1. Announcements I will be writing PS #1 over the weekend, and posting it by Monday… It will be due Feb 9 th .

2. Clarification: The angle of Earth’s tilt does not change during the year! Views of the Earth from the Sun’s perspective It only looks that way from the sun’s frame of reference .

3. The axis is always parallel to itself.

4. Quiz 2!

5. 2. Sun Angle: insolation curves

6. 2. Sun Angle: insolation curves Winter Summer Autumn Spring Winter

7. Insolation 23.5 o axis tilt 0 o axis tilt

8. An Equation for the Sun Angle On an equinox Declination = 0 °

9. An Equation for the Sun Angle On an equinox Declination = 0 ° At the equator Lat = Sun angle = 0 ° 90 °

10. An Equation for the Sun Angle On an equinox Declination = 0 ° At the north pole Lat = Sun angle = 90 °N 0 °

11. An Equation for the Sun Angle On an equinox Declination = 0 ° At some latitude x Lat = Sun angle = x °N 90 °- x° x ° 90 °- x°

12. But then we have to adjust for declination! Equator is sub-solar point North pole tilted toward the sun North pole tilted away from the sun Equator is sub-solar point Summer Winter Fall Spring

13. But then we have to adjust for declination! Sun Angle = 90 °-x° Sun Angle = 90 °-x° Sun Angle = 90 °-x°-23.5° Sun Angle = 90 °-x°+23.5° Summer Winter Fall Spring

14. Final Formula Sun Angle at Noon = 90 ° - Latitude° + declination° Summer Note: this formula is for the angle with the southern horizon, so it makes the most sense to only use it in the Northern Hemisphere

15. Lithosphere: solid Earth

18. Grand Canyon Layers

20. A roadcut photo that I stole… WV maybe?

22. Roadcut near Moab, UT

23. A B C D Events: A deposited B deposited C deposited D deposited Faulting Erosion of Surface X Erosion of Canyon But in what order? Order of Events: D deposited C deposited B deposited Faulting Erosion of Surface X A deposited Erosion of Canyon X

24. Events: A deposited B deposited C deposited D deposited E deposited F deposited G deposited Folding Erosion of Surface X Order of Events: G deposited F deposited E deposited D deposited C deposited Folding Erosion of Surface X B deposited A deposited A B C D X E F G

25. Events: A deposited B deposited C deposited D deposited E deposited F deposited Folding Faulting Erosion of Surface X Erosion of Surface Y Order of Events: F deposited E deposited D deposited C deposited Folding Erosion of Surface Y B deposited Faulting Erosion of Surface X A deposited A B C D X E F Y

26. Events: Cooling of Granite A Deposition of Sandstones B, E, & I Deposition of Shales C & H Deposition of Limestone D & F Cooling of Basalt G Folding (Tilting) Faulting Erosion of surfaces X, Y, Z Formation of mesa Order of Events: 1 . A 9 . E 2 . X 10 . F 3 . B 11 . Z 4 . C 12 . G 5 . D 13 . H 6 . fold/tilt 14 . I 7 . Y 15 . mesa 8 . fault