This is a powerpoint covering some of the main points of the earth's sources of internal and external energy. 9th Grade honors Physical Science covers this area very briefly.

1. Internal and External
Sources of Energy
by Emily Block and Lindsey LaBrie

2. Earth's Energy Sources
-Earth gets its energy in two ways:
-Internal (radioactive decay and gravitational
energy)
-External (the sun)

3. Earth's Early Internal Energy
-Far greater than what it is now due to 3
intense processes:
-Extraterrestrial Impacts (comets, meteors, etc)
-Gravity
-Radioactive Decay

4. Extraterrestrial Impacts
-Includes meteorites which contained iron and
stone, and comets
-When these things impacted the earth, they
added mass as well as size
-This increase in size lead to a greater
gravitational force

5. What it May Have Looked Like...

6. Gravity (Gravitational Energy)
-As the force of gravity
increased within the
earth, gravitational
energy made the
earth more
compact, which
turned into heat
energy
-Rocks are not good
conductors of heat,
and that is why the
core is much hotter
than the crust
-The heat that is present
in the core cannot
escape quickly

7. -Early earth had many more radioactive
elements than today, which means its core
used to be a lot hotter
-Radioactive elements break down over time
and release heat
-Some elements have a longer decay rate than
others, so they are still releasing heat energy
in the core

8. What Internal Energy Does
-Moves the continents around the globe
-Forms volcanoes and mountain ridges
-Causes earthquakes

9. Volcanoes
-Volcanoes are openings in Earth's crust that
release molten lava, ash, and gases.
-The molten rock is magma while under ground
and it is lava when it is above ground.
-Materials put off during a volcanic eruption:
-Lava, Water vapor, Hydrogen sulfide, Carbon dioxide,
volcanic bombs, lapilli (rock fragments), and ash.

10. 4 Types of Usable Internal Energy
-Chemical
-Nuclear
-Geothermal
-Rotational (least usable)

11. Internal Energy
-Results from the breaking down of
radioisotopes over time
-Drives plate tectonics due to conduction
-Renews the surface of the Earth

12. External Energy
-The Earth gets its external energy from the
sun
-The sun radiates its energy in all directions so
only a small fraction of it reaches the Earth
-On a sunny day, the planet receives 1,350 Joules of
energy per second.
-Sun's radiation is sufficient enough to run
Earth's processes

13. Solar Radiation
-Only 51% of the solar radiation that reaches the Earth is
absorbed by the surface
-19% is absorbed by the
atmosphere
-16% by gases and dust
-3% by clouds
-30% is lost in space
-24% is reflected upward
-6% is scattered upward

14. Radiation
-The numbers on the chart are an average for
the Earth as a whole
-Different materials reflect things in different
ways
-Shiny and light-colored objects reflect more
radiation than dark-colored objects

15. Albedo
-An albedo is the amount of radiation an object
reflects
-Snow reflects 90% of the radiation that hits it, it
absorbs the rest. Therefore, snow has an
albedo of 0.9
-A dark forest reflects 5% of the radiation that
reaches it, so it has an albedo of 0.05

16. Runaway Albedo Effect
-If the entire Earth were to be covered in ice, it would take a
great amount of time for it to all melt away.
-If the Earth were a ball of ice, the volcanic systems would
continue to produce and give off carbon dioxide.
-The carbon dioxide would soon fill up our atmosphere and
make the snow and ice melt away.
-The process of filling the atmosphere with CO2 would take
millions of years.

17. Citations
-Earth's Energy Budget. N.d. Photograph. Docstock.com. Malj, 14 July 2011. Web. 29
Apr. 2013.
Global Sources of Energy. N.d. Photograph. etap.orgWeb. 30 Apr 2013.
-"Internal and External Energy; Energy Budget." Earth Science Lesson 4--Energy in
the Earth System. N.p., n.d. Web. 29 Apr. 2013.
-Schuller, Jason. "Rock Of Ages." Wreckroom. N.p., n.d. Web. 02 May 2013.
-Simmons, Marty. "External Sources of Energy of the Earth." EHow. Demand Media,
28 Mar. 2011. Web. 01 May 2013.
-Sun and Earth Images. 2013. Photograph. hdwallpaperspics.comWeb. 30 Apr 2013.
-Tariq, Malik. "Giant Sun Eruption Captured in NASA Video -- Science &
Technology -- Sott.net." SOTT.net. Space.com, 17 Nov. 2012. Web. 07 May 2013.
-"The Earth's Heat Furnace." How Volcanoes Work. N.p., n.d. Web. 30 Apr. 2013.
-The Rock Scientist. "Earth As A Snowball Part 3." Mind Blowing Science. N.p., 10
May 2012. Web. 08 May 2013
-"Unit 8: The Earth's Internal Energy." Unit 8: The Earth's Internal Energy.
Slideshare, n.d. Web. 07 May 2013.