Active volcanic vent on Mars?
Robert Clark
Portion of Valles Marineris.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34528
Bob Clark
George
"Robert Clark" <rgrego...@yahoo.com> wrote in message
news:832ea96d.04021...@posting.google.com...
Interesting dark spot. I've seen this picture recently. It doesn't look
like any volcano I've seen. It looks more like a crater on a mesa (the
crater being located at the top of the dark spot. It would be interesting
if they waiting a few months and took another picture, and looked for
changes.
David Knisely
Nope, sorry, its no volcanic vent. Its just a small dark albedo feature which
is underexposed enough so that you can't see the underlying topography. It
shows up in the MGS Atlas pretty well as a teardrop-shaped darker spot, and is
also visible in the old Viking MDIM images. Clear skies to you.
--
David W. Knisely KA0...@navix.net
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/
**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
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**********************************************
John Curtis
while erupting into near-vacuum.
The emissions of a volcano are determined by the medium
into which a volcano erupts; thus the sea-floor volcano is
characterized by reduced minerals (sulfides, silicates),
while the open air (21% oxygen) volcano produces oxides:
CO2, SO2, hematite, quartz.
When water and oxygen are no longer a factor, a martian
volcano may exhibit third type of volcanism; the primordial
(hydrogen based) ingredients, such as CH4, H2O, NH3, H2S
are exiting unscathed from the planetary interior.
Hydrogen based iron (FeH2) has been postulated as
comprising Earth's core.
http://epp.eps.nagoya-u.ac.jp/~okuchi/abs/AGU98.GIF
John Curtis
Robert Clark
> Robert Clark wrote:
>
> > Take a look at a hires image on this page:
> >
> > Portion of Valles Marineris.
> > http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34528
>
> Nope, sorry, its no volcanic vent. Its just a small dark albedo feature which
> is underexposed enough so that you can't see the underlying topography. It
> shows up in the MGS Atlas pretty well as a teardrop-shaped darker spot, and is
> also visible in the old Viking MDIM images. Clear skies to you.
> --
Take a look at a hires image on the page, in either JPEG or TIFF
format.
The dark material gives the definite appearance of emanating from the
crater. It also has a key characteristic suggestive of a geyser or a
vent: the dark material is light right next to the vent but heavier
further away. This is suggestive of material being thrown up with some
velocity and then coming back down some distance away.
Another key characteristic of a vent or geyser I consider to be the
fact that the origin is quite small compared to the widest portion of
the dark area. If this was just a wind blown deposit it wouldn't widen
out to this degree. It remain more or less the same width as the
origin.
A noted Valles Marineris expert has argued for recent volcanism in
Marineris.
More on RECENT(?) Dark Volcanic Patches in the Valles Marineris, Mars
Lucchitta, B. K.
LUNAR AND PLANETARY SCIENCE XVII, PP. 496-497.
http://adsabs.harvard.edu/cgi-bin/bib_query?1986LPI....17..496L
Bob Clark
David Knisely
> Take a look at a hires image on the page, in either JPEG or TIFF
> format.
I did. With some image stretching, I can see the underlying terrain (small
impact craters and a few rides). In any case, it has been there at least
since the mid 1970's and probably a lot earlier.
> The dark material gives the definite appearance of emanating from the
> crater. It also has a key characteristic suggestive of a geyser or a
> vent: the dark material is light right next to the vent but heavier
> further away. This is suggestive of material being thrown up with some
> velocity and then coming back down some distance away.
Appearances can be deceiving. There are similar dark patches on the floor of
Gusev (Spirit landed in one), but there isn't any signs of current volcanic
activity. Mostly what they are made up of is darker surfaces which have been
swept clean of fine dust (lots of dark dust-devil tracks are visible in the
high-res MGS images). There are two volcanoes near Gusev, but they do not
show these dark streaks emanating from them.
> Another key characteristic of a vent or geyser I consider to be the
> fact that the origin is quite small compared to the widest portion of
> the dark area. If this was just a wind blown deposit it wouldn't widen
> out to this degree.
Again, winds can do interesting things to surface albedoes. Many craters have
broad dark down-wind streaks caused by the removal of dust. The feature has
been there for a long time, and it is *not* evidence for an active volcanic vent.
George
> Robert Clark wrote:
>
> > Take a look at a hires image on the page, in either JPEG or TIFF
> > format.
>
> I did. With some image stretching, I can see the underlying terrain
(small
> impact craters and a few rides). In any case, it has been there at least
> since the mid 1970's and probably a lot earlier.
>
> > The dark material gives the definite appearance of emanating from the
> > crater. It also has a key characteristic suggestive of a geyser or a
> > vent: the dark material is light right next to the vent but heavier
> > further away. This is suggestive of material being thrown up with some
> > velocity and then coming back down some distance away.
>
> Appearances can be deceiving. There are similar dark patches on the floor
of
> Gusev (Spirit landed in one), but there isn't any signs of current
volcanic
> activity.
The dark streaks in the area that Spirit landed in are caused by dust
devils.
Greg Crinklaw
> The dark streaks in the area that Spirit landed in are caused by dust
> devils.
It's all ultimately the same process. Wind removes topsoil. Soil
beneath is darker than the dusty soil above. Except in Meridiani (and
perhaps a few places elsewhere), where the dark soil is on top of light
material.
--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)
SkyTools Software for the Observer:
http://www.skyhound.com/cs.html
Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html
To reply remove spleen
George
"Greg Crinklaw" <capellas...@yahoo.com> wrote in message
news:102qc54...@corp.supernews.com...
I was trying to point out that it wasn't vlcanic activity that was causing
the dark streaks.
