Difference between revisions of "August 19, 2009"

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=A Rille That Doesn't Know What To Do with Itself=
 
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<em>image from [http://wms.lroc.asu.edu/lroc_browse/view/nacl00005e30" rel="nofollow LROC Browse Gallery], ASU and NASA</em><br />
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<em>image from [http://wms.lroc.asu.edu/lroc_browse/view/nacl00005e30 LROC Browse Gallery], ASU and NASA</em><br />
 
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Lavas flow downhill, but sometimes they don't seem to be in a hurry. This 600-700 m wide rille twists and turns like a kid told to go to bed. On Earth many rivers (of water) do the same thing when they flow across very gentle slopes. With such slopes <em>downhill</em> is well defined from a distance, but on the surface, minor deviations in topography swing the flowing liquid helter and skelter. Water [http://www.cleo.net.uk/resources/displayframe.php?src=309/consultants_resources%2F_files%2Fmeander4.swf" rel="nofollow flowing] around the outside of a bend goes fast and erodes the bend. Over time adjacent bends intersect, cutting off a loop which becomes an ox-bow lake. Meanders in rivers take time to develop, but in the completely different case of lava flows can develop almost [http://www.geology.sdsu.edu/how_volcanoes_work/Thumblinks/Lavalevee_page.html" rel="nofollow instantly]. This rille is the famously illusive one on the floor of [http://lroc.sese.asu.edu/news/uploads/LROCiotw/AristarchusPlateau.jpg" rel="nofollow Schröter's Valley,] the biggest rille on the Moon. Rilles within rilles occur a few places on the Moon, and it seems that the inner one is usually tightly meandering. Presumably the inner rille forms from a later eruption that sends lava flowing down the gently sloping flow surface of the first channel.<br />
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Lavas flow downhill, but sometimes they don't seem to be in a hurry. This 600-700 m wide rille twists and turns like a kid told to go to bed. On Earth many rivers (of water) do the same thing when they flow across very gentle slopes. With such slopes <em>downhill</em> is well defined from a distance, but on the surface, minor deviations in topography swing the flowing liquid helter and skelter. Water [http://www.cleo.net.uk/resources/displayframe.php?src=309/consultants_resources%2F_files%2Fmeander4.swf flowing] around the outside of a bend goes fast and erodes the bend. Over time adjacent bends intersect, cutting off a loop which becomes an ox-bow lake. Meanders in rivers take time to develop, but in the completely different case of lava flows can develop almost [http://www.geology.sdsu.edu/how_volcanoes_work/Thumblinks/Lavalevee_page.html instantly]. This rille is the famously illusive one on the floor of [http://lroc.sese.asu.edu/news/uploads/LROCiotw/AristarchusPlateau.jpg Schröter's Valley,] the biggest rille on the Moon. Rilles within rilles occur a few places on the Moon, and it seems that the inner one is usually tightly meandering. Presumably the inner rille forms from a later eruption that sends lava flowing down the gently sloping flow surface of the first channel.<br />
 
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<br />
<em>[mailto:tychocrater@yahoo.com" rel="nofollow Chuck Wood]</em><br />
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<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br />
 
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<strong>Technical Details</strong><br />
 
<strong>Technical Details</strong><br />
More[http://lroc.sese.asu.edu/news/?archives/90-Rille-within-a-rille!.html" rel="nofollow interpretation] of this rille.<br />
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More[http://lroc.sese.asu.edu/news/?archives/90-Rille-within-a-rille!.html  interpretation] of this rille.<br />
 
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<strong>Related Links</strong><br />
 
<strong>Related Links</strong><br />
Rükl plate [http://the-moon.wikispaces.com/Rukl+18 18]<br />
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Rükl plate [https://the-moon.us/wiki/Rükl_18 18]<br />
 
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<p><b>Yesterday's LPOD:</b> [[August 18, 2009|Buoyant And Superhot]] </p>
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<p><b>Tomorrow's LPOD:</b> [[August 20, 2009|Succession]] </p>
 
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Latest revision as of 19:34, 18 August 2018

A Rille That Doesn't Know What To Do with Itself

LPOD-Aug19-09.jpg
image from LROC Browse Gallery, ASU and NASA

Lavas flow downhill, but sometimes they don't seem to be in a hurry. This 600-700 m wide rille twists and turns like a kid told to go to bed. On Earth many rivers (of water) do the same thing when they flow across very gentle slopes. With such slopes downhill is well defined from a distance, but on the surface, minor deviations in topography swing the flowing liquid helter and skelter. Water flowing around the outside of a bend goes fast and erodes the bend. Over time adjacent bends intersect, cutting off a loop which becomes an ox-bow lake. Meanders in rivers take time to develop, but in the completely different case of lava flows can develop almost instantly. This rille is the famously illusive one on the floor of Schröter's Valley, the biggest rille on the Moon. Rilles within rilles occur a few places on the Moon, and it seems that the inner one is usually tightly meandering. Presumably the inner rille forms from a later eruption that sends lava flowing down the gently sloping flow surface of the first channel.

Chuck Wood

Technical Details
Moreinterpretation of this rille.

Related Links
Rükl plate 18

Yesterday's LPOD: Buoyant And Superhot

Tomorrow's LPOD: Succession



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