1. Waves and Water Dynamics
© 2011 Pearson Education, Inc.

2. Chapter Overview
 Most waves are
wind-driven.
 Most waves are
generated by
storms.
 Waves transmit
energy across the
ocean surface.
 Tsunami are
special fast, long
waves generated
by seismic events.
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3. Wave Generation
 Disturbing force causes
waves to form
 Wind blowing across
ocean surface
 Interface of fluids with
different densities
 Air – ocean
interface
 Ocean waves
 Air – air
interface
 Atmospheric
waves
 Water – water
interface
 Internal waves
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4. Internal Waves
 Associated with
pycnocline
 Larger than surface
waves
 Caused by tides,
turbidity currents,
winds, ships
 Possible hazard for
submarines
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5. Other Types of Waves
 Splash wave
 Coastal
landslides,
calving icebergs
 Seismic sea wave
or tsunami
 Sea floor
movement
 Tides
 Gravitational
attraction
among Moon,
Sun, and Earth
 Wake
 Ships
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6. Speed of Deep Water Waves
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7. Energy in Ocean Waves
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8. Wave Movement
 Waves transmit energy
 Cyclic motion of particles in ocean
 Particles may move
 Up and down
 Back and forth
 Around and around
 Particles in ocean waves move in orbital
paths
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9. Progressive Waves
 Progressive waves oscillate uniformly and progress
without breaking
 Longitudinal
 Transverse
 Orbital
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10. Orbital Waves (3 types)
 Waves on ocean surface
 Anatomy
 Crest
 Trough
 Wave height (H)
 Wavelength (L)
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11. Orbital Wave Characteristics
Wave steepness = Height/Length
 If wave steepness > 1/7, wave breaks.
EX:: A wave 7 meters long can only be 1 meter
high without breaking. If the wave is any higher
than that, it will break.
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12. Garrett McNamara Breaks Big Wave World Record: 100 ft wave. Portugal.

13. Wave period (T) = time for one wavelength to
pass fixed point (The time it takes for two wave
crests to pass a given point.)
Wave frequency = inverse of period or 1/T
Note: Frequency is the reciprocal of the time taken to complete
one cycle (the period), or 1/T.
EX 2: Waves with a period of 12 seconds will have a frequency of 1/12 or
0.083, which converts to 5 periods/minute.

14. Orbital Wave Characteristics
 Diameter of orbital
motion decreases with
depth of water
 Wave base = ½ L
 Hardly any motion
below wave base due to
wave activity
 Ex: A wave that has a
wavelength with 10
meters will have
negligible movement at 5
meters below the still
water level.
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15. Circular Orbital Motion
 Wave particles move in
a circle
Wave Motion
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16. 1. Deep-Water Waves
 Water depth is greater than wave base (>½L)
-depth is greater than ½ wavelength
 Wave speed = celerity (C)
 C = L (Wavelength)/T (Period)
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17. 2. Transitional Waves
 Characteristics of both deep- and shallow-water waves
 Celerity depends on both water depth and wavelength
- Wavelength is 2 to 20 that water depth.
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18. 3. Shallow-Water Waves
 Water depth is < ½ L
 C (meters/sec) = 3.13 √ d(meters) or
 C (feet/sec) = 5.67 √d (feet)
 Where d is water depth
-tsunamis and tides are types of waves are examples of shallow
water waves.
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19. Write out:
Wave Type Deep vs. Shallow Affects the ocean
bottom?
Wind Wave Deep Does not affect bottom
(depth > ½ wavelength)
Tsunami Shallow Strongly affects bottom.
(depth is < ½ of
wavelength).
Tides Shallow Affects bottom.