Carsten Troelsgaard
"John Curtis" <jo...@curtis.ms> skrev i en meddelelse
news:48473241.04021...@posting.google.com...
> rgrego...@yahoo.com (Robert Clark) wrote in message
news:<832ea96d.04021...@posting.google.com>...
> > Take a look at a hires image on this page:
> >
> > Portion of Valles Marineris.
> > http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34528
> >
> > Bob Clark
> >
> >
> The image meets my expectation of how a volcano should look
> while erupting into near-vacuum.
> The emissions of a volcano are determined by the medium
> into which a volcano erupts; thus the sea-floor volcano is
> characterized by reduced minerals (sulfides, silicates),
reduced because of lack of oxygen?
> while the open air (21% oxygen) volcano produces oxides:
> CO2, SO2, hematite, quartz.
C, S, Fe and Si oxidized at the moment of extrusion? ... do you have a
reference to that? I figured that atleast subduction-related volcanism had
CO2 from subducted marine carbonates. I never thought of oxidation of C as a
possibility - but why not.
> When water and oxygen are no longer a factor, a martian
> volcano may exhibit third type of volcanism; the primordial
> (hydrogen based) ingredients, such as CH4, H2O, NH3, H2S
The spheric texture often seen in the sediment may have an origin in
volcanism that involves water. This could work with the primordial
ingredients you mention. Would you have a proposition as to the faith of H2S
in such a scenario?
> are exiting unscathed from the planetary interior.
> Hydrogen based iron (FeH2) has been postulated as
> comprising Earth's core.
> http://epp.eps.nagoya-u.ac.jp/~okuchi/abs/AGU98.GIF
> John Curtis
kindly
Carsten
Robert Clark
latitude/longitude given on the Mars Express page, 5° North and 323°
East:
Area between 0°and 15° Latitude and 30°and 45° Longitude.
http://ida.wr.usgs.gov/html/areasg/c_07n037.htm
Floor of valley at Hydroates Chaos--Simud Vallis junction
http://ida.wr.usgs.gov/html/m15008/m1500839.html
(probably the closest one.)
Scarp and chaos in Simud Valles system
http://ida.wr.usgs.gov/html/m09050/m0905031.html
Sample wall and chaos in secondary Simud Vallis
http://ida.wr.usgs.gov/html/m07040/m0704002.html
Shalbatana Vallis floor
http://www.msss.com/moc_gallery/m13_m18/images/M15/M1500198.html
It is interesting the Mars Express image lies within an area of
chaotic terrain on Mars. This has been interpreted as due sudden
removal of subsurface water or ice, causing the surface material to
slump and break into blocks. This would be consistent with
hydrovolcanism.
It's also notable that the "Sample wall and chaos in secondary Simud
Vallis" and "Scarp and chaos in Simud Valles system" images seem to
have the Malin/Edgett gullies attributed to recent liquid water flow.
If so, these would be quite rare examples of these flows occurring at
near equatorial sites.
However, from these MGS images it is impossible to tell if the dark
area existed at this prior time as well. If you know of Viking images
that show this dark area in Marineris I would like to see them to make
a comparison between its appearance at the two times.
Bob Clark
David Knisely <ka0...@navix.net> wrote in message news:<c0aXb.1597$FO....@fe01.usenetserver.com>...
John Curtis
> "John Curtis" <jo...@curtis.ms> skrev i en meddelelse
> news:48473241.04021...@posting.google.com...
> > rgrego...@yahoo.com (Robert Clark) wrote in message
> news:<832ea96d.04021...@posting.google.com>...
> > > Take a look at a hires image on this page:
> > >
> > > Portion of Valles Marineris.
> > > http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34528
> > >
> > > Bob Clark
> > >
> > >
> > The image meets my expectation of how a volcano should look
> > while erupting into near-vacuum.
> > The emissions of a volcano are determined by the medium
> > into which a volcano erupts; thus the sea-floor volcano is
> > characterized by reduced minerals (sulfides, silicates),
>
> reduced because of lack of oxygen?
>
>
> > while the open air (21% oxygen) volcano produces oxides:
> > CO2, SO2, hematite, quartz.
>
> C, S, Fe and Si oxidized at the moment of extrusion? ... do you have a
> reference to that? I figured that atleast subduction-related volcanism had
> CO2 from subducted marine carbonates. I never thought of oxidation of C as a
> possibility - but why not.
>
by 21% oxygen at volcano temperatures. On the other hand, when
there is no oxygen, there is no CO2, SO2, hematite or quartz as
illustrated by the plumes of the deep-sea volcanos:
http://www.pmel.noaa.gov/vents/chemistry/images/vents2.gif
>
>
> > When water and oxygen are no longer a factor, a martian
> > volcano may exhibit third type of volcanism; the primordial
> > (hydrogen based) ingredients, such as CH4, H2O, NH3, H2S
>
> The spheric texture often seen in the sediment may have an origin in
> volcanism that involves water. This could work with the primordial
> ingredients you mention. Would you have a proposition as to the faith of H2S
> in such a scenario?
>
condense into water under current conditions. John Curtis
David Knisely
> It is interesting the Mars Express image lies within an area of
> chaotic terrain on Mars. This has been interpreted as due sudden
> removal of subsurface water or ice, causing the surface material to
> slump and break into blocks. This would be consistent with
> hydrovolcanism.
It would also be consistent with impact-induced heating and disruption of
sub-surface ice-bearing layers of soil and rock. Also, mechanical
liquifaction from impact or surface movement (ie: Marsquakes or tectonic
shifts in the crust).
