1. Notes on “Waves & Tides” Earth/Space

2. S.W.B.A.T. Describe wave formation Describe wave formation Distinguish between the movement of water particles in a wave and the movement of the wave Distinguish between the movement of water particles in a wave and the movement of the wave Explain how ocean tides form Explain how ocean tides form

3. Wave Characteristics Wave – a rhythmic movement that carries energy through matter and space Wave – a rhythmic movement that carries energy through matter and space Wind, earthquakes, landslides, the Sun & Moon (tides) all generate waves Wind, earthquakes, landslides, the Sun & Moon (tides) all generate waves

4. Wave Characteristics Only the energy moves forward in a wave Only the energy moves forward in a wave Water particles do not move forward unless a wave is breaking on shore Water particles do not move forward unless a wave is breaking on shore

5. Wave Characteristics The crest, trough, wavelength and wave height describes a wave The crest, trough, wavelength and wave height describes a wave Crest – high point in a wave Crest – high point in a wave Trough – low point Trough – low point

6. Wave Characteristics Wavelength – horizontal distance from crest to crest or trough to trough Wavelength – horizontal distance from crest to crest or trough to trough Wave height – vertical distance between crest & trough Wave height – vertical distance between crest & trough

7. Wave Characteristics Energy is transmitted through the water in 3- dimensions Energy is transmitted through the water in 3- dimensions Orbital waves – water particles move in circles or orbits Orbital waves – water particles move in circles or orbits This allows energy transfer between liquids and/or gases This allows energy transfer between liquids and/or gases

8. Water Orbital Wave Movement

9. Wave Characteristics Other wave characteristics include frequency and fetch Other wave characteristics include frequency and fetch Frequency – number of wavelengths that pass a fixed point over time Frequency – number of wavelengths that pass a fixed point over time Fetch – describes speed & constant wind direction over time and distance Fetch – describes speed & constant wind direction over time and distance

10. Wave Characteristics Fetch can create huge waves Fetch can create huge waves Highest wave ever experienced at sea was over 112ft! (U.S.S. Ramapo 1933) Highest wave ever experienced at sea was over 112ft! (U.S.S. Ramapo 1933)

11. Wave Characteristics Rogue waves – rare and unpredictable ocean waves Rogue waves – rare and unpredictable ocean waves Wave heights are huge & damaging to ships Wave heights are huge & damaging to ships Rogue waves are probably the result of extensive fetch and a combining of swells Rogue waves are probably the result of extensive fetch and a combining of swells

12. Ocean Swells Can Combine to Form Larger Waves

13. Rogue Waves Can Occur in Non-Stormy Seas Video (1:32) “Rogue Wave Hits Cruise ShipVideo (1:32) “Rogue Wave Hits Cruise Ship” Video (1:32) “Rogue Wave Hits Cruise Ship

14. Tides Tides - gradual rise & fall (high & low) in sea level Tides - gradual rise & fall (high & low) in sea level Tides can have a wave height of only 1-2 meters Tides can have a wave height of only 1-2 meters However - tide wavelength can be thousands of km long However - tide wavelength can be thousands of km long

15. Tides Tides are caused by the gravitational pull of the Sun & Moon Tides are caused by the gravitational pull of the Sun & Moon The Moon exerts a stronger pull because it is closer to Earth The Moon exerts a stronger pull because it is closer to Earth

16. Tides Change as the Earth Rotates and the Moon Orbits the Earth

17. Tides Tidal range – difference between high & low tides Tidal range – difference between high & low tides As Earth rotates its surface passes through both high and low positions As Earth rotates its surface passes through both high and low positions Most coastlines experience two high and low tides each day – depending on ocean basin shape & size Most coastlines experience two high and low tides each day – depending on ocean basin shape & size

18. Mont-Saint-Michel - Normandy, France at High Tide

19. Mont-Saint-Michel at Low Tide - 13.5m Difference

20. Tides Extreme tidal ranges occur due to shoreline shape Extreme tidal ranges occur due to shoreline shape Bay of Fundy in Nova Scotia, Canada has a tidal range of 15m due to its funnel-like shape Bay of Fundy in Nova Scotia, Canada has a tidal range of 15m due to its funnel-like shape Video (1:52) “Bay of Fundy’s TidesVideo (1:52) “Bay of Fundy’s Tides” Video (1:52) “Bay of Fundy’s Tides

21. Tides Spring Tides – when the Moon, Earth & Sun line-up to produce even higher tides Spring Tides – when the Moon, Earth & Sun line-up to produce even higher tides This happens about twice a month This happens about twice a month

22. Tides Neap Tides – when the Moon, Earth & Sun are at right-angles Neap Tides – when the Moon, Earth & Sun are at right-angles Gravity is nearly “canceled out” giving very little tidal pull Gravity is nearly “canceled out” giving very little tidal pull This also happens about twice a month This also happens about twice a month

23. Class Activity Many planets have more than one moon Many planets have more than one moon Explain what tides might be like if Earth had two moons Explain what tides might be like if Earth had two moons