The African Plate in theory must have gone under the European Plate causing an uplift and hastening the end of the last Great Ice Age. ( I'm thinking of Europe here.) England became ice free, etc. Westwind.
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The African Plate in theory must have gone under the European Plate causing an uplift and hastening the end of the last Great Ice Age. ( I'm thinking of Europe here.) England became ice free, etc. Westwind.
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how do you make that out ? africa is moving northward, meaning that the Atlas mountains move away from the tropics
and england is only free of ice during interglacials, in which we live now
I think the move into an interglacial stage is adequately explained by variations in Earth's orbital and axial characteristics as expressed in the Milankovitch cycles. In what way is your proposal a better explanation? Also, since the northward movement of Africa has been an ongoing process for millions of years, how do you account for the alternation of glacial and interglacial periods? Plus, the point made by marnix.
I regret it seems your idea is a good one destroyed by the evidence against and the lack of evidence for.
I was thinking moving northwards from the Southern Temperate Zone. Also I was looking for a reason that an apparent climate shift took place around 14/18 thousand years ago, rapidly leading to drier and warmer conditions. ( In and around the Atlas Mts. ). A human occupation zone became uninhabital. westwind.
John Galt. Forum Professor. Thank you for your informative Post. Also thanks to marnix. My brief response to marnix ( first post ), was to try to put a feeler out there for a sudden positional shift of the African Plate northwards. It has been proposed the movement of Atlas Mt. Peoples move to the Nile Valley was because their former existance became untenable. Something like the position of the Aztecs. I agree with Milankovitch cycles etc for a line drawn in the sand, but there is an elephant in the room somewhere. westwind.
don't forget the effect of rainfall - if, say, monsoon rains reach what is now the Sahara, then it will turn into a savannah
if these rains fail, as they now often do in Ethiopia, then over time that area will turn into a desert
+ that includes the Atlas mountains
Thanks marnixR. Very plausible explanation. The shifting of monsoonal weather Systems certainly influence climate. I'll dwell on that one. These Monsoons are another Thing altogether, perhaps more research is required into this aspect of our weather, eg; were there Monsoons during the Glacial Periods? ( Ice Age ). Do They start up where Pressure Systems leave off?. westwind.
I thought the title was strange, namely because the Atlas mountains aren't' snow free--in fact a couple ski areas operate in Morocco. Also the Altas mountains arent' the produce of the African plate collision with European plate which started about ~50 million years ago, but from much earlier collision ~300-500 million years ago when it was colliding with the North American plate.
Thank you Lynx, I was wondering much the same thing.
I think you need to do a bit of research on how atmospheric circulation works to produce monsoon, desert and temperate areas of land.The shifting of monsoonal weather Systems certainly influence climate. I'll dwell on that one. These Monsoons are another Thing altogether, perhaps more research is required into this aspect of our weather,
Far from the Atlas Mountains becoming more likely to become monsoonal, they're in a prime areas to become drier when Hadley cells expand. Hadley cell? Atmospheric circulation - Wikipedia, the free encyclopedia (Click the link to the Hadley cell page.)
Briefly put. Moist air is carried upwards from the equatorial regions and moves polewards. It then descends providing rainfall to the temperate regions. This means that the moisture skips over the continental deserts - Africa and Australia are the outstanding instances here. Africa in particular. A central swathe of equatorial tropical rainforests, arid regions to both the south and the north of that region. The northern limit of Africa is literally on the edge of Hadley cell governed precipitation - after all Spain and Greece are both pretty dry - it's the regions above 45 degrees N latitude that get the most benefit. (In much the same way as Perth and Adelaide are (35 deg S) at the southern edge of Australia.)
Any expansion of the Hadley cells will mean that the region around the Atlas Mountains will get even less precipitation than now. It does not mean that the monsoon area will expand to enlarge the tropical equatorial region.
on the other hand, the north african climate cycle is thought to be linked with shifts in the strength of the north african monsoon
North African climate cycles
as to how this would specifically have affected the Atlas mountains i have no idea
if the monsoon referred to still comes from the south-east, that would mean that the Atlas is furthest away from an incursion of monsoon rains
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