Hydrology Review

The Mississippi River is over 2,000 miles long and empties into the Gulf of Mexico.  The Gulf of Mexico has a salinity of 36 parts per thousand.  However, the water in the gulf near the mouth of the Mississippi has a salinity of 24 parts per thousand.  What best explains why the salinity of the Gulf of Mexico changes?

• The Mississippi river is acidic and causes the salinity of the Gulf of Mexico to increase. 
  
• The Mississippi river is freshwater and decreases the salinity when mixed with gulf water.
• The Gulf of Mexico is near the equator which increases the amount of evaporation causing the salinity to decrease in certain locations.
• The Gulf of Mexico is near the equator which increases the amount of precipitation causing the salinity to increase in certain locations.

What percent of the earth is covered by water?

• 20%
• 50%
• 70%
• 85%

Oceans contain many dissolved elements like calcium, sodium, and chlorine.  These elements, plus others, combine to form the salts in the oceans. Which of the following sources is a major source of sodium chloride in oceans?

• Gases from volcanoes
• Weathering and erosion of rocks
• Pollutants from industrial wastes
• Acid rain caused by pollution

Which of the following features does not make up the continental margin?

• Shelf
• Rise
• Trench
• Slope

Which statement accurately describes both waves and currents?

• Both are caused by differences in densities.
• Both move great amounts of water long distances.
• Both can be caused by winds.
• Both influence the climate of  region.

What process of the water does the image best model?

• Precipitation
• Evaporation
• Transpiration
• Condensation

Refer to the diagram above.  High and low tides occur twice daily at regular intervals. Which of the following letters indicates where high tide is occurring and best explains why? 

• Letters B and D indicate high tides, where the tidal bulges would occur because of the Coriolis Effect.
• Letters A and B indicate high tides, where the tidal bulges would occur because of the strong winds blowing across the oceans. 
• Letters C and D indicate high tides, where the tidal bulges would occur  because of the gravitational pull between the Earth and the moon.
• Letters A and C indicate high tides, where the tidal bulges would occur because of the gravitational pull between the Earth and the moon. 

Use the diagram to answer the following question: What feature does 2 represent?

• Continental shelf
• Continental slope
• Seamount
• Mid-ocean ridge

Use the diagram to answer the following question: What is the correct order of features 1 - 5?

• Abyssal Plain, trench, seamount, continental slope, continental shelf
• Continental slope, continental shelf, mid-ocean ridge, trench, abyssal plain
• Continental shelf, continental slope, mid-ocean ridge, trench, abyssal plain
• Continental shelf, continental slope, seamount, trench, abyssal plain

The oceans absorb much of the sunlight reaching Earth.  When water in the oceans absorb sunlight and heat up, what process can happen to the water?

• Accumulation
• Condensation
• Evaporation
• Precipitation