REVIEW QUESTIONS FOR EXAM 3

Note: correct answers to multiple choice questions are underlined

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

     True:  magnitude depends only on the shock wave amplitude at the epicenter at
     the time of the earthquake and therefore does NOT vary with distance.

3.  A Magnitude 4 earthquake (on the Richter scale):

     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.

4.  The moment magnitude scale:

     a.  is used to quantify the extent of damage during an earthquake.
     b.  records earthquake magnitude at various "moments" during an earthquake.
     c.  is the best way to quantify the total energy released during an earthquake.
     d.  cannot be used to quantify the energy released during small earthquakes.
     e.  has been abandoned by geologists in favor of the Richter scale.

5.  The modified Mercalli scale:

     a.  is used to quantify the extent of damage during an earthquake.
     b.  quantifies shock wave intensity at the epicenter during an earthquake.
     c.  is the best way to quantify the total energy released during an earthquake.
     d.  cannot be used to quantify the energy released during small earthquakes.
     e.  has been abandoned by geologists in favor of the Richter scale.

6.  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.

7.  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. 

8.  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.

9.  Which of the following can effect earthquake intensity at any given location?

     a.  The types of geologic materials present.
     b.  The types of buildings present.
     c.  Distance from the epicenter.
     d.  The topography.
     e.  All of the above.  

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

       True:  the fastest body waves travel faster than sound waves and can make audible sounds.

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

      True.

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

      True:  a dormant volcano could erupt in the future, so it is still potentially active.

13.  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.  

14.  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.  

15.  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.

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

       True: it could evolve into a lava dome as the magma's SiO₂ content increases over time.

17.  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. 

        True:  basaltic magma does not produce explosive eruptions.

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

        True.

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

       False: weather patterns are affected by large volumes of ash that reflect solar radiation.

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

       True (if they live in river valleys).

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

        False: volcanic gases are poisonous and can produce acidic rainfall.