REVIEW QUESTIONS FOR EXAM 3

(Answers to Review Questions)

1.  Seismic shock waves:

      a.  travel fastest when they move along the land surface.
      b.  are amplified the most when moving through solid bedrock.
      c.  cause more damage to buildings when they travel faster.
      d.  are "dampened" when they move through soft, wet sediments.
      e.  none of the above is true. 

2.  Earthquake damage would be worst for: 

      a.  tall buildings constructed directly on bedrock.
      b.  short buildings constructed directly on bedrock.
      c.  tall buildings constructed on thick deposits of loose sediment.
      d.  short buildings constructed on thick deposits of loose sediment.
      e.  none: all buildings would suffer the same damage.

3.  True or false:  earthquake intensity varies with distance from the epicenter, but
     magnitude does not. 

4.  A Magnitude 4 earthquake is:

     a.  releases twice as much energy as a Magnitude 2 earthquake.
     b.  releases 10 times as much energy as a Magnitude 2 earthquake.
     c.  releases 20 times as much energy as a Magnitude 2 earthquake.
     d.  releases 100 times as much energy as a Magnitude 2 earthquake.
     e.  releases 1000 times as much energy as a Magnitude 2 earthquake.

5.  Liquefaction:

     a.  is the process of injecting liquid wastes into a deep well for disposal.
     b.  only happens during earthquakes having magnitudes of less than 5.
     c.  occurs when the shock wave frequency and fundamental period of a building match.
     d.  occurs when seismic shock waves shake loose, wet sediments.
     e.  is the process cereal makers use to pack cereal into their boxes. 

6.  Resonance:

     a.  is the process of injecting liquid wastes into a deep well for disposal.
     b.  only happens during earthquakes having magnitudes of less than 5.
     c.  occurs when the shock wave frequency and fundamental period of a building match.
     d.  occurs when seismic shock waves shake loose, wet sediments.
     e.  is the process cereal makers use to pack cereal into their boxes.  

7.  True or false: some seismic shock waves travel faster than the speed of sound.

8.  True or false: several earthquakes have killed more than 100,000 people at one time. 

9.  True or false:  a dormant volcano is considered an active volcanic.

10.  Most of the earth's active volcanoes:

       a.  occur over mantle hot spots.
       b.  occur over divergent plate boundaries.
       c.  occur over subduction zone boundaries.
       d.  occur over collision zone boundaries.
       e.  occur within lithospheric plates.  

11.  The "Ring of Fire":

       a.  contains most of the world's most explosive volcanoes.
       b.  develops around the crater of an erupting shield volcano.
       c.  contains volcanoes that extrude mostly basaltic magma.
       d.  describes the distribution pattern of the Hawaiian volcanoes.
       e.  is a cloud of hot ash and volcanic gases that flows quickly down slope.  

12.  The explosiveness of a volcanic eruption depends mainly on:

       a.  the temperature of the magma that is extruded.
       b.  the gas content of the magma that is extruded.
       c.  the silica (SiO₂) content of the magma that is extruded.
       d.  how long the eruption lasts.
       e.  the size of the volcano.

13.  True or false: a composite (strato) volcano could be become more explosive over time
       (i.e., as it becomes older).

14.  True of false:  nuees ardentes and lahars are hazards that could be associated with
       composite (strato) volcanoes and lava domes but not with shield volcanoes. 

15.  True or false:  shield volcanoes occur over rift zones and mantle "hot spots".

16.  True or false:  global weather patterns can be affected by the heat released during
       volcanic eruptions.

17.  True or false:  residents living near the Cascade volcanic peaks face the potential risks
       that are posed by lahars.

18.  True or false:  volcanic gases are only dangerous when mixed with pyroclastic debris.
 

19.  Why might the risks to human health caused by chronic exposure to the geologic
       environment be difficult to identify?

       a.  Contamination could obscure the effects of the natural environment.
       b.  People often eat foods that are imported from areas outside where they live.
       c.  Exposure pathways can vary from house to house in the same area. 
       d.  Some areas experience high rates of immigration and emigration.  
       e.  All of the above are true.
       f.  None of the above are true.  

20.  Studies have linked high rates of stomach cancer to:

       a.  eating food grown in soils that contain relatively high concentrations of trace
            elements for a long period of time.
       b.  drinking water that contains relatively low sulfate concentrations for a long period
            of time.
       c.  inhaling air that contains relatively high concentrations of carbon dioxide for a long
            period of time.
       d.  living in a house that has relatively high levels of radon.  

