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Article: How the Isthmus of Panama put ice in the Arctic: drifting continents open and close gateways between oceans and shift Earth's climate.(Earth-Climate)
- Article from:
- Oceanus
- Article date:
- September 22, 2004
- Author:
CopyrightCOPYRIGHT 2004 Woods Hole Oceanographic Institution. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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The long lag time has always puzzled scientists: Why did Antarctica become covered by massive ice sheets 34 million years ago, while the Arctic Ocean acquired its ice cap only about 3 million year ago?
Since the end of the extremely warm, dinosaur-dominated Cretaceous Era 65 million years ago, heat-trapping greenhouse gases in the atmosphere have steadily declined (with the anomalous exception of the last century), and the planet as a whole has steadily cooled. So why didn't both poles freeze at the same time?
The answer to the paradox lies in the complex interplay among the continents, oceans, and atmosphere. Like pieces of a puzzle, Earth's moving ...