Oceanography
Learning Objectives and Study Questions for Chapter 11
1. Add arrows to a diagram of the Earth and Moon showing the correct directions and relative
strengths of the gravitational and "centrifugal" forces that interact to raise tides according
to the equilibrium tidal model.
2. Identify the times of spring and neap tides on a tide graph and correlate the timing of these
tides with relative positions of Earth, Sun, and Moon.
3. Knowing the speed of Earth's rotation and the depth of the ocean at a given latitude, predict
whether the tide wave will move as a free wave or a forced wave and explain your decision.
4. Add arrows to a sketch map of an ocean basin between 0 and 60° N or S to indicate the
direction the tide wave will move off of each wall to produce a rotary standing wave.
5. Predict whether you would be likely to observe a larger tidal bore in a river mouth or estuary
that widens or narrows as it moves inland from the coast, and briefly explain your reasoning.
1. Because of its greater distance, the Sun’s effect on Earth’s tides is _____ the Moon’s effect.
A. equal to
B. greater than
C. less than
D. more variable than
E. erratic compared to
2. With typical diurnal tides, there are ____ highs and _____ lows each day.
A. 1, 1
B. 1, 2
C. 2, 2
D. 2, 4
E. 4, 4
3. The tide raising forces are the difference between _____ and _____ forces.
A. centripetal, centrifugal
B. gravitational, magnetic
C. centrifugal, magnetic
D. gravitational, centrifugal
E. centrifugal, irresistible
4. People in city A in the accompanying sketch
are experiencing a _____, _____ tide.
A. high, neap
B. high, spring
C. low, neap
D. low, spring
E. new, improved
5. The most pronounced neap tide of
September 1991 in Bridgeport, CT
occurred on about _____.
A. 2nd-3rd
B. 8th-9th
C. 16th-17th
D. 24th-25th
E. indeterminate, cannot tell
6. The tide wave moves as a _____ wave below about 60°N and S because Earth rotates faster
than the wave can travel through the ocean.
A. forced
B. free
C. rotary
D. spilling
E. standing
7. The spilling wave produced as a tide wave moves inland through a narrow river channel or
bay is known as a _____.
A. tsunami
B. free wave
C. tidal bore
D. progressive tide
E. total bore