Earth Science Geology, the Environment, and the Universe

Section 2: Seawater

Self-Check Quizzes-English

1
The salinity of seawater has been _______ over geologic time.
A)increasing
B)decreasing
C)constant
D)always changing
2
Why are salinities lower than average in some areas close to the equator?
A)rapid evaporation
B)abundant precipitation
C)larger clouds
D)stronger winds
3
In the figure below, what does the middle layer, labeled Y, represent?
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A)a zone of consistently warm water temperature
B)a zone of consistently cool water temperature
C)a zone where the water temperature rapidly decreases with depth
D)a zone where the water temperature rapidly increases with depth
4
The density of seawater is dependent on _________
A)salinity and temperature
B)temperature and currents
C)salinity only
D)temperature only
5
What is one source of sodium ions found in the ocean?
A)the shells of marine organisms
B)volcanic gases
C)ultraviolet radiation
D)evaporation
6
Why is water dark below about 100 m depth?
A)Light rays can only penetrate that far.
B)The water is too dense for light to penetrate.
C)Cold water doesn't transmit light as well as warm.
D)Suspended sediment in water blocks the light from going deeper.
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