Posted on 04/30/2006 4:35:48 PM PDT by blam
Ice Ages Blamed on Tilted Earth
By Michael Schirber
LiveScience Staff Writer
posted: 30 March 2005
In the past million years, the Earth experienced a major ice age about every 100,000 years. Scientists have several theories to explain this glacial cycle, but new research suggests the primary driving force is all in how the planet leans.
The Earth’s rotation axis is not perpendicular to the plane in which it orbits the Sun. It's offset by 23.5 degrees. This tilt, or obliquity, explains why we have seasons and why places above the Arctic Circle have 24-hour darkness in winter and constant sunlight in the summer.
But the angle is not constant – it is currently decreasing from a maximum of 24 degrees towards a minimum of 22.5 degrees. This variation goes in a 40,000-year cycle.
Earth's Wobble ...
.
... is like the precession of a spinning top.
IMAGE: NASA
Peter Huybers of Woods Hole Oceanographic Institution and Carl Wunsch of the Massachusetts Institute of Technology have compared the timing of the tilt variations with that of the last seven ice ages. They found that the ends of those periods – called glacial terminations – corresponded to times of greatest tilt.
"The apparent reason for this is that the annual average sunlight in the higher latitudes is greater when the tilt is at maximum," Huybers told LiveScience in a telephone interview.
More sunlight seasonally hitting polar regions would help to melt the ice sheets. This tilt effect seems to explain why ice ages came more quickly – every 40,000 years, just like the tilt variations -- between two and one million years ago.
"Obliquity clearly was important at one point," Huybers said.
Colder planet
The researchers speculate that the glacier period has become longer in the last million years because...
(Excerpt) Read more at livescience.com ...
GGG Ping.
More speculation... one heck of a job if you can get it. Make up stuff and get paid.
Bush's fault
Damn. Beat me to it.
Are they talking about Ice Ages or the cycles of glaciation within an Ice Age? IIRC we are now in an Ice Age but the glaciers have retreated for moment.
This is all junk science hogwash.
Anybody with half a brain knows that it's Bush's fault.
Ever hear of Kyoto?
That's quite a statement, and what happens in the intermediary time when the seasons are shifting?
Maybe if we could get Michael Moore to move to South America, it would straighten the earth back up again?
"What we have here is a great laboratory for seeing how climate changes naturally," he said. "But this is a 100,000-year cycle, whereas global warming is happening a thousand times faster.”
These guys just don't seem to realize that they are destroying their credibility on serious, important science.
I thought is was caused by Uncle Teddy.
Lie the wobbling of a drunken singer.
Seems this fact of earth's geological history is an inconvenient reality for the Kyoto mad lefties.
Are they serial?
These idiots can't tell you with certainty that it will rain within the next 24 hours yet can predict events 10,000 years in the future. OK, then, I'll buy the bridge that goes from manhattan to brooklyn.
"That's quite a statement"
And an erroneous one at that, since winter begins in December.
No, silly!
Everyone knows that Karl Rove controls the weather machine!
But if they passed Kyoto, it would stop Global Tilting!
"But if they passed Kyoto, it would stop Global Tilting!"
Hence the title "Earth In The Balance."
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