A question about European water pressure.

[DaveGarland]

I've just been watching an old beeb series "The Planets" and there's a bit about sinking a probe through the ice of Europa and then exploring the European sea. This got me thinking. On earth as you go deeper into the sea the pressure increases as you go down because of the weight of the sea and atmosphere above you. But, on Europa, you would have a sealed crust above you. Would this stop this effect?

[gkec]

No because it is gravity causing the pressure.

However I a struggling with European and European.

[DaveGarland]

Glad I'm not the only one trying to think after a glass of wine

[swag72]

And here was me ready to rant about my useless water pressure here in Spain - I was wondering why you wanted to know

[Knight of Clear Skies]

So, if you connected a pipe between Europe and Europa, which way would the water flow? 

[Mr Spock]

Europan water is probably under great pressure. Evidence for this comes in the form of water fountains hundreds of miles high, also, the high pressure would assist the water being liquid rather than frozen.

[SlyReaper]

Europan water is probably under great pressure. Evidence for this comes in the form of water fountains hundreds of miles high, also, the high pressure would assist the water being liquid rather than frozen.

Not sure about that.  Even if the oceans are deeper, the gravity is small.  Pressure results from the weight of the water and ice above, so I'd expect the bottom of the Earth's oceans to be under much higher pressure than Europa's. 

[Knight of Clear Skies]

Good point. On the other hand the Europan ocean is thought to be about 100km deep, someone would have to do the math to be sure.

[Mr Spock]

Pressure at the bottom doesn't matter. Pressure at the surface would be created by any force acting down upon it, such as gravity (or air pressure - surface tension). Deeper down you would have the added pressure of the water from above. In this case we have a solid crust of ice, of unknown thickness, which may be contracting enough to create great pressure in the water underneath.

[Alkaid]

My profession is Engineering and if this helps, the equation relating pressure in a fluid and depth is:

Pressure (Pascals) = pgh

Where:

p = Density of the fluid.

g = gravity.

h = depth.

However, I'm not sure if the density of water on Europa would remain the same as here on earth. Density is mass/volume. The mass always stays the same, but will the volume? Having answered that question, you would then need to look up the gravitational constant 'g' for Europa. The depth is about 100Km as mentioned.

This would only give the pressure at the bottom of the Europan ocean though, not the pressure near the surface.

Ice is less dense than water (why it floats) so this sum assumes that the pressure from above is all from water.

Cheers Steve