2. I. What Causes Tides? 1. Tides- The daily rise and fall of Earth’s waters on its coastlines. 2. High tide- as tide comes in, water level increases gradually and reaches its highest point. 3. Low tide- tides goes out, flowing back toward the sea and reaches its lowest point.

3. High and Low Tides

5. A. Gravity and Tides 1. Tides are caused by the interaction of Earth, moon, and sun. It is caused by GRAVITY. 2. As the distance btwn objects increases, gravity’s pull grows weaker. 3. Fig. 12 p. 367

6. Teach time Teach your neighbor: 1. what high tide and low tide is. 2. what causes tides.

7. 4. The moon pulls on the water on the side of Earth closest to it more strongly than it pulls on the center of the Earth. This pull creates a bulge of water called a tidal bulge on the side facing the moon. 5. The moon also pulls on the earth, pulling it away from the water on the other side. 6. The water farthest from the moon is pulled toward the moon less than other parts of Earth and is “left behind” forming a second bulge.

8. 6. High Tide- place where there are tidal bulges. 7. Low Tide- Place btwn the bulges. 8. There are 2 high tides and 2 low tides each day. 9. High tides occur about 12 hrs and 25 min. apart. 10. How do landforms and the basins at the mouths of rivers affect the height of the tide?

10. Oral Quiz 1. How many high tides are there in one day? 2. How many low tides are there in one day? 3. How many hours is one high tide from the next high tide? 4. How many hours is it from high tide to low tide?

11. Ocean Tides  www.brainpop.com

12. B. Spring Tides 1. Twice a month at new and full moons, the sun and moon are lined up with earth. 2. The gravity is much greater at this time and it produces the greatest difference btwn the heights of high and low tide called spring tide.

13. C. Neap Tides 1. When the sun and moon pull at right angles, so there is little difference btwn high and low tide is called neap tide. 2. A tide with the least difference btwn high and low tide is neap tide.. 3. P. 369

15. Teach Time Teach your neighbor about spring tide and neap tide.

16.  1. Sailors, marine scientists, people who fish, and others who live along a coast need to know about tides. Why?  2. The energy stored in tides is potential energy. (energy that is stored up and not used yet).  3. The energy of tide water moving back to sea powers generators that produce electricity for tidal power plants. This is clean energy.

18. Spring and neap tides