Caught In The Act - Water Seepage Photo's!

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yevaud

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<img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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yurkin

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<font color="yellow">A much more likely explanation is that we are looking at changes in albedo caused by sublimation of a winter coat of CO2 (snow, frost) ice off the underlying permanent H2O ice cap.</font><br /><br />Of course this is still very interesting.<br />
 
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JonClarke

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Most certainly. I am really grateful that this example of change over time has been found. People tend to think of ice caps as rather boring places when in fact they are very dynamic. What happens on the surface of the Martian caps is very important to those thinking of planning bases there in the future. There is a multi-year BIS project doing this at the moment.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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JonClarke

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Sorry, I don't see channels, just irregular patches of albedo changes.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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yevaud

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Well, there are indications of catastrophic outflow in the past. Call them very temporary rivers. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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JonClarke

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Fair enough, I stand corrected. That is a great collection of images, but I don't think a river of water is a required explanation. But given the elevated air pressure, the abaundance of water ice, and the presence of reent volcanism, you never know.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>
 
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conradk1

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Yevaud, I agree however the big question I have is why is there melting/sublimation of the frost in spring along the path of the "river" before there is melting/sublimation on the "banks"? <br /><br />That tends to indicate that there is something actively going on right now. If not then, looking at the sand dunes that have been flattened and distorted by water flow, it would tell us that all of the dunes down there are frozen solid and have been since the water stopped flowing. Whenever that was.
 
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yevaud

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First, as to the movement / changes seen in the very first image posted:<br /><br />Well, you have to remember the following:<br /><br />There are trace amounts of Water Vapor, as well as CO2 in the Martian atmosphere. And the nighttime temperatures on Mars can go down as low as (IIRC) -170 or more degrees C at night. So it can freeze out of the atmosphere as a fine layer of frost.<br /><br />Or, there is the (Martian) yearly melting of the poles, which can release a great deal of water vapor and CO2 into the atmosphere.<br /><br />Or, the yearly Summer dust storms that occur.<br /><br />So, see, there's a whole range of conditions that could cause all of the changes we see in the imagery (including the frost / snow you think is there). <br /><br />Although, myself, I still think it's a simple change in reflectance, due to changes in the type and nature of the surface of windblown sand. That would fit the other changes we see in the image.<br /><br />********<br /><br />As to the catastrophic outflow channels: these are when subsurface pockets of ice or permafrost melt and their water flows, suddenly and catastropically (hence the name) out to the surface.<br /><br />As to where the ice / permafrost occurs is another matter. So why not more of these where the "bottom" of the river is, and less on the "banks?"<br /><br />Also, remember that these catastrophic outflows occur under the reduced gravity, temperatures, and atmospheric pressure of Mars.<br /><br />Better? <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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yevaud

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<i>...well at certain times of the year, daytime temps on mars can be as high as 60F. <br /><br />no hurricane wilma, though. </i><br /><br />Under the conditions present on Mars, sandstorms can occur that clock at well over 200 kph. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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conradk1

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Yevaud,<br /><br />The "river" we were discussing does not have anything to do with the first image. I put together a photo mosaic of the "river" highlighting some of my observations. These are the issues that I am looking to find the answers to.<br /><br />The image: http://64.70.34.77/overview/<br /><br />The observations:<br />In images "A" I have taken a wide angle image of the area and adjusted the contrast. As you can see the last adjustment clearly shows what appears to be the path of a river. It winds around high ground which would rule out wind driven influences. The flow is from left to right. The dark areas are not dark sand dunes as you can clearly see where the sand dunes are located in image "D". In the top left of image "D" streaking can be seen coming from some of the sand dunes. This streaking is perpendicular to the direction of the prevailing winds (as indicated by the shape of the local dunes).<br /><br />In image "B" once again the "river bed" is much darker than the surrounding area and streaking is again visible coming from the sand dunes.Regarding the melting/sublimation of the frost on the sand dunes in the path of the "river", the color image clearly highlights the extreme contrast between the frost on the banks and the lack of frost in the "river bed".<br /><br />Clicking on "C" will open up an A/B animation of a portion of the "river". The two images were taken a week apart and it can be clearly seen that the frost is vanishing faster on the dunes that are closest to the "river". The frost in the upper right hand side is not. Steam can also be clearly be seen rising from the location of the river in both images.<br /><br />Lastly in "A" there is a red ring around a white spot. This white spot is a peak that seems to rise about a 1000 meters above the surrounding area. I believe that this may be a barely active volcano that is providing heat to the area.<br /><br /> Images mentioned ab
 
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yevaud

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Yes, I do understand that. But you did pose a question or two about them as well, and provided several links to the images of them, so I thought I'd respond to that as well.<br /><br /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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conradk1

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Yevaud, <br /><br />I apologize, I misunderstood you last post. I thought it was in reference to the single a/b image with the patch that looked like it was reflecting sunlight.
 
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yevaud

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Actually, I answered commentary about both, all in the same post. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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