Venus global volcanism outbreak due to hypothetical instant removal of atmosphere

[Findthepin1]

What would happen if Venus lost its whole atmosphere to space instantly? Would the planet try to expand instantly and end up covering itself in magma, or would it be slower like postglacial rebound (and do the same thing)?

I think it would crack the surface into pieces and between the pieces lava would come up and engulf the pieces. Basically it tries to explode but is too heavy. What do you think would happen?

[LN400]

If, for some bizarre reason, the entire atmosphere disappeared, I'd think not much would happen other than:

The mean temperature would be lower.

The temperature would be a lot less uniform.

Venus would be a lot more friendly to manned explorations, with the acid rain, high temp and high pressure gone.

We could observe the surface using plain old telescopes.

Venus would be a lot duller on the evening/morning sky.

There would be more points but these are the ones I'd think would be most noticable.

[Wesreidau]

Little if anything would change. A mere 90-100 bar of pressure being relieved from the surface makes no significant difference when one considers the pressures involved in volcanism and geology as a whole.

[LN400]

In addition to the last couple of post: I'm not sure where any notion that the atmosphere is what keeps a planet together comes from.

[Windspren]

In addition to the last couple of post: I'm not sure where any notion that the atmosphere is what keeps a planet together comes from.

Yeah, I once saw an ad for a "science book" that said that gravity doesn't exist and it's all from the atmosphere . I was like,

[vger]

In addition to the last couple of post: I'm not sure where any notion that the atmosphere is what keeps a planet together comes from.

I think OP is comparing it to something like rapid depressurization. Something is under high pressure, and then is instantly under lower pressure. Some man-made things, for example, would be likely to explode. A planet, not so much.

[Scotius]

Probably there would be some pretty intense outgassing from upper layers of surface though. And since apparently Venus does have active volcanoes, i think atmosphere-less period wouldn't last long. New atmosphere would be less dense and not so hellish (though still nasty, composed mostly from volcanic gases) - so it could be a good thing for future explorers

[Camacha]

Little if anything would change. A mere 90-100 bar of pressure being relieved from the surface makes no significant difference when one considers the pressures involved in volcanism and geology as a whole.

Are you sure? Glaciers and seas, even relatively shallow ones, have been known to influence the crust of our planet in significant ways. I find it hard to believe this will make no difference.

[AngelLestat]

Are you sure? Glaciers and seas, even relatively shallow ones, have been known to influence the crust of our planet in significant ways. I find it hard to believe this will make no difference.

It does not make difference.. earth has undersea eruptions with the same frequency and strenght than surface eruptions, the pressure of magma breaking the rock is like two orders of magnitud higher than 1000m of water.

In fact, the heat is a bigger factor here than the pressure, if you dont have atmosphere in venus would be very cold, the heat of venus (originate due radiation decay) can be more easily radiate to the space, which will produce less pressure over the surface.. this is also a minor factor, but bigger than the pressure.

[PB666]

What would happen if Venus lost its whole atmosphere to space instantly? Would the planet try to expand instantly and end up covering itself in magma, or would it be slower like postglacial rebound (and do the same thing)?

I think it would crack the surface into pieces and between the pieces lava would come up and engulf the pieces. Basically it tries to explode but is too heavy. What do you think would happen?

What would happen to venus depends largely on how similar it once was to Earth. Venus has alot of sulfate in its atmosphere and the heat and sulfate lock the water off the surface. On earth's crust sulfate and carbon tirnover on the surface is governed by subduction at the plate edges. As organic carbon and sulfate are subducted lower, the pressure increases but so does the heat, eventually the heat is more important and even 1000 km down the lighter elemnts will coalesce and cause a rise under the upper plate, this results in the ring o fire phenomena. But the biggest reservoir of sulfate is the ocean, the alkali elements trap both carbon and sulfate as counter ions. This is also driven by redox potntials created by phototrophs and the phototroph deposits on land and in petroleum resrvoirs. Venus does not have these, and if the acidic atmospere disappears a very alkalin surface is likely scavenge and raise the boiling point of any counter-ions that exist. Thus I would make the following prediction

