Vacationing on Venus Basic Geology Series Part 1
Guest post by Steven Goddard
Magellan radar imaged Venus – NASA Image
In some ways, Venus is similar to earth. It is about the same size as the earth, has a nickel-iron core, and has volcanic activity due to radioactive heating in the interior. But that is where the similarities end. Venus has some serious problems as a vacation spot – mainly that it is extremely hot and the atmosphere is a thick cloud of sulfuric acid, CO2 and other unpleasant chemicals.
So how did Venus get to be like that, and why is the earth different?
- Venus is closer to the sun, which makes it hotter and prevents formation of oceans due to excessive evaporation.
- Venus suffered a traumatic collision in it’s early days, which causes it to rotate very slowly and parallel to the ecliptic. This makes for long afternoons (thousands of hours long) which get extremely hot.
- Because of 1 and 2, Venus was never able to sequester CO2 in limestones like the earth.
For the last few billion years, volcanoes on earth have been spewing out the greenhouse gases H2O, CO2 and CH4, as well as, H2SO4, SO2, H2S, HCl and Cl2. If not for the oceans and limestone sequestration, we would have a very thick, hot acidic atmosphere like Venus which could not support life. Fortunately, temperatures and other conditions on earth were just right to allow huge volumes of CO2 to move into the oceans and precipitate carbonate rock layers, where the CO2 became sequestered. This makes earth the pleasant place which we all enjoy.
Wikipedia image – carbonate rocks in Italy, uplifted miles above sea level.
One of the oft stated concerns by the IPCC and others is excess CO2 from cement production, which involves heating carbonate rocks and has the side effect of returning CO2 to the atmosphere. Dr. Hansen and others have also suggested that periods of rapid warming in the past have been due to limestone formations being subducted into hot volcanic regions and losing their CO2 to the atmosphere.
But make no mistake, without the CO2 sequestered in limestone and other carbonate rocks, earth would be hot, toxic and probably unlivable – like Venus.
Some more detailed discussion here and here .
Part 2 will be a discussion of how fossil fuels fit into the picture.
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Of possible interest concerning water on a developing Earth,
“Other research has suggested that a zone between the mantle and the crust also contain a great deal of water, the Japanese researchers noted. If so, there could be more than ten times the amount of water inside the planet as there is on its surface.”
http://news.nationalgeographic.com/news/2002/03/0307_0307_waterworld_2.html
A thread about Venus? Comparative planetology? My favourite part of Environmental Science. 🙂
Let’s discuss planetary atmospheres and mineral sinks for carbon dioxide gas.
Venus has an atmosphere in which the predominant gas is carbon dioxide, but there is no water. Earth by contrast, has extensive oceans with water in abundance (albeit salty) and carbon dioxide as a minor component of its atmosphere. Why the difference between these two terrestrial planets? Is this all due to temperature?
Earth, like Venus, also has carbon dioxide in abundance. The difference is that on Earth the carbon dioxide is stored in the rocks as limestone & dolomite (calcium & magnesium carbonates), while on Venus the carbon dioxide remains in its atmosphere as a gas.
To compare Earth and Venus we shall first start with some simple assumptions:-
1. Let us assume that there is no stable mineral store of carbon dioxide in the rocks of Venus, and that all of the carbon dioxide in its atmosphere has out-gassed from the planet during the course of its existence.
2. That there has been no loss of molecular carbon dioxide to space, because the temperature profile of the Venusian atmosphere means that carbon dioxide’s kinetic velocity does not exceed the escape velocity of Venus.
3. The molecular weight & chemical stability of carbon dioxide means that this gas is trapped on Venus, in its atmosphere, for the lifetime of the planet.
4. Let us assume that the total mass of carbon dioxide, now present on Venus, is its planetary lifetime production to date, and that this mass of gas can be used as a proportionate estimate of Earth’s lifetime carbon dioxide gas production.
Earth’s Limestone store of Carbon Dioxide
For ease of calculation we will just discuss calcium carbonate, or calcite, the mineral constituent of limestone rock. Calcium carbonate has the chemical formula CaCO3. Elemental calcium has a mass of 40.078 Atomic Mass Units (AMU), elemental oxygen has a mass of 15.995 AMU and elemental carbon has a mass of 12.0107 AMU. Calcite mineral (technically a salt) has an equivalent molecular weight of 100 AMU, so calcite consists of approximately 56% by weight of calcium oxide and 44% by weight of carbon dioxide.
