Energy in Earth Processes

1. Energy in Earth Processes It’s All About Work

2. Energy • The ability to do work. • Everything that is done in the universe involves the use or transfer of energy. • ***Energy from the sun drives most Earth surface processes.***

3. Electromagnetic Energy • Transverse waves radiated by the sun. • Transverse waves vibrate at right angles to the direction of movement. • Most familiar is visible light. • ***Different types distinguished by wavelength.*** • See page 14 of ESRT.

4. Electromagnetic Spectrum Microwaves

5. Electromagnetic Spectrum • On the chart – Longer wavelength to the right, shorter wavelength to the left. • ***Visible light is the only part that can be seen with the human eye.*** • ***Heat is given off as infrared radiation.***

6. What happens when electromagnetic energy comes in contact with a material? • It can be refracted or bent. • The direction of the waves are changed.

7. It can be reflected or bounced off.

8. Transmitted or passed through.

9. Absorbed or taken into the material. • Dark colors absorb more than light colors. • Rough texture absorbs more than smooth. • ***Thus, dark, rough objects are the best absorbers of the sun’s energy.***

10. Energy Transfer • Energy (heat) moves from an area of high concentration (source) to an area of low concentration (sink). • This will continue until the energy between the source and the sink are even (dynamic equilibrium).

11. 3 Methods of Transfer • Conduction, convection and radiation

12. Conduction – transfer of heat energy from atom to atom or molecule to molecule. Ex. Hot pot handle. • Convection – transfer of heat by movement in fluids, liquids and gasses. Convection currents transfer heat throughout Earth’s atmosphere, hydrosphere and mantle. Ex. Smoke rising from a campfire. • Radiation – heat transferred via electromagnetic waves. Can go across empty space. Fastest – travels at the speed of light.

13. Heat & Temperature • Temperature – average kinetic energy of particles in a substance. • Heat – total kinetic energy of particles in a substance. • Heat always flows from higher energy to lower energy.

14. Calorie • Different substances heat up at different rates. • Unit for measuring heat quantity is the calorie. • Defined as the quantity of heat needed to raise the temperature of 1 gram of water 1 degree Celsius.

15. Specific Heat • The quantity of heat required to raise the temperature of 1 gram of a substance 1 degree Celsius. • Every substance has its own specific heat, and it is different from all other substances. • Liquid water is the highest at 1.0 cal/goC. • Page 1 ESRT.

16. In simple terms specific heat is the resistance of a substance to heating up or cooling off. • ***Large bodies of water have a major moderating effect on weather and climate because water has the highest specific heat of any natural substance.***

17. Heat Energy and Changes of State • Melting – solid to liquid • Solidification or freezing – liquid to solid • Evaporation or vaporization – liquid to gas • Condensation – gas to liquid • Sublimation – solid to gas

18. Stored Heat and Changes of State • When a material is in one of the 3 states, its temperature rises as heat is added to it. • If the material is in the process of changing state, its temperature remains the same.