Mars Water Debate Rages (archival thread reposting #4)

[serak_the_preparer]

Welcome to the fourth attempt to resurrect a lost thread, consigned to the abyss while still enjoying a productive life. They said it was a stroke. Luckily, a close neighbor had a set of paddles and applied the defribulator. Sadly, though it returned from the brink, the thread had run out of time. Even a minute or two without the regular life-support of a healthy forum, without electrons ceaselessly nourishing it, can do irreparable damage. Sometimes, when they come back not all of them comes back...<br /><br />Mars Water Debate Rages<br /><br />~Serak_the_Preparer (Interstellar Culinary Specialist, Retired Pong Champion, Mad Archivist)

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/24/02 07:48 PM<br /><br />Mars Water Debate Rages<br />By Larry O'Hanlon, Discovery News<br />October 23, 2002<br /><br /><br />===============================<br /><br />Note: The Stewart and Nimmo paper was published in the Journal of Geophysical Research-Planets, not Geophysical Research Letters, though I suspect most laypersons would not grasp the difference.<br /><br />===============================<br /><br />Alex R. Blackwell<br />University of Hawaii</b>

 

[serak_the_preparer]

spaceseed<br />(<b>O</b>)<br />10/24/02 09:28 PM<br /><br />I would think with the recent discovery of all the near-surface ice that this particular debate would be over.<br /><br />Before the discovery, the models predicted that any water would have to be deep underground, with CO2 above it. I suspect these models were based on the assumption that the water was always there, and would be correct if that was the case. Near-surface water may have arrived more recently via comets. I wonder if there is a way to estimate the rate of water arrival?

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/24/02 09:33 PM<br /><br />For the cognoscenti, the citation of the Stewart and Nimmo paper is:<br /><br />Stewart, S. T., and F. Nimmo, Surface runoff features on Mars: Testing the carbon dioxide formation hypothesis, J. Geophys. Res., 107(E9), 5069, doi:10.1029/2000JE001465, 2002.<br /><br />Abstract<br /><br />Fresh gully-like features on Mars strongly suggest that fluid flowed on the surface in the recent past. Here we consider the possibility that CO2 vapor-supported flows formed the gullies. We find that neither condensed CO2 nor CO2 clathrate hydrate are likely to accumulate in significant quantities in the Martian crust. In addition, if condensed CO2 were present under lithostatic pressures, exposure to the atmosphere would produce features analogous to terrestrial pyroclastic flows, not surface runoff. Finally, the source volume of CO2 required to support a flow excludes clustered or episodic gully formation. Therefore, we conclude that CO2 cannot have formed the gullies. In light of these results, liquid water flow remains the preferred formation mechanism for the recent surface runoff features.<br /><br />====================================<br /><br /><br />Alex R. Blackwell<br />University of Hawaii</b>

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/24/02 09:44 PM<br /><br />spaceseed wrote:<br />I would think with the recent discovery of all the near-surface ice that this particular debate would be over.<br /><br />Alex writes:<br />Perhaps, though for many (myself included) the clincher will be to actually detect extant liquid H2O, almost certainly in the subsurface, via long-wavelength radar sounding (e.g., Mars Express MARSIS or Mars Reconnaissance Orbiter SHARAD).<br /><br />Be aware, however, that the 2001 Mars Odyssey GRS findings of higher-than-expected hydrogen in the near surface are not seen as fatal to the models proposed by the "CO2 crowd," most notably Nick Hoffman of "White Mars" fame.<br /><br />spaceseed wrote:<br />Near-surface water may have arrived more recently via comets. I wonder if there is a way to estimate the rate of water arrival?<br /><br />Alex writes;<br />Sure. Do you happen to have a good value lying around for the "recent" impactor flux at Mars?<br /><br /><br />Alex R. Blackwell<br />University of Hawaii<br /></b>

 