Mineral calcite has a density of 2.83 tonnes/m3, so a cubic metre block of pure marble limestone (with zero porosity) will have a slab weight of 2.83 tonnes, of which 1.2443 tonnes will be carbon dioxide (43.9676% of the total slab weight). The total thickness of pure calcite which will store 10 tonnes per square metre of carbon dioxide is just over 8 metres.
The atmosphere of Venus has a surface pressure of 950 tonnes/sq metre and as carbon dioxide forms 96.5% of the Venusian atmosphere, the mass of carbon dioxide gas on each square metre of Venus is 916.8 tonnes. The average surface temperature of Venus is 464 degrees C. Studies of the dissociation temperature of calcite suggest that the mineral will be stable at the surface pressure and temperature of Venus. If we could convert carbon dioxide gas into calcite mineral we could store the total atmosphere of Venus in a planetary carapace of mineral rock 737 metres thick. Is this possible? Well no, but curiously it is conceivable. The following chemical reaction could do the job:-
Slaked lime (calcium hydroxide) plus carbon dioxide gas produces mineral calcite and water. Ca(OH)2 + CO2 => CaCO3 + H2O
Comparing Venus and Earth.
Venus is a terrestrial planet, slightly smaller than Earth, with a carbon dioxide atmosphere of 4.21888E+17 tonnes. The Earth’s planetary mass is 1.227 that of Venus, so if we assume that the same geochemical processes occur on both planets, then the expected mass of Earth’s lifetime planetary carbon dioxide out-gassing will be 1.227 times larger i.e. 5.17661E+17 tonnes. Earth is a physically larger planet and so the putative surface pressure of Earth’s lifetime carbon dioxide atmosphere will be spread out over a larger planetary surface area and be 1015 tonnes/sq metre. This carbon dioxide atmosphere is equivalent to and can be stored on Earth in a planetary calcite carapace 816 metres thick.
We now need to ask the geologists two questions:-
1. Does the geological record support the existence of this quantity of calcium (& magnesium) carbonate stored in the sedimentary basins and metamorphic rocks of the Earth, both as limestone & dolomite rock and marble and also as carbonate mineral cements in clastic sedimentary rocks?
2. Where has all the calcium and magnesium come from to allow the creation and growth of this mineral carbon dioxide sink throughout the geological history of the Earth?
I hope to address the answer to Question 2 in a subsequent post.
Links:
Calcium Atomic Mass
Oxygen Atomic Mass
Carbon Atomic Mass
Calcite Density
Venus Surface Area & Mass
Surface Pressure of Venusian Atmosphere
Earth Surface Area & Mass
Surface pressure of Earth’s atmosphere
Philip,
Great stuff, don’t stop.
Also, the difference in gravitational fields would make the 950 tons per sq. meter on Venus correspond to more CO2 molecules per sq meter than the equivalent pressure on Earth. But you could just consider the two planets of equal mass and size for a ballpark estimate.
Maybe you know how the nitrogen got here?
Steven Goddard,
you apparently missed the article quoting data from our nuclear submarine fleet where the CO2 has peaks about 8,000ppm before the scrubbers turn on.
Here are rather interesting articles on high doses of CO2:
http://www.kk.org/outofcontrol/ch9-c.html
http://www.erowid.org/chemicals/carbogen/carbogen_article1.shtml
You also didn’t mention the high level of vulcanism that appears to be current on Venus providing a possible explanation for the temperature.
The ASSUMPTION that all the known planets CONDENSED out of a primeval soup is slowly falling apart due to data on the lack of cohesion for the particles supposedly involved. No cohesion, no buildup to the point where gravitation would attract more.
This also goes to your ASSUMPTION that the nickel iron meteorites are from broken planets. Exactly what FACTS support this hypothesis?? For that matter, they could be left over bits from the collision that is hypothesized to have created the moon!! In other words, they may only tell us what the EARTH and MOON are made of!!
The FACT that we DON’T KNOW whether the known planets originated here or were captured is also an issue as to whether Venus really has the same make-up as earth..
As you mentioned in your post, Venus may very well have suffered a catastrophic impact which would explain the vulcanism as that impact would have generated enourmous energy to be RADIATED away at a much later time than the rest of the planets.
All in all, there are very few hard FACTS supporting a GREENHOUSE caused by CO2 as opposed to CO2 being a result.
