Ocean Stratification
What is ocean stratification?
The layering of ocean water caused by differences in properties such as temperature, salinity, and density.
What unit density would you most likely see for a liquid?
g / mL
Calculate the density of a 40 g sample with a volume of 10 mL. Give your answer with the proper units.
4.0 g/mL.
What does salinity measure?
The concentration of dissolved salts in water.
Which layer is defined by a rapid change in temperature with depth?
The thermocline.
Two samples have the same volume. Which is denser: 50 g or 80 g?
The 80 g sample.
A seawater sample has a density of 1.5 g/mL and a volume of 100 mL. What is its mass?
150 grams
What unit is commonly used to report ocean salinity?
ppt (parts per thousand)
Which layer is defined by a rapid change in salinity with depth?
The halocline.
If an object has a density of 1.02 g/cm3 will in float or sink in salt water?
A sample has a density of 2.5 g/mL and a volume of 20 mL. What is its mass?
50 g
Name one process that can increase surface-ocean salinity.
Evaporation. Sea-ice formation can also increase salinity in nearby water.
Which layer is defined by a rapid change in density with depth?
The pycnocline.
What generally happens to water density as temperature decreases, assuming salinity stays constant?
It generally increases.
A sample has a mass of 72 g and a density of 3.0 g/mL. What is its volume?
24 mL.
Why does adding freshwater from rain or melting ice generally lower salinity?
It dilutes the dissolved salts without adding a proportional amount of salt.
Why can warm, less-dense surface water remain above colder, denser deep water?
Density differences create stable layering; denser water tends to remain below less-dense water unless mixing disrupts the layers.
What would have a higher density if three of the same volume boxes are filled with basketballs, golf balls, and sand? Why?
Sand
Do to the smaller size sand is able to fill more of the empty space in the box causing a higher density.
A marine sample has a mass of 585 g and volume of 500 mL. Find its density and compare it with freshwater at about 1.0 g/mL. Will it sink or float?
1.17 g/mL; it is denser than freshwater it will sink.
How can salinity affect ocean stratification?
Salinity changes water density, so salinity differences can contribute to density layering and formation of a halocline or pycnocline.