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Thread: Cornice Avalanches on Mars

  1. #61
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    Quote Originally Posted by Reality Check View Post
    FYI: I also assume that ice crystals can reach the ground from these low clouds. I also assume until you provide evidence otherwise that they do what ice crystals tend to do - melt!
    When the RSLs are active it is cold enough at night that snow might not melt right away. In many of the RSL pictures there are these white things that look like cornices. Winds going over the crests of hills concentrated the snow fall into the area just past the crest of the hill. If enough snow falls on one spot then for sure the ground temp will get down to freezing. The white things come and go. It is too warm to be dry ice. They seem to all be on one side of high points (as we would expect cornices to be). Snow is white. Snow cornices could come and go. Does anyone have a more reasonable explanation for the white things in the pictures at the crests of hills than my snow cornice explanation?

    Remember Feynman and how science works. We are looking for the most reasonable explanation that is consistent with all observation/evidence. Not a proof. We don't need a robot taking pictures 20 feet from the cornice for this to be the most reasonable explanation. Any assumptions you make are not evidence against my theory.

    My theory predicted white things at the crests of hills at RSL sites, I went looking for white things and found them. Kind of supports my theory. My theory needs snow fall during RSL season and it is the same season there is snow fall. Another support. I need the wind going from behind the RSL cliff toward the cliff. If I find this, would it change anyone's opinion?


    https://www.youtube.com/watch?v=EYPapE-3FRw
    Last edited by vincecate; 2016-Feb-18 at 11:44 AM.

  2. #62
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    Quote Originally Posted by Reality Check View Post
    No one knows how old the RSL are. They exist on features that have existed for thousands or million or billions of years (craters, apparently dunes, hills, canyons).
    You get my argument though? If the craters were made after the atmosphere was thin, then whatever process made the RSLs would only have the same tools to work with that are still available today. If the atmosphere got thin like 3 or 4 billion years ago then if I can find any of the craters with RSLs that are younger than this, it means, however they were formed, the same process could be going on today. The existing theory for how the RSL grooves were carved out of the rock of "some ancient water thing" would be contradicted if we knew an RSL site that was not ancient. Right?

    So dating RSL sites seems interesting, but I am not having any luck with that so far.
    Last edited by vincecate; 2016-Feb-18 at 05:23 PM.

  3. #63
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    Quote Originally Posted by Reality Check View Post
    Citations please.
    Here is one, "The flow features are narrow (one-half to five yards or meters wide), relatively dark markings on steep (25 to 40 degree) slopes at several southern hemisphere locations. "

    http://www.nasa.gov/multimedia/image...ture_2095.html

    Quote Originally Posted by Reality Check View Post
    Your imagination about what you see in images is not scientific evidence for anything, vincecate!!
    IF03: Please cite the scientific literature on the "white cornices in many of the pictures" showing that they are cornices.
    Remember Feynman now. He did not say, "science is stuff in scientific literature". He said that the computed/predicted results of a theory had to match observation. If my theory predicts white things at the crests of hills at RSL sites and I then look at the evidence and there are white things at the crests of hills, I am in fact doing science. There is some chance that there is some other explanation for those white things. But at the moment my theory is not contradicted, as far as I can see. This is the best any theory can really have, "not contradicted by any observation so far". Again, it is like you are asking for "proof" and that is not how science works. If my theory stands the tests over time, somebody will write it up in scientific literature eventually. At the moment though, this is an "against the mainstream" theory and not the one you find in the scientific literature. If you feel discussing this is wasting your time, you are free to leave this thread at any time.
    Last edited by vincecate; 2016-Feb-18 at 12:38 PM.

  4. #64
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    Quote Originally Posted by Reality Check View Post

    Not for sure unless you cite the observation of frost on Mars, i.e. ice on the ground.