> However, from these MGS images it is impossible to tell if the dark
> area existed at this prior time as well. If you know of Viking images
> that show this dark area in Marineris I would like to see them to make
> a comparison between its appearance at the two times.
The dark spot appeared in both the MGS and Mars Express images, so it clearly
existed prior to the current time. As for the Viking images, there are
several sources for these (including several Mars Atlases on the Internet), so
you might want to try using a simple search engine from time to time. One
based on the Viking images is the Mars Atlas CD-ROM, available at:
http://cmex-www.arc.nasa.gov/Atlas96/Atlas96.htm, and will give you large and
medium scale images to about 1 kilometer resolution. I have an old version
of the commerical software MARS EXPLORER which used the Viking orbiter images
from the Mars Digital Image Mosaic (MDIM). The newest version of the Viking
MDIM is available from the USGS web site:
http://astrogeology.usgs.gov/Projects/MDIM21/ The MDIM series of images from
Viking are also available on CD-ROM from NASA if you want to play with the
real images yourself (you may need some companion software however). Again,
the Viking image clearly shows the dark spot in the same location as in the
MGS images and the ESA Mars Express image, although the resolution is not
nearly as high. Clear skies to you.
Robert Clark
http://cmex-www.arc.nasa.gov/Atlas96/WEST/WM2_4/WH5_1.htm
It is one of the two dark patches in the square at the upper
right-hand corner of the image.
It's also visible here:
http://astrogeology.usgs.gov/mdim-bin/dataListPage.pl?lat=15N&lon=338E
Measuring from the bottom left corner, about 1/3 of the way up and
1/4 of the way to the right there are three dark patches. I believe
it's the most teardrop shaped one.
In the MGS Hydroates Chaos page, it also appears in the Viking
context image:
Floor of valley at Hydroates Chaos--Simud Vallis junction
http://ida.wr.usgs.gov/html/m15008/m1500839.html
It's one of the two dark patches near the center of the Viking
context image, but I can't determine which one.
You can't tell if it changed in size or shape between the Viking
images and the Mars Express image. The Viking images do not have
sufficient resolution.
Even if this deposit formed from volcanic activity within the last
hundreds of thousands of years, that would still suggest volcanism is
current within this area in Marineris.
One thing to look for would be if the deposit covered dunes in the
area, since dunes are relatively young. This fact was used to conclude
the Malin/Edgett gullies were recent.
Bob Clark
"David Knisely" <ka0...@navix.net> wrote in message news:a5vXb.6787$FO....@fe01.usenetserver.com...
Robert Clark
Other perspectives of the same area:
http://www.esa.int/export/externals/images/2_3a4.jpg
http://www.esa.int/export/externals/images/ob_18_mesa_p.jpg
Bob Clark
David Knisely
> It's one of the two dark patches near the center of the Viking
> context image, but I can't determine which one.
It is quite easy to determine which dark spot it is. There is a bay-like
intrusion into the western wall of the valley where there is a lot of chaotic
terrain. The dark spot is in the middle of that bay on its floor (coordinates
are 5.2N, 37.3W).
> Even if this deposit formed from volcanic activity within the last
> hundreds of thousands of years, that would still suggest volcanism is
> current within this area in Marineris.
However, there is no compelling evidence at all that this dark spot is due to
volcanism. Again, there are many dark spots like this in various regions all
over the planet. High resolution images tend to show extensive dark
dust-devil tracks over these spots, showing that wind is the probable agent in
their formation. The volcanic regions of Mars, by contrast, tend to be
somewhat lighter in albedo than these darker areas. Clear skies to you.
Robert Clark
discussed this one before, discovered by Dr. Leonard Martin:
Aug. 9, 2000
Is Mars water old news?
By Billy Cox
A FLORIDA TODAY column
http://www.floridatoday.com/news/columnists/cox/080900cox.htm
It appears in Viking images 775a10 and 775a11, reproduced here:
http://www.lauralee.com/JPL.htm
I'm trying to find the latitude and longitude of this proposed
venting to locate it in MGS images. The Viking images are supposed to
be centered at latitude 16S and longitude 80W but I have not been able
to match up the features in 775a10 and 775a11 with the Viking maps to
more precisely locate the coordinates of the "vent" itself. Here's a
Viking map of the area:
MDIM 2.1: Mars Global Digital Image Mosaic
Quad ID: MC-18
Quad Name: Coprates
Center Latitude of Quad: 15°S
Center Longitude of Quad: 293°E
http://astrogeology.usgs.gov/mdim-bin/dataListPage.pl?lat=15S&lon=293E
The Viking images can be downloaded from here:
http://wufs.wustl.edu/geodata/vo1_vo2-m-vis-2-edr-v2/vo_1029/f775axx/
You'll need NASAView to decode and view these images.
Bob Clark
David Knisely <ka0...@navix.net> wrote in message news:<G9EXb.8426$FO....@fe01.usenetserver.com>...
Carsten Troelsgaard
"Robert Clark" <rgrego...@yahoo.com> skrev i en meddelelse
news:832ea96d.04022...@posting.google.com...
snip
> > > It's one of the two dark patches near the center of the Viking
> > > context image, but I can't determine which one.
> >
> > It is quite easy to determine which dark spot it is. There is a
bay-like
> > intrusion into the western wall of the valley where there is a lot of
chaotic
> > terrain. The dark spot is in the middle of that bay on its floor
(coordinates
> > are 5.2N, 37.3W).
> >
> >
> > > Even if this deposit formed from volcanic activity within the last
> > > hundreds of thousands of years, that would still suggest volcanism is
> > > current within this area in Marineris.
