REVIEW QUESTIONS FOR EXAM 1

Note: correct answers to multiple choice questions are underlined

1.  True or false:  the scientific method only applies to the natural sciences. 

      False: the scientific method applies to many disciplines, including social
      sciences and forensic science.

2.  True or false:  natural science relies exclusively on controlled experiments to test
      hypotheses. 

      False: sometimes hypotheses (especially in geology) can only be tested by
      using circumstantial evidence or by making a prediction based on a model
      that is developed form the hypothesis. 

3.  Why does geology (the study of the earth) often require the use of circumstantial
      (indirect) evidence?

      Often the hypotheses made in geology (especially hypotheses about what has
      occurred in the past) cannot be tested by conducting repeatable laboratory
      experiments and so must be scrutinized based on circumstantial evidence.

4.  A hypothesis that has been accepted after being subjected to proper testing:  

      a.  is known as a theory.
      b.  is a proven fact.
      c.  by definition does not rely on any auxiliary assumptions.
      d.  all of the above are true.
      e.  only a. and b. are true.

5.   An Indian legend describes the origin of Devil's Tower in Wyoming as the result of a  
      giant bear scratching claw marks in the rock as it pursued Indian braves (or children,
      depending on the version).  What aspects of this story make it unscientific?

      a.  It relies on anecdotal evidence.
      b.  It relies on circumstantial evidence.
      c.  It draws from an invalid analogy.
      d.  It wrongly infers a cause and effect relationship.
      e.  all of the above are true.

6.  True or false:  if the devil really made Devil's Tower, that fact would be outside the
      realm of scientific discovery. 

      True: as most scientists define "science", it would be impossible to test this
      hypothesis; therefore, it is outside the realm of what can be known through
      scientific discovery.

7.  The principal problem with Wegener's hypothesis of "continental drift" was that:

      a.  it contradicted what was known about the earth's magnetic field.
      b.  his mechanism for continental drift was not plausible.
      c.  it relied on anecdotal evidence.
      d.  he believed Greenland to be moving away from Europe.
      e.  it relied primarily on circumstantial evidence.

8.  True or false: because of its relatively low density, continental crust cannot subduct.

      True.

9.  True or false: the asthenosphere is partially melted and capable of slow, plastic flow.

      True.

10.  True or false: the lithosphere includes the Mohorovicic Discontinuity.

        True.

11.  True or false:  deep ocean trenches occur over divergent (rift zone) boundaries.

        False: trenches occur over subduction zone boundaries.

12.  True or false: continental mountain ranges along a coastline often occur adjacent to 
       subduction zones.

       True.

13.  True or false:  collision zones always involve two continental plates.

        True.

14.  What does the information shown in this linked figure suggest?

       a.  The occurrence of earthquakes is randomly distributed around the globe.
       b.  All earthquakes occur along plate boundaries.
       c.  Only large earthquakes occur along plate boundaries.
       d.  Some earthquakes occur in locations that would not be predicted by the locations
            of plate boundaries.
       e.  There are more than 100 earthquakes around the world each year. 

15.  Based on your understanding of plate tectonics, would you predict that a large earth-
       quake will occur in Wisconsin within the next 100 years?

       No: Wisconsin is located within the interior of a tectonic plate, far from
       any active plate boundaries (where large earthquakes are likely to occcur).
 

16.  What type of evidence has convinced scientists that the polarity of the Earth's magnetic
       field periodically reverses itself (see p. 50-51 in your textbook)?

        a.  Observations of the reversals as they occur.
        b.  Data collected from laboratory experiments.
        c.  Theoretical calculations.
        d.  Circumstantial evidence.
        e.  all of the above are true.
 

17.  What evidence does the Benioff Zone provide for plate tectonics?

        The Benioff Zone refers to a descending band of earthquake foci that are
        apparently the result of subduction (where one tectonic plate is forced down
        beneath another plate).  The distribution of earthquakes defines the contact
        between the two tectonic plates. 
 

18.  The theory of plate tectonics suggests that:

        a.  Greenland is moving farther away from Europe.
        b.  the United States is moving farther away from Europe.
        c.  India is moving closer to the Eurasian continent.
        d.  South America is moving farther away from Africa.
        e.  all of the above.
 

19.  Is the island of Maui (see page 62 in your textbook) an extinct (dead) or a dormant 
       ("sleeping") volcano?  Why?

       Extinct: the Pacific Plate has moved Maui away from the stationary hot spot
       that is currently beneath the island of Hawaii.  Therefore Maui is no longer
       located over a source of magma (lava) that could produce future eruptions. 
 

20.  Yellowstone National Park in Wyoming occurs over a mantle "hot spot" (see page 61
       in your textbook).   Which of the following facts might this explain?

       a.  That land surface elevations in this area are rising.
       b.  That geysers (eruptions of hot water and steam) occur within the park.
       c.  That extinct volcanic features occur to the west of Yellowstone in Idaho.
       d.  That Yellowstone often experiences large forest fires during the summer.
       e.  That there are volcanic rocks present at the land surface within the park.

21.  Isostasy has been compared to ice floating in water, but mountain peaks are not like
       "tips of the iceberg" in relation to their "roots".  In other words, "roots" are not that
       much larger than their peaks.  This fact suggests that:

       a.  floating ice is an invalid analogy for isostasy.
       b.  the density contrasts between the crust and mantle are different than those between  
            ice and water.
       c.  a better analogy might be a ship floating on water.
       d.  isostasy is an unfalsifiable hypothesis.
       e.  isostasy is not a theory.
        f.  both b. and c. are true.
 

22.  Which of the two models for isostasy (Airy's or Pratt's) appears to be true?  What is
       the evidence for this?

       Airy's model appears to be generally a better explanation.  The evidence for
       this includes measurements which suggest that the earth's density varies in
       the way predicted by Airy's model.