Water density and compressibility

In summary, water can be compressed, but it requires a significant amount of pressure to increase its density by 10 or 20%. This is demonstrated by deep ocean pressure measurements and the fact that pure water at 1086 bar has a density of 1205.154 kg/m3. Salt water has a maximum density of approximately 12700 kg/m3. This property of water is why it is used as a hydraulic fluid and plays a role in geological processes such as the formation of leucogranites and aquifers.
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Water is compressible, but it takes a lot of pressure to increase the density by 10 or 20%

Deep Ocean pressure measurements
http://nctr.pmel.noaa.gov/Dart/Pdf/Eble_J_atmo_91.pdf

http://seagrant.gso.uri.edu/factsheets/abyss.html

http://www.windows2universe.org/earth/Water/density.html

http://www.csgnetwork.com/water_density_calculator.html

Pure water would have a density of 1205.154 kg/m3 at pressure = 1086 bar
1086 bars (15750 psi) from en.wikipedia.org/wiki/Mariana_Trench

or a density of 1100 kg/m3 at pressure at 263.835 bar, which is about 20% higher than the pressure in a PWR.

Salt water has a maximum density of ~12700 kg/m3.
 
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Was there a question in there?
 
  • #3
That's one reason water is used as a hydraulic fluid. Add a little anti-bacterial and presto! Water is also under immense pressure in the lithosphere. Leucogranites form when expelled water melts its new host rock environment - found in places like Tibet. My home state of Texas sits ontop of North America's 3rd largest aquifer - the Gulf Coast aquifer, formed from high pressures of slumping mud wedges going into the Gulf of Mexico basin.
 

What is water density?

Water density refers to the measure of how much mass is contained in a certain volume of water. It is typically measured in grams per cubic centimeter (g/cm^3) or kilograms per cubic meter (kg/m^3).

How does water density change with temperature?

Generally, water density decreases as temperature increases. This is because as water molecules are heated, they gain energy and move further apart, resulting in a decrease in density. However, at temperatures close to freezing and above 4 degrees Celsius, the density of water actually increases slightly due to the unique arrangement of water molecules in its solid form (ice).

What is the relationship between water density and salinity?

The higher the salinity (salt content) of water, the greater its density. This is because the dissolved salt particles displace water molecules, resulting in a higher mass per unit volume. This is why seawater, which has a higher salinity than freshwater, is more dense and can support objects with greater buoyancy.

How does pressure affect the compressibility of water?

Water is considered to be an incompressible fluid, meaning that its volume does not significantly change when subjected to pressure. However, under extreme conditions such as in the deep ocean or in hydraulic systems, water can be compressed to a small degree. As pressure increases, the water molecules are forced closer together, resulting in a slight decrease in volume.

What is the compressibility of water at different depths in the ocean?

The compressibility of water increases with depth in the ocean due to the increasing pressure. At the surface, the compressibility of water is very low, but it increases by about 4.96 x 10^-10 per bar of pressure. This means that at the bottom of the ocean, where the pressure can be over 1000 bars, water is significantly more compressed than at the surface.

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