> >
> > However, there is no compelling evidence at all that this dark spot is
due to
> > volcanism. Again, there are many dark spots like this in various
regions all
> > over the planet. High resolution images tend to show extensive dark
> > dust-devil tracks over these spots, showing that wind is the probable
agent in
> > their formation. The volcanic regions of Mars, by contrast, tend to be
> > somewhat lighter in albedo than these darker areas. Clear skies to you.
I've got another one of the crazy unfounded ideas that thrives so well
thinking of Mars.
I apparently misplaced a picture of an impactcrater that is dark in the
bottom and seems to vent dark 'smoke' so I cannot illustrate what I think
of. The 'smoke' emanates a way that I believe precludes the disturbance of
dust form wind-turbulence. I have had this recurrent vision of something
boiling like ... a soda-pop - and it occurs to me that it may after all not
be that far off. But it will take some explaining:
The general idea is that it is degassing of clathrates. An Australian
geologist Hoffman has advocated for the gasrelease of clathrates to account
for the impressive landslides (as I understand him), so the idea is not new.
Clathrates evolve on Earth under deep oceanic pressure by incorporating
bubbling gas into a subsurface H2O structure in sediment-porespace... and
the clathrates may evolve to constitute 50 % of a sediment. If clathrates
has evolved underground then the pressure-release of the overburden that is
removed in a crater may start the degassing. The bubbling and spray of fine
mud-spheres suffers under my expectation that such a wet environment would
have been detected from measurements from orbit - but since Nasa themselves
recently has not precluded some moist 10 cm underground, the idea may be
valid.
The point of seeing the gas-seep prolonged after the impact is a possibility
that the pressure-release may become effective far into the strata that
contains the clathrates - the decay of the clathrates provide continued
conduits for further release of gas. My best hopes for this point is, that
the fine 'spray' that seems to raise from the crater can make an account for
the widespread occurrence of spheres - if it does not, it may still be cold
(vs. volcanic) degassing disturbing dust in the bottom of the crater.
Carsten
David Knisely
> Perhaps you can help me locate another proposed venting on Mars. We
> discussed this one before, discovered by Dr. Leonard Martin:
>
> Aug. 9, 2000
> Is Mars water old news?
> By Billy Cox
> A FLORIDA TODAY column
> http://www.floridatoday.com/news/columnists/cox/080900cox.htm
>
> It appears in Viking images 775a10 and 775a11, reproduced here:
>
> http://www.lauralee.com/JPL.htm
That is *very* probably a dust devil (a big one, but a dust devil
nonetheless). In the second of the two images, the dust-devil track can be
seen extending below and well beyond the shadow of the plume.
Thomas Lee Elifritz
Carsten Troelsgaard wrote:
> My best hopes for this point is, that
> the fine 'spray' that seems to raise from the crater can make an account for
> the widespread occurrence of spheres - if it does not, it may still be cold
> (vs. volcanic) degassing disturbing dust in the bottom of the crater.
Feel free to publish your crackpot theory retraction here.
Thomas Lee Elifritz
http://elifritz.members.atlantic.net
Carsten Troelsgaard
"Thomas Lee Elifritz" <crac...@everywhere.net> skrev i en meddelelse
news:4037BDF8...@everywhere.net...
> February 21, 2004
> Feel free to publish your crackpot theory retraction here.
Are you afraid that your silence will be interpretated as consensus?
Oppose me with an argument Ellifrits
George
> Perhaps you can help me locate another proposed venting on Mars. We
> discussed this one before, discovered by Dr. Leonard Martin:
>
> Aug. 9, 2000
> Is Mars water old news?
> By Billy Cox
> A FLORIDA TODAY column
> http://www.floridatoday.com/news/columnists/cox/080900cox.htm
>
> It appears in Viking images 775a10 and 775a11, reproduced here:
>
> http://www.lauralee.com/JPL.htm
That is ridiculous. The ony difference between these two photos is the
apparent brightness (the second being much brighter than the first), and the
angle relative to the Martian surface at which the photos were taken, and of
course, the confused imagination of Laura Lee. The difference in brightness
is an artifact of the photography, not to any alleged venting. How is this
possible? Because the entire second photograph is much brighter than the
first. If it was some kind of venting, one would expect the brightness to
occur only in the region of the vent. This is not the case. In addition,
if you want to make the case that the dark streak is the vented material,
the problem with that is that this streak appears in both photos, making a
before and after scenario ludicrous. The dark streak can easily be
explained by the occurence all over Mars of dust devils and the many dark
tracks they have left behind. The fact that Dr. Leonard Martin thought it
was something else is only a testament to how much more we know about Mars
today than we knew in 1980.
Robert Clark
that allow its positioning by latitude/longitude. A problem is that
the Viking maps show a criss-cross pattern where the feature is
supposed to be at 16S, 80W but in the images of the feature this
criss-cross pattern is not evident.
Bob Clark
David Knisely <ka0...@navix.net> wrote in message news:<SoOZb.1729$c33....@fe01.usenetserver.com>...
Robert Clark
The color combinations were done by Keith Laney:
http://www.keithlaney.com/colormars/V04437003color.jpg
The individual THEMIS filter images are here:
http://themis-data.asu.edu/img/V04437003.html
This image raises another possible explanation for why there is a gap
between the dark material and the crater. In this Mars Odyssey image
it looks like lighter dust has been blown from the crater to cover the
area immediately adjacent to it.
The same may be the case in the Mars Express image. However, in both
these cases the dark material still appears to emanate from the
crater. And there is a widening of the dark material away from the
crater. For a case of simple wind blown dust, the width of the dark
streak should stay about the same.
