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Energy in Earth
Processes
It’s All About Work
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.***
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.
Electromagnetic Spectrum
Microwaves
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.***
What happens when
electromagnetic energy comes in
contact with a material?
It can be refracted
or bent.
The direction of
the waves are
changed.
It can be reflected or bounced off.
Transmitted or passed through.
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.***
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).
3 Methods of Transfer
Conduction, convection and radiation
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.
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.
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.
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.
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.***
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
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.