1. Do Now Estimate what time the sun rose this morning Estimate what time the sun will set today What has been happening to the hours of daylight?

2. Overview Effect

3. Chapter 26.2 Movements of Earth

4. Aim: What is rotation and what are its effects?

5. Objectives Provide evidence for Earth’s rotation Explain how Earth’s rotation is related to day-night cycles and time zones

6. What is rotation? Spinning of Earth on its axis

7. What is the axis? Axis –I–Imaginary line running through Earth –A–Axis tilted 23.5 0 –A–Axis points to Polaris –T–Tilt is constant

8. What evidence is there to prove rotation? Focault Pendulum (1851) Wind & Coriolis Effect –N hemisphere = deflected right –S hemisphere = deflected left

10. What is the rate of rotation? 1 complete turn = 24 hours 15 0 per hour Rotation faster at the equator than poles

11. What are the effects of rotation? Coriolis effect Day and night –Apparent moving of the sun across the sky each day

12. Handout Intro to Insolation What is insolation????

13. How do we measure time? Position of the sun Solar noon = sun’s highest point –Moves 15 0 each hour

14. Why do we have standard time zones? To solve the problem of having different solar times in nearby areas 24 world wide time zones (15 0 apart) International Date Line

16. What is the starting point for the time zones? Prime Meridian –“–“line” running through Greenwich, England –W–West = move clocks back –E–East = move clocks ahead

18. Time warp…the International Date Line Imaginary line representing the longitude at which so much time is gained or lost…the date changes West = day later East = day earlier Lies within a time zone, so time is the same…but date is different!!!!