Bob Clark
rgrego...@yahoo.com (Robert Clark) wrote in message news:<832ea96d.04021...@posting.google.com>...
George
> Here's an analogous image in a different area taken by Mars Odyssey.
> The color combinations were done by Keith Laney:
>
> http://www.keithlaney.com/colormars/V04437003color.jpg
>
> The individual THEMIS filter images are here:
>
> http://themis-data.asu.edu/img/V04437003.html
>
> This image raises another possible explanation for why there is a gap
> between the dark material and the crater. In this Mars Odyssey image
> it looks like lighter dust has been blown from the crater to cover the
> area immediately adjacent to it.
> The same may be the case in the Mars Express image. However, in both
> these cases the dark material still appears to emanate from the
> crater. And there is a widening of the dark material away from the
> crater. For a case of simple wind blown dust, the width of the dark
> streak should stay about the same.
>
>
> Bob Clark
>
After examining the above images very closely, several things become
apparent in my mind. First of all, the hummocky material surrounding the
large impact crater on all sides constitutes the original impact ejecta from
the formation of the crater itself. Some of the ejecta consists of large
blocks that can be easily seen immediately west (to the left) of the crater
in the light-colored area in which you refer. These blocks show up as
bright hills on the flanks of the crater. Blocks such as these can also be
seen farther from the crater and within the area of the dark material as
well. Some of these blocks apparently are so high in elevation that they
appear light-colored, which indicates that 1) either the dark material did
not attain a high altitude relative to these blocks, and was never was
deposited at the summits of these block (which seems unlikely to me
considering the broad dispersal pattern of the material), or 2) that dark
material was deposited at the summits and was later stripped away by the
Martian wind. An alternative to those two scenarios is that the
loght-colored summits of the blocks within the dark area are high enough to
not be affected the wind in the same way that the lower elevations are
affected. More on this later
The rim of the large crater is much higher in altitude than the surrounding
landscape, and is likely creating a wind break or wind shadow on the
downwind side (west) of the crater, as is evidenced by the fact that no dark
material has been deposited in that area (or exposed, if it is covered by
lighter-colored material. If the dark material constitued some sort of
material vented from within the crater, or even material blown out of the
crater by the wind, this area should also be covered with dark material.
Secondly, if you look at the following links of the eruption of Mt. Etna, in
Sicily, you will note that a similar dispersal pattern of material is seen
from its eruption. What you should also note is that the material erupting
from the volcano emanates from at least one of the summit cones, and is
blanketing everything downwind of the volcano, including the downwind flank.
There is no wind shadow downwind of the volcano during the eruptive phase.
http://www.usgs.gov/volcanoes/etna/752_0713.html
Realize, of course, that the above images are of an active volcanic eruption
phase. On the earth, a lot of ash will get washed away during rain events,
and so the resulting fallout pattern would necessarily look different than
anything we sould see on Mars. However, given no rainfall, and significant
preservation of fallout material from an eruption, the dispersal pattern
should look similar on the Earth and on Mars. Having said that, although we
see a simlar broad dispersal pattern on Mars (indicating that it was
influenced by the wind), there is no material on the immediate downwind
flank of the crater.
One explanation for the lack of dark material on the west flank of the
crater is that sometime after it was deposited, the wind changed direction
for a considerable length of time, and blew up the west flank of the crater,
and stripped the dark material away. But if that was the case, where did the
dark material get re-deposited? Additionally, if this were the case, you
would see a similar pattern occur at the other craters in the image which
have dark material downwind of them. This is not the case, for the rest of
them do not show a similar light area to the west of their respective
craters.
This poses a problem for the idea that the material was ejected from the
crater in a venting event. What is interesting is that where the wind blows
around the northern and southern edge of the crater, we do see dark material
deposited on the surface. I propose that the high crater rim is affecting
low level wind patterns downwind from the crater, possily creating eddies in
the atmosphere (dust devils) which are stripping away surface material and
exposing dark material buried underneath. This is consistent with the other
craters in the image, since they also have high crater rims relative to
their respective surroundings (such as the small craters to the north of the
large one). Finally, when you look at the images from the Mars Spirit
rover, located within Gustov crater, you will note that nearly everything
appears to be covered in a light-colored dust layer. However, as was the
case with the rock called Adirondack, when the light-colored dust was
brushed away, it exposed the dark rock beneath.
http://marsrovers.jpl.nasa.gov/gallery/all/2/p/035/2P129469596EFF0327P2578R2M1.HTML
I hope this helps.
Carsten Troelsgaard
" George" <Geo...@george.net> skrev i en meddelelse
news:yT0_b.82503$8a5....@bignews1.bellsouth.net...
I agree that the observation does not conform to a hot eruption. What seems
to appear as a faint 'smoke' emanating from some of the craters - I consider
a 'cold' venting possible (but I'm not an expert) - could be small particle
'projectiles'. Considering the ease on lifting particulate material (low
gravity) from the surface in a modest pressure venting may in my opinion
well lift dust and particles sufficiently high to fall at rest in at a small
distance from the crater.
The eddy-currents from turbulence you mention George, wouldn't they erode
closer to the crater-rim? Like what happens around the stem of a pole in
water with a sandy bottom. - I won't eat my hat on it though, given the
array of physical parameters of density, viscosity and meteorology that
influences the process. My scenario ascribes the covered area to the path of
a light projectile carried in a down-wind direction.
Carsten
George
??? Please clarify what you mean.
>Considering the ease on lifting particulate material (low
> gravity) from the surface in a modest pressure venting may in my opinion
> well lift dust and particles sufficiently high to fall at rest in at a
small
> distance from the crater.
