Section #: 15.2
Seawater
Practice Test
1.
The density of seawater is dependent on __________.
a.
salinity only
b.
temperature only
c.
salinity and temperature
d.
temperature and currents
Hint
2.
Why are salinities lower than average in some areas close to the equator?
a.
abundant precipitation
b.
rapid evaporation
c.
stronger winds
d.
larger clouds
Hint
3.
The salinity of seawater is __________ over geologic time.
a.
increasing
b.
decreasing
c.
always changing
d.
constant
Hint
4.
What is the thermocline?
a.
the formation of cold water coming from Antarctica
b.
a transitional layer in the ocean where temperature decreases rapidly with depth
c.
a change in salinity with depth
d.
a layer of cold water in the ocean
5.
What is one source of sodium ions found in the ocean?
a.
volcanic gases
b.
evaporation
c.
the shells of marine organisms
d.
ultraviolet radiation
6.
What is the densest and coldest water mass of all Earth's oceans?
a.
North Atlantic deep water
b.
Antarctic intermediate water
c.
Gulf Stream
d.
Antarctic bottom water
7.
Which element is not an ion found in ocean water?
a.
Ni
b.
Na
c.
Cl
d.
K
Hint
8.
What is the cause of ocean layering?
a.
polar ice caps
b.
evaporation
c.
currents
d.
density differences
Hint
9.
In the graph, what is the sharp drop in temperature from about 20° to about 7° called?
a.
the trophocline
b.
the thermocline
c.
the tomocline
d.
the temperaturcline
Hint
10.
What is the average salinity of ocean water?
a.
35 ppt
b.
30 ppt
c.
37 ppt
d.
37 percent
