Geosphere Notes

1. LAYERS OF THE EARTH Geosphere
2. Geosphere • Solid part of the Earth’s crust that consists of all rock, and the soils and sediments on Earth’s surface. • Most located in Earth’s interior
3. Earth’s Interior • Seismic Waves: the waves that travel through the Earth’s interior during an earthquake. • Altered by the type of material that it travels through.
4. Seismologists • Scientists who measure changes in these waves to determine that the earth’s interior is made in layers.
5. Composition of the Earth • Three layers: • crust • mantle • core • Density increases towards the center of the Earth
6. Crust • Thin, outer layer. • Made up of light elements • less than 1% of Earth’s mass • 5-70km thick
7. Mantle • Layer beneath the crust • 84% of mass of Earth • 2,900 km thick • Made of • Lithosphere (20%) • Asthenosphere (9%) • Mesosphere (55%)
8. Lithosphere • Outer layer • cool, rigid • divided up into huge tectonic plates
9. Asthenosphere • 250 km thick • solid, plastic layer made of rock • flows very slowly and allows tectonic plates to move across
10. Mesosphere • 2,250 km thick • “middle” sphere • lower part of mantle
11. Core • 3,248 km radius • sphere of hot, dense nickel and iron • 4,000 - 5,000 °C • 15% of the Earth • Made of • Outer Core (7.5%) • Inner Core (7.5%)
12. • Outer Core; 2,200 km thick, outer shell, made of liquid nickel and iron • Inner Core: 1,228 km radius; a sphere of solid iron and nickel
13. • Be able to draw and label the three layers of the earth (crust, mantle, and core) as well as the 5 layers based on physical properties (lithosphere, asthenosphere, mesosphere, outer and inner core).
14. What is the rock cycle? • To show how rocks slowly change through time, scientists have created a model called the rock cycle. • It illustrates the processes that create and change rocks.
15. Rock Cycle Continued • The rock cycle shows the three types of rock— igneous, metamorphic, and sedimentary—and the processes that form them. • Weathering and Erosion – Weathering is the natural break down of rocks into smaller and smaller pieces. Erosion is the movement of broken rock from higher to lower elevations (down mountains and along streams). • Melting – Solid rock changing into magma due to very high heat • Heat and Pressure – Under many layers of earth’s crust, rock is exposed to a lot of heat and pressure
16. The Rock Cycle explains how Rocks and Natural Processes are related weathering Sedimentary Metamorphic Igneous
17. The Geosphere and Us • Volcanoes, earthquakes, and landslides • Provides soil, energy, and minerals • Mining and pollution affect geosphere