Keyword: saharaforest
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Ancient pollen and charcoal preserved in deeply buried sediments in Egypt's Nile Delta document the region's ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt's Old Kingdom, the era known as the pyramid-building time... said Christopher Bernhardt, a researcher with the U.S. Geological Survey... "Even the mighty builders of the ancient pyramids more than 4,000 years ago fell victim when they were unable to respond to a changing climate," said USGS Director Marcia McNutt. "This study illustrates that water availability was the climate-change Achilles Heel then for Egypt, as it may well...
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Once green, the Sahara expanded 5,500 years ago, leading ancient herders to follow the rain and grasslands south to eastern Africa. But about 2,000 years ago, their southward migration stalled out, stopped in its tracks, archaeologists presumed, by tsetse-infested bush and disease. As the theory goes, the tiny tsetse fly altered the course of history, stopping the spread of domesticated animal herding with a bite that carries sleeping sickness and nagana, diseases often fatal for the herder and the herded. Now, isotopic research on animal remains from a nearly 2,000-year-old settlement near Gogo Falls in the present-day bushy woodlands of...
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Out Of AfricaDust, the Thermostat How tiny airborne particles manipulate global climate Sid Perkins On April 15, 1998, Mongolia's Gobi Desert lay between an area of low atmospheric pressure on the eastern end of the country and a zone of high pressure to the west. As swift winds rushed across the desert floor, they lofted sand and dust into the heart of a storm system racing southward into China. During the next 2 days, a yellow, muddy, acidic rain fell in a wide swath that covered Beijing and the Korean peninsula. On April 16, 1998, a strong storm system passing ...
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"Previous spatial analysis of the regional topography has shown there are major watersheds that are dry today but which would drain north from these [the Ahaggar and Tibesti ranges in the south] mountains towards the Mediterranean," says Coulthard, et. al. "Satellite imagery reveals traces of major river channels linked to these watersheds, now partially buried under sand dune deposits." It "provides the first strong quantitative evidence for the presence of three major river systems flowing across the Sahara during MIS 5e [Marine Isotope Stage 5e, or 130,000 years ago]".* "Whilst we cannot state for certain that humans migrated alongside these...
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How dust from the Sahara is fuelling the Amazon
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Scientists flew a plane into high up cirrus clouds and used a sampler that resembled a hair dryer to examine cloud formation © Karl FroydMineral dust that swirls up into the atmosphere from Earth’s surface plays a far more important role in both cloud formation and cloud chemistry than was previously realised. The findings will feed into models of cloud formation and chemistry to help produce more accurate assessments of the role of clouds in climate change.Relatively little is understood about the formation of cirrus clouds, wispy ‘horsetails’ that are made of ice crystals and form at extremely high altitudes...
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New evidence of a lost civilization in an area of the Sahara in Libya has emerged from images taken by satellites. Using satellites and air photographs to identify the remains in one of the most inhospitable parts of the desert, a team from the University of Leicester in England has discovered more than 100 fortified farms and villages with castle-like structures and several towns, most dating between AD 1 to 500. "It is like someone coming to England and suddenly discovering all the medieval castles. These settlements had been unremarked and unrecorded under the Gadhafi regime," said project leader David...
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researchers into the Garamantes -- a "lost" Saharan civilisation that flourished long before the Islamic era -- are hoping that Libya's new government can restore the warrior culture, mentioned by Herodotus in his Histories, to its rightful place in Libya's history. For while the impressive Roman ruins at Sabratha and Leptis Magna -- both world heritage sites -- are rightly famous, Libya's other cultural heritage, one that coexisted with its Roman settlers, has been largely forgotten. It has been prompted by new research -- including through the use of satellite imaging -- which suggests that the Garamantes built more extensively...
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...in 1992, a young American graduate student, John Coleman Darnell, and his wife and fellow graduate student, Deborah, decided to take a very different tack. The couple began trekking ancient desert roads and caravan tracks along what they called "the final frontier of Egyptology." Today, John Darnell, an Egyptologist in Yale's Near Eastern Languages and Civilization department, and his team have succeeded in doing what most Egyptologists merely dream of: discovering a lost pharaonic city of administrative buildings, military housing, small industries, and artisan workshops. Says Darnell, of a find that promises to rewrite a major chapter in ancient Egyptian...
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Wet spells in the Sahara may have opened the door for early human migration. According to new evidence, water-dependent trees and shrubs grew there between 120,000 and 45,000 years ago. This suggests that changes in the weather helped early humans cross the desert on their way out of Africa... While about 40 per cent of hydrocarbons in today's dust come from water-dependent plants, this rose to 60 per cent, first between 120,000 and 110,000 ago and again from 50,000 to 45,000 years ago. So the region seemed to be in the grip of unusually wet spells at the time. That...
