1. TIDES The EBB and FLOW

2. Tides are affected by... Gravitational pull of the moon Gravitational pull of the sun Centrifugal force of earth as it rotates Position of the sun & moon Angle of orbit of moon around earth

3. The Earth... Makes one revolution around the sun per year Rotates on its axis about once per day

4. The Moon... Revolves around the Earth at an angle 28.5 o to the Earth’s equator Revolves once every 29.53 days

5. A TIDE is... The alternate rising and falling of sea level as a result of the gravitational forces exerted on the Earth by the sun and moon

6. Flood Tide: A rising tide, moving inward

7. EbbTide: A falling tide, moving outward

8. Two competing forces produce tides... Gravitational between moon and Earth Centripetal between sun and Earth

9. Tidal Range: The difference in height between successive high and low tides

10. Spring Tides- High Highs & Low Lows Spring tides- during a new and full moon, when earth, sun & moon line up- produces highest of high and lowest of low tides

11. Neap Tides Medium Highs & Lows Neap tides- during the 1 st & 3 rd quarter moons, when the earth, sun, and moon are at right angles (work against each other) -Produces small high and low tides.

12. Equatorial & Tropic Tide: Caused by angle and pull of moon at different positions to the Earth

13. Diurnal Tides: One high and one low per day (one cycle) DAY ONEDAY TWO

14. Semidiurnal Tides: Two highs and two lows per day (two cycles) DAY ONEDAY TWO

15. Tides are modified by Land Weather Coriolis force

16. Lunitidal Interval: The lag in time between when you expect the tide and when it actually occurs

17. Tidal Bore: A true tidal wave that moves up a river

18. Tide tables The moon circles the earth every 24 hours 50 minutes. Tides occur 50 minutes later each day. Tides can be easily calculated in order to ensure safe navigation in areas like harbors

19. Put on your thinking cap!

20. What can happen to a ship if a seaman fails to check his tide table?

21. It could get stuck at low tide!

22. How can knowing the time of high and low tide aid in fishing?

23. High tide carries fish in, they get trapped at low tide.

24. At which tide level would you have the best luck beachcombing?

25. LOW TIDE!

26. Why are tides important to estuaries, bays, and marshes?

27. Tides bring fish in to spawn and for food.

28. Are tides a source of energy?

29. They have been harnessed to produce energy in power plants!