Environmental Science
Test 4 (Oceans) Study Guide
1. Define/explain the following terms:
a. Evaporation – When liquid turns into gas/vapor/steam
b. Condensation – Water vapor in the air gets cold and changes back into
liquid. I the atmosphere, this is caused by adiabatic cooling.
c. Precipitation – Precipitation occurs when so much water has condensed that
the air cannot hold it anymore. Rain, sleet, snow, hail.
d. Transpiration – Water even evaporates from plants
e. Evaportanspiration – The transport of water into the atmosphere from
surfaces, including soil (soil evaporation), and from vegetation
(transpiration). Scientist use this as measure of the water content in an
ecosystem.
f. Percolation – Water moves downward through openings in the soil to
replenish aquifers under the ground (ground water).
g. Run-off – Water that travels over the ground surface and helps to fill lakes
and rivers.
2. When water falls on land, what are the 3 routes it can take?
1. It can evaporate back into the atmosphere or be absorbed by plants where it
evaporates through transpiration.
2. It can percolate into the ground to fill aquifers.
3. It can run-off into streams, lakes, rivers where it will eventually flow into the
ocean.
3. What percent of the Earth’s water is salt water?
97%
What percent is fresh?
3%
Environmental Science
Test 4 (Oceans) Study Guide
4. What 4 oceans make up the World Ocean?
a. What is their order from smallest to largest?
Arctic Ocean, Indian Ocean, Atlantic Ocean, Pacific Ocean
b. In which ocean is Challenger Deep found?
The Pacific Ocean
c. What is pack ice and where is it found?
An expanse of large pieces of floating ice driven together into a nearly
continuous mass, as occurs in polar seas.
5. Define salinity.
The relative proportion of salt in a solution.
6. What is the average salinity of the ocean?
35 ppt (parts per thousand) = 3.5% by weight
7. How can we increase salinity?
Salinity can be increase by evaporating some the water. It can also increase by
freezing the water.
8. How can we decrease salinity?
Salinity can be decreased by adding fresh water to the system. An example is an
estuary (where a fresh water river or water source flows into the ocean).
9. What are the major components of salt water?
Sodium (30.6%) & Chlorine (55.0%)
10. What is a salt?
A salt is a form of an ionic compound. It is the result of a metal bonding with a
nonmetal.
Environmental Science
Test 4 (Oceans) Study Guide
11. What are the three temperature divisions of the ocean?
Surface zone, Thermocline, & Deep Zone
a. What are their depths?
Surface zone – 0m, Thermocline – 300m, Deep zone – 700m to ocean floor
b. What does temperature do in each zone?
In the surface zone, the temperature remains fairly constant (warm) due to
the energy from the sun and the surface currents and waves churning the
water (mixes the surface zone water). In the Thermocline, the temperature
drops rapidly. In the Deep zone, the temperature continues to decrease but
at a slower rate than the thermocline.
c. What is the average temperature in the bottom one?
2 degrees Celsius
12. Define/explain the following:
a. Gyres – large scale patterns of H2O circulation
b. Upwelling – when a surface current diverges (divides), deep ocean water
moves up to fill the void. (Usually occurs along the West coast of most
continents.) Brings nutrients from the Deep Ocean and sea floor to shallower
water. The increase in nutrients allow for a greater biodiversity of life.
c. Thermohaline circulation – a global circulation of deep, cold ocean water
13. Which direction do ocean currents flow in the Northern Hemisphere?
Clockwise
14. Which direction do ocean currents flow in the Southern Hemisphere?
Counter Clockwise
15. Explain why the waters off of the East coast of the US are warmer than the water
off of the West coast?
The water is warmer because the water is coming up from the equator where it is
warmer. On the west coast, the clockwise currents bring colder surface waters from
the Arctic region.