Heat From The Earth - Geothermal

The earth's geothermal layers consist of the crust, the upper mantle, the lower mantle, the outer core and the inner core. The distance from the outer crust of the earth to the inner core is nearly 4,000 miles. The geothermal temperature increases with depth, making the crust the coolest point and the inner core the warmest point with the temperature reaching nearly 2,200 degrees Fahrenheit, 1,200 degrees Celsius. The majority of the geothermal heat created within the depths of the planet can be attributed to the natural decay of radioactive materials produced within the earth's center. Heat is also created from the electromagnetic pull on the earth and from the natural cycle of the earth's tides.

Geothermal energy is easier to trap in some spots than it is in others. Hot spots are located throughout the planet where the molten rock of the earth's depths is more readily at its surface, such as in areas with a frequency of volcanic activity. This is especially true in many of the islands in the Pacific, often referred to by scientists as the Ring of Fire, where the places of the ocean floor create friction along the continental places. Hot spots are also in locations in South America as well as other geographic areas. In fact, nearly seventy-percent of Iceland's energy is geothermal. Magma traveling to the earth's surface is most responsible for the internal radiation of heat. Geothermal energy is made most manifest in the formation of volcanoes on the earth's surface.

Geothermal reservoirs also exist throughout the globe. If these reservoirs are close enough to earth's surface, much of the geothermal energy is able to be reached by the drilling of wells into the depths. Such reservoirs are located through the use of magnetic and seismic surveys.