> The eddy-currents from turbulence you mention George, wouldn't they erode
> closer to the crater-rim?
Actually no. The reason is that this region is at a relatively high
elevation, before you even consider the elevation of the crater rim. The
atmosphere is very thin. Most of the wind in this region would necessarily
be at a lower elevation than the crater rim, or the tops of the large blocks
or hills I referred to.
>Like what happens around the stem of a pole in
> water with a sandy bottom. - I won't eat my hat on it though, given the
> array of physical parameters of density, viscosity and meteorology that
> influences the process. My scenario ascribes the covered area to the path
of
> a light projectile carried in a down-wind direction.
>
> Carsten
>
Actually, your first thought there probably fits the facts better than you
may realize. I had thought of it myself. Take a cylinder and stick it in
water. Then initiate a flow stream around the cylinder. If you inject dye
into the stream, you will see turbulence eddies form downstream of the
cylinder and fan out. Now, if you leave the very top of that cylinder, and
the summits of the ejecta blocks above the water stream....
See what I mean? I think this whole process could easily be modeled in the
laboratory. You would simply recreate the area in question with a model
composed of layers of various materials, and various colors (for instance,
you would have a top layer of thin material like sand or silt covering a
darker, more resistent material. You run a stream of water across the model
so that it flows around the model crater (but not over the top or over the
tops of the large ejecta blocks), and watch the light colored material be
carried away. It makes perfect sense to me. But that's just the way I am.
I see a perfect chance to request a grant from the NSF. Don't you?
Carsten Troelsgaard
snip
> > I agree that the observation does not conform to a hot eruption. What
> seems
> > to appear as a faint 'smoke' emanating from some of the craters - I
> consider
> > a 'cold' venting possible (but I'm not an expert) - could be small
> particle
> > 'projectiles'.
>
> ??? Please clarify what you mean.
The vented particles are pushed off from the bottom and take a projectile
trajectory + gently are lead in a downwind direction.
> >Considering the ease on lifting particulate material (low
> > gravity) from the surface in a modest pressure venting may in my opinion
> > well lift dust and particles sufficiently high to fall at rest in at a
> small
> > distance from the crater.
> > The eddy-currents from turbulence you mention George, wouldn't they
erode
> > closer to the crater-rim?
(crater-rim understood as circumference of crater )
> Actually no. The reason is that this region is at a relatively high
> elevation, before you even consider the elevation of the crater rim. The
> atmosphere is very thin. Most of the wind in this region would
necessarily
> be at a lower elevation than the crater rim, or the tops of the large
blocks
> or hills I referred to.
>
> >Like what happens around the stem of a pole in
> > water with a sandy bottom. - I won't eat my hat on it though, given the
> > array of physical parameters of density, viscosity and meteorology that
> > influences the process. My scenario ascribes the covered area to the
path
> of
> > a light projectile carried in a down-wind direction.
> >
> > Carsten
> >
>
> Actually, your first thought there probably fits the facts better than you
> may realize.
The 'projectile trajectory', 'cold venting' or 'erosion by turbulence'?
> I had thought of it myself. Take a cylinder and stick it in
> water. Then initiate a flow stream around the cylinder. If you inject
dye
> into the stream, you will see turbulence eddies form downstream of the
> cylinder and fan out. Now, if you leave the very top of that cylinder,
and
> the summits of the ejecta blocks above the water stream....
>
> See what I mean?
I'm not sure - but taking the physical parameters into considration could
possibly give reason to the idea
> I think this whole process could easily be modeled in the
> laboratory. You would simply recreate the area in question with a model
> composed of layers of various materials, and various colors (for instance,
> you would have a top layer of thin material like sand or silt covering a
> darker, more resistent material. You run a stream of water across the
model
> so that it flows around the model crater (but not over the top or over the
> tops of the large ejecta blocks), and watch the light colored material be
> carried away. It makes perfect sense to me. But that's just the way I
am.
> I see a perfect chance to request a grant from the NSF. Don't you?
I've considered something like that throughout the passed dayes - as far as
to contact one of my professors for advise. I'm a 'dog on a boling-ally' in
this respect, but foremost non of my university-grades encourage to persue a
career as a phd. May I approach you in private mail if I get stuck in a
related problem ?
Carsten
George
No. Read below/
You don't need a PhD to conduct said research.
>I'm a 'dog on a boling-ally' in
> this respect, but foremost non of my university-grades encourage to persue
a
> career as a phd. May I approach you in private mail if I get stuck in a
> related problem ?
>
> Carsten
>
Why?
Carsten Troelsgaard
snip
> Why?
I actually thought that you referred to another idea than what you did, so I
understand your question.
George
Ok.
Robert Clark
two separate streaks that are emanating from opposite sides of the
crater. That again could be due to light colored dust being blown to
cover the area nearest the crater. However, there is a separate
instance that suggests this is in fact due to venting of some kind.
In the southern polar regions there have been observed strange
spider-like forms in the region covered by a seasonal CO2 cover. These
branching spider-like ravines have been attributed by Kieffer et.al.
to venting of CO2 gas beneath a CO2 ice cover. Interestingly, in
support of this interpretation there were given some images of dark
fan-like spots emanating from craters that are seen in association
with the spiders. Many of these fan-like spots have that same
charactertic of two separate streaks emanating from opposite sides of
the crater. But they are interpreted as due to the CO2 jets venting to
the surface.
