1. Ocean Waves and Tides

2. Waves
A Wave is a rhythmic movement that carries energy through matter or space.
In oceans, waves move through seawater

4. Waves Caused by: Wind Earthquakes
Gravitational force of the Moon and Sun.

5. Parts of a Wave Crest – highest point of a wave
Trough – lowest point of a wave
Wave Height – vertical distance between the crest and the trough
Wavelength – horizontal distance between two crests or two troughs

6. Wavelength
Crest
Wave Height
Still Water
Trough
Wave Parts

7. Wave Movement
When a wave passes through the ocean, individual water molecules move up and down but they do not move forward or backward.

9. Wave Movement
When a wave breaks against the shore, the crest outruns the trough and the crest collapses.
Called a breaker.
In this case, water does move forward and backward.

11. Waves Caused by Wind
When wind blows across a body of water, friction causes the water to move along with the wind.
Wave Height depends on –
Wind speed
Distance over which the wind blows
Length of time the wind blows

15. Deep Water Waves
Deep water do not move horizontally, most of the water is actually moving in a circular pattern

16. Shallow Water Waves
As waves enter shallow water, they become taller and slow down, eventually breaking on the shore.

17. Lesson Check #1 What moves forward in a wave? A. Molecules B. Energy
C. Water
D. Bobbers

18. Lesson Check #2
Would waves be higher or lower on a very windy day? Why?

19. Lesson Check #3
Write a sentence describing a wave’s crest and its trough.

20. Opening: 10/28
Yesterday you learned how wind can shape a wave. Would you rather go to the beach on a windy day, a calm day, or during a storm? Predict what the waves will be like each day.

21. POP Question #1
What is a tide?

22. Tides The rise and fall in sea level is called a tide.
Caused by a giant wave.
One low-tide/high-tide cycle takes about 12 hrs and 25 min.
Tidal range is the difference in ocean level between high-tide and low-tide

23. To find the difference what do you do?
What is the Tidal Range?
HT = 30 ft, LT = 20 ft
HT = 20 ft, LT = 12 ft
HT = 50 ft, LT = 20 ft
To find the difference what do you do?

24. Answers
30 ft - 20 ft  10 ft
20 ft - 12 ft  8ft
50 ft - 20 ft  30ft

25. POP Question #2
What is the moon’s relationship to tides?

26. Gravitational Effect of the Moon
Two big bulges of water form on the Earth:
one directly under the moon
another on the exact opposite side
As the Earth spins, the bulges follow the moon.

28. POP Question #3
Explain what a Spring Tide is.

29. Gravitational Effect of the Sun
Spring Tides
Earth, Moon, and Sun are lined up
High Tides are higher and Low Tides are lower than normal

31. POP Question #4
Explain what a Neap Tide is.

32. Gravitational Effect of the Sun
Neap Tides
Earth, Moon, and Sun form right angles
High Tides are lower and Low Tides are higher than normal

34. Lesson Check #1
Describe what causes high tides.

35. Lesson Check #2
Describe what causes Spring Tides.

36. Lesson Check #3
Describe what causes Neap Tides.

37. Draw illustrations explaining Wave Parts, Spring Tides, & Neap Tides
Homework
Draw illustrations explaining
Wave Parts, Spring Tides, & Neap Tides