[serak_the_preparer]

jetjock70<br />(<b><font color="red">protostar</font>/b>)<br />10/25/02 12:13 AM<br /><br />How often is subsuface CO2 detected?</b>

 

[serak_the_preparer]

voyagerwsh<br />(<b><font color="orange">K</font>/b>)<br />10/25/02 10:30 AM<br /><br />Large outflow channels are more likely formed by rapid runoff of groundwater than CO2 in crater walls of Mars...<br /><br />Suggest reading: AQUEOUS FLOWS FORMED THE OUTFLOW CHANNELS ON MARS.(PDF) Neil M. Coleman, Member,American Geophysical Union and the Health Physics Society. LPSC XXXIII<br /><br />Odyssey's hydrogen detection, though shallow in depth, however 35-50% wt of dirty water-ice content would be more supportive to water than CO2 model.</b>

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/25/02 12:23 PM<br /><br /><br />voyagerwsh wrote:<br />Large outflow channels are more likely formed by rapid runoff of groundwater than CO2 in crater walls of Mars...<br /><br />Alex writes:<br />Thanks for the tip. Actually, I support the H2O-based models for the formation of the catastrophic outflow channels, ancient valley networks, and the Malin and Edgett seepage sites. The geomorphologies of these features are fairly convincing that they were formed by subaerial fluid flows, the most plausible erosive agent being H2O or some H2O-dominated fluid. That said, however, those promulgating the CO2-based models as a formation mechanism for the above-named features on Mars have sharpened the debate by pointing out some flaws (glaring ones in some cases) in the current popular models. This has forced the "H2O-crowd" to actually defend their models with hard numbers and cold logic, and not by simple hand waving.<br /><br />As for your suggested reading, thank you, but I'm very familiar with the peer-reviewed (and non-peer-reviewed, such as LPSC abstracts) literature on Mars. In fact, my own personal library (at home, not at UH) has over 5,000 papers, books, magazine articles, etc. on Mars alone. My in-tray at any given moment has ~10 papers for review (final publications, drafts for peer-review, etc.). Just to give you a flavor, I am currently completing a draft of two Mars-related papers: one to be submitted to the Journal of Geophysical Research - Planets, the other to Icarus. I'm also preparing two abstracts for next year's LPSC (one Mars-related, the other related to the icy satellites of Saturn). In the midst of all that, I'm reviewing drafts of two other Mars-related papers given to me b</b>

 

[serak_the_preparer]

rlb2<br />(<b><font color="yellow">F</font>/b>)<br />10/27/02 01:48 PM<br /><br />Alexblackwell<br /><br />If this question wasn’t asked before, then it should be seriously looked at. To add to the debate and solve it at the same time. How does the carved out gullies look for hydrogen content? There should be subsurface traces of Hydrogen in the gullies that were carved out by recent surface runoff of water. This should be a question that has already been asked. Is the Odyssey spacecraft calibrated good enough to detect hydrogen in such a localized area?</b>

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/28/02 11:16 AM<br /><br />rlb2 wrote:<br />If this question wasn’t asked before, then it should be seriously looked at. To add to the debate and solve it at the same time. How does the carved out gullies look for hydrogen content? There should be subsurface traces of Hydrogen in the gullies that were carved out by recent surface runoff of water. This should be a question that has already been asked. Is the Odyssey spacecraft calibrated good enough to detect hydrogen in such a localized area?<br /><br />Alex writes:<br />The gullies, presumably the features discovered by Malin and Edgett, are on the spatial scale of hundreds of meters. To detect hydrogen at the elemental abundance level, scientists would use the 2001 Mars Odyssey Gamma Ray Spectrometer suite. Unfortunately, however, the GRS suite instruments can only spatially resolve H concentrations at the hundreds of <i>kilometers</i> level; in other words, only a regional to global scales.<br /><br />One would have a much better chance utilizing data from the THEMIS instrument, which has an ~100 m/pxl resolution. Instead of detecting elemental hydrogen, one would peruse the THEMIS data to find hydrogen locked up in mineralogical form (e.g., hydrates). That said, even THEMIS would have challenges to resolve many of the individual gullies and seepage sites, though some clusters and larger examples may well return data. Stay tuned. From what I understand, the THEMIS team has several papers in preparation with various journals as we speak.<br /><br />Alex R. Blackwell<br />Univesity of Hawaii</b>

