1. Waves transfer energy through water in the ocean. Individual water particles move in circles as a wave passes by rather than moving forward with the wave. 2. Key characteristics of waves include the crest (highest point), trough (lowest point), wavelength (distance between crests), and wave height (distance between crest and trough). Wavelength determines wave speed and how deep the wave disturbs the water. 3. As waves approach shore they slow down and steepen, eventually collapsing in breakers where the crest curls over. Tides are caused by gravitational attraction of the Earth, Moon, and Sun, and vary in daily and monthly cycles.

1. OCEAN
MOVEMENTS
1

2. Waves
A wave is a rhythmic movement that
carries energy through space or
matter, such as ocean water.
2

3. Waves
In deep water, a wave is a forward
motion of energy, not water. In fact,
the water does not move forward with
a wave. If we followed a single drop
of water during a passing wave, we
would see it move in a circular pattern
returning to a point near its original
position at the wave’s end.
3

4. Wave Characteristics
• A crest is the highest point of a
wave.
• A trough is the lowest point of a
wave.
4

5. •The vertical distance between crest
& trough is the wave height.
•The horizontal crest-to-crest
distance is the wavelength.
5
Wave Characteristics

6. Wave Characteristics
• The wavelength determines the
wave base, which is the depth to
which the wave disturbs the
water.
• Wave speed increases with
wavelength.
6

7. Wave Height
Wave height is determined by:
the strength of the wind, the expanse of water that the wind blows across (or the fetch), & the length of time of the dust (or duration.)
Large storm waves have higher than average heights.
7

8. Breaking Waves
 Ocean waves begin to lose energy
& slow down near the shore
because of friction with the ocean
bottom.
 As the wave approaches more
shallow water, or water that is
half the wavelength or less deep,
the incoming wave crests gradually
catch up with the slower wave
crests ahead.
8

9. collapse
forward when
the wave
becomes higher,
steeper, &
unstable as it
nears shore.
9
Breakers occur
where the crests

10. Breaking Waves

11. Breaking Waves
11

12. Tides
• Tides are the periodic rise &
fall of sea level.
• High tides are the highest
level to which water rises in
an area.
• Low tides are the lowest level
to which water recedes in an
area. 12

13. Tides
Generally, the daily cycle of tides is
determined by the Earth’s rotation &
the Moon’s orbit around Earth. As
the Earth rotates once on its axis (in
24 hours), the Moon is revolving
1/30th
of the way around in its orbit.
It takes a given location on Earth
about 50 minutes to “catch up with”
the orbiting Moon, so a particular
tide returns in approximately 24
hours & 50 minutes. 13

14. Differences in topography & latitude
cause three different daily tide
cycles.
The 3 tide cycles are:
1) Areas with semidiurnal cycles
experience two high tides per day.
2) Areas with mixed cycles have
one pronounced & one smaller high
tide each day.
14
Different Daily Tide Cycles

15. 3) Areas with diurnal cycles have
one high tide per day.
15
Different Daily Tide Cycles

16. 16
Different Daily Tide Cycles

17. Causes of Tides
• The basic causes of tides are the
gravitational attraction among the
Earth, Moon & Sun, as well as
the fact that gravitational
attraction decreases with
distance.
• The Moon has a greater affect
because it is closer to Earth. The
Sun, even though it is much larger
than the Moon, has a lesser affect
because it is farther from Earth. 17

18. 18
Monthly Tide Cycles: Spring & Neap Tides

19. 19
Monthly Tide Cycles: Spring & Neap Tides

20. Spring tides occur twice a month
during the full & new Moon. When
the Sun, Earth, & Moon are
aligned causing high tides to be
higher than normal & low tides to
be lower than normal.
20
Monthly Tide Cycles: Spring Tides
Spring think “straight line.”

21. Neap tides occur when the Sun,
Earth, & Moon form a right angle, as
seen during 1st
& 3rd
quarter Moon
phases. The gravitational pull of the
Sun & Moon “fight” each other, & we
notice smaller difference between
high & low tides. High tides are lower
& low tides are higher than normal.
21
Monthly Tide Cycles: Neap Tides
Neap think “ninety degrees.”

22. 22
Monthly Tide Cycles: Spring & Neap Tides

23. Ocean Currents
Currents are the movement of
water caused by differences in
temperature & salinity (density),
or caused by wind.
23

24. What causes the currents to flow in
different directions?
The CORIOLIS EFFECT
• The CORIOLIS EFFECT occurs
because Earth rotates East to West,
water and particles are deflected.
• In Northern hemisphere currents flow
clockwise & in the Southern
hemisphere currents flow
counterclockwise.
24
CORIOLIS EFFECT is responsible
for the patterns of currents &
WEATHER!

25. Surface Currents: Caused by the
movement of wind across the
oceans surface.
Deep or Denisty Currents: Caused
by the differences of temperature
or salinity of the water. 25

26. Surface Currents you need to know:
Gulf Stream, Canary, California,
North Equatorial, South Equatorial,
Kuroshio, East Australia, Peru,
Benguela, Antarctic Circumpolar,
Aguihas, North Atlantic, Greenland,
Labrador, & Brazil currents.
26

27. Deep Ocean or Denisty Currents:
Currents caused by the differences
in temperature & salinity. Not
affected by wind because they are
too deep.
These
currents are
known as
the Global
Conveyor
Belt.
27

28. Other Important Ocean Movements
Upwelling is where low-oxygen deep
water is moved up to the surface
due to differences in density. This
water is rich in nutrients which
supports marine life.
28