The Geosphere

1. The Geosphere Honors Biology Chapter 3

2. Definition • The solid part of the earth, including all rock, soil, and sediments • 6378 km radius • Determined by seismic studies

3. Composition • Crust – 70 km thick; light elements; brittle (1% of mass) • Mantle – 2900 km thick; medium density materials; fluid (64% of mass) • Core – 3400 km radius; densest metals (35% of mass)

4. 5 Layer Structure • Lithosphere – 15-300km; cool and rigid; crust and upper mantle; divided into the tectonic plates

6. 5 Layer Structure • Asthenosphere- 250km; plastic layer that can flex and allows plates to move on it

7. 5 Layer Structure • Mesosphere – 2550km; lower mantle

8. 5 Layer Structure • Outer core – 2200km; liquid nickel and iron

9. 5 Layer Structure • Inner core – 1228 km radius; solid nickel and iron

11. Plate Tectonics • Internal forces move plates • Divergent, convergent, and transform fault boundaries • Causes mountain building, seafloor spreading (below), earthquakes and volcanism

13. Mountain Building

14. Earthquakes • Fault – crack along which movement occurs • Quake – vibrations from movement • Magnitude – amount of energy released, measured by Richter Scale (2.0 felt and 9.5 largest measured); 7.0 is 31.7 times more energy than 6.0 • Majority occur on crustal plate boundaries

18. Volcanoes • Mountain built from magma/lava • Often near tectonic plate boundaries that are separating or colliding • Occur on land and under the sea

28. Erosion of the Geosphere • Removal and transport of materials • Removable because of weathering • Smooths and rounds features • Done by numerous agents: wind, water, gravity

29. The Wai'anae and Ko'olau mountain ranges no longer have rounded tops. They are two extinct jagged mountain ranges that have been cut into by streams and rain washing away rocks and dirt. This is called erosion.

31. The End (for now)