TG Daily: Ancient flood path triggered Big Freeze
After 30 years of debate, scientists believe they've discovered the trigger for the last great freeze of the Earth, some 12,900 years ago.
They say they've established that the flood waters from the melting of the enormous Laurentide Ice Sheet flowed northwest into the Arctic first, weakening ocean thermohaline circulation and cooling global climate.
If instead it had flowed east into the St Lawrence River valley, they say, Earth's climate would have remained relatively unchanged.
"This episode was the last time the Earth underwent a major cooling, so understanding exactly what caused it is very important for understanding how our modern-day climate might change in the future," says University of Massachusetts Amherst geoscientist Alan Condron. ...
... "Our results are particularly relevant for how we model the melting of the Greenland and Antarctic Ice sheets now and in the future. It is apparent from our results that climate scientists are artificially introducing fresh water into their models over large parts of the ocean that freshwater would never have reached," says Condron. ...
