Earth’s Interior

1. Earth’s Interior

2. 1. What is the science of geology? • The Study of planet Earth

3. 2. What do geologist do? • They study the processes that create Earth’s features

4. 3. Describe 2 forces that change the surface of Earth • Destructive Forces: processes that destroy landforms. • 2 types: Slow (weathering) and Fast (Erosion) • Ex. landslides, volcanic eruptions, earthquakes, floods • Constructive forces:forces that build up an existing landform or create a new one. • Caused by: water, gravity, wind and glaciers. • Ex: deposition, landslides, volcanic eruptions, floods

5. Mechanical weathering:the breaking of rock into smaller pieces by forces due to gravity, ice, plant roots, or other physical forces.

6. Chemical Weathering: the changing of materials in a rock by chemical processes.

7. Grand Canyon Video Erosion • Erosion: the destructive movement of materials away from one place by wind, water, ice and gravity. Wave Erosion- caused by water Wind Erosion (Dust Storm)

8. Landslides • Landslides: occur when gravity quickly pulls rock and dirt downhill.

9. Floods Floods: a great flow of water over an area that is usually dry land.

10. Volcanic Eruptions • Volcano: an opening in the Earth’s crust through which steam, lava and ashes erupt. • Cause both destructive and constructive changes to landforms.

11. Mount St. Helens http://scetv.pbslearningmedia.org/resource/idptv11.sci.ess.earthsys.d4kmsh/mount-st-helens/ Saint Helen’s Before Saint Helen’s After

12. Volcanoes can be constructive, but also destructive…

13. Earthquakes • Earthquakes: the shaking of Earth’s surface caused by the release of energy along a fault. San Andreas Fault, California

14. Erosion & Deposition • Deposition: the placing of materials in a new place (constructive force). • Ex. Sandbars

15. Water Erosion & Deposition • River Delta- Deposits of sediment at the mouth of the Mississippi River creating new land called a delta.

16. Wind Erosion & Deposition • Sand Dunes- sand is moved by wind Desert Sand Dunes Ocean Sand Dunes

17. 4. How do geologist study the inside of the Earth? • Seismic waves produced by earthquakes and lava from volcanoes

18. 5. What are the main layers of the earth? • A.Crust-Thin layer of cool rock • Continental crust includes all contients and some islands • Oceanic crust includes all ocean floors • B. Mantle • Earth’s thickest layer (1700 mi) • Made of hot rock that is less dense than the metallic core • C. Core • Inner Core- a ball of hot solid metals • Outer Core- layer of liquid metals that surround the inner core.

19. http://www.learner.org/interactives/dynamicearth/structure.htmlhttp://www.learner.org/interactives/dynamicearth/structure.html

20. 6. Describe the Crust • Position- Outermost layer; thinnest under the ocean, thickest under continents; crust and top of mantle called the lithosphere • Density- Least dense overall layer; Oceanic crust (basalt) is more dense than continental crust (granite) • Composition- solid rock- mostly silicon and oxygen; oceanic crust-basalt; continental crust- granite

21. 7. Describe the Mantle • Position- Middle layer, thickest layer; top portion called the asthenosphere • Density- Density increases with depth because of increasing pressure • Composition- Hot softened rock; contains iron and magnesium

22. 8. Describe the Core • Position- Inner layer; consists of two parts – outer core and inner core • Density- Heaviest material; most dense layer • Composition- Mostly iron and nickel; outer core – slow flowing liquid, inner core - solid