Chapter 3 key terms

Chapter 3 The Dynamic Earth
Key Terms
1. Geosphere – the solid part of the Earth that consists of all rock, as well as the soils and loose
rocks on Earth’s surface.
2. Crust – Earth’s thin outer layer, composed almost entirely of light elements.
3. Mantle – layer beneath the crust, makes up 64% of the mass of the Earth.
4. Core – Earth’s innermost layer, densest elements
5. Lithosphere – Earth’s outer layer, includes crust and upper mantle, broken into tectonic plates.
6. Asthenosphere – layer beneath the lithosphere, plastic, solid layer of the mantle mad of rock
that flows very slowly and allows tectonic plates to move on top of it.
7. Tectonic plate – a block of lithosphere that consists of the crust and the rigid outermost part of
the mantle
8. Erosion – process in which the materials of Earth’s surface are loosened, dissolved, or worn
away and transported from one place to another by a natural agent, such as wind water, ice, or
9. Atmosphere – a mixture of gases that surrounds a plant, such as Earth
10. Troposphere – the lowest layer of the atmosphere, in which temperature drops at a constant
rate as altitude increases; the part of the atmosphere where weather conditions exist
11. Stratosphere – the layer of the atmosphere that lies between the troposphere and the
mesosphere and in which temperature increases as altitude increases; contains the ozone layer
12. Ozone – a gas molecule that is made up of three oxygen atoms.
13. Radiation – the energy that is transferred as electromagnetic waves, such as visible light and
infrared waves.
14. Conduction – the transfer of energy as heat through a material.
15. Convection – the movement of matter due to differences in density that are caused by
temperature variations; can result in the transfer of energy as heat.
16. Greenhouse effect – the warming of the surface and lower atmosphere of Earth that occurs
when carbon dioxide, water vapor, and other gases in the air absorb and reradiate infrared
17. Water cycle – the continuous movement of water between the atmosphere, the land, and the
18. Evaporation – the change of state from a liquid to a gas.
19. Condensation – the change of state from a gas to a liquid.
20. Precipitation – any form of water that falls to the Earth’s surface from the clouds; includes rain,
snow, sleet, and hail.
21. Salinity – a measure of the amount of dissolved salts in a given amount of liquid.
22. Fresh water – water that contains insignificant amounts of salts, as in rivers and lakes.
23. Biosphere – the part of Earth where life exists.