Research links Southeast Asia megadrought to drying in Africa [mid-Holocene]

EurekAlert! ^ | August 21, 2020 | University of Pennsylvania

[SunkenCiv]

Physical evidence found in caves in Laos helps tell a story about a connection between the end of the Green Sahara, when once heavily vegetated Northern Africa became a hyper-arid landscape, and a previously unknown megadrought that crippled Southeast Asia 4,000 to 5,000 years ago.

In a paper published in Nature Communications, scientists at the University of California, Irvine, University of Pennsylvania, William Paterson University of New Jersey, and other international institutions explain how this major climate transformation led to a shift in human settlement patterns in Southeast Asia, which is now inhabited by more than 600 million people...

To create a paleoclimate record for the study, Johnson and other researchers gathered stalagmite samples from caves in Northern Laos. In her UCI laboratory, they measured the geochemical properties of the oxygen and carbon isotopes, carbon-14, and trace metals found in the specimens. This helped them verify the occurrence of the drought and extrapolate its impacts on the region...

The modeling experiments suggested that reduced plant growth in the Sahara led to increased airborne dust that acted to cool the Indian Ocean and shift the Walker circulation pattern eastward, causing it to behave in ways similar to modern-day El Niño events. This, ultimately, led to a large reduction in monsoon moisture across Southeast Asia that lasted more than 1,000 years, according to Johnson.

Anthropologists and archaeologists have previously studied the effects of the demise of the Green Sahara, also known as the African humid period, on population centers closer to Western Asia and North Africa, noting the collapse of the Akkadian Empire of Mesopotamia, the de-urbanization of the Indus Civilization (near present-day Pakistan and India) and the spread of pastoralism along the Nile River.

[SunkenCiv]

Subtitle: Previously unknown mid-Holocene event led to major changes in human settlement, according to findings from University of California, Irvine, University of Pennsylvania and William Paterson University

To create a paleoclimate record for the study, co-author Kathleen Johnson, UCI associate professor of Earth system science, and other researchers collected stalagmite samples from caves in Northern Laos. The specimens hold geochemical evidence of past climate change in the highly populated Asian monsoon region. Credit: Amy Ellsworth

[SunkenCiv]

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[SunkenCiv]

Here are the other GGG topics introduced since the previous Digest ping:

• 400 Mysterious Ancient Stone Structures Discovered in Saudi Arabia [2017]
• Archaeologists are mystified by ancient "gates" in Saudi lava fields [2017]
• Isaac Newton: World Will End in 2060 [2020]
• Left-Handed People in the Bible: Is there a genetic link to Benjamite lefties? [2020]
• Macron says Mont Blanc glacier melting proves global warming [2020]
• Medieval DNA suggests Columbus didn't trigger syphilis epidemic in Europe [2020]
• Portrait of Shakespeare Unveiled [2009]
• Thousands of Rare Artifacts Discovered Beneath Tudor Manor's Attic Floorboards [2020]
• Today is Victory over Japan Day [2020]

[SunkenCiv]

[KarlInOhio]

I don't believe it. Climate (and weather) stayed exactly the same, year after year, until the SUV was invented.

[BenLurkin]

Interesting. Is there any info on where the rain activity moved to during that same time frame?

[SunkenCiv]

Caves reveal clues to UK weather
by Tom Heap
Saturday, December 2, 2000

At Pooles Cavern in Derbyshire, it was discovered that the stalagmites grow faster in the winter months when it rains more. Alan Walker, who guides visitors through the caves, says the changes in rainfall are recorded in the stalactites and stalagmites like the growth rings in trees. Stalagmites from a number of caves have now been analysed by Dr Andy Baker at Newcastle University. After splitting and polishing the rock, he can measure its growth precisely and has built up a precipitation history going back thousands of years. His study suggests this autumn's rainfall is not at all unusual when looked at over such a timescale but is well within historic variations. He believes politicians find it expedient to blame a man-made change in our weather rather than addressing the complex scientific picture.

(I like that closing sentence -- "future decision-making could be made based on scientific data and not on political expediency". I wouldn't count on it, but that would be great.)