 

[serak_the_preparer]

voyagerwsh<br />(<b><font color="orange">K</font>/b>)<br />10/29/02 10:42 AM<br /><br />Gullies in the crater walls of Mars were probably cut by liquid water mixed with minerals or brine but not by carbon dioxide. Since some scientists considered liquid water can not exist in the current Martian condition, however brine or minerals-rich water can substantially lower the triple point of water.<br /><br />Martian upper crust does not have enough CO2 to cut gullies globally, according to the study of Sarah Stewart of Caltech and Francis Nimmo of University College London.<br /><br />Martian water is prime candidate</b>

 

[serak_the_preparer]

spaceseed<br />(<b>O</b>)<br />10/29/02 12:40 PM<br /><br />Is it possible to tell if these gullies were formed by a few large (presumably) water eruptions, or have gradually eroded over time? The former would require occasional geothermal heating, while the latter could be caused by warm temeratures melting the brine. Surface temperatures do approach the melting point of water, and maybe there are occasional warmer periods.

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/29/02 01:58 PM<br /><br />spaceseed wrote:<br />Is it possible to tell if these gullies were formed by a few large (presumably) water eruptions, or have gradually eroded over time?<br /><br />Alex writes:<br />Clearly, there is evidence of episodicity in many of the gullies (i.e., repeated flow events). The temporal resolution is, unfortunately, not good enough to discern the timescales of reactivation.<br /><br />I suspect, however, that your question goes more to whether the evidence suggests that individual gullies were created by "catastrophic-type" outbursts or by less energetic events operating over longer timescales. The bulk of the evidence (e.g., V-shaped channel morphologies, lack of dust mantling over the length of the channels for "fresh" events, stability and erosional capability of H2O at the surface over long timescales, etc.) suggests the former.<br /><br />Alex R. Blackwell<br />University of Hawaii</b>

 

[serak_the_preparer]

voyagerwsh<br />(<b><font color="orange">K</font>/b>)<br />10/29/02 05:18 PM<br /><br />Ice Dam model proposed by Dr. Ken Edgett of Malin Space Science Systems can be explained here.<br /><br />Rapid liquid groundwater runoff behind the breaking ice dam could be catastrophic phenomenon downward...</b>

 

[serak_the_preparer]

cubancat<br />(<b><font color="yellow">F</font>/b>)<br />10/29/02 08:06 PM<br /><br />Alex, how would <i>you</i> attribute the following features to any substance other than water? This is why I’d have to agree with <i>spaceseed</i> totally, in that the debate should be over, with overwhelming support for water on Mars, now, in substantial quantities. What other fluid could be postulated? A high-volatility organic compound? Moreover, if so, where would that originate?<br /><br />My features of interest are:<br /><br /> 1. The seeps and stains evidenced in numerous MOC images?<br /> 2. The entrapped lake?<br /> 3. THEMIS image 20021002 with very strange crater in Terra Sirenum? See a little imaging work I did on that feature on this board on a thread titled Mars Terra Sirenum, with attachment. Notes in the thread itself for features.<br /><br /><br />All of the above, an incomplete list to be sure, have indicia of surface liquid or surface liquid flow. How are all of these explained, and since there are about 112,000+ images in the MSSS database, alone, there’s got to be lots more indication of surface fluid, of whatever composition.<br /><br />The chance usually never occurs to have dialectic with a planetary scientist on these subjects related to Mars. </b>

