AUSTRALIA'S $46 million Antarctic airstrip is melting, leaving the government scrambling to find a new air link to the frozen continent.
The Wilkins runway - carved into ice near Casey station, about 3400 kilometres south-west of Hobart - was commissioned under the Howard government and hailed at its 2008 opening by the then Environment Minister, Peter Garrett.
But unexpected surface melt has sharply curtailed use of the summer airstrip.
Instead of up to 20 chartered flights by an Airbus A-319, as predicted by the Australian Antarctic Division before the runway opened, only four flights landed last season. In 2010-11 there were two. The division has confirmed it is examining creating a new airfield at the ice-free Vestfold Hills, with the likely - and costly - option of building a rock runway.
The division's chief scientist, Nick Gales, recently told a parliamentary committee that trends in Antarctic ice cap melt were faster than almost any records, but the pace was uneven. A University of Tasmania-led study published in Nature yesterday showed a net loss of ice across Antarctica.
The division also revealed there had been problems for two ski-equipped workhorse aircraft used to shuttle expeditioners between polar stations and field camps.
''We are exploring a range of other possible options over the longer term,'' the spokeswoman said. ''No decision has been made to stop using Wilkins runway into the future.''
The first site to be investigated is Vestfold Hills near Davis station, which a 1999 study found was one of the few ice-free Antarctic areas with potential for a conventional gravel runway.
It could be possible to build a year-round runway there big enough to handle the largest jet aircraft, according to the scoping study. But it said even a short gravel runway suitable for Hercules aircraft would be a major undertaking, and ruled out the option because of cost.
An attempt by France to build a rock runway at Dumont d'Urville base survived green protests but ended in failure in 1994 when a wave from an ice-shelf break damaged it beyond repair.