    You know, to defend vincecate, some things are so commonly known that a citation is not needed. Ice on the ground? We have pictures of it.

    http://media-2.web.britannica.com/eb...4-C5FDB0BB.jpg
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  5. #65
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    Quote Originally Posted by Reality Check View Post
    No one knows how old the RSL are. They exist on features that have existed for thousands or million or billions of years (craters, apparently dunes, hills, canyons).
    None have been seen on dunes or hills. All of the RSL seen to date are observed on bedrock with very steep slopes, canyon and crater rims basically.
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  6. #66
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    Quote Originally Posted by vincecate View Post
    When the RSLs are active it is cold enough at night that snow might not melt right away. ...
    Followed by fantasies about what might happen, vincecate. Making up stories is not science - you need evidence as well. A theory that predicts "white things" is not a theory, it is basically fiction. Scientists do not point at "white things" in images and say they are snow, just like they do not point "black things" in images and say they are coal!
    IF01: Please cite the text from the paper the explicitly states that snow or ice crystals reached the ground.
    IF02: Please cite the scientific literature that "water ice crystals formed in the atmosphere" are deposited on the ground (especially in amounts large enough to form cornices).
    IF03a: Please cite the scientific literature on the "white cornices in many of the pictures" showing that they are snow.
    IF03b: Please cite the scientific literature on the "white cornices in many of the pictures" showing that the snow has formed cornices.

  7. #67
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    Quote Originally Posted by vincecate View Post
    You get my argument though?
    I get that your argument is irrelevant because arguments against a mainstream idea not arguments for your idea (logical fallacy of false dichotomy).
    For that matter, you have an unsupported assertion of "RSL grooves were carved out of the rock". Look up what RSL are - they are generally described as streaks of dark soil.
    Which reminds me that snow is white! so
    IF04: Why are the RSL dark streaks rather than snowy white streaks?
    IF05: How do you explain the lack of images with parts of the RSL being avalanche debris, i.e. white?

  8. #68
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    Quote Originally Posted by vincecate View Post
    Here is one, "The flow features are narrow (one-half to five yards or meters wide), relatively dark markings on steep (25 to 40 degree) slopes at several southern hemisphere locations. "

    http://www.nasa.gov/multimedia/image...ture_2095.html
    Good,
    Pity you follow up with misinterpreting Feynman. Try to guess where observation are reported, vincecate. That is right - in the scientific literature! Thus you need to backup your story about "white stuff" being snow with scientific evidence, not your personal opinion yet again.
    IF03a: Please cite the scientific literature on the "white cornices in many of the pictures" showing that they are snow.
    IF03b: Please cite the scientific literature on the "white cornices in many of the pictures" showing that the snow has formed cornices.

    I am not asking for "proof" - I am asking for you to defend your idea by producing evidence to support it.
    You could do a spectrographic analysis of the "white stuff" and show that it is H20 and thus snow.
    You could cite the analysis that scientists have done that shows that the "white stuff" is H2O and thus snow.
    Or you could realize that the scientists studying Mars are competent . When they went looking for surface water they did not ignore the "white stuff" in images. When they looked for sources of eater to explain RSL as brine flows they did not ignore the "white stuff" in images of RSL. Thus a lack of observations of snow is evidence against your idea.

  9. #69
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    Quote Originally Posted by crosscountry View Post
    You know, to defend vincecate, some things are so commonly known that a citation is not needed. Ice on the ground? We have pictures of it
    IMO That there is CO2 frost on the ground is well known but that there can be a sprinkling of water frost is less well known. Also depending on things being well known is not good for a scientific idea.
    vincecate's idea needs much more. H2O frost that persists though winter days so that it builds up to snow. Snow that gets thick enough to be shaped into cornices. Cornices that avalanche. Rebuilding of the cornices during spring and summer to produce more avalanches.

  10. #70
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    Quote Originally Posted by crosscountry View Post
    None have been seen on dunes or hills. All of the RSL seen to date are observed on bedrock with very steep slopes, canyon and crater rims basically.
    Seasonal flows on warm Martian slopes
    Also, there are apparent RSL on equatorial dunes composed of permeable sand, unlikely to be a groundwater source.[17]
    I have one reference to RSL on hills: Recurring Slope Lineae in Juventae Chasma
    The RSL are active on the north-facing slopes of these hills when the subsolar point is north of this latitude, and they are active on south-facing slopes when the sun is to the south. However, they are not continuously active, and exactly what controls the timing of activity is not yet known.
    The slopes containing RSL are described as steep (as in vincecate's citation) rather than "very steep".