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/30/02 01:19 PM<br /><br />cubancat wrote:<br />Alex, how would you attribute the following features to any substance other than water?<br /><br />Alex writes:<br />First of all, as I mentioned earlier in this thread, I believe that liquid water was (is) responsible for forming many features on (or under) the Martian surface, namely the Malin and Edgett gullies, the Hesperian-aged catastrophic outflow channels, and the Noachian-aged valley networks. I'm hardly alone in this view, which is widely held in the Mars science community.<br /><br />I remember reading the Palermo and England presentation when it first came out. Perhaps I was a bit harsh in my initial criticism (on The Habitable Zone Space BBS) of their conclusions regarding what they label as "seeps"; however, their paper does not present some of the rigorous physical and mathematical arguments that I am accustomed to from peer-reviewed publications. Their list of references is much less comprehensive (e.g., relying a great deal on web sites than formal publications or presentations) than those of other workers in the field. These dark slope streaks were noticed in Viking Orbiter imagery in the mid-1980s, and some workers claimed even then that liquid water was a suspected erosive agent. However, in their original presentation Palermo and England (P&E) did not reference this earlier work or really address some of the detailed discussions by Sullivan et al. and Edgett et al. beyond, IMHO, simple hand waving. That said, their work is definitely an area that others have been pursuing for quite some time. I really do not claim to know their qualifications, but if P&E could construct a more comprehensive work, incorporating rigo</b>

 

[serak_the_preparer]

cubancat<br />(<b><font color="yellow">F</font>/b>)<br />10/30/02 03:52 PM<br /><br />Alex, I did read your position as you note, but my curiosity was peaked by being able to ask somebody with credentials as to how they would or could explain the examples I mentioned.<br /><br />I can understand your position with respect to the P&E presentation. My understanding is that England has a degree in computer science, and if I recall correctly, Palermo may have a degree, but I’m not sure in what. It’s been a while since I spoke to either of them via e-mail. Neither degrees account for much with respect to geophysics.<br /><br />With respect to flow equations, there’s too many parameters that are still unknown with respect to a given seep to be able to accurately present an equation for a given seep morphology, IMHO. Parameters such as ground slope, atmospheric pressure, fluid chemistry, etc. With respect to some of the things I’ve done on an amateur basis, as an example, it’s very hard to determine slope conclusively from an overhead image, even having the MOLA data, sun altitude, and sun azimuth parameters. The problem is that the MOLA data is coarse, usually, with respect to the feature of interest, or is far from the area of interest, and presumptions occur. See Figure 5 at this link. Shape from shading, such as BRICE, has its own problems, and may lead one to wildly invalid conclusions with regard to a feature<br /><br />With respect to the other examples, what do you feel, in your own personal opinion, these features represent? What fluids could be postulated to be flowing in the 20021002 image that would form that non-crater and the flow that proceeds</b>

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/30/02 07:12 PM<br /><br />cubancat wrote:<br />I can understand your position with respect to the P&E presentation. My understanding is that England has a degree in computer science, and if I recall correctly, Palermo may have a degree, but I’m not sure in what. It’s been a while since I spoke to either of them via e-mail. Neither degrees account for much with respect to geophysics.<br /><br />Alex writes:<br />Just to be clear, my objection(s) "to the P&E [seeps] presentation," actually the Palermo, England, and Moore presentation to the Mars Society Convention, is not due to their qualifications or lack thereof, though some planetary sciences training (especially a greater familiarity with Mars research) would certainly make them more credible. My objection lies rather with the characteritics of their paper itself. As I noted, I was not too terribly impressed with their references section, which did not even directly reference the primary works that posit the very models they are trying to refute. For example, at a minimum their references section should address the following (though the JGR-Planets paper published by Sullivan et al. in the October 25, 2001 MGS Special Issue, which gives a much more detailed explanation than the various LPSC abstracts, may have been published afterwards) :<br /><br />=============================<br /><br />Sullivan, Robert; Thomas, Peter; Veverka, Joseph; Malin, Michael; Edgett, Kenneth S. 2001<br />Mass movement slope streaks imaged by the Mars Orbiter Camera<br />J. Geophys. Res. Vol. 106 , No. E10 , p. 23,607 (2000JE001296)<br />MGS Special Issue (October 25, 2001)<br /><br />http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058</safety_wrapper</b>

