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How Earth's orbital shift shaped the Sahara
Physorg Earth Sciences ^ | December 21, 2010 | Anuradha K. Herath

Posted on 12/21/2010 10:03:52 AM PST by LucyT

The Sahara, the world's largest desert, was once fertile grassland. This fact has been common knowledge in the scientific community for some time, but scientists are still grappling with historic data to determine whether that transition took place abruptly or gradually.

At the European Geosciences Union General Assembly held in Vienna, Austria earlier this year, researchers presented new evidence showing that the eastern region of the Sahara desert, particularly the area near Lake Yoa in Chad, dried up slowly and progressively since the mid-Holocene period.

(Excerpt) Read more at physorg.com ...


TOPICS: Agriculture; Science
KEYWORDS: catastrophism; climate; earth; godsgravesglyphs; herodotus; lakechad; laketritonis; lakeyoa; orbit; sahara
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A change in the Earth’s orbit, many scientists believe, transformed the “Green Sahara” into what is now the largest desert on the planet.
1 posted on 12/21/2010 10:03:55 AM PST by LucyT
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To: LucyT

Owl gore says different.


2 posted on 12/21/2010 10:07:28 AM PST by mountainlion (concerned conservative.)
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To: LucyT

I ran across another idea once that at one time North America and South America were separated by a strait through which a large ocean current flowed.

When Central America rose, cutting off the current, the climate of Africa changed.

According to that particular article, the African climate change was what led to the evolutionary rise of homo sapiens.


3 posted on 12/21/2010 10:10:48 AM PST by DuncanWaring (The Lord uses the good ones; the bad ones use the Lord.)
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To: LucyT
Fred's Fault!


4 posted on 12/21/2010 10:13:03 AM PST by Uncle Miltie (0bamanomics: Punish Success, Reward Failure. Destroying America is the point.)
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To: LucyT; SunkenCiv

This relates to the archaelogy work conducted at the dry lake west of the nile by a few hundred kilometers. The links below are from different historical eras.

http://news.discovery.com/earth/ancient-egypt-mega-lake.html

Sunkenciv pinged a thread discussing that lake recently.
Shuttle images reveal Egypt’s lost great lake

http://www.freerepublic.com/focus/chat/2636761/posts
· 12/03/2010 4:09:49 AM PST ·
· Posted by SunkenCiv ·
· 26 replies ·
· Science News ·
· Wednesday, November 24th, 2010 ·
· Alexandra Witze ·
Radar images taken from the space shuttle confirm that a lake broader than Lake Erie once sprawled a few hundred kilometers west of the Nile, researchers report in the December issue of Geology. Since the lake first appeared around 250,000 years ago, it would have ballooned and shrunk until finally petering out around 80,000 years ago... Since then, desert winds have eroded and sands have buried much of the region’s landscape, says Maxine Kleindienst, an anthropologist at the University of Toronto. But during next summer’s field season, she and her colleagues will be checking for ancient shorelines at the elevations...

older thread:
http://www.freerepublic.com/focus/chat/2579098/posts
The Lost City: A discovery in the desert could rewrite the history of ancient Egypt
Yale Alumni Magazine ^ | September/October 2010 | Heather Pringle


5 posted on 12/21/2010 10:16:38 AM PST by JerseyHighlander (p.s. The word 'bloggers' is not in the freerepublic spellcheck dictionary?!)
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To: LucyT

It was all those ancient Israelites and their SUVs. They parked them all close together and shifted the Earth’s orbit.


6 posted on 12/21/2010 10:21:46 AM PST by samtheman
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To: LucyT

Ah the money quote:

‘For a long time, the belief was that the Earth’s tilt would change only insignificantly in the next century. However, recent research is suggesting that the effects of global warming—particularly the oceans—could cause a change in the Earth’s axial tilt. Scientists from NASA’s Jet Propulsion Laboratory say that the current melting of ice in Greenland is already causing the tilt to change at a rate of approximately 2.6 centimeters each year. They predict that his change could increase in the years ahead.’

Uh huh. Now global warming is causing tilt shifts in the earth.