Disaster that struck the ancients

Professor Fekri Hassan, from University College London, UK, wanted to solve the mystery, by gathering together scientific clues. His inspiration was the little known tomb in southern Egypt of a regional governor, Ankhtifi. The hieroglyphs there reported "all of Upper Egypt was dying of hunger to such a degree that everyone had come to eating their children". Dismissed as exaggeration and fantasy by most other Egyptologists, Fekri was determined to prove the writings were true and accurate. He also had to find a culprit capable of producing such misery. He studied the meticulous records, kept since the 7th Century, of Nile floods. He was amazed to see that there was a huge variation in the size of the annual Nile floods - the floods that were vital for irrigating the land. But no records existed for 2,200BC. Then came a breakthrough - a new discovery in the hills of neighbouring Israel. Mira Bar-Matthews of the Geological Survey of Israel had found a unique record of past climates, locked in the stalactites and stalagmites of a cave near Tel Aviv. What they show is a sudden and dramatic drop in rainfall, by 20%. It is the largest climate event in 5,000 years. And the date? 2,200 BC.

4,000-year-old planned community unearthed
Oct 13 2000

"'Evidently, the conception of what was urban in 2500 to 2000 B.C. was not all that different from what is considered urban today,' said Guillermo Algaze, an associate professor of anthropology at the University of California, San Diego, who has been directing the excavation of Titris Hoyuk, a 125-acre walled urban site in the Euphrates River Basin in southeastern Turkey that flourished for a brief time in the third millennium Bronze Age. In its heyday, Titris had about 10,000 residents. Titris was a failure as a city and as a civilization, rising and falling within a 300 year period, never again to be reoccupied. But, said Algaze, Titrus's failure -- probably due to a shifting in trade routes -- is also the key to its appeal to modern archaeologists."

Tuba
Oct 13 2000

"The women in the tomb were highly ornamented. The ibex (goat above) was made of lapis lazuli which was available only in Afghanistan at the time. Evidence amassed thus far by Schwartz and Curvers indicates that Tubaarose as a political and economic center around 2500 BC, with a population of 5,000 to 7,500 people. The city, which was on a major east-west trade route that connected the Mediterranean coast with upper Mesopotamia, collapsed and was abandoned around 2100 BC possibly due to drought, only to resurrect itself as the primary urban center of the Jabbul plain until around 1200 BC."

[SunkenCiv]

The 18 October 03 issue of New Scientist had an article (p 15) "Warm oceans caused Sahel droughts", but it is not alas online. Luckily there are similar stories elsewhere, although the global warming demagoguery runs rampant. See also the "in reply to" link:

Oceans linked to Sahel drought

The droughts, in which over a million people are thought to have died, were initially blamed on human degradation of the local environment... The study looked at the Pacific - in particular the effect of the El Nino phenomenon and the effect on the Sahel rainfall - Atlantic, and Indian oceans. It was found that the Indian Ocean was a powerful indicator of the level of precipitation in the Sahel over the long term, while the Pacific affected seasonal rainfall... There were broadly two hypotheses to explain what happened in this semiarid region of Africa. One blamed the drought on changes brought about by human land use... The other hypothesis focused on temperature changes in the global oceans as the main culprit behind the drought... It is hoped that, with such a link established, the model can now be used to predict future rainfall in the Sahel. This could be crucial in giving time to plan for any forthcoming drought.

[Alas Babylon!]

Well, in Africa, the annual Monsoon would cover the North and kept the Sahara area green. Then it stopped, never getting more North than the Southern Sahel. It persists this way to the present.

The Monsoon is still vigorous in South and Southeast Asia, watering India through Vietnam every year. Why hasn’t it returned in Africa?

[SunkenCiv]

A list of linked topics, from the forbidden depths of the hard drive.

• Ancient megadrought entombed dodos in poisonous fecal cocktail [2015]
• Climate change caused empire's fall, tree rings reveal [2014]
• The Ghost Empire - Climate Change, Global Warming, Drought and Desertification [2013]
• Climate and Drought Lessons from Ancient Egypt [2012]
• Ancient Egypt was destroyed by drought, discover Scottish experts [2011]
• Ancient City Mysteriously Survived Mideast Civilization Collapse [2011]
• Comets And Disaster In The Bronze Age [2007]
• Climate Key To Sphinx's Riddle [2007]
• Drought That Destroyed A Civilisation [2003]
• Great Pyramid may still contain Khufu's intact pharaonic tomb [2005]
• Evidence for Major Impact Events in the late Third Millennium BC [2002]
• Comets,Meteors & Myth: New Evidence For Toppled Civilizations And Bibical Tales [2002]
• Deconstructing the Walls of Jerico [2002]
• Meteor Clue To End Of Middle East Civilisations [2002]
• Disaster That Struck The Ancients [2001]

[Rurudyne]

The formation she’s standing next to looks a bit like the legs, hips and lower back of some poor guy imbedded in the stone upside down as if hanging by his feet.

It even looks like a section of his right leg bone is exposed.

[M Kehoe]

LOL.

