ocean depth - ice

[Moontanman]

What would conditions at the bottom of the ocean be if the ocean was 2000 miles (3200K) thick? Planets like Neptune and Uranus have deep water oceans but even though the temperature at the waters surface of hundreds of degrees and hotter the deeper you go the bottom of that ocean is water ice. Made ice due the high pressure. if the earths oceans were 2000 miles deep would the bottom be ice?

[insane_alien]

depends on the temperature. it's likely to be much hotter down there.

 

its 1.96133×10^10 Pa (19.6GPa) assuming constant density.

 

however, the magnitude of that pressure means we cannot assume that the density is constant, water would be quite compressible at that pressure so its going to be greater than that.

 

according to this diagram( http://upload.wikimedia.org/wikipedia/commons/d/de/WaterPhaseDiagram.png ) it'd always be ice though even at the pressure given. even up to 600K.

 

it'd be ice VII

[Moontanman]

What i am thinking about is a planet 24,000 miles in diameter it has a core similar in composition to the earth but 16,000 miles in diameter this would mean an ocean 4,000 miles deep. An atmosphere of 150 psi 33% oxygen, 60% nitrogen, 7% stuff like Noble gasses and CO2, surface water temps of 80 degrees Fahrenheit. How far down would the water go before it became one of the strange forms of ice?

 

Used to be a really cool site where you could plug in the parameters of a hypothetical planet and get understandable numbers but i can't find it any more.. Can any one help with this? Knowing Gravity at the surface would a big part of it too...