Chapter 21 Section 2 Handout
Ocean Waves
Matching
1.
2.
3.
4.
5.
6.
wave period
crest
wave height
wave
wavelength
trough
a.
b.
c.
d.
e.
f.
the lowest point between two
crests of a wave
the vertical distance between
the crest and the trough of a
wave
a periodic disturbance in a
solid, liquid, or gas as energy
is transmitted through it
the highest point of a wave
the time required for two
consecutive wave crests to
pass a given point
the horizontal distance
between two consecutive
crests or two consecutive
troughs
7
• The formula for calculating the speed at
which a wave moves is
– wave speed = wavelength / wave period
8
• Moving air caused by the uneven heating
of Earth’s atmosphere is called _______.
– wind
9
• What causes small waves or ripples to
form on the ocean?
– Friction from moving air and water.
10
• What causes a wave to become larger?
– The longer the wind blows from a given
direction, the more energy is given to water.
11
• Explain why larger wave tend to grow
larger and smaller waves die out.
– Large waves have a larger surface area and
receive more energy from wind than smaller
waves.
20
• What kind of wind produces very large
waves?
– Steady high winds that blow across a long
fetch.
21
• What kind of wind produces choppy water
with waves of various heights and
lengths?
– strong, gusty winds
22
• One of a group of long, rolling waves of
similar size is called a(n) ____________.
– swell.
23
• What causes a whitecap to form?
– When winds blow the crest of a wave off.
24
• Why could whitecaps possibly have an
effect on climate?
– They reflect solar radiation keeping the ocean
water cool.
25
• At what point does a wave touch the
ocean bottom in shallow water near the
coastline.
– Where the depth of water is about half the
wavelength.
26
• What causes a wave near the coastline to
break?
– The bottom of the wave is slowed by friction
but the top of the wave continues moving fast.
27
• A foamy mass of water that washes onto
the coastline is called a(n) ________.
– breaker.
28
• What is the height of a wave when it
breaks?
– One to two times the height of the original
wave.
39
• A current that forms when waves approach
the beach at an angle is called a(n)
______________.
– longshore current.
40
• Longshore currents flow _________ to the
shore.
– parallel
41
• Explain how a sandbar forms.
– If there is a bay or an inlet along the shoreline
where waves retract, sand carried by
longshore currents is deposited as wave
energy lessons.
42
• Which of the following is the most common
cause of tsunamis?
– earthquakes on the ocean floor
43
• Why is it incorrect to call a tsunami a tidal
wave?
– because a tsunami is not caused by tides
44
• The wave height of a tsunami in deep
water is usually
– less than 1 m.
45
• The wavelength of a tsunami in deep
water may be as long as
– 500 km.
46
• A tsunami has a huge amount of energy
because of
– its long wavelength.
The End
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RqrV4&NR=1