Physical Geography

1. Physical Geography

2. Milky Way

3. Our Solar System • Mercury • Venus • Earth • Mars • Jupiter • Saturn • Uranus • Neptune • Earth is 93 Million Miles from the Sun

4. The Earth • Earth is 24,900 miles in circumference • 7,900 miles in diameter

5. The Earth Inside Out • Inner and Outer Core – solid metallic center - made up of iron and nickel • Mantle – molten rock about 1,800 miles thick • Magma – molten rock - created when the mantle melts the underside of the crust • Crust – thin layer of rock at the earth’s surface

6. Earth has four spheres Atmosphere Lithosphere Hydrosphere Biosphere These spheres are interconnected and each one affects the others Earth’s Spheres

7. Earth’s Spheres • Atmosphere – layer of gasses surrounding the earth • Lithosphere – the solid rock portion of the earth’s surface - some is below the water and is the ocean floor

8. Earth’s Spheres • Hydrosphere – water elements of the earth (oceans, rivers, lakes, etc.) • Biosphere – part of the earth where plants and animals live

9. Hydrologic Cycle • The continuous circulation of water between the atmosphere, the oceans, and the earth.

10. Pangaea • Continental Drift • The earth was once a supercontinent that divided and slowly drifted apart over millions of years. • Pangaea • From the Greek meaning “all earth”

12. Oceans • 71 % of the earth is covered by the ocean • 60 % of the Northern Hemisphere • 81 % of the Southern Hemisphere • Atlantic Ocean, Pacific Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean

14. Ocean Motion • Ocean Currents – like rivers flowing through the ocean • Winds blow over the water and are either heated or cooled – then blow over the land and moderate the temperature of the air over the land • The motion of the ocean helps distribute heat on the planet

16. Ocean Motion • Waves – swells or ridges produced by winds • Tides – regular rises and falls of the ocean created by the gravitational pull of the moon and sun • The motion of the ocean helps distribute heat on the planet

17. El Nino • El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific. • As opposed to La Niña, which characterized by unusually cold ocean temperatures in the Equatorial Pacific. • El Niño is an oscillation of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe. • http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html

18. El Nino • Among these consequences are increased rainfall across the southern tier of the US and in Peru, which has caused destructive flooding, and drought in the West Pacific, sometimes associated with devastating brush fires in Australia. • Observations of conditions in the tropical Pacific are considered essential for the prediction of short term (a few months to 1 year) climate variations.

19. Lakes • Lakes hold over 95% of the earth’s fresh water • Lake Baikal (Russia) – 18% of all fresh water • Fresh water lakes – result of glaciers • Salt water lakes – result of the ocean outlets being cut off Example) Great Salt Lake (Utah)

20. Rivers and Streams • Rivers and streams flow through channels and move water to or from larger bodies of water • Rivers and streams work like branches of a tree – the smaller tributaries feed into larger and larger rivers. • The area drained by a major river and its tributaries is a drainage basin

21. Landforms • Landforms are naturally formed features on the surface of the earth.

22. Oceanic Landforms • Similar to those above the water • Ridges • Valleys • Canyons • Plains • Mid-Atlantic Ridge – longest continuous under water mountain range

23. How Are Islands Formed? • Volcanic Action • Deposits of Sand • Coral Skeletons

24. Topographical Maps • Show the landforms with their vertical dimensions and their relationship to other landforms.

25. Internal Forces Shaping the Earth

26. Plate Tectonics • Internal forces that shape the earth’s surface begin beneath the lithosphere • Tectonic plates are enormous moving pieces of the earth’s lithosphere • These moving plates causes the continuing reshaping of the earth

27. Tectonic Movement • Divergent • Convergent: Subduction • Convergent: Collision • Transform

29. Fault • Fracture in the earth’s crust • It is at the fault line that the plates move past each other

30. Earthquakes • As the plates grind or slip past each other at a fault line, the earth shakes or trembles. • Thousands of earthquakes occur every year – most aren’t strong enough to feel • Some, however, are VERY destructive

32. Seismograph • Seismograph measures the size of the waves created by an earthquake.

33. Earthquake Location • Focus – location in the earth where an earthquake begins • Epicenter – the point directly above the focus on the earth’s surface • 95% of all earthquakes occur around major plate boundaries

34. Richter Scale • Uses information collected by seismographs to determine the relative strength of an earthquake. • 2 – probably wouldn’t even feel it • 4.5 – probably reported in the news • 7 or more – major earthquake

35. Tsunami • Can produce waves 50 to 100 feet high. • Video 2

37. Volcanoes • Lava – Magma that has reached the earth’s surface

38. Caldera • http://en.wikipedia.org/wiki/File:Origin_of_volcanic_caldera_via_analogue_model.gif

39. Ring of Fire

40. Mt. St. Helens • Video 1 • Video 2

41. Geyser