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When Paul C. Sereno went hunting for dinosaur bones in the Sahara, his career took a sharp turn from paleontology to archaeology. The expedition found what has proved to be the largest known graveyard of Stone Age people who lived there when the desert was green. The first traces of pottery, stone tools and human skeletons were discovered eight years ago at a site in the southern Sahara, in Niger. After preliminary research, Dr. Sereno, a University of Chicago scientist who had previously uncovered remains of the dinosaur Nigersaurus there, organized an international team of archaeologists to investigate what had...
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WASHINGTON (AFP) - A US-led team of archaeologists said Thursday they had discovered by chance what is believed to be the largest find of Stone Age-era remains ever uncovered in the Sahara Desert. Named Gobero, the site includes remarkably intact human remains as well as the skeletons of fish and crocodiles dating back some 10,000 years to a time when what is now the world's largest desert was a swampy wetland.
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The African source of the Amazon's fertilizer Sid Perkins In the winter months in the Northern Hemisphere, massive dust storms from the African Sahara waft southwest across the Atlantic to drop tons of vital minerals on the Amazon basin in South America. Now, scientists have pinpointed the source of many of those dust storms and estimated their dust content. ON THE WAY. Satellite photo shows dust (arrow), bound for the Amazon, blowing away from the Sahara's Bodélé depression. NASA The Amazonian rainforest depends on Saharan dust for many of its nutrients, including iron and phosphorus (SN: 9/29/01, p. 200: http://www.sciencenews.org/articles/20010929/bob9.asp)....
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At the end of the last Ice Age, the Sahara Desert was just as dry and uninviting as it is today. But sandwiched between two periods of extreme dryness were a few millennia of plentiful rainfall and lush vegetation. During these few thousand years, prehistoric humans left the congested Nile Valley and established settlements around rain pools, green valleys, and rivers. The ancient climate shift and its effects are detailed in the July 21 issue of the journal Science. When the rains came Some 12,000 years ago, the only place to live along the eastern Sahara Desert was the Nile...
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The Sahara has not always been the arid, inhospitable place that it is today – it was once a savannah teeming with life, according to researchers at the Universities of Reading and Leicester. Eight years of studies in the Libyan desert area of Fazzan, now one of the harshest, most inaccessible spots on Earth, have revealed swings in its climate that have caused considerably wetter periods, lasting for thousands of years, when the desert turned to savannah and lakes provided water for people and animals. This, in turn, has given us vital clues about the history of humans in the...
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Prehistoric Desert Town Found in Western Sahara Thu Aug 19, 2004 01:52 PM ET RABAT (Reuters) - The remains of a prehistoric town believed to date back 15,000 years and belong to an ancient Berber civilization have been discovered in Western Sahara, Moroccan state media said on Thursday. A team of Moroccan scientists stumbled across the sand-covered ruins of the town Arghilas deep in the desert of the Morocco-administered territory. The remains of a place of worship, houses and a necropolis, as well as columns and rock engravings depicting animals, were found at the site near the town of Aousserd...
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he paleontologists were driving across the scorched and trackless Ténéré Desert of Niger, following a low ridge of rock bearing dinosaur fossils. Suddenly, someone on the team, led by Dr. Paul Sereno of the University of Chicago, spotted something dark against the tawny dunes.Getting out of their vehicles, they stepped into sand littered with the fossilized bones of modern crocodiles, hippos, camels and birds — interesting creatures, to be sure, but not exactly the quarry of these paleontologists. "But then things got really strange," recalls Gabrielle Lyon, a member of the expedition who is Dr. Sereno's wife and the director...
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June 09, 2003Disease DustupDust clouds may carry infectious organisms across oceans By Otto Pohl> Image: ORBITAL IMAGING CORPORATION Photo Researchers, Inc. SANDSTORM blows particulates out from the Sahara Desert in Africa (landmass at right) over the Canary Islands in the Atlantic Ocean. The storm occurred in February 2001. On February 11, 2001, an enormous cloud of dust whipped out of the Sahara Desert and moved north across the Atlantic, reaching the U.K. two days later. A few days afterward, counties across the island began reporting simultaneous outbreaks of foot-and-mouth disease, a viral sickness of livestock (sometimes confused with mad cow...
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African Ice Core Analysis Reveals Catastrophic Droughts, Shrinking Ice Fields, Civilization Shifts COLUMBUS, Ohio – A detailed analysis of six cores retrieved from the rapidly shrinking ice fields atop Tanzania's Mount Kilimanjaro shows that those tropical glaciers began to form about 11,700 years ago. The cores also yielded remarkable evidence of three catastrophic droughts that plagued the tropics 8,300, 5,200 and 4,000 years ago. Lastly, the analysis also supports Ohio State University researchers' prediction that these unique bodies of ice will disappear in the next two decades, the victims of global warming. These findings were published today in the journal...
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