  11. #71
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    Quote Originally Posted by Reality Check View Post
    IMO That there is CO2 frost on the ground is well known but that there can be a sprinkling of water frost is less well known. Also depending on things being well known is not good for a scientific idea.
    vincecate's idea needs much more. H2O frost that persists though winter days so that it builds up to snow. Snow that gets thick enough to be shaped into cornices. Cornices that avalanche. Rebuilding of the cornices during spring and summer to produce more avalanches.
    It's clear that cornices are not involved with RSL formation. You seemed to be attacking the argument from sides that are not in dispute, which I found unfair.
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  12. #72
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    Quote Originally Posted by Reality Check View Post
    Seasonal flows on warm Martian slopes

    Also, there are apparent RSL on equatorial dunes composed of permeable sand, unlikely to be a groundwater source.[17]

    This is news to me. I'll ask the authors and report back.
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  13. #73
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    Quote Originally Posted by crosscountry View Post
    It's clear that cornices are not involved with RSL formation. You seemed to be attacking the argument from sides that are not in dispute, which I found unfair.
    I agree that cornices cannot not involved with RSL formation. It is vincecate who is disputing this. It is fair to hold a person proposing a scientific idea to similar standards to anyone else proposing a scientific idea, e.g. scientists.
    Or more humorously: Yes it is unfair to point out what happens in the real world (e.g. no detection of enough snow on the ground to form cornices anywhere on Mars) !

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    Quote Originally Posted by crosscountry View Post
    It's clear that cornices are not involved with RSL formation.
    Please explain why it is clear to you. It is not yet clear to me.

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    Quote Originally Posted by Reality Check View Post
    (e.g. no detection of enough snow on the ground to form cornices anywhere on Mars) !
    As the snow falls wind could concentrate some into cornices. Other snow would make a thin layer and sublimate in the early morning sun, if not before. So HiRise, which only passes over RSL locations in the afternoon during the season they are active, would not see a thin layer of snow on the ground even if there were such during the night. There are these white things at the right position to be cornices. I am puzzled at how confident you are that I am wrong when there does not seem to be any evidence that I am wrong. Why are you so sure? Just because nobody in any scientific literature has written that the white things are cornices? So if sometime in the next year a new scientific paper came out that said the white things are cornices you would then agree? How can you be so sure such a paper won't come out? You do understand that the scientific method is used to figure out new things on a regular basis?
    Last edited by vincecate; 2016-Feb-19 at 06:38 PM.

  16. #76
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    Quote Originally Posted by Reality Check View Post
    vincecate's idea needs much more. H2O frost that persists though winter days so that it builds up to snow. Snow that gets thick enough to be shaped into cornices. Cornices that avalanche. Rebuilding of the cornices during spring and summer to produce more avalanches.
    You don't have a correct understanding of my theory yet. First, snow is defined as ice crystals formed in an atmosphere. Frost is ice crystals formed on a solid surface. I am not proposing that a thin layer of either of these survives long in Martian sun.

    My theory is that during the summer nights snow does get to the ground and while it is doing this the wind and crests of hills make some of the snow concentrate into cornices. These cornices then lose structural strength during the warmer daytime and fall. As they slide down some H2O is left in the soil. Any snow left after an avalanche is either sublimating before HiRise gets over the site in the afternoon or in such small pieces it does not show up.

    So it is not that the cornices are formed in one season and falling in another. It is that they are formed during the cold night (when a paper seems to indicate snow can get to the ground during that season) and collapsing during the day. H2O ice is not as structurally strong when it gets close to melting. It is like iron getting soft long before it turns to liquid.

    Have I now explained it well enough that it makes sense? :-)
    Last edited by vincecate; 2016-Feb-19 at 06:59 PM.

  17. #77
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    Quote Originally Posted by vincecate View Post
    Please explain why it is clear to you. It is not yet clear to me.
    There is no snow at locations with RSL.


    Quote Originally Posted by vincecate View Post
    So it is not that the cornices are formed in one season and falling in another. It is that they are formed during the cold night (when a paper seems to indicate snow can get to the ground during that season) and collapsing during the day.