Example of the "spiders":
MOC narrow-angle image M11-00396
South Chasma Australe scarp
http://www.msss.com/moc_gallery/m07_m12/images/M11/M1100396.html
Example of the fan-like deposits:
MOC narrow-angle image M07-03150
sample
http://www.msss.com/moc_gallery/m07_m12/images/M07/M0703150.html
Discussions of the spiders and fan-like deposits:
BEHAVIOR OF SOLID CO2 ON MARS: A REAL ZOO. Hugh H. Kieffer, U. S.
Geological Survey [Emeritus], Flagstaff, AZ
86001, USA, (hkieffer@******.net).
Sixth International Conference on Mars (2003) 3158.pdf
http://www.lpi.usra.edu/meetings/sixthmars2003/pdf/3158.pdf
ANNUAL PUNCTUATED CO2 SLAB-ICE AND JETS ON MARS. H. H. Kieffer, U.S.
Geological Survey,
2255 N. Gemini Dr., Flagstaff, AZ 86001
Mars Polar Science 2000 4095.pdf
http://www.lpi.usra.edu/meetings/polar2000/pdf/4095.pdf
Sublimation of Mars's southern seasonal CO2 ice cap and the
formation of spiders.
Sylvain Piqueux, Shane Byrne, and Mark I. Richardson
Division of Geological and Planetary Sciences, California Institute of
Technology, Pasadena, California, USA
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. E8, 5084,
doi:10.1029/2002JE002007, 2003
http://www.gps.caltech.edu/~shane/2002JE002007.pdf
Bob Clark
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rgrego...@yahoo.com (Robert Clark) wrote in message news:<832ea96d.0402...@posting.google.com>...
MarsFossils
Unfortunately I don't know where this picture was taken. The black
dust on this one looks like it has been blown around by dust devils
rather than by a geyser or volcano. The white to black contrast is
remarkable, as in the first.
http://aix1.uottawa.ca/~weinberg/mars/xblack_spot_mars.jpg
Does anyone know where this picture was taken?
Michael
Mars Fossils, Pseudofossils, and Problematica
http://aix1.uottawa.ca/~weinberg/mars/
Robert Clark
Geysers On Mars.
http://mars4all.tripod.com/geysersonmars/index.html
Bob Clark
rgrego...@yahoo.com (Robert Clark) wrote in message news:<832ea96d.04031...@posting.google.com>...
Ralph Nesbitt
> Here's a page showing other examples of these south polar geysers:
>
> Geysers On Mars.
> http://mars4all.tripod.com/geysersonmars/index.html
>
>
> Bob Clark
>
site with what may be a reasonable explanation for a phenomena, then include
Pictures without a scale for same for perspective.
Ralph Nesbitt
MarsFossils
the Hellas Basin. But I don't have a specific site.
> http://aix1.uottawa.ca/~weinberg/mars/xblack_spot_mars.jpg
Regarding the original picture of the dark smudge in the Valles
Marineris, notice that the mesa is in the middle of a chaos. A chaos
is a collapsed area from which a large flood of water, no doubt
originating from melted permafrost, has flowed away.
> http://www.esa.int/export/externals/images/2_3a4.jpg
When I look at the picture, my guess is that the deep ground
permafrost - water or CO2 - is sublimating, and blowing up dark
particles - basalt or volcanic ash - along with it. Every goes up
through the little crater, that is common, and are blown downwind by
prevailing winds. I suspect the eruptions/sublimations are happening
fairly regularly, or else the smudge would have be dusted over after
the last few dust storms. That is what it looks like to me.
Michael
marsf...@canada.com
George
> two separate streaks that are emanating from opposite sides of the
> crater. That again could be due to light colored dust being blown to
> cover the area nearest the crater. However, there is a separate
> instance that suggests this is in fact due to venting of some kind.
> In the southern polar regions there have been observed strange
> spider-like forms in the region covered by a seasonal CO2 cover. These
> branching spider-like ravines have been attributed by Kieffer et.al.
> to venting of CO2 gas beneath a CO2 ice cover. Interestingly, in
> support of this interpretation there were given some images of dark
> fan-like spots emanating from craters that are seen in association
> with the spiders. Many of these fan-like spots have that same
> charactertic of two separate streaks emanating from opposite sides of
> the crater. But they are interpreted as due to the CO2 jets venting to
> the surface.
>
There are copious amounts of CO2 at the poles. There is no evidence that this
is the case in the region in question.
George
"MarsFossils" <marsf...@canada.com> wrote in message
news:89fc81af.04031...@posting.google.com...
But then, you believe the spherules found on Mars are fossils. And we are
supposed to consider you to be an expert? I don't think so.
Robert Clark
active vents on Mars:
The Mars Express spacecraft in orbit around MarsMars Express confirms
methane in the Martian atmosphere.
30 March 2004
"During recent observations from the ESA Mars Express spacecraft in
orbit around Mars, methane was detected in its atmosphere."
http://www.esa.int/esaCP/SEMZ0B57ESD_index_0.html
Scientists Unsure if Methane at Mars Points to Biology or Geology
By Tariq Malik
Staff Writer
posted: 04:30 pm ET
29 March 2004
http://space.com/scienceastronomy/mars_methane_040329.html
Also some of the reports suggest the methane is concentrated at the
equator which is the location of Valles Marineris.
Robert Clark
Marsh gas on Mars
By Charles W. Petit
"Astronomy team leader Vladimir Krasnopolsky of Catholic University in
Washington, D.C., finds it "more or less impossible" to explain the
Mars methane by anything but microbes--perhaps just a smattering of
them in a few damp, warm oases under the surface. But Bernard Foing,
chief scientist for the European Space Agency, says that while life is
a contender, new images from Mars Express suggest volcanic heat could
be at work. Mars's volcanoes are supposed to be long dead, but the
images show signs of activity recent enough that hot magma could still
lie just below."
http://www.usnews.com/usnews/issue/040412/tech/12methane.htm
Bob Clark
rgrego...@yahoo.com (Robert Clark) wrote in message news:<832ea96d.0403...@posting.google.com>...
