Planet Four Talk

#ParallelLines #TramLines

  • BlueMoon58 by BlueMoon58

    Any you guys got any thoughts on how these lines were formed. When I see these type of images it kinda reminds me about Erich von Däniken theories

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  • BlueMoon58 by BlueMoon58

    No takers I see

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  • AUricle by AUricle

    BlueMoon,
    They are called "yardangs".
    There is a very detailed answer at the blog site, but I'm pasting it here to get you started....

    These are yardangs, traces of aeolian (that is wind-related) erosion. They are long parallel ridges. They form when wind removes soft, friable material and are oriented along the direction of the strongest winds. Yardangs are known in deserts on the Earth and are abundant on Mars. In this particular place, yardangs are remarkably regular, long, parallel. This fascinating regularity is probably caused by coincidence of two things. First, the material here is very homogeneous; it is slightly cemented dust; there are no embedded boulders, etc. This is the material of the South polar layered deposits, it was deposited from the atmosphere as a mixture of snow, frost and dust under different climate conditions in the past. Recently (geologically recently, hundreds of thousands of years) ice (former snow and frost) sublimated (evaporated) from the near-surface layer of this material, and the remaining slightly cemented dust is friable and homogeneous. Second, the strongest winds in this place are very stable. The polar layered deposits have a general shape of a ~700 km wide ~3 km high dome. The strongest winds here are so-called katabatic winds made by flow of cold (=dense) air from the pole on top of the dome downhill. People who have been to Antarctica or Greenland know katabatic winds very well. Because katabatic winds are controlled by slopes, they are much more stable than winds controlled by weather phenomena. The direction of the spring-time fans in this region often differs from the direction of the yardangs, because spring-time winds are not those strongest winds that shape the surface.
    Here is the link to the blog; http://blog.planetfour.org/ Just scroll down to "You have asked"....Anya ( the scientist) provides the info

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