Name _____________________________
Group ________________________________
Waves & Tides Study Guide – Chapters 10 & 11
1. Vocabulary Words - Define the following terms:
a. Waves –
b. Generating Force –
c. Restoring Force –
d. Free Waves –
e. Forced Waves –
f.
Capillary Waves –
g. “Cat’s paws” –
h. Crest –
i.
Trough –
j.
Wavelength –
k. Wave height –
l.
Amplitude –
m. Period –
n. Frequency –
o. Stokes Drift –
p. Wave base –
q. Celerity –
r.
Deep Water Waves –
s. Intermediate Waves –
t.
Shallow Water Waves –
u. Wave Train –
v. Constructive Wave Interference –
w. Destructive Wave Interference –
x. Fetch –
y. Significant wave height –
z. Episodic Wave –
aa. Potential Energy –
bb. Kinetic Energy cc. Wave Steepness –
dd. Beaufort Scale –
ee. Refraction –
ff. Reflection –
gg. Diffraction –
hh. Plunging Breakers –
ii. Spilling Breakers –
jj. Tsunami –
kk. Internal waves –
2. As a wave approaches, a water particle will trace a circular path (orbital motion). The diameter of the orbit at
the surface is equal to the ________________________________.
3. The same type of orbital motion is transferred to the water particles below the surface, but less energy of
motion is found at each successive depth. The diameter of the orbits becomes (smaller/larger) as depth
increases.
4. Wave particle orbits become undetectable below __________________ the wavelength in depth; therefore the
wave base will occur at a depth of ____________________ of the wave length.
5. If a wave’s wavelength is 40 feet, how deep will scuba divers need to dive in order to avoid wave induced
motion (below the wave base)?
6. What is the equation for wave speed?
7. If a wave has a wavelength of 60 meters and a period of 20 seconds/cycle, what is the wave celerity?
8. Equations you should know how to use:
a. Deep Water:
L = (g/2π)T2
C = 1.56T
b. Group (Wave Train) Speed:
V = C/2
c. Wave Energy:
E = 1/8ρgH2
d. Wave Steepness:
S = H/L
e. Shallow Water:
C = gD
9. If a deep water wave has a period of 45 seconds/cycle, what is the wavelength? What is the speed?
10. If a wave train has a speed of 75 meters/minute, what is the group speed (velocity)?
11. If a shallow water wave travels over water with a depth of 4 meters, what is its speed?
12. Assume: Wave A – H = 18 feet; Wave B – H = 5 feet.
a. If the two waves interfere with one another constructively, what will the wave height be?
b. If the two waves interfere with one another destructively, what will the wave height be?
13. There is a maximum possible wave height for any given wavelength of a wave. If a wave becomes overly steep,
the water particles in the crest of the wave will be thrown forward and the wave will topple. What is the
maximum steepness ratio?
14. Using the maximum steepness ratio, calculate the maximum height of a wave with a wavelength of 70 meters.
15. Surf zone characteristics are different based on the location of the storm that is producing the waves. Explain
why this is and describe the differences between a surf zone consisting of waves from a distant storm versus a
surf zone with waves from a local storm.
16. Why is it inaccurate to call a Tsunami a “tidal wave”?
17. What typically causes Tsunamis?
18. Is a Tsunami a deep water wave or a shallow water wave? Why?
19. Which ocean basin sees the most Tsunamis? Is it possible to have a Tsunami in a large lake?
Tides
20. Vocabulary Words - Define the following terms:
a. Tidal range –
b. Diurnal Tide (also give example of a location) –
c. Semidiurnal Tide (also give example of a location) –
d. Mixed Semidiurnal Tide (also give example of a location) –
e. Average Tide –
f.
Tidal Datum –
g. Minus Tide –
h. Flood –
i.
Ebb –
j.
Slack Water –
k. Tidal bulge –
l.
Centrifugal Force –
m. Barycenter –
n. Spring Tide –
o. Neap Tide –
p. Syzygy –
q. Perihelion –
r.
Aphelion –
s. Perigee –
t.
Apogee –
u. Declinational Tide –
v. Dynamic Tidal Analysis –
w. Equilibrium Tidal Theory –
x. Amphidromic Point –
y. Rose Diagram –
z. Progressive Vector Diagram –
aa. Tidal Resonance –
bb. Seiche Effect –
cc. Tidal Bore –
dd. Tide Table –
ee. Tide Current Table –
21. Who is given credit for proposing the Equilibrium Tidal Theory that was later developed by other
mathematicians?
22. What are the “incorrect” assumptions that are made for the Equilibrium Tidal Theory?
23. What are the two generating forces of tides?
24. Which is more important in gravitational attraction, mass or distance? Give the equation for Tide Raising Force
that mathematically shows this importance.
25. Explain what causes the ocean to “bulge” in two places on the face of the Earth.
26. Why is the center of rotation (the barycenter) for the Earth and the moon so much closer to the Earth (in fact it
is located 1060 km inside the Earth)?
27. Diurnal tides occur every 24 hours and 50 minutes, while semidiurnal tides occur every 12 hours and 25 minutes.
Why are the times not 24 hours and 12 hours, respectively? What’s up with the extra time?
28. Why is the Sun’s influence on tides less important than the moon?
29. A lunar month is 29.5 days. In this time period, the moon phases through 4 phases. What are they? Spring
Tides coincide with which phases and why? Neap Tides coincide with which phases and why?
30. The Dynamic Tidal Analysis takes into account land masses, the seafloor, Coriolis Force, size and shape of basins,
reflection, refraction, and diffraction. Why is this so important?
31. Explain how the reflection of a tide wave can create a rotary standing wave.
32. Explain two reasons why the Bay of Fundy has the perfect characteristics for the formation of a tidal bore.
33. Give two more examples of tidal bores.
34. Review how to use Tide Tables and Tide Current Tables.
35. Currently we have two systems to extract, or harness, the energy from the tides. Briefly explain the Singleaction power cycle and the Double-action power cycle. Give examples of both. Explain their advantages and
disadvantages.
36. We discussed an interesting possibility for future tidal power. Briefly explain the proposed underwater water
mills. Explain their advantages and disadvantages.