    Collapse? Nowhere on Mars does it snow water-ice more than 0.5 mm per year. You seem to be calling for several cm per night? There isn't that much water vapor in the entire atmospheric column. Water vapor is measured in precipital microns - that means if you condensed all of the water vapor on a given night it would still be 0.000005 m per night.
    Last edited by crosscountry; 2016-Feb-19 at 07:01 PM.
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  18. #78
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    Quote Originally Posted by crosscountry View Post
    There is no snow at locations with RSL.
    What makes you sure of this? What do you think the white things that come and go at the crests of the hills at RSL sites are?
    Last edited by vincecate; 2016-Feb-19 at 07:03 PM.

  19. #79
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    Quote Originally Posted by Reality Check View Post
    It is fair to hold a person proposing a scientific idea to similar standards to anyone else proposing a scientific idea, e.g. scientists.
    Or more humorously: Yes it is unfair to point out what happens in the real world (e.g. no detection of enough snow on the ground to form cornices anywhere on Mars) !

    You seem to think that a guy on the internet with an idea should be held to the same standard as trained scientists that work on projects for several years before publishing. Wouldn't that then make the OP part of the mainstream? The point of this forum is to give beginners the chance to test their ideas - not pass peer review.
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    Quote Originally Posted by crosscountry View Post
    Collapse? Nowhere on Mars does it snow water-ice more than 0.5 mm per year. You seem to be calling for several cm per night? There isn't that much water vapor in the entire atmospheric column. Water vapor is measured in precipital microns - that means if you condensed all of the water vapor on a given night it would still be 0.000005 m per night.
    Now this is interesting! Can you cite a source for this interesting info?

    If it were even a few milimeters a night it might be collected into a pile past the crest of a hill that could stick to the steep slope while the snow was cold but then slide when it got warmer in the daytime. So I would not agree that I need several cm; however, 0.5 mm per year does seem a problem for my theory.

    I am surprised that with this tiny amount of moisture that a sat could track the snow with radar all the way to the ground.
    Last edited by vincecate; 2016-Feb-19 at 07:15 PM.

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    Quote Originally Posted by vincecate View Post
    What makes you sure of this? What do you think the white things that come and go at the crests of the hills at RSL sites are?
    Do you have evidence of "white things that come and go at the crests of the hills at RSL sites?" I have seen none.
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    Quote Originally Posted by crosscountry View Post
    Do you have evidence of "white things that come and go at the crests of the hills at RSL sites?" I have seen none.
    Look at this video from 1:04 to 1:10:
    http://video.foxnews.com/v/146874107...#sp=show-clips

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    Quote Originally Posted by crosscountry View Post
    Do you have evidence of "white things that come and go at the crests of the hills at RSL sites?" I have seen none.
    Here is a GIF of that. Click on this to make it large.

    Click image for larger version. 

Name:	Warm_Season_Flows_on_Slope_in_Newton_Crater_%u00252528animated%u00252529.gif 
Views:	78 
Size:	289.9 KB 
ID:	21336

    Perhaps it is just overexposed. But maybe it is overexposed because white snow reflects a lot of light. As Reality Check has pointed out, I don't have any scientific literature saying these white things are cornices. But it does seems consistent with that possibility.
    Last edited by vincecate; 2016-Feb-19 at 07:34 PM.

  24. #84
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    Quote Originally Posted by vincecate View Post
    Now this is interesting! Can you cite a source for this interesting info?

    https://scholar.google.com/scholar?h...e+microns+Mars




    Quote Originally Posted by vincecate View Post
    Here is a GIF of that. Click on this to make it large.

    Click image for larger version. 

Name:	Warm_Season_Flows_on_Slope_in_Newton_Crater_%u00252528animated%u00252529.gif 
Views:	78 
Size:	289.9 KB 
ID:	21336

    Perhaps it is just overexposed. But maybe it is overexposed because white snow reflects a lot of light. As Reality Check has pointed out, I don't have any scientific literature saying these white things are cornices. But it does seems consistent with that possibility.
    You said earlier that by the time HiRISE arrives the snow would have sublimed. Now you use a HiRISE gif to support the idea of white material?