5.56mm

[GreyFriar]

SunkenCiv,

The Daily Mail’s headline took a different stance:

“Sahara turned from lush green grassland to a barren wasteland just 4,000 years ago and triggered a megadrought that crippled Southeast Asia for 1,000 years”

And that warming happened before fossil fuels were being mined/pumped and burned.

Cheers, G-F

Link to its article:

https://www.dailymail.co.uk/sciencetech/article-8650403/Sahara-turned-grassland-wasteland-4-000-years-ago-triggering-megadrought-Southeast-Asia.html

[SunkenCiv]

the rest of Curse of Agade keyword, chrono:

• Strong winter dust storms may have caused the collapse of the Akkadian Empire [2019]
• How climate change caused the world's first empire to collapse [2019]
• Evidence of Sodom? Meteor blast cause of biblical destruction, say scientists [2018]
• Welcome to the Meghalayan Age - a new phase in history [2018]
• The Best Radiocarbon-dated Site in Recent Iberian Prehistory [sudden end] [2018]
• 4,000-year-old Sumerian port found in southern Iraq [2018]
• Did Egypt's Old Kingdom Die -- or Simply Fade Away? [2015]
• Have archaeologists discovered the biblical city of Sodom? [2015]
• ARCHAEOLOGISTS CLAIM TO HAVE FOUND ANCIENT CITY OF SODOM (AND GOMORRAH) [2015]
• Archaeologist Believes Remains of Sodom's Fiery Destruction Have Been Found [2015]
• Archaeologists discover possible ruins of ancient Sodom in the Holy Land [2015]
• Possible site of ancient Sodom yields more finds [2015]
• Archeologists Explain Historical Climate Change 4,000 Years Ago [2015]
• Ancient megadrought entombed dodos in poisonous fecal cocktail [2015]
• New Thoughts on the Impact of Climate Change in Neolithic China [2015]
• Climate change caused empire's fall, tree rings reveal [2014]
• The Ghost Empire - Climate Change, Global Warming, Drought and Desertification [2013]
• 200-year-long drought may have killed Sumerian language [2012]
• Climate and Drought Lessons from Ancient Egypt [2012]
• Ancient Egypt was destroyed by drought, discover Scottish experts [2011]
• Ancient City Mysteriously Survived Mideast Civilization Collapse [2011]
• Clay tablet holds clue to asteroid mystery [2008]
• Comets And Disaster In The Bronze Age [2007]
• Climate Key To Sphinx's Riddle [2007]
• Charcoal reveals wildfire history [2006]
• Jordan site may be Biblical city of Sodom [2006]
• The Roots Of Civilization Trace Back To ... Roots [2005]
• Ancestors Of Turks Came To Anatolia In 2000s BC [2004]
• Mesopotamian Climate Change (8,000 Years Ago) [2004]
• Drought That Destroyed A Civilisation [2003]
• The Dark Ages: Were They Darker Than We Imagined? [2003]
• Meteor Clue To End Of Middle East Civilisations [2003]
• Dawn Of American Religion Found (2,250 BC) [2003]
• An Impact Event in 3114BC? The beginning of a Turbulent Millennium. [2003]
• Evidence for Major Impact Events in the late Third Millennium BC [2002]
• The Law Code of Hammurabi. (Complete Translation) [2002]
• Comets,Meteors & Myth: New Evidence For Toppled Civilizations And Bibical Tales [2002]
• Deconstructing the Walls of Jerico [2002]
• Archaeologists Unearth 1,700 Year-Old Canal System Near Lake Okeechobee (Florida) [2002]
• Meteor Clue To End Of Middle East Civilisations [2002]
• Disaster That Struck The Ancients [2001]
• Comets, Meteors & Myth: New Evidence for Toppled Civilizations and Biblical Tales [2001]
• Slam, bang, thanks Saddam: new meteor theory [2001]

[Cold Heart]

Meanwhile you missed the alien that looks part man part beast looking down at you. Had this been a shoot no shoot you would have been eaten.