George
> Science & Society
> Marsh gas on Mars
> By Charles W. Petit
> "Astronomy team leader Vladimir Krasnopolsky of Catholic University in
> Washington, D.C., finds it "more or less impossible" to explain the
> Mars methane by anything but microbes--perhaps just a smattering of
> them in a few damp, warm oases under the surface. But Bernard Foing,
> chief scientist for the European Space Agency, says that while life is
> a contender, new images from Mars Express suggest volcanic heat could
> be at work. Mars's volcanoes are supposed to be long dead, but the
> images show signs of activity recent enough that hot magma could still
> lie just below."
> http://www.usnews.com/usnews/issue/040412/tech/12methane.htm
>
>
> Bob Clark
>
Interesting find. Doesn't the Mars Odyssey have an infrared camera? Couldn't
it pick up this heat source?
Joe Knapp
"George" <geo...@george.net> wrote in message
news:kN1cc.20298$tT3....@bignews6.bellsouth.net...
Is that article saying they found a hot spot? It seems rather to be saying
that they found visual evidence of "recent" activity and inferred that hot
magma "could" be below.
Joe
George
"Joe Knapp" <j...@worldnet.att.net> wrote in message
news:5b2cc.50740$2G5....@newssvr16.news.prodigy.com...
Yes, I think that is what it says. My question is couldn't the Mars Oddyssey's
infrared camera pick up such a heat source?
Joe Knapp
"George" <geo...@george.net> wrote
> > Is that article saying they found a hot spot? It seems rather to be
saying
> > that they found visual evidence of "recent" activity and inferred that
hot
> > magma "could" be below.
>
Oddyssey's
> infrared camera pick up such a heat source?
According to the advance gush anyway. When Oddyssey (like the spelling, BTW)
snapped its first THEMIS (IR) picture of the south polar cap back in 2001,
Ed Weiler of NASA said:
"This spectacular first image of Mars from the 2001 Mars Odyssey spacecraft
is just a hint of what's to come. After we get Odyssey into its final orbit
it will be much closer to Mars than when it took this image, and we'll be
able to tell whether or not there are any hot springs on Mars, places where
liquid water may be close to the surface. If there are any such locations
they would be places we might like to explore on future missions.''
The resolution of THEMIS is about 3km and 0.1 degree C. "We ought to be able
to determine the actual temperature of the surface to within about a tenth
of a degree." (Steve Saunders, Odyssey scientist)
So no news is no hot springs/vents or magma?
Score one for methane=life.
Joe
Ralph Nesbitt
-----------------------------------------------
In the air. Last week's news came from Europe's Mars Express satellite,
which arrived in December and has seen the signature of methane in infrared
light from Mars's atmosphere. The data back similar claims from astronomers
using the Canada-France-Hawaii infrared telescope in Hawaii. Both teams get
the same tiny concentration--about 10 parts per billion.
------------------------------------------------
Note the reference is to a finding atmospheric methane of 10 parts per
billion from 2 sources. The article mentions opinions as to the possible
source of this methane; 1 biological & 1 volcanic.
Considering polar temps it is possible there is some amount of "Methane
Solids" encapsulated in the polar caps.
Ralph Nesbitt
Ralph Nesbitt
bacteria that give off methane directly or give off methane as part of their
decomposition process?
Ralph Nesbitt
George
"Ralph Nesbitt" <ralph-...@sbcglobal.net> wrote in message
news:P3ecc.5356$jJ2....@newssvr24.news.prodigy.com...
Sure, but they haven't identified any hot springs yet. So if the methane is
biogenic, it is probably coming from the soil, IMHO.
Ralph Nesbitt
methane is due melting methane ice at the poles.
Ralph Nesbitt
George
I agree that that is entirely a possibility.
Joe Knapp
"George" <geo...@george.net> wrote
> > Agreed, but at ambient temps on Mars it is entirely possible the
atmospheric
> > methane is due melting methane ice at the poles.
> > Ralph Nesbitt
> >
>
> I agree that that is entirely a possibility.
According to Vittorio Formisano, Ph.D. (Physicist), Principal Investigator,
ESA's Planetary Fourier Spectrometer (PFS), Institute of Physics and
Interplanetary Science, Rome, Italy:
"10.5 parts per billion of methane amounts to 33,000 tons of methane in the
atmosphere. So, that should be the result of integration over say 300 to 350
years, which means 100 tons per year produced, which means 300 kilograms per
day. So, one has to find a source which is able to produce these amounts of
methane." http://www.earthfiles.com/news/news.cfm?ID=689&category=Science
According to Wikipedia (http://en.wikipedia.org/wiki/Methane_clathrate),
typical methane clathrate ice contains one mole methane for each 5.75 moles
water. One mole of methane weighs 16 grams and one mole of water weighs 18
grams, therefore the methane is 16/(5.75*18) or about 15% by weight. Taking
Formisano's figure of 100 tons (1e8 grams) of methane being produced every
year, that means 1e8/0.15 or about 7e8 grams of methane ice on balance
evaporate every year, or about 7e8 cm^3 (700 m^3). For each million years
such a process has been going on, that's 700 cubic kilometers of methane
ice, if indeed any exists (unproven) in the ice caps.
Joe
George
Relatively speaking, that certainly is not a lot of methane.