We really need a TRUTH IN SCIENCE group to go around and slap people who continue to propagate hypothesis and theories as FACTS!!! In my opinion dark matter and energy are right up there with Phlogiston!!! Sounded good at the time!!
kuhnkat
Well the theory i buy for the forming of the solar system is that its the result of an exploding super nova that throws out plasma ted matter, this is where the heavier elements are formed. But any way, the super heated gas/matter is thrown out, with the center o mass remaining center. So it curves the matter into an orbit. With varying amounts of different molecules at different distances from the center. The center is the sun. The matter basically forms in belts around the sun… and over time through random chance/gravity colliding molecules snow ball. Until a planet is formed.
Now im not going to go hunting for links, but i know that this theory works mathematically…
As for dark matter, that has been proved through focal lensing, it bends the light from distant stars, as well as the mass of galaxies is not great enough to hold them together, there must be more mass.
Sorry, im a bit lazy to go hunting for links. But i still see no connection between Earth and Venus. They have more differences than similarities.
http://www.kvoa.com/Global/story.asp?S=9824385&nav=HMO6HMaW
You have those in Tucson who believe in global warming, and on the flip side, you have your skeptics, like Dr. Ben Herman at the University of Arizona.
Dr. Herman agrees that carbon dioxide has warmed the atmosphere but not that much. “It’s warmed about 1.5 degrees in the last 100 years or about 1/10th of a degree every 10 years. That’s a very small effect”, says Dr. Herman.
As far as his solution? “A better road to pursue right now is not to try to stop every bit of carbon dioxide going in the atmosphere, but to start looking for alternate fuels”, says Dr. Herman.
Yet, among the arguments neither professor disagrees with the fact that the atmosphere is changing, and that something needs to be done. The disagreement lies in the degree of change.
Venus has about 4 times as much nitrogen in it’s atmosphere as Earth. If we assume that Venus and Earth were similarly formed, and being of similar size, that means that Earth lost 3/4 of it’s atmosphere some time in the past. That could be explained by a collision that formed the moon if 3/4 of the outgassing that created the atmospheres of Venus and Earth occurred before the collision.
This says that Philip only needs to remove 1/4 of the CO2 in his original calculation. This also says that it was unlikely that Venus suffered a major collision after it solidified. I also suspect that a major collision in Venus’ early history would have made it less likely to have the most circular orbit of any planet.
Also, the amounts of argon on Earth and Venus are similar. Since argon comes from the decay of potassium 40, its addition to the planetary atmospheres would not have been so concentrated at the beginning, and the moon-creation collision would not have been as catastrophic to its current concentration on Earth.
I believe Venus is a new planet.
Loads of evidence in support of this theory.
http://www.kronia.com/library/journals/venair.txt
Dr. Herman agrees that carbon dioxide has warmed the atmosphere but not that much. “It’s warmed about 1.5 degrees in the last 100 years or about 1/10th of a degree every 10 years. That’s a very small effect”, says Dr. Herman.
This is the U. of A.’s idea of a “skeptic”? He still believes C02 is the culprit for the warming. The fact that he’s less alarmed about it is the only difference between the two. Some debate. Give me a break!
Bruce Cobb,
Dr. Herman is a scientist, not a faith based religious devotee to any particular point of view.
As far as CO2 warming goes, it is rather basic physics. I don’t know of any scientist on either side of the AGW debate who disputes that a doubling of CO2 will cause warming of at least 1C. “
This statement could not be wronger .
There is nothing “basic” about radiative transfer and it belongs to the most complex areas of physics .
That is also why there are so few people who really understand what happens .
Why isn’t it basic at all ?
First we are talking about a purely quantum mechanical process .
In 99% of physics the “classical” view is a reasonable approximation and QM can be safely ignored .
Radiative transfer belongs to the 1% where ignoring QM only leads to absurd results or unreasonable approximations .
It is not for nothing that the QM was precisely born from unsolvable difficulties concerning matter/radiation interactions .
Second is that in the semi-classical view , radiative transfer can be considered as an interaction between a matter gaz and a photon gaz .
But this photon gaz is a highly exotic and non trivial thing .
It is relativistic (photons go with velocity c) and doesn’t conserve the number of photons as opposed to the matter gas where the number of molecules is conserved .
There is also the problem that photons being massless , they have no temperature even if an equivalent concept can be defined .
Third is that most people use a naive model in which the badly named “greenhouse” effect is explained by saying that CO2 absorbs IR and “heats” the air .
This is of course completely wrong because CO2 (or H2O or whatever for that matter) not only absorbs IR but is also forced by the QM laws to emit IR .