[SunkenCiv]

Thanks! From the Sahara keyword:

• The ups and downs of a mega-lake (rest of this list posted here)
• Entomologist Confirms First Saharan Farming 10,000 Years Ago [2018]
• More Evidence of a Wet Sahara [2017]
• Fossil of massive crocodile found on edge of Sahara desert [2016]
• A Carpet of Stone Tools in the Sahara [2015]
• Ancient Africans used 'no fly zones' to bring herds south [2015]
• NASA video shows how dust from Sahara Desert fuels Amazon rain forest [2015]
• Violence and climate change in prehistoric Egypt and Sudan [2014]
• Ancient bone fragments help describe diet, health of Saharan ancestors [2014]
• Study Confirms Ancient River Systems in Sahara 100,000 Years Ago [2013]
• Mineral dust plays key role in cloud formation and chemistry [2013]
• Lost Civilization Discovered in Sahara Desert [2011]
• Ancient Egypt was destroyed by drought, discover Scottish experts [2011]
• Fish Swam the Sahara, Bolstering Out of Africa Theory [2010]
• Lost Cities of the Sahara [2010]
• Geology Picture of the Week Extra: GoogleEarth searcher finds pristine impact crater in Egypt [2010]
• Strange Ancient Crocodiles Swam the Sahara [2009]
• Stone Age humans crossed Sahara in the rain [2009]
• Giant stone-age axes found in African lake basin [2009]
• Graves Found From Sahara's Green Period [2008]
• Graves Found From Sahara's Green Period [2008]
• US scientists find stone age burial ground in Sahara [2008]
• In Search Of The Lost Sahara [2008]
• Once Lush Sahara Dried Up Over Millennia, Study Says [2008]
• Sahara dried out slowly, not abruptly: study [2008]
• The Tassili n'Ajjer [Algeria] : birthplace of ancient Egypt ? [2008]
• Egypt's Earliest Agricultural Settlement Unearthed [2008]
• UN vandals spray graffiti on Sahara's prehistoric art [2008]
• Ruins of 7,000-year-old city found in Egypt oasis [2008]
• Maltese claims extraordinary discovery in Sahara desert [2007]
• Space Data Unveils Evidence of Ancient Mega-lake in Northern Darfur [2007]
• The African Source Of The Amazon's Fertilizer [2006]
• Exodus From Drying Sahara Gave Rise to Pharaohs, Study Says [2006]
• Sahara Desert Was Once Lush and Populated [2006]
• Ancient lakes of the Sahara [2006]
• Ancient drought 'changed history' [2005]
• Stone Age Cemetery, Artifacts Un Earthed In Sahara [2005]
• Prehistoric Desert Town Found In Western Sahara (15,000 Years Old) [2004]
• Scientists Explore Lakefront Property, in the Sahara [2004]
• African Ice Core Analysis Reveals Catastrophic Droughts, Shrinking Ice Fields, Civilization Shifts [2002]

[Ouchthatonehurt]

I didn’t drive my Suburban at all one Spring - we had a very cool Summer ;-)

[SunkenCiv]

The (in)Complete Index of Omni Magazine doesn't list it, so I can't give a date. Here's the full text though, saved it off the original archival website, and the updated website (different URL) is also long gone.

We smell fish, lots of fish.

Lake Victoria, Africa's largest lake, is home to more than 300 species of cichlids. These fish, which are popular in aquariums, are deep-bodied and have one nostril, rather than the usual two, on each side of the head.

So what, you say? Well, what's surprising is that Lake Victoria was bone dry not very long ago, suggesting that all the cichlids in it have evolved in a remarkably short time. Seismic profiles and cores of the lake taken by a team headed by Thomas C. Johnson of the University of Minnesota, reveal that the lake dried up completely about 12,400 years ago. This means that the rate of speciation of cichlid fishes has been extremely rapid: something on average of one new species every 40 years!

All this progress has some people thinking, particularly anomaly hunter and The Sourcebook Project compiler William Corliss. In his newsletter, Science Frontiers, Corliss asks the question on everybody's mind: "Can random mutations -- the accepted source of evolutionary novelty -- have generated so many new species in such a short time?" We decided to pose that question to Boston University biologist Les Kaufman, who does research on these fish in the Lake Victoria region.

"My work suggests that the actual duration of the burst that produced the current fauna was much shorter than even the 12,400 years that the lake has been recently full of water," Kaufman says. "It is likely that many of the species formed during the refilling of the lake. However, they appear to be derived from a diversity of lineages that evolved during previous episodes during which there was a large lake in the basin.

"By the way," Kaufman adds, "as remarkable as the timing may sound, there is nothing in it that is inconsistent with existing evolutionary theory. It is just jarring to be reminded that evolution is real and happens quickly." Fresh fish, indeed.

Evolution in Your Face by Patrick Huyghe

[Berosus]

As you know, I record the History of Southeast Asia Podcast, and aside from the Ban Chiang culture in Thailand, and the exploration of Southeast Asia’s islands by the ancestors of today’s Malays, Indonesians and Filipinos, I don’t think much was happening in Southeast Asia at the time proposed for this drought. No empire to bring down by the change in climate, anyway.