Ice Ages Dried Up African Monsoons

New Scientist ^ | 6-10-2007

[blam]

Ice ages dried up African monsoons

10:00 10 June 2007
NewScientist.com news service

When ice ages held Europe in their grip, Africa also felt the pinch - though in a different way.

It has long been suspected that there is a connection between the west African monsoon and climate at higher latitudes - especially over geological timescales, says David Lea at the University of California, Santa Barbara. "But until now, there hasn't been enough supporting evidence." Now Lea, with team leader Syee Weldeab and colleagues, has reconstructed the most detailed history of the monsoon yet, spanning 155,000 years and two ice ages.

The team analysed the amount of barium in plankton shells found in an ocean sediment core drilled beneath the Gulf of Guinea. Barium is found in freshwater run-off from the river Niger, says Lea, and is a gauge of past run-off levels and monsoon intensities. When the northern latitudes were frozen over, monsoon rains were much weaker, only gaining strength again when the temperatures in the north increased, the team found.

They also discovered big swings in monsoon activity over timescales as small as 100 years, linked to rapid climate change caused by changes in ice sheet size (Science, vol 316, p 1303). "Something that happens right up in the poles can have a dramatic effect on the climate in the tropics," says Lea.

[blam]

Cold = Dry

Hot = Wet

[blam]

Ice Ages Blamed On Tilted Earth

[sgtbono2002]

Does this mean that with Global warming and the ice melting,that the Sahara will soon be a tropical region?

[VeniVidiVici]

Does this mean that with Global warming and the ice melting,that the Sahara will soon be a tropical region?

If so, then the Left will whine that the Western nations are ruining the Saharan culture.

[Free as the breeze]

Does this mean that with Global warming and the ice melting,that the Sahara will soon be a tropical region?

If so, then the Left will whine that the Western nations are ruining the Saharan culture.

If so, let them. The more important issue to pay attention to is that the impending worldwide disruptions due to climate change will negatively affect the security of ourselves and our allies. There is a good chance the next war in the Mid-East will be fought over water, for example.

[SunkenCiv]

Thanks Blam.

· join · view topics · view or post blog · bookmark · post new topic ·

[SunkenCiv]

Thanks Blam. I really hate it when the Earth tilts. Today I peeled through another thirty or so pages of the Adovasio book, mostly about Pleistocene glaciation etc.

To all -- please ping me to other topics which are appropriate for the GGG list. Thanks.

Please FREEPMAIL me if you want on or off the
"Gods, Graves, Glyphs" PING list or GGG weekly digest
-- Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
Gods, Graves, Glyphs (alpha order)

[blam]

"Today I peeled through another thirty or so pages of the Adovasio book, mostly about Pleistocene glaciation etc."

I'm slugging my way through this one: After the Ice: A Global Human History 20,000-5000 BC (Hardcover) by Steven Mithen (Author)

If this SOB mentions man-made global warming one more time I'm likely to throw this book in the trash.

[SunkenCiv]

Adovasio refers to the origin of the ice ages as being “murky”, and makes a couple of references to CO2. After I rip through this one, and write an Amazon review of it (along with the memoir “Alvarez”), I plan to start “Bones”. Seems like there’s another one around here... oh yeah, I’ve got to do some excavation and locate that book on the Clovis extinction...

[SunkenCiv]

---

After the Ice: A Global Human History 20,000-5000 BC by Steven Mithen

---

[SunkenCiv]

---

Bones: Discovering the First Americans by Elaine Dewar

---

[nicollo]

Okay, dammit, I’ll have to read this thing. Meanwhile, here’s my best guess:

Climates were more largely spread across latitudes pre-Ice Age, making for less competition over food sources, and, thereby, rewarding hunting/gathering. Ice Age and thereafter restricted food supplies into similar latitudes and created more competition over food sources, thus rewarding control over food supply and social organizations.

Well, there’s my best economic model for the Rise of Civilation...

[blam]

Let me know if you like ‘Bones.’ It sounds like a subject I’m interested in.

[blam]

"Well, there’s my best economic model for the Rise of Civilation..."

Sounds reasonable. However, I think there have been civilizations of which we'll never find any physical evidence...sort-of (ahem) Sunken Civilizations.

[SunkenCiv]

Wow, glad we forced you to read it, that’s an excellent analysis IMHO.

[SunkenCiv]

Even if I were to start it tomorrow, I spend far too much of my time online (especially considering it’s summer), and the thing is about 2 1/2 inches thick (if memory serves, I’ve not looked for it in a while).

[SunkenCiv]

See, I had a motive...

[nicollo]

Well, thanks, but I haven’t read the book yet. I’m kinda mad at you and Blam for bringing it up at all. I was hoping for a LIGHT reading list this summer...

Thanks for all your hard work on these threads. Fantastic stuff!

[SunkenCiv]

82,000 Year Old Jewellery Found
Oxford Mail | 6-4-2007 | Fran Bardsley
Posted on 06/04/2007 1:43:44 PM EDT by blam
http://www.freerepublic.com/focus/f-chat/1844620/posts

[SunkenCiv]

Many thanks. You might try this one first (this is the one I've lost somewhere in the house):

---

The Cycle of Cosmic Catastrophes: Flood, Fire, and Famine in the History of Civilization by Richard Firestone, Allen West, Simon Warwick-Smith

---