More pictures of civilization crumbling at BoredPanda.com.
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| Click here for high-res image. (Photo: NASA / Earth Observatory / Robert Simmon) |
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| The final section of the spire is raised to the top of One World Trade Center. (CNN) |
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| President Barack Obama shoots clay targets on the range at Camp David, Md., Saturday, Aug. 4, 2012. (Official White House Photo by Pete Souza) |
This official White House photograph is being made available only for publication by news organizations and/or for personal use printing by the subject(s) of the photograph. The photograph may not be manipulated in any way and may not be used in commercial or political materials, advertisements, emails, products, promotions that in any way suggests approval or endorsement of the President, the First Family, or the White House.Don't worry. No one has ever accused me of saying or doing anything "that in any way suggests approval or endorsement of the President."
What causes these long, strange clouds? No one is sure. A rare type of cloud known as a Morning Glory cloud can stretch 1,000 kilometers long and occur at altitudes up to two kilometers high. Although similar roll clouds have been seen at specific places across the world, the ones over Burketown, Queensland Australia occur predictably every spring. Long, horizontal, circulating tubes of air might form when flowing, moist, cooling air encounters an inversion layer, an atmospheric layer where air temperature atypically increases with height. These tubes and surrounding air could cause dangerous turbulence for airplanes when clear. Morning Glory clouds can reportedly achieve an airspeed of 60 kilometers per hour over a surface with little discernible wind. Pictured above, photographer Mick Petroff photographed some Morning Glory clouds from his airplane near the Gulf of Carpentaria, Australia.