    The gif that you present has changes in brightness due to the pictures being taken at different times of day. HiRISE and MRO can roll, so sometimes it looks right - to later times in the day, while sometimes it looks left, to earlier times in the day. A photo of any slope taken at different times of day will give you different brightness.
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    Thanks for the google link but do you have a particular one you can recommend?

    Quote Originally Posted by crosscountry View Post
    You said earlier that by the time HiRISE arrives the snow would have sublimed. Now you use a HiRISE gif to support the idea of white material?
    The theory is that, although a few mm of snow on the ground would not last till HiRise, that some snow blown into a deeper cornice could sometimes last till the next afternoon.

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    All the links say the same thing, only a few precipitable microns are available for the entire atmospheric column. That's something like 0.005 mm - and if every possible water molecule from the atmosphere directly above somehow fell on the ground, an impossibility given that it takes more than 12 hours for a molecule to fall to the ground from more than 4 km altitude.

    Furthermore, the places where RSL are most frequently observed never have snow.
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    Quote Originally Posted by vincecate View Post
    As the snow falls wind could concentrate some into cornices. ...
    Sorry, vincecate, but merely repeating a story again does not make it true!
    To defend your idea you need to support your assertions, e.g. by answering questions from your own research.
    IF01: Please cite the text from the paper the explicitly states that snow or ice crystals reached the ground.
    IF02: Please cite the scientific literature that "water ice crystals formed in the atmosphere" are deposited on the ground (especially in amounts large enough to form cornices).
    IF03a: Please cite the scientific literature on the "white cornices in many of the pictures" showing that they are snow.
    IF03b: Please cite the scientific literature on the "white cornices in many of the pictures" showing that the snow has formed cornices.
    IF04: Why are the RSL dark streaks rather than snowy white streaks?
    IF05: How do you explain the lack of images with parts of the RSL being avalanche debris, i.e. white?

    It is generally known that there is CO2 snow on the ground (irrelevant to your idea).
    It is generally known that there are small amount of water snow on the ground which is evidence against your idea (no indication of enough snow to form cornices).

  28. #88
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    Quote Originally Posted by vincecate View Post
    You don't have a correct understanding of my theory yet.
    Nitpicking about a word does not make your idea correct, vincecate: vincecate's idea needs much more. H2O snow that persists though winter days so that it builds up to snow. Snow that gets thick enough to be shaped into cornices. Cornices that "avalanche" - the proper word is collapse. Rebuilding of the cornices during spring and summer to produce more collapses.
    Plus:
    * Invisible snow covering the ground that scientists are incapable of observing.
    * Invisible cornices at the tops of RSL that scientists are incapable of observing.
    * Invisible avalanche long along RSL that scientists are incapable of observing.
    IOW the implied assumption that scientists are incompetent in analyzing bots Martian images in the search for surface water including snow and the images of RSL.
    Last edited by Reality Check; 2016-Feb-21 at 08:28 PM.

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    Quote Originally Posted by vincecate View Post
    If it were even a few milimeters a night ....
    crosscountry's figure is "snow water-ice more than 0.5 mm per year". A Martian year is 779.96 days. If we assume snowfall only in half a year then that is 390 days each getting a coverage of .3/390 = 0.0009 mm. Your idea demands that this sprinkling of snow does not melt and forms into cornices that collapse thousands of times (there are RSL with 1000s of streaks). So do you really think a cornice maybe a millimeter high collapses say 100 times and form an RSL that is hundreds of meters long? If the numbers are wrong then provide your own calculations.

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    Quote Originally Posted by Reality Check View Post
    crosscountry's figure is "snow water-ice more than 0.5 mm per year". A Martian year is 779.96 days. If we assume snowfall only in half a year then that is 390 days each getting a coverage of .3/390 = 0.0009 mm. Your idea demands that this sprinkling of snow does not melt and forms into cornices that collapse thousands of times (there are RSL with 1000s of streaks). So do you really think a cornice maybe a millimeter high collapses say 100 times and form an RSL that is hundreds of meters long? If the numbers are wrong then provide your own calculations.
    It's actually harder than that. 0.5 mm per year is the max accumulation on the planet, near the poles. Most RSL are in places that it never snows.
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