And it emits EXACTLY the same amount of IR as it absorbs .
This is a consequence of the Maxwell Boltzmann distribution of the quantum energy levels at LTE which forces the molecules to maintain a constant population of each energy level .
Or in simple words if it emits less than what it absorbs for a certain frequency then it emits more than it absorbs for other frequencies .
Fourth is that even if in LTE the problems are “simpler” , the upper parts of the atmosphere are far from LTE and a complete QM treatment becomes necessary .
So be all very sure that radiative transfer has nothing “basic” and the quantification of the X°C per doubling even less .
While there is indeed not much room to dispute the qualitative effect for those who understand the process well , there is a whole world of room to dispute the quantitative treatment .
anna v (13:02:44) :
Such a scenario would satisfy my reasoning much better than all these angles of Jupiter with Saturn etc. correlated to our known forces.(Still science fiction at the moment, these new forces could turn gravity to electomagnetism and vice versa).
I wonder if you really understand how “the angles” might influence our Sun. perhaps you could enlighten me?
Steven Goddard (19:57:56) :
Bruce Cobb,
Dr. Herman is a scientist, not a faith based religious devotee to any particular point of view.
What on earth are you talking about, Steven? If anything, it is those who believe, as Dr. Herman apparently does, that manmade C02 is entirely responsible for the warming the past century who are the “Faith based religious devotee”(s), since It certainly isn’t based on science.
It is also interesting that you play the old AGWer trick of “appealing to authority”.
Michael,
While there are legitimate questions about Venus’ atmosphere, there’s no way that Venus’ rotation rate synchronized with it’s closest approach to Earth in a mere 10,000 years. Also, it’s very difficult for something dropping in from outside to end up in a highly circular orbit.
nobwainer (Geoff Sharp) (05:49:11) :
I had said :
Such a scenario would satisfy my reasoning much better than all these angles of Jupiter with Saturn etc. correlated to our known forces.(Still science fiction at the moment, these new forces could turn gravity to electomagnetism and vice versa).
and you ask:
“I wonder if you really understand how “the angles” might influence our Sun. perhaps you could enlighten me?”
Are you talking of my science fiction?
I said previously that I do not understand how magnetic and electric theories could fit the data we know considering the fields we know, so how can I offer any enlightenment?
Eilert (11:03:39) :
The reason that Venus is so hot is the enormous pressure (density) of the atmosphere. If one would exchange Venus atmosphere with that of the Earth (i.e mostly Nitrogen and Oxygen, some water vapour and some other trace greenhouse gasses) the temperature would actually be 200 degrees Celsius hotter, since the air of Earth has a somewhat higher energy coefficient then the CO2 dominated atmosphere of Venus.
Sorry I missed this post.
I did an adiabatic compression of earth’s atmosphere to Venus’ 90 bars, and got 769 °C. Since that was much hotter than Venus’ 480 °C, I thought I’d goofed up. Maybe not.
That would mean most of Venus’ blast furnace surface is not due to some “runaway” greenhouse CO2 effect, but due to the huge pressure, just as Eilert says.
anna v (08:19:48) :
Your post is perhaps a little cryptic, but I thought you may have been comparing your science fiction scenario with other theories that use Jupiter and Saturn angles (primarily angular momentum) as a solar driver, and I wondered how much you knew on this topic (angular momentum)
This is of course completely wrong because CO2 (or H2O or whatever for that matter) not only absorbs IR but is also forced by the QM laws to emit IR .
And it emits EXACTLY the same amount of IR as it absorbs .
This is a consequence of the Maxwell Boltzmann distribution of the quantum energy levels at LTE which forces the molecules to maintain a constant population of each energy level .
Or in simple words if it emits less than what it absorbs for a certain frequency then it emits more than it absorbs for other frequencies.
Not true Vonk as I’ve told you before, I wish it were true it would have made some of my experiments much simpler.
nobwainer (Geoff Sharp) (14:37:33) :
Well, I am a physicist with a doctorate so I should know enough.
I know that coordinate systems do not matter, except by making things simple or complicated. It is the forces that define the best/simplest coordinate system in which to form and solve equations.
I know that apart from em radiation the only exchanges between planetary bodies and the sun are gravitational, and thus the only influence the planets can have are on tides, and these turn out to be miniscule ( mm or something).
I have made my position clear in this forum : taking the barycenter as a point of reference is irrelevant to the forces we know, just an extra complication, like the geocentric system with the epicycles.
