On Line: 02 April 2012 06:09
In Print: Tuesday 03 April 2012
OXFORD, England (UPI) — Studies of corals off Tahiti hint an ancient “mega flood” occurred when massive ice sheets collapsed and raised sea levels by 45 feet, European researchers say.
Scientists from Aix-Marseille University in France and Britain’s Oxford University said they’ve confirmed the event occurred between 14,650 and 14,310 years ago, during a period of rapid climate change known as the Bolling warming.
Scientists modeling future climate-change scenarios can use the findings to factor in the dynamic behavior of major global ice sheets, they said.
“Our work gives a window onto an extreme event in which deglaciation coincided with a dramatic and rapid rise in global sea levels — an ancient ‘mega flood,'” Alex Thomas of Oxford University’s Department of Earth Sciences said.
“Sea level rose more than 10 times more quickly than it is rising now! This is an excellent test bed for climate models: if they can reproduce this extraordinary event, it will improve confidence that they can also predict future change accurately,” he said in an Oxford release.
During the so-called Bolling warming high latitudes of the Northern hemisphere warmed as much as 27 degrees Fahrenheit in less than a century, the researchers said.
The “Tahitian coral is important because samples, thousands of years old, can be dated to within plus or minus 30 years,” Thomas said. “Because Tahiti is an ocean island, far away from major ice sheets, sea-level evidence from its coral reefs gives us close to the ‘magic’ average of sea levels across the globe; it is also subsiding into the ocean at a steady pace that we can easily adjust for.”
The new evidence suggests a considerable portion of the sea-level rise at that time must have come from melting of the ice sheets in Antarctica, which sent a ‘pulse’ of freshwater around the globe, the researchers said.