Slide 1
The interior of the earth is divided into a core, mantel and crust. The upper mantel is divided into a lower plastic layer known as the asthenosphere and an upper rigid layer known as the lithosphere. There are two types of crust, thick continental crust composed of less dense granitic rocks and thinner oceanic crust composed of more dense basaltic rocks.
Slide 2
A large amount of heat energy is escaping from the earth. However, because it is spread out over a large area this heat energy is useless.
Slide 3
The geothermal gradient is the increase in temperature with depth in the earths crust. Geothermal resources occur in areas with a high geothermal gradient such as areas above igneous intrusions.
Slide 4
The earths lithosphere is divided into a number of large rigid plates which ride on top of the more plastic asthenosphere. Geologic phenomena such as earthquakes, volcanoes and mountain building occur at the boundaries between these plates. Areas of potential geothermal resources occur at plate boundaries.
  • Geothermal 3
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