SYDNEY; Editing by Ed Davies and Balazs Koranyi)