Ancient Mega-Lake Found in Egyptian Desert

Discussion in 'Middle East' started by Margot, Mar 18, 2012.

  1. Margot

    Margot Account closed, not banned

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    It does explain the fish fossils..

    There is also a HUGE aquifer under Darfur.

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

    Ancient Mega-Lake Found in Egyptian Desert

    One of the driest places in the world was once home to a lush lake nearly the size of Lake Michigan.

    THE GIST

    A mega-lake in today's hyper-arid western Egypt might have been fed by the earliest Nile floods.
    The discovery helps explain fish fossils in the desert.
    An alternative hypothesis is that the mega-lake fed the Nile, not the other way around.

    The hyper-arid deserts of western Egypt were once home to a lush mega-lake fed by the Nile River's earliest annual floods.

    Fossil fish and space shuttle radar images have defined the bed and drainage channels of the long lost lake, which at times was larger than Lake Michigan, stretching as far as 250 miles west of the Nile in southwestern Egypt.

    The discovery pushes back the origin of the "Gift of the Nile" floods to more than a quarter million years ago and paints a drastically different picture of Egypt's environment than is seen today.

    It also explains the longstanding puzzle of the fossilized fish found in the desert -- fish that are of the same kinds that live in today's Nile River.

    It took a lot of staring at the high-resolution radar topographic maps from the 1980s and 1990s -- and tinkering with the colors of those maps -- to make sense of it all.

    "It just struck me that: 'Hey, maybe that was the level for the lake,'" said Ted Maxwell of the Smithsonian Institution's Center for Earth and Planetary Studies.

    Although the topography is compelling, the evidence by itself isn't sufficient to prove a lake was there or how it was created.

    For one thing, there needs to be a source for all the water. That would likely have been Wadi Tushka, a pass to the west of the Nile, which is low enough for the Nile River to have flooded through provided there was more rainfall and larger annual floods than are known today.

    Then there are the fish fossils, which are unmistakable evidence for there having been Nile-related water filling the basin.

    There are also archaeological sites, said Maxwell, that help to roughly confine the dates of the lake's surface elevation in more recent times. Maxwell and his coauthors Bahay Issawi and C. Vance Haynes, Jr., published their study in the December issue of the journal Geology.

    Despite the radar maps, fish and archaeology, however, there is a lot of evidence that should be there, but isn't, said Maxwell.

    Take the old shorelines, or "bathtub rings," that are often the definitive evidence of long-lost mega-lakes of wetter times in other parts of the world, including in Utah, Nevada and California. In Egypt those shorelines have probably been sandblasted away over the millennia by scouring winds, Maxwell said.

    And what about some distinctively lake-formed sediments in the basin itself?

    "The problem is there is no sedimentary evidence," Maxwell told Discovery News. And so the mega-lake is harder to prove than most.

    Despite this, other researchers looking at the area find there are more reasons for believing that a long lineage of great lakes filled the basin that might not have needed the Nile as their source.

    "Other possibilities for the source of the water include drainage from the highlands to the west, groundwater recharge from the south, and local rains, potentially from different directions and sources," said researcher Christopher Hill of Boise State University.

    The older sedimentary remnants associated with springs and archaeological artifacts seem to point to local rains or groundwater creating lakes that were smaller and smaller over time and not from the Nile, said Hill. Those sources could have, perhaps, enlarged the lake enough to join and flow into the the Nile and allow the fish to move upstream into the lake, without Nile flooding. That would mean the water at Wadi Tushka would have been flowing east into the Nile rather than west into the lake.

    In other words, the lake certainly existed, but the jury is still out on how it got there.
     
  2. mikezila

    mikezila New Member

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    the entire Sahara has gone through repeated cycles of desert to rain forest back to desert. climate change happens w/o humans.
     
  3. Margot

    Margot Account closed, not banned

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    Qattara Depression

    Elevation: 133 meters below sea level (approximate)
    Country: Egypt

    Latitude/Longitude: 29°32′N 27°07′E

    The Qattara Depression is located in the Libyan Desert of northwestern Egypt. At 133 meters below sea level it is the second lowest point in Africa. The depression has no settlements and other than nomadic herders it supports no commercial activity.

    [​IMG]
     
  4. Margot

    Margot Account closed, not banned

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    Fyi..........................
     
  5. OverDrive

    OverDrive Well-Known Member Past Donor

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    I thought that the melting of the last ice age flooded the Med over and filled in the Sahara depression? When the Med was fresh water B4 the over-flowing cascades of the Atlantic....but there are lots of fossils in that region, including the big dinosaurs of long ago (just as being discovered in the arctic and antarctic regions).
     
  6. Margot

    Margot Account closed, not banned

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    Can't say I fully understand it.........
     
  7. OverDrive

    OverDrive Well-Known Member Past Donor

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    Supposedly (last I recollect) the under ground river presently flows from the Med, S., then W., and then possible back to the Med up N. , or delta's out in the SW Sahara......?
     
  8. Margot

    Margot Account closed, not banned

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    Hmmmmmmmmm.. that would be in the Eastern Libyan desert?????
     
  9. OverDrive

    OverDrive Well-Known Member Past Donor

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    Yeah, somewheres down thar..
     
  10. ncrosth

    ncrosth New Member

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    Well it wouldnt surprise me . After all, most of the Sahara has been green and fertile with trees and rivers roughly every forty thousand years as the Earths axis shifts between extremes.
     
  11. Margot

    Margot Account closed, not banned

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    What do you mean... the axis shifts?
     
  12. ncrosth

    ncrosth New Member

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    What i mean is that the seasons are not caused by the distance from the Sun , but by the tilt of the Axis of the Earth. At the moment the tilt is about 23.5degrees, but over much longer periods the tilt can change from 22.8degrees to 24.21 degrees.This period roughly takes about 40,000 years, and thats why the Sahara was once a lush fertile area, and could well be again over time. The northern half of Africa which is mostly desert once had one of the largest lakes in the world, roughly the size of France.
     
  13. Margot

    Margot Account closed, not banned

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    I thought the earth tilting on its axis was science fiction.
     
  14. ncrosth

    ncrosth New Member

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    No not science fiction. I reckon if you dug down far enough anywhere in the Egyptian or the Sahara you will come across plenty of underwater water courses.
     
  15. OverDrive

    OverDrive Well-Known Member Past Donor

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    Studies have shown that there is more water within the mantel of the earth than all the surface water/ice, etc by a factor of 3-10 times as much:

    Inside Planet Earth

    Discovery 2 hr Special 2009

    About the Inside of the earth: the crust, outer mantel, inner mantel, outer core, inner core, and the many transitional layers are like looking at an onion.

    Interesting note: There is more water from ocean plate subduction within the mantel (1800 miles thick) than all the surface water (& ice) of the earth (3-10 times as much). If all were brought to the surface, Mt. Everest would be covered by 1-1 1/2 miles of water.
     

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