God's Bathtub

Twenty percent of the world's fresh water is in a single lake, Russia's Lake Baikal. Its surface is smaller than Lake Superior — but it's a mile deep.

But an even better story is this -

Officially it's known as Blue Lake, but to the scientists studying it, it has taken on a new name: God's Bathtub.

Blue Lake on North Stradbroke Island, Queensland. (Photo: Ashley Natt, courtesy University of Adelaide)

Blue Lake sits on North Stradbroke Island in the Australian state of Queensland. The tiny lake with crystal-clear waters was already known as one of the country's most beautiful sites, but new research reveals something even more remarkable: the lake has been relatively unaffected by changes in climate or the effects of humans for more than 7,000 years.

"Blue Lake is one of those rare, beautiful lakes in Australia," Dr. Cameron Barr of the University of Adelaide said in a news release this week. "It's unusual because it's more than 10 meters deep, but it's so clear you can see to the bottom. We didn't realize just how unique and unusual this lake is until we started looking at a wide range of environmental markers."

Barr and his fellow researchers looked at records kept about the lake for the past 117 years as well as fossil information about pollen and algae. By looking at photographs and a great deal of other data, they came to a remarkable conclusion: the depth and water chemistry of Blue Lake has remained almost unchanged for millennia.

The research was published April 26 in the journal Freshwater Biology. {Read on}