UNIT 1 – Geosphere Vocabulary Definitions
1. Nuclear Fission – when large nuclei are split into smaller nuclei; emit neutrons and heat energy; process used in nuclear power plants
2. Nuclear Fusion – when smaller nuclei combine into larger nuclei; emits massive amounts of energy; process used by stars to produce energy
3. Radiation – the transfer of heat energy through space by electromagnetic waves
4. Electromagnetic Waves/Spectrum – the arrangement of electromagnetic radiation according to wavelengths
5. Cosmic Rays – immensely high energy radiation; mainly originate outside the Solar System
6. Rock Cycle – the model that illustrates the origin of the three basic rock types and the relationships between Earth materials and processes
7. Metamorphic Rock – form from changes in temperature and pressure; examples are slate and marble
8. Igneous Rock – crystallize from magma; examples are obsidian and basalt
9. Sedimentary Rock – form from compacted and cemented sediments; examples are sandstone and shale
10. Plate Tectonics – theory that explains the structure of Earth’s crust as rigid plates that move slowly over the underlying mantle
11. Mantle Convection – transfer of thermal energy by movement of heated matter; ridge push and slab pull
12. Lithosphere – rigid outer shell of Earth including the crust and solid uppermost part of the mantle
13. Convergent Boundary – where two tectonic plates are moving toward each other; form trenches, island arcs, folded mountains; destroy Earth’s crust
14. Divergent Boundary – where two tectonic plates are moving away from each other; form volcanoes, earthquakes, high heat flow; create Earth’s crust
15. Transform Boundary – where two tectonic plates slide horizontally past each other; form long faults, shallow earthquakes; conserve Earth’s crust
16. Faults – a fracture in Earth along which movement has occurred
17. Focus – place along a fault line from which an earthquake originates
18. Epicenter – the location on Earth’s surface directly above the focus (origin) of an earthquake
19. Magnitude – a measure of the size of seismic waves, or the amount of energy released at the source of an earthquake
20. Magma – a body of molten rock found at a depth in the Earth; includes any dissolved gases and crystals
21. Mechanical Weathering – when physical forces break rock into smaller pieces without changing the rock’s composition; ice wedging
22. Chemical Weathering – the process where the internal structure of a mineral/rock is altered by the removal/addition of elements; dissolving of limestone by acid rain
23. Erosion – movement of weathered materials from one location to another
24. Deposition – final stage of erosion process when sediments are laid down on the ground or settle to the bottom of a body of water
25. Foliation – a zone of weakness in a sedimentary rock
26. Mass movement – movement of loose sediments and weathered rock due to the force of gravity
27. Soil – a combination of minerals, organic matter, water and air; produced over long periods of time by the processes of weathering, erosion and deposition