UCL in the News: Antarctic surface thaw 'most significant' in 30 years

Vast areas of snow in Antarctica melted in 2005, when temperatures warmed up for a week in the summer.

Snow melts such as this may have ramifications for larger scale melting of the ice sheets if they are severe or sustained over time, NASA said on Tuesday. …

A new analysis of satellite data showed that an area the size of California melted and then re-froze - the most significant thawing in 30 years. …

Professor Duncan Wingham [UCL Earth Sciences] says the event is "notable". But he underlines that it is, for now, a single weather event and should not be confused with long-term climate change.

"If we were to start seeing this happen every single year, then we would have to say: 'Yes this [Antarctica] is not the sort of deep freeze we have been thinking'," he told New Scientist. …

The melt was intense enough to create an extensive ice layer when water refroze after the melt, they say. Such "ice lenses", where ice has melted and re-formed, have been seen in Antarctica before but not so far into the centre of the continent. "Clearly there has been a warm event," says Wingham. …

Catherine Brahic, 'New Scientist'