That is why I call for a science fiction scenario if I want to correlate planetary motions with solar parameters. Much more energy has to be exchanged than the one that is given by the forces we know.
anna v (21:41:30) :
Well, I am a physicist with a doctorate so I should know enough.
Everyone has their strengths, but that doesnt mean they are strong in every dept….and sometimes the most intelligent, miss the easy stuff in front of their eyes, common sense can be elusive.
I can tell by your response that you may have just skimmed the area of planetary influence and have perhaps ridden on other peoples opinions. My area of science is not about gravity or tides, its about angular momentum which is real and measurable and also correlates very strongly with grand minima of all forms, every 172 years for the last 6000 years at least.
If you have the time, have a look at my work….always good to have some intelligent feedback.
http://landscheidt.auditblogs.com/archives/95
On correlations:
There is the standard: correlation is not causation, of course.
But on top of that, when one has chaotic systems that will often produce patterns, sinusoidal like waves or whatever ( viz some cloud patterns) one can always take two unrelated plots and find correlations. It is like the famous ( Von Neuman I think) saying: “give me four parameters and I can fit you anything. With a fifth I fit an elephant.” Expressed in a functional form.
Take the waves in two different oceans. You can correlate them. There is no causation and the only real commonality will be the strength of the wind with respect to the shore line and bottom line. But they are not even caused by the same wind.
It is different if there exists a specific physical theory that predicts correlations. It gives a causal path, and it may not even be correct ( viz the geocentric system of the heavenly sphere. It worked very well for navigation, and the fact that a better physical theory overcame it does not make the workings invalid).
anna v (00:16:55) :
There is the standard: correlation is not causation, of course
We have causation, angular momentum looks to affect the differential rotation of the Sun.
I can see it might be hard to get through your protective systems, but I would like to see you explain how you can ignore reduced solar activity every 172 years average…the 11000 year 14C record does not lie?
nobwainer (Geoff Sharp) (03:51:34) :
you say:
We have causation, angular momentum looks to affect the differential rotation of the Sun.
Angular momentum is a conserved quantity. For the angular momentum of a body to change there must be an interaction, an exchange of forces. The only known available interaction of bodies in space is gravity. I have not done the calculations, but I trust Leif when he says that the tidal effects of the planets ( gravitational exchanges) are of the order of 2 mm. That seems to me not to be enough energy to affect anything, particularly considering the size of the sun.
That is why I am talking of a science fiction scenario. If the 172 years period is real and not an artifact of the measurements ( we are talking of paleo something here after all) it is either a coincidence, or another force has to be postulated to explain the orders of magnitude extra energy ( over gravitational) that is needed to affect the sun’s output. Maybe it is the second proof of dark matter.
Science fiction from here on:
After all, what does dark matter mean ? At the level we know of particle physics it means that all the matter we know has a shadow counterpart in other dimensions and the only common interaction is gravity. So one could assume that in this science fiction model part of the gravitational fields of Saturn and Jupiter are due to excess dark matter which can then interact with the dark matter in the sun with new and unknown yet forces ( depending on the model chosen) transforming gravitational energy to electromagnetic energy and affecting the plasma etc. with 172 year period related to their orbits.
Or: There could be a dark matter periodic gravitational field in which all the sun system is embedded and which has an 172 year period affecting both the Saturn and Jupiter orbits and the sun. ( after millenia things tune up with each other)
I said science fiction, did I not?
anna v (05:04:24) :
Anna, this is not about tidal forces and I recommend sourcing the data yourself, rather than relying on others. Its about angular momentum which is completely different. The tidal affects of Saturn & Neptune & Uranus are near zero, but their contribution to angular momentum are superior.
It happens every 172 yrs…there is nothing else that can explain it. The planets line up and it happens…end of story.
But I like your thinking on dark matter…perhaps it might turn out to be gravity itself?
Nevertheless, angular momentum transfer needs two things: a force and a sufficiently rigid arm. While there is virtually plenty of force, we just don’t see an arm, currently. I recommend to read the 2006 paper by James Shirley (http://science.jpl.nasa.gov/people/Shirley/) on “Axial rotation, orbital revolution and solar spin-orbit coupling” , as it clarifies also this widespread source of confusion. Getting your hands on the paper is challenging, even if you are part of an university network. The abstract reads (bold mine):
(http://adsabs.harvard.edu/abs/2006MNRAS.368..280S)