
1   The semidiurnal solar tide has a period of: 
  A)  24 hours 50 minutes. 
  B)  24 hours. 
  C)  12 hours 25 minutes. 
  D)  12 hours. 


2   The tidal datum is usually equal to: 
  A)  higher low water. 
  B)  lower low water. 
  C)  mean low water. 
  D)  lower high water. 


3   Slack water occurs during: 
  A)  ebb tide. 
  B)  flood tide. 
  C)  neap tide. 
  D)  the change from flood to ebb tide or vice versa. 
  E)  spring tide. 


4   The tideraising, or tidegenerating, force is proportional to the difference between: 
  A)  centrifugal force and gravitational force. 
  B)  centripetal force and gravitational force. 
  C)  gravitational force and frictional force. 
  D)  windgenerated force and traction. 
  E)  Both A and B can be considered correct. 


5   If the high tide of a diurnal tide occurs at 10:00 A.M. on one day, when will the next high tide occur? 
  A)  10:25 P.M. the same day 
  B)  10:50 A.M. the next day 
  C)  10:00 A.M. the next day 
  D)  10:00 P.M. the same day 
  E)  10:25 A.M. the next day 


6   A mesotidal coast has a tidal range of: 
  A)  less than 2 meters. 
  B)  over 4 meters. 
  C)  between 2 and 4 meters. 
  D)  less than 0.5 meters. 
  E)  over 10 meters. 


7   Lines drawn to mark the location of the tide crest at set intervals of time are called: 
  A)  temporal crest lines. 
  B)  cocrest lines. 
  C)  cotidal lines. 
  D)  isocrests. 
  E)  corange lines. 


8   The tide generating force of a body is proportional to the inverse of the distance between the body and the Earth to this power. 
  A)  4 
  B)  3 
  C)  2 
  D)  1 
  E)  0 


9   The highest water level in a mixed semidiurnal tide is called: 
  A)  high water. 
  B)  low water. 
  C)  maximum water. 
  D)  higher high water. 
  E)  megawater. 


10   The period of the lunar semidiurnal tide is: 
  A)  12 hours 25 minutes. 
  B)  12 hours. 
  C)  24 hours 50 minutes. 
  D)  24 hours. 
  E)  none of the above 


11   If you observe a semidiurnal high tide at 3:00 P.M., the next high tide will occur at about what time the next day? 
  A)  2:50 P.M. 
  B)  2:25 A.M. 
  C)  1:10 P.M. 
  D)  3:50 P.M. 
  E)  3:25 A.M. 


12   The tides with the greatest tidal range during the month are the _________ tides. 
  A)  diurnal 
  B)  neap 
  C)  semidiurnal 
  D)  mixed semidiurnal 
  E)  spring 


13   Over a period of roughly 20 years the Moon will be directly overhead between which latitudes? 
  A)  23.5 degrees N & S 
  B)  28.5 degrees N & S 
  C)  30 degrees N & S 
  D)  15.5 degrees N & S 
  E)  45 degrees N & S 


14   When the lunar and solar tides are 90 degrees out of phase with one another they add: 
  A)  destructively. 
  B)  constructively. 
  C)  to produce neap tides. 
  D)  A and C above 
  E)  B and C above 


15   The period of the lunar diurnal tide is: 
  A)  12 hours 25 minutes. 
  B)  12 hours. 
  C)  24 hours 50 minutes. 
  D)  24 hours. 
  E)  none of the above 


16   The Earth and the Moon rotate: 
  A)  around their center of mass. 
  B)  within a period of about 24 hours. 
  C)  around the Sun. 
  D)  twice per year. 
  E)  A and C above 


17   When tides are studied mathematically in response to the laws of physics, they are known as: 
  A)  equilibrium tides. 
  B)  computational tides. 
  C)  dynamic tides. 
  D)  kinetic tides. 
  E)  none of the above 


18   When the low tide occasionally falls below mean lower low water it is called a: 
  A)  deficit tide. 
  B)  negative tide. 
  C)  minus tide. 
  D)  submarine tide. 
  E)  abyssal tide. 


19   The tide generating force of the Sun is about ___________ percent as large as the tide generating force of the Moon. 
  A)  23 
  B)  46 
  C)  17 
  D)  62 
  E)  80 


20   The angle between the plane of the Moon's orbit and the Earth's equator is called the Moon's: 
  A)  inclination. 
  B)  declination. 
  C)  azimuth. 
  D)  elevation. 
  E)  altitude. 


21   What force or forces hold the tide crest in position on earth? 
  A)  moon's attraction and friction. 
  B)  friction and gravity. 
  C)  westward displacement and friction. 
  D)  centrifugal force. 


22   Which of the following is a mixed semidiurnal tidal pattern? 
  A)  1 high and 1 low tide per day. 
  B)  2 high and 1 low tide per day. 
  C)  2 high and 2 low tides of equal height per day. 
  D)  2 high and 2 low tides of unequal height per day. 


23   What is the period of a tidal wave in a diurnal system? 
  A)  12 hours. 
  B)  12 hours 25 minutes. 
  C)  24 hours. 
  D)  24 hours 50 minutes. 


24   How often does a spring tide occur? 
  A)  every 12 hours 25 minutes 
  B)  every two weeks 
  C)  every 29.5 days 
  D)  once per year 


25   Tides extend out from an amphidromic point along: 
  A)  corange lines. 
  B)  cotidal lines. 
  C)  rotaries. 
  D)  forced waves. 


26   Which of the following objects has the greatest tide generating force on Earth? 
  A)  the moon 
  B)  the sun 
  C)  Venus 
  D)  Mars 