 

[serak_the_preparer]

cubancat<br />(<b><font color="yellow">F</font>/b>)<br />10/30/02 09:57 PM<br /><br />I’m speaking specifically of the image of the ’flower petal’ looking crater that appears in the tiff located at the THEMIS/ASU site for October 2, 2002. The streaks you mention surround this image, and are more concentrated to the North of the image linked here. I agree, the streaks have long ago been explained as being caused by ‘dust devils’, as you mention, with at least one actually being caught on a MOC image, to my knowledge. This feature that I link here has nothing to do with the streaking.<br /><br />On the tiff, the feature of interest is located at (504, 2470), with the origin of the coordinate system at the top left corner of the tiff. There is another crater that appears to be a splatter crater (a rock falling into mud) at (624, 1732). The morphology of both of these craters is unusual compared to surrounding craters. There are other unusual craters in the tiff field, but these easily stand out.<br /><br />I haven’t looked at the QUB yet, as I couldn’t find it when I searched, as I think it hasn’t been released yet. The closest MOC image is M0306164, which misses this feature but is in the same main crater as THEMIS 20021002. I’ve placed an uncompressed JPG format file at the link above as I work exclusively in GIMP, and its lossless format, XCF, is not interpretable in any other application, as far as I know. I can probably upload in any format except GIF, that being due to the Unisys LZW patent fiasco.<br /><br />My proposal for the image linked above is that this ‘flower petal’ looking feature is</b>

 

[serak_the_preparer]

sci_man_mjl<br />(<b><font color="blue">B</font>/b>)<br />10/31/02 02:24 AM<br /><br />I am not convinced there is significant moisture in the soils of Mars, even based on the conjecture put forth here. I personally believe that these dunes are being redistributed by their own built up mass. Mass that was propelled onto these areas by wind storms or dust devils. You can walk outside to any sand dune and experiment for yourself. Just take handfulls of sand and slowly pour it down one side of a small dune and when the mass on that side becomes sufficiently heavy it will begin to colapse downhill to equalize pressure. It creates runs just like what you seen in some of these pictures. I believe that NASA and others are going to be in for a letdown in the ground water theory. I don't think the atmosphere contains sufficient density to account for subsurface ices throughout the planets surface. The only places, i feel, it is still possible is the polar caps, either on the surface or some meters under the crust of a another frozen element. I suppose we will all see when the next lander arrives there and digs in the soil to experiment. Until then i will completely disbelieve the theory simply because it is based on what someone thinks they see in a photograph.</b>

 

[serak_the_preparer]

voyagerwsh<br />(<b><font color="orange">K</font>/b>)<br />10/31/02 10:18 AM<br /><br />Search for Subsurface Water on Mars.<br /><br />MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) on the 2003 Mars Express orbitor will be capable of detecting any possible subsurface ice and groundwater up to 5 km deep.<br /><br />Low frequence radio waves echoing from the martian crust should tell if possible subsurface ice or water exists. By sending two different frequences, the differentials of time and strenth should be able to measure underground properties.<br /><br />Reference<br /><br />1. MARSIS: Subsurface Sounding Radar/Altimeter</b>

 

[serak_the_preparer]

cubancat<br />(<b><font color="yellow">F</font>/b>)<br />10/31/02 03:35 PM<br /><br />Interesting. Brings an off-thread recent topic to mind. Why are the Egyptians putting up 7m (22 ft) rebarred concrete walls around the Giza plateau? Did they use a similar technology to see into the Giza plateau at depth and found something important enough to do so?<br /><br />Al of the Cats<br /><br />"Live Free Or Die, Death Is Not The Worst Of Evils",<br />Gen. John Stark, 7/1807</b>

