Heat From The Earth - GeothermalGeothermal refers to the production of heat in the depths of the earth and often refers to the utilization of this energy as a primary heating source for use by humans. The internal geothermal energy created by the earth begins primarily deep within the depths of the earth's core with the production and substantiation of molten magma or lava under the rock layers of the earth's many layers. This heat is furthered by the degeneration of rock resulting in the production of several molten metals as well such as uranium. Geothermal elements are then radiated out through the outer layers of the earth. The term "geothermal" is derived from the Greek "geo" meaning "earth" and "therme" meaning heat; thus, the term literally means "earth heat." Though the origins of geothermal energy are many, its origin is thought to have been due to the earth's consolidation of dust and gas during its formation billions of years ago. Geothermal energy, however, is still being created. Since the flow of heat is from hot to cold, the geothermal energy radiates from the inner layers outward, decreasing in temperature with each layer through which the heat is passed. 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. |