Geology Reference
In-Depth Information
Figure 15-1:
Parts
of a wave.
Height:
Wave
height
is the distance from the top of a crest to the bottom of the
trough.
Length:
Wave
length
is the distance from one crest to another or from one trough to
another.
Period:
The
period
of a wave is the time it takes a wave to pass a certain point.
Velocity:
The
velocity
of a wave is the speed a wave is traveling.
These features of a wave are determined by four characteristics of the wind:
The wind speed
How long the wind blows across the water surface, or its
duration
The direction of the wind and whether it blows from one direction or multiple dir-
ections
The distance the wind moves across the surface of the water, or its
fetch
Starting to roll
The force of the blowing wind causes the water to move in a rolling pattern. This pattern
is called
oscillatorymotion.
In the middle of the ocean, when the water moves in oscillat-
ory motion, the water itself moves only a small distance while the energy of the wave
keeps moving. This process is illustrated in Figure 15-2.