21.  True or false: fluoride (F)  is an example of an element that can be either beneficial or
       harmful to human health depending on it's intake concentration.

22.  The former incidence of goiter within the U.S. (known as the "goiter belt"):

       a.  was the result of high arsenic concentrations in the groundwater.
       b.  demonstrates that health problems can be caused by chronic deficiencies in the diet.
       c.  corresponded to areas that also have granite bedrock.
       d.  was restricted to areas of the southwest, where rainfall is very low.
       e.  was eliminated when people stopped drinking water pumped from the ground.

23.  Suppose that traces of uranium are found in the bedrock that occurs underneath your
       house.   Is  it certain that radon levels will be high in your home? 

24.  True or false:  only rocks with higher-than-average uranium contents can lead to high
       (> 4 piC/L) radon levels in your home.

25.  Chronic health risk means:

        a.  a risk that results from long-term exposure.
        b.  a risk that recurs frequently over a long time period.
        c.  a risk that is not very serious.
        d.  a risk that recurs infrequently over a long time period.

26.  What type of climate favors chemical weathering?  In what type of climate is physical 
       weathering most effective?

27.  The mineral halite (rock salt) is used to melt ice and snow in the winter.  What is likely
       to happen to this mineral in the spring time when the snow disappears? 

28.  Clay minerals: 

       a.  form as a result of hydrolysis.
       b.  are resistant to chemical weathering.
       c.  are also called secondary minerals.
       d.  retain much of the aluminum and silicon released during weathering.
       e.  all of the above.

29.  Granite is an igneous rock composed mostly of silicate minerals.  Therefore, granite:

       a.  has a low resistance to chemical weathering.
       b.  is rock type in which caves can form.
       c.  cannot be a source rock for radon.
       d.  has high intergranular porosity.
       e.  contains no trace elements that are harmful to human health.
       f.  all of the above.
       g.  none of the above.

30.  True or false: the presence of harmful constituents in groundwater means that
       there must be a human source of contamination.

31.  True or false:  in general, calcium (Ca) occurs in minerals that are more easily
       weathered than do silicon (Si) or aluminum (Al).

32.  True or false: a standard set for a cancerous constituent usually means that if a person
       inhales or ingests that concentration for any length of time, he/she will get cancer .

33.  Why are hydrothermal fluids often enriched in trace elements?

34.  Which of the following rock types would not dissolve in water?

        a.  Rocks composed of calcite (e.g., limestone and marble).
        b.  Rocks composed of chemical precipitates (e.g., rock salt and gypsum).
        c.  Rocks composed of quartz (e.g., sandstone and quartzite).
        d.  All of the above.
        e.  None of the above. 

35.  A cave:

       a.  is most likely to form in rocks that weather by the process of solution.
       b.  is one place where an "underground stream" can actually occur.
       c.  allows groundwater to move at higher than normal rates.
       d.  is unlikely to occur in a rock composed of silicate minerals.
       e.  all of the above.

36.  If your house has high radon levels, will your water supply also have a high radium
       concentration?

37.  Sulfide minerals (i.e., minerals containing S):

       a.  weather relatively slowly by the process of hydrolysis.
       b.  normally produce acidity when they weather.
       c.  are common rock-forming minerals.
       d.  all of the above.
       e.  none of the above.

38.  Carbonic acid (H₂CO₃):

        a.  is the acid produced by the oxidation of sulfide minerals.
        b.  is a naturally occurring acid that forms in the atmosphere.
        c.  is produced naturally when uranium decays to radium.
        d.  causes the natural pH of rain to be less than 4.

39.  True or false:  an aquifer is, by definition, very permeable.

40.  True or false:  a highly porous material is also highly permeable.

41.  What potential advantage(s) does a confined aquifer have over a water table aquifer
       in terms of its groundwater quality?

       a.  Confined aquifers are usually deeper than water table aquifers, which means that
            they contain groundwater that is naturally more pure.
       b.  Confined aquifers contain groundwater under pressure, which is naturally better.
       c.  Confined are protected from surface contamination except in their recharge areas;
            whereas water table aquifers are everywhere susceptible to contamination.
       d.  All of the above.
       e.  None of the above. 

42.  Why does arsenic in a bedrock aquifer underlying eastern Wisconsin not dissolve in
       groundwater until wells are drilled and groundwater is pumped out?

43.  True or false: most dissolved substances in groundwater come from geologic sources. 

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