Terms in this set (16)
Describe how the density of pure water changes with decreasing temperature. Where is the point of maximum density? Why is ice less dense than liquid water?
Maximum temperature is 4 Degrees Celsius.
As water gets cooler it increases in density, but from 4 degrees to zero degrees the density of water decreases.
What are the effects of adding salts to water?
It increases the density of water.
How do the freezing point of water and the temperature of maximum density change with increasing salinity?
The temperature of maximum density moves toward the freezing point as salinity increases.
What is the suspended matter in seawater? Does it contribute to salinity?
floating clay, silt, and some
What is the dissolved matter in seawater? Does it contribute to salinity?
Major constituents (salts)
Dissolved gases - O2, N2, and CO2.
Nutrients - the elements N, P, and Si.
Trace Elements - I, Fe, Mn, Zn, Pb, Hg, and Cd.
What is salinity? What is the average salinity of seawater?
Salinity is a measure of the total amount of dissolved material present in seawater.
The average salinity of the world oceans is 34.7 g/kg or 34.7‰ or 34.7 parts per thousand.
List the major dissolved ions in seawater.
Chloride, Sodium, Sulfate, Magnesium, Calcium.
What is the theory that explain the salinity of the oceans?
Theory of Constant Proportion.
How does water move through the hydrologic cycle?
Refer to Seawater Slide 16.
Explain the Principle of Constant Proportion.
Whether the salinity is 25‰, 30‰
or 35‰, the percentage of the major
constituents is the same (e.g., Cl- 55.04%; Na+ 30.61%) and their ratio is constant.
What does it mean that the oceans are in a 'steady state'?
Sea-salt composition and probably seawater salinity have not varied much over the past billion year or longer.
What are some of the sources and sinks of ocean's salinity?
Sources: rivers, volcanic eruptions, hydrothermal activity.
Sinks: salt sprays, biological processes, precipitation of
authigenic minerals, adsorption to the surface of sinking
clays, hydrothermal activity.
How do temperature and salinity affect density of seawater?
Salinity adds to the mass so the more salinity the denser the water.
Lower temperatures make the water more dense.
What are the 3 density zones in the ocean? Describe them.
Define the pycnocline. How does it change with latitude?
Pyconcline is a layer in a body of water where the density is the greatest.
It becomes thinner with increases in latitude.
Where does vertical movement of seawater occur in the ocean?
A high latitudes.