<
https://theconversation.com/kgaris-unique-ancient-lakes-once-dried-out-could-this-happen-again-270371>
"The lakes on the world’s biggest sand island, K'gari, are famous. Pivotal to
the World Heritage listing of the Queensland island formerly known as Fraser
Island, their turquoise waters feature in international tourism campaigns and
social media posts.
K'gari has more than 40 unique lakes, some more than 55,000 years old. They
range from the photogenic clear waters of Boorangoora (Lake McKenzie), pictured
above, which filters through the sand dune it rests in, to the emerald-green
waters of Lake Wabby, a window lake which is (very) slowly being swallowed by a
giant sand dune.
In fact, K'gari is home to more than half of the world’s perched lakes, more
than 50, including Boorangoora. Perched lakes form when sand is cemented
together with decomposed organic matter (such as leaves and bark), aluminium
and iron. This creates an impermeable layer well above sea level. It’s
remarkable these lakes exist, given water usually passes quickly through sand.
Until now, it was believed K'gari’s lakes would have contained water since the
last ice age ended, about 11,500 years ago. But our new research found some of
the island’s deepest lakes dried out only 7,500 years ago. In the current era
of climate change, it’s possible this could happen again."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
