In Alaska, thousands of mysterious lakes are all the same shape and have grown steadily for thousands of years, the geological record shows. They are the fastest growing lakes known in the world.
Scientists have tried various ideas to explain the steady growth -- the lakes expand up to 15 feet every year -- and the lakes' consistent shape and orientation, but no theory has held up.
Now a scientist who has worked previously on puzzles as wide-ranging as the spiral shape of Mars ice caps says he's solved the terrestrial mystery.
The solution might also help explain a series of oddly similar lakes near the U.S. East Coast.
Heat waves
The lakes range from puddle-sized to more than 15 miles long. They are shaped like stretched-out eggs, with their skinny ends always pointing northwest. They're grouped in a vast field twice the size of Massachusetts. ...cont'd
http://www.livescience.com/forcesofnature/050627_strange_lakes.html__________________
Lakes disappearing virtually overnight
125 Large Northern Lakes Disappear
By Robert Roy Britt
LiveScience Senior Writer
posted: 03 June 2005
02:31 pm ET
A new study finds 125 large lakes in the Arctic have vanished as temperatures rose over the past two decades. Many other lakes have shrunk.
The lakes once sat atop permanently frozen soil called permafrost. Other studies have shown permafrost is melting around the world, causing low-lying ground to slump and rock to fall from mountains.
"We think that climate warming is thawing the permafrost," said lead researcher Laurence Smith of the University of California, Los Angeles. "It's like pulling the plug out of a bathtub. There's nothing to prevent lake water from percolating through the soil to aquifers below."
Changes seem to come abruptly.
"From what we can tell from space, a lake is either just fine or it's gone," Smith said.
The sudden draining could alter entire continental ecosystems, affecting birds and other wildlife that depend on the waterways, Smith and his colleagues say. Migratory birds count on the lakes during summer to feed their young.
The research is reported today in the journal Science.
...cont'd
http://www.livescience.com/environment/050603_lakes_gone.htmlEarlier thread on this:
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