7 posted on 12/21/2010 10:22:24 AM PST by Free Vulcan (The cult of Islam must be eradicated by any means necessary.)
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To: mountainlion

Oh, but did you get to the punchline in the article?? The one that says that Global Warming and the rising oceans are actually going to CAUSE the earth’s axis to tilt, leading to MORE global warming? Face-palm.


8 posted on 12/21/2010 10:23:54 AM PST by Explorer89 (And now, let the wild rumpus start!!)
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To: LucyT
"How Earth's orbital shift shaped the Sahara"

Read Velikovski -'Worlds in Collision'. Now largely discredited but very interesting reading, and you never know, maybe he was on to something.

9 posted on 12/21/2010 10:27:02 AM PST by I am Richard Brandon
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To: LucyT
A change in the Earth’s orbit, many scientists believe, transformed the “Green Sahara” into what is now the largest desert on the planet.

Obviously, they haven't heard of George W. Bush.

10 posted on 12/21/2010 10:27:13 AM PST by JRios1968 (This is me, in a nutshell: "Let me out of here...I'm trapped in a nutshell!!!!")
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To: LucyT

>>A change in the Earth’s orbit, many scientists believe, transformed the “Green Sahara” into what is now the largest desert on the planet.<<

No way! We all know it was the smoke from Cromagnon camp fires.


11 posted on 12/21/2010 10:27:31 AM PST by freedumb2003 (Nothing sharpens the mind like not being able to get a job. /Nonstatist)
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To: LucyT

Did you ever see a top spinning around and suddenly it gives a big twitch then stabilizes again for a short time...

i think that ‘twitch’ would be quite a shcok if it happened to the spinning earth.

It would also explain a lot of things- like why we find landmarks 100 feet underwater that used to be cities, and sea life fossils on mountain tops


12 posted on 12/21/2010 10:29:08 AM PST by Mr. K ('Profiling' you is worse than grabbing your balls)
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To: Mr. K; LucyT
Did you ever see a top spinning around and suddenly it gives a big twitch then stabilizes again for a short time...

That happens because the top is spinning on a surface and is slowing down due to friction. The twitch is because of a surface irregularity encountered by the spinning axis of the top. There are no surface irregularities in space.
13 posted on 12/21/2010 10:32:50 AM PST by aruanan
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To: LucyT

It’s almost like a ‘dry band’ that goes around much of the Earth. You can look at the Sahara on a global map, and nearly all the way around the planet, there is desert, across the Middle East, all the way around to the South Western US/Mexico. It varies some, but you can definitely see the pattern.


14 posted on 12/21/2010 10:33:01 AM PST by KoRn (Department of Homeland Security, Certified - "Right Wing Extremist")
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To: samtheman
Somewhere in the Bible, it is written that Jesus and his disciples "all went out in one (Honda?) Accord."
15 posted on 12/21/2010 10:33:37 AM PST by LucyT
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To: LucyT

Second rate, second hand alarmism.

The article actually describes a difference in the phasing between perihelion and vernal equinox and changes in the tilt or obliquity of the earth’s rotational axis, which are all part of the familar Milankovitch Theory.

The article did talk about a 2.6 cm/year change in the earth’s tilt caused by melting of Greenland’s ice cap. This would produce a change in tilt of 0.000023 degrees per century. Compared to the 0.01 degrees per century due to astronomical torques, it’s in the friggin’ noise.


16 posted on 12/21/2010 10:35:53 AM PST by Lonesome in Massachussets (Socialists are to economics what circle squarers are to math; undaunted by reason or derision.)
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To: LucyT

Saharan Shape Shifter


17 posted on 12/21/2010 10:41:02 AM PST by JoeProBono (A closed mouth gathers no feet - Visualize)
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To: Free Vulcan

“Now global warming is causing tilt shifts in the earth.”

Well, that nullifies sceptics- deniers- who use Milankovitch periodic axial tilt to debunk Global Warming, or Global Cooling, or Global Catastrophic Climate Change or whatever today’s flavor of global socialism is.


18 posted on 12/21/2010 10:48:36 AM PST by DBrow
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To: DuncanWaring

Take your lefty lies somewhere else!


19 posted on 12/21/2010 10:49:30 AM PST by sanescold
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To: sanescold

No one else wants them.


20 posted on 12/21/2010 10:57:16 AM PST by DuncanWaring (The Lord uses the good ones; the bad ones use the Lord.)
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