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Paleoclimate
Cretaceous Climate (144 to 65 million years ago)
Reduced solar radiation at the South Pole because of Antarctica
While the dinosaurs were still alive,
Antarctica was located farther north than it is now. It was a part of a
supercontinent called Gondwanaland, and was attached to Australia and
South America. About 65 million years ago, Antarctica began to move into its
present location. By about 30 million years ago, it had moved far enough south
to start to have glaciers.
Glaciers and snow
reflect up to 90% of the
incoming solar radiation, and so they reinforce the cold temperatures caused
by the poleward movement of Antarctica.
Also, by 15 million years ago, Antarctica separated from the tip of South America and became completely surrounded by the Southern Ocean. A very cold ocean current around the continent was set up. Antarctica was already pretty cold, but now it became even more isolated from the rest of the world by the cold ocean and resulting winds.
In Antarctica today, the average summertime temperatures are 20 F
(-7 C) and average wintertime temperatures are -30 F (-34 C). It eventually became completely frozen, like it is today, furthering the reflected solar radiation and helping to cool global temperatures.
Next page -> cretaceous climate, continued
Links and resources
Cretaceous Climate (144 to 65 million years ago)
Reduced solar radiation at the South Pole because of Antarctica
While the dinosaurs were still alive,
Antarctica was located farther north than it is now. It was a part of a
supercontinent called Gondwanaland, and was attached to Australia and
South America. About 65 million years ago, Antarctica began to move into its
present location. By about 30 million years ago, it had moved far enough south
to start to have glaciers.
Glaciers and snow
reflect up to 90% of the
incoming solar radiation, and so they reinforce the cold temperatures caused
by the poleward movement of Antarctica.Also, by 15 million years ago, Antarctica separated from the tip of South America and became completely surrounded by the Southern Ocean. A very cold ocean current around the continent was set up. Antarctica was already pretty cold, but now it became even more isolated from the rest of the world by the cold ocean and resulting winds.
In Antarctica today, the average summertime temperatures are 20 F
(-7 C) and average wintertime temperatures are -30 F (-34 C). It eventually became completely frozen, like it is today, furthering the reflected solar radiation and helping to cool global temperatures.
Next page -> cretaceous climate, continued
Links and resources
