Volcanoes, geysers, hot springs, and fumaroles are examples of this. Volcanoes erupt and spew magma from deep in the earth and somehow found its way to the surface. Fumaroles, which emit mixtures of steam and other gases, are fed by pipes that pass through the water table before reaching the surface of the ground. Geysers, on the other hand, are hot springs that become thermodynamically unstable and periodically erupt, throwing water into the air. Because our fossil fuels are rapidly deteriorating, we are continually searching for energy sources to take their place.
Geothermal energy seems to be a very likely candidate for many reasons.
It is a clean alternative that does not pollute our environment like fossil fuels do when we attempt to harness their power. More importantly, geothermal energy is renewable. This means that our use of it is limitless. Other uses of geothermal energy include the generation of electricity and the production of heat.