 

[serak_the_preparer]

AlexBlackwell<br />(<b><font color="blue">B</font>/b>)<br />10/31/02 03:38 PM<br /><br />cubancat wrote<br />I’m speaking specifically of the image of the ’flower petal’ looking crater that appears in the tiff located at the THEMIS/ASU site for October 2, 2002.<br /><br />Alex writes:<br />Well, I tried loading the Geocities.com page you referenced, but no image appeared in any of the browsers I used; therefore, I dowloaded the TIFF image.<br /><br />cubancat wrote:<br />On the tiff, the feature of interest is located at (504, 2470), with the origin of the coordinate system at the top left corner of the tiff. There is another crater that appears to be a splatter crater (a rock falling into mud) at (624, 1732). The morphology of both of these craters is unusual compared to surrounding craters. There are other unusual craters in the tiff field, but these easily stand out.<br /><br />Alex writes:<br />OK, I see the two craters to which you refer, but in my image processing software the coordinates for these two features (referenced from 0,0 at the top left of the TIFF) are different than the ones you gave. Just to be clear, I downloaded the TIFF "as is" and performed no rotation or cropping.<br /><br />At any rate, these two craters, especially the more northerly of the two, appear to be very similar to multitudes of other craters on Mars with rampart-type ejecta lobes. The conventional view is these types of craters represent impacts into volatile-rich targets, which produces fluidized flows emanating from the impact. Mars researchers have used the depth-to-diameter ratio (d/D) for these classes of craters to estimate the depth-to-volatile, and have also attempted to classify th</b>

 

[serak_the_preparer]

cubancat<br />(<b><font color="yellow">F</font>/b>)<br />10/31/02 10:19 PM<br /><br />Thanks for mentioning the link problem. It still referenced the local hard disk file instead of the website file, ergo, you couldn't upload it.<br /><br />I'll read the papers as you say and then comment. Perhaps I'll find an image site that has a putative 'dust slide' in line with an MOLA track so we can see if the angle of repose is close to the maximum or exceeded for known materials.<br /><br /><br />Al of the Cats<br /><br />"Live Free Or Die, Death Is Not The Worst Of Evils",<br />Gen. John Stark, 7/1807</b>

 

[serak_the_preparer]

rlb2<br />(<b><font color="yellow">F</font>/b>)<br />11/01/02 12:03 PM<br /><br />Alex<br /><br />Thanks for your reply above it was very informative.<br /><br />Forgive me for repeating myself over and over from other posts but my focus on Mars is towards the Hellas basin. We have talked about this before but I am totally mystified by it. One of the few pictures NASA has released on Mars says it all.<br /><br />"Right now on Mars it is winter in the southern hemisphere. This means that the usually cloudy Hellas Basin is relatively free from clouds. Even though there is little cloud cover, the atmosphere is still much thicker due to the deeper basin compared to elsewhere on Mars, making image details not as crisp as when viewed through thinner atmosphere. In the center of the image are several dark streaks which originate from the side of a higher standing butte. The dark material is likely being eroded from a single layer within the cliff face. Wind has moved some of the eroded dark material to form the streaks."<br /><br />http://themis.la.asu.edu/zoom-20021007a.html<br /><br />To me this is more Earth like then anywhere else on the planet. Hellas basin is the most cloudy place on Mars and the atmosphere is the most densest. Hellas is one big hole in the ground that is 1,500 miles in diameter. At one time in the Martian past the Hellas basin may have been one big lake. It is completely surrounded by 5-mile high cliffs or higher. The last global dust storm started there. But yet as stated above it is the least studied. I believe if we are to find life today on Mars it would be in this big hole in the ground.</b>