1. Ocean Motion Part 1: Waves

2. Define wave: Wave – a rhythmic movement that carries energy through matter or space. Wave – a rhythmic movement that carries energy through matter or space. – in the ocean, waves move through seawater.

3. Parts of a wave Crest Trough Wavelength

4. Parts of a wave: Crest – the highest part of a wave. Crest – the highest part of a wave. Trough – the lowest part of a wave. Trough – the lowest part of a wave. Wavelength – the distance between two adjacent crests. Wavelength – the distance between two adjacent crests. Wave height – the vertical distance between the lowest part and the highest part. Wave height – the vertical distance between the lowest part and the highest part.

5. Most waves caused by wind Friction from the wind moving over the water causes the water to move along with the wind. Friction from the wind moving over the water causes the water to move along with the wind. If the wind speed is high enough, the water begins to pile up and a wave is formed. If the wind speed is high enough, the water begins to pile up and a wave is formed.

6. How water moves in a wave: Particles of water move around in circles. The farther below the surface, the smaller the circle. Waves move the water in a circular motion, and the energy travels across the water. At a depth about equal to half the wavelength, the motion stops.

7. Energy Wind blown steadily over a great distance will create a large amount of energy. Wind blown steadily over a great distance will create a large amount of energy. Eg. northeast trade winds across the Pacific Ocean near Hawaii or Westerlies across the Atlantic Ocean Eg. northeast trade winds across the Pacific Ocean near Hawaii or Westerlies across the Atlantic Ocean The energy can be harnessed as an energy source. The energy can be harnessed as an energy source.

8. At the beach: Wavelength decrease and wave height increases as waves approach the shore. Wavelength decrease and wave height increases as waves approach the shore. Constant Wavelength Waves drag against the bottom and wave length decreases

9. At the beach, part 2 As the wave slows, its crest and trough come closer together. The top of the wave is not slowed by friction and moves faster than the bottom. As the wave slows, its crest and trough come closer together. The top of the wave is not slowed by friction and moves faster than the bottom. The top of the wave outruns the bottom and falls over. This collapsing wave is called a breaker.

10. Tides Caused by the gravitational pull of the moon Caused by the gravitational pull of the moon When the moon is directly overhead, the water is pulled towards it. When the moon is directly overhead, the water is pulled towards it. There is a similar bulge on the opposite side of the Earth There is a similar bulge on the opposite side of the Earth Low tides are at right angles Low tides are at right angles

11. Tides

12. Types of Tides Spring Tides: Spring Tides: –occur when the sun aligns with the moon. –Happens about twice a month –Tides are higher than normal Neap Tide Neap Tide –the line of the sun and moon are perpendicular –The pulls works against each other –Tides are lower than normal

13. Timing of the Tides The tide cycle takes 12 hours and 25 minutes The tide cycle takes 12 hours and 25 minutes Eg. low tide at 7am, the evening low tide will be at 7:25pm. Eg. low tide at 7am, the evening low tide will be at 7:25pm. High tide occurs halfway through High tide occurs halfway through – Approx. 1:12pm The tidal time moves forward about 50 minutes each day. The tidal time moves forward about 50 minutes each day.