Scientists put a damper on Australia’s arid plain
Research by scientists at Swansea University has provided strong evidence that an area of Australia famed for its high temperatures and arid climate once had a much wetter climate than previously thought.
The Nullarbor Plain – its name means ‘the place with no trees’ – is a barren plateau of limestone rock west of Adelaide that covers 200,000 square kilometres. Some places in Wales can receive more rain in a single day than the average on Nullarbor Plain for a whole year and the temperature can reach anything up to 50 degrees Celsius (120 degrees Fahrenheit).
Travelling across the plain – which is ten times the size of Wales – has become a right-of-passage for many Australians who consider it a major challenge to endure the oppressive heat and mind-numbing monotony of the landscape even in the comparative safety of a vehicle.
Researchers at Swansea University led by Dr Stefan Doerr have revealed that despite its featureless surface, the vast interior of the plain is built like a giant Swiss cheese with water having formed huge cave networks below the surface. Until now, it was thought that such underground caves were restricted to the southern, coastal fringe of the plain.
Traditionally, studies of remote and inhospitable areas like the Nullarbor Plain have relied on aerial photography backed up with a few isolated ground observations. Dr Doerr and his team married traditional techniques to data collected from high resolution radar sensors onboard the Space Shuttle. As a result, for the first time, they were able to see numerous subtle features that could only have been caused by substantial rainfall.
The rain would have reacted with carbon dioxide in the atmosphere to produce a very weak acid that dissolved the limestone rock while soaking through to create underground water channels.
The Swansea University researchers also discovered that the plain – which Australians had always assumed sloped gently uphill as you travel north – actually slopes downhill over a large area.
Dr Doerr has been invited to present the Swansea University findings at the annual meeting of the prestigious Geological Society of America – which will be attended by more than 6,000 geoscientists – in Denver, Colorado later this month.
