A rare phenomenon underway in Australia’s biggest and driest lake is part of a change in weather systems that scientists say could end the country’s worst drought in 100 years.
|Lake Eyre draws in water from one-sixth |
of the Australian continent
At 15 metres below sea level, Lake Eyre is the lowest point in Australia. It is effectively a giant sink hole, drawing in water from one-sixth of the continent, an area equivalent to the combined size of Germany, France and the United Kingdom.
The lake itself is massive too. It takes an hour to fly from one end to the other.
For the last 7 years Lake Eyre has been mostly full of dried salt, but now that is changing.
Water is licking across the lake in the shape of a giant tongue, transforming it from dry salt pan to wildlife wonderland.
Despite being bordered by deserts it only takes a few weeks of water before thousands of birds and fish start calling Lake Eyre home - within months there will be millions of them.
The catalyst is water but the secret ingredient is hidden in the muddy earth, kept moist by the salt crust.
- Largest lake in Australia
- 15 m below sea level
- Filled to capacity only three times in past 150 years
Millions of tiny eggs laid by different marine species before the waters last receded can sit and wait for up to 20 years if they have to.
"As soon as that water arrives basically all of this is just ready to go," says environmental scientist Richard Kingsford of the University of New South Wales.
He describes it as one of the "great phenomena of the Australian inland".
|Birds travel thousands of kilometres |
to feast on the lake's riches
"It just sets off this cascade of different animals and plants that are all reacting to the water arriving."
Within days the lake is transformed into a smorgasbord so tempting that pelicans will fly more than a 1,000 kilometres for a main course.
Quite how the news of this feast reaches the average pelican on Australia's east coast is not known.
"How they actually know from somewhere on the east coast that there’s going to be this bonanza of fish is just a real mystery to us," Professor Kingsford says.
The water has traveled a long way too, taking two months to snake its way through a maze of rivers and creeks left parched by Australia’s worst drought in 100 years.
That rain came with the demise of El Nino, the dry weather system dreaded by Australian farmers.
|Scientists believe the changes may herald |
an end to Australia's record drought
It occurs when the waters of the Pacific Ocean are cooler causing reduced evaporation and therefore less rain clouds in northern Australia.
But climate scientists believe it may now be switching to a wetter system known as La Nina – a system not seen in Australia since 2000, the year Lake Eyre last flooded.
"It doesn’t guarantee rain," says Professor Matthew England from the Climate Change Research Centre. "But generally speaking a year where there’s a La Nina event we’ll see higher rainfall to the north of Australia and we’re seeing the start of those effects this year with northern Australia getting a lot of rainfall."
Most Australians never get to see the Lake Eyre phenomena because it happens on average only once every decade and it is a very long way from anywhere.
The closest community to Lake Eyre is the South Australian town of William Creek – population grand total of five.
"Here we are the smallest town in Australia in the middle of nowhere," explains local pilot Trevor Wright.
|Flying above the lake is the only way |
to appreciate its vast scale
"But the moment the lake has water in it we have people ringing up from all around the world because it’s just such a unique river system and it hasn’t been changed by man," he says.
"Hopefully it will stay that way."
Trevor's been taking scenic flights over Lake Eyre for the past 15 years and also provides road trips to sections of the lake accessible by car.
For most who travel on the dirt road known as the Oodnadatta Track, a four wheel drive vehicle is a necessity but Trevor prefers a battered Toyota Camry sedan.
"It only cost me $600 and should last me about 6 weeks," he says with pride.
As he travels along the dirt road at 100 kilometres per hour, each thunderous bump on the undercarriage must be wiping at least a few days off the expected life span.
But Lake Eyre has seen speeds far greater than this.
In 1964 British driver Donald Campbell set a world land speed record on the dry salt lake – 648 kilometres per hour in his famed Bluebird car.
The place where he achieved that is now underwater and will stay that way for most of the year before the waters of Lake Eyre evaporate once again.
Source: Al Jazeera