Venus cools, its crust will further solify and crack, you would see multiple mid atlantic typ ridge formations. This would probably go on for another 200 million years and the increase solar output would cause an equilibration.

in this model if we put a giant reflector between venus and sun at L1. What might happen, venuses atmosphere would begin to collapse, but the resulting acid rain would react with th alkalin surface causing chemoturbulation of the surface. Venus would take years to equilibrate under this scenario because alkalin reserves in venus would be like coal and oil reserves on earth. In fact you really would not need a power source on venus because you could drll down, inject brine and turn the sea/drill shaft into a giant battery. Secondarily the crusts temperature at surface is ckoser to its mantle temperature, so that heat flow to the surface would provide a good source of geothermal power, add in subsurface a fissure chemothermal heat sources. IMHO Venus has probably lost some of its acidifyers due to the height and thermal convection of its atmosphere. Thus the cooler venus will tilt in favor of an extremely acidic surface. Its very diificult to loose alkali elements to degassing.

Venus will always be a violent place for life, but early life formed in such a violent place so ......., better ti cool and drop the bugs first.

I disagree that venus is within the goldilocks zone of Sol, I think sulfate in addition to carbon , both essential elements to life, and sulfate particularly the evolution of Archea, and bacteria are somewhat dependent on archea early on in carbon and nitrogen cycle....so. If sulfate is important, locked away in huge amounts inoy oceans, but causes venus to be a greenhouse disaster, the problem is not the sulfate, its the size and proximity of the planet to the sun. The reason we see little evidence for habitable planets is that such planets are much rarer than the optimist propose. I don't think the solar proximity effect can be reversed even with wishful technology. Venus has been marked by the sun, if sun were to blinkout in one gigantic sterlizing burst of light and forming a brown dwarf, any visitor landing on the inner planets would realize that Venus and Mercury were lifeless and Earth had and Mars might have had life. Even if you put a colony there while it was cooling they would come to the same conclusion, it was not a genesis planet.

[Camacha]

It does not make difference.. earth has undersea eruptions with the same frequency and strenght than surface eruptions, the pressure of magma breaking the rock is like two orders of magnitud higher than 1000m of water.

I am not sure what you are talking about. One force does not exclude another force having an influence (except when they are somehow perfectly opposed, of course).

[Findthepin1]

I think OP is comparing it to something like rapid depressurization. Something is under high pressure, and then is instantly under lower pressure. Some man-made things, for example, would be likely to explode. A planet, not so much.

.Yes.

- - - Updated - - -

...The heat of Venus (originate due radiation decay)...

Venus' heat is not primarily caused by radiation decay. As far as I know, the majority of the heat comes from a very strong greenhouse effect caused by the thick atmosphere (90 bars of CO2). The sheer density of the air close to the ground traps photons in the atmosphere, because whatever direction a photon tries to go, there'll very likely be a molecule in the way and it'll probably bounce back. Volcanoes also add a significant amount of heat to the air.

[AngelLestat]

I am not sure what you are talking about. One force does not exclude another force having an influence (except when they are somehow perfectly opposed, of course).

It does not exclude the influence, but this one is negligible against the other.

.Yes.

Venus' heat is not primarily caused by radiation decay. As far as I know, the majority of the heat comes from a very strong greenhouse effect caused by the thick atmosphere (90 bars of CO2). The sheer density of the air close to the ground traps photons in the atmosphere, because whatever direction a photon tries to go, there'll very likely be a molecule in the way and it'll probably bounce back. Volcanoes also add a significant amount of heat to the air.

I never said that venus´s heat is only by radiation decay, I was just mentioning the one originate by radiation decay.

[Findthepin1]

I never said that venus´s heat is only by radiation decay, I was just mentioning the one originate by radiation decay.

oh ok