Sample Questions representing the topics covered since the last exam.

1.  Unlike other moving things, wind waves travel over great distances in virtually straight lines. This is physically possible because
 A. while the wave is moving, some water molecules are traveling in closed circles.
 B. the waves donπt move as fast as speeding cannon balls, so Coriolis effecthas no influence on them.
 C. waves carry only energy, and energy has no mass, and is therefore not subject to Coriolis deflection.
 D. waves curve one way in the southern hemisphere and the other way in the northern hemisphere. So waves only look like they are coming in a
straight line from their point of origin. Itπs all a gigantic optical illusion, actually.
 E. Wrong! Waves are deflected in the same way as everything else that moves
on a turning planet. Coriolis effect does not play favorites.

2.   Waves with the greatest propagation rate or velocity
 A.   have the longest wavelengths.
 B.   occur in shallow water only.
 C.   form when the wind is blowing less than 0.5 nautical miles per hour.
D. have wave periods of less than one second.

3.   As the wind velocity increases during a storm,
 A.   the wave height increases.
 B.   the wave velocity decreases.
 C.   the wind tends to flatten the ocean surface.
D. mass transport decreases in the open ocean.

4.   Waves at the shore will start to break when the
 A.   water depth is about twice the wavelength.
 B.   crest flattens into a rounded form.
 C.   wave period increases to 15 seconds.
 D.   water depth is about four-thirds the wave height.

5.   Internal waves are thought to be generated by
 A.   movements of large fish or marine mammals.
 B.   subsea volcanoes or vigorous hydrothermal vents.
 C.   energy from wind waves or tides moving into deeper water.
 D.   movements of the Earthπs crustal plates.

6.   When a tsunami reaches shore,
 A.   the wave height is increased by entry into shallow water.
 B.   it always arrives at the time of a high tide.
 C.   the wave will appear as a single huge breaking wave.
 D.   it will always race hundreds of meters inland.

7.   The primary force(s) that cause(s) tides in the sea is (are)
 A.   coastal earthquakes and landslides.
 B.   wind and storms at sea.
 C.   the gravitational attraction of the moon and the sun.
 D.   the gravitational attraction of Mars and Venus.
 E.   the rotation of the moon on its axis.

8.   A tide pattern of two equally high and two equally low each day describes a
 A.   diurnal tide.
 B.   mixed tide.
 C.   solar tide.
 D.   semidiurnal tide.

9.   An amphidromic point is
 A.   a "no tide" point in the ocean around which the tide crest rotates through one tidal cycle.
 B.   a place in the ocean where tides are highest.
 C.   a place in the ocean where tidal datum is displaced to the right (in the northern hemisphere), or to the south (in the southern hemisphere).
 D.   a "no tide" point at the coast where there is a daily high tide, but nolow tide.

10.   Describe a primary coast. Describe a secondary coast. How are they similar and different?

11.   What are the features of a typical sandy beach? How do these features change through a year?

12.   Steep, narrow, rocky beaches are usually found in areas of
 A.   summer beach conditions.
 B.   wave deposition.
 C.   high wave energy.
 D.   small inlets and bays.

13.  The velocity of the longshore current varies as a function of

A.     water temperature
B.     salinity
C.     wave height
D.     sand size

14.   Which of the following statements applies to mineral resources from the sea?
 A.   They are easier to recover than from the land.
 B.   They are usually found in concentrated ores.
 C.   They are in greater variety than minerals on land.
 D.   They are less expensive to recover than from land.
 E.   They are more dilute, harder to reach, and more difficult to recover.

15.  A long-term effect of wave refraction is

A.  to straighten a coast
B.  to build out points of land
C.  to erode and deepen bays
D.  to remove sand from beaches

16.   About% of the crude oil used by humans is derived from the seabed.
 A.   18
 B.   50
 C.   28
 D.   14
 E.   5

17. The ocean can supply alternative energy through
A.   tides
B.   waves
C.   currents
D.   thermal gradient.
E.   all the above
  

18. The greatest amount of energy can theoretically be derived from
A.   tides
B.   waves
C.   currents
D.   thermal gradient.
E.   salinity difference

19.  What is the velocity of a wave with a 50 meter wavelength in water 1 meter deep?

A.  3.1 m/sec
B.  50 m/sec
C.  5 m/ sec
D.  1 m/sec

20.  Given the following coastline, in which direction is the longshore current flowing toward?

A.  West
B.  North
C.  East
D.  South

21. The groin between beaches 4 & 5 was just recently constructed.  Which of the following is likely to happen?

A.  The #4 beach will shrink
B.  The #4 beach will expand
C.  The #5 beach will expand
D.  The #6 beach will expand