Mineral and Power Resources-Geothermal Fields

Geothermal fields are sources of electricity, as several experiments have proven that one can generate electricity through formation of vapors. Hot water streams which arise on the earth’s surface have the capability of generating electricity while replacing older sources. Eventually, this can help with meeting the electricity demand of such a huge population all across the whole world. The formation of geothermal fields is not a difficult process, as just a heat source, a space where the water can be stored and vaporized along with a cover layer is required for the whole process taking place within.   

What does one know about geothermal fields? 

Water seeping down through the cracks caused within rocks while covering a distance of several thousand kilometers in order to reach the hottest core of earth results in the formation of geothermal fields. As the water finally reaches the hot inner surface, a process of convection takes place, and water starts getting vaporized. The hot vapors formed again travel back to the surface of the earth and are often found in hot springs, or fumaroles, also known as hot mud holes. Along the boundaries of a tectonic plate, this phenomenon is a common one; however many times the pathway of water ascending is blocked due to the presence of an impermeable rock layer. As a result, the water which cannot reach the hot core region gets accumulated within the porous rocks which lie under the impermeable layer. The water which gets collected in the process can attain a temperature that is more as compared to that attained at the surface. These geothermal fields are of great advantage in several aspects, so they are bored through the impermeable layers. As soon the impermeable layer is bored, and a hole gets created, the hot water which is present inside tries its best to get out. Due to high pressure created within, the water emerges on the surface which is utilized wherever needed. Digging boreholes through hot springs has revealed how the hot water reservoirs are created within, and from where this hot water is emerging continuously. Quite remarkable research works have been carried out till date so that more detailed information can be gathered. In order to locate the underground spots, so that they could be drilled and when hot water emerges on the ground, they are utilized wherever needed. Several tools have been invented and launched into the market which are capable of identifying spots of hot water reservoirs, which are capable of developing hot springs. Besides hot springs, there are few spots that only produce steam, such spots are difficult to find, as they are rarely seen. Hot water springs are the most common behavior, found in several countries around the world.  

Where are geothermal fields found? 

In general, the geothermal fields are identified through hot springs, especially found in Italy, California, and New Zealand along with several other countries. Those spots which produce only streams are rare to be found, while Geysers of California and Larderello which is present in Italy are two examples of these rare type spots. Active geothermal resources are majorly found along the boundaries of tectonic plates. Volcanoes are also found to be situated along the boundaries of tectonic plates, and Ring of Fire is the name of one among the list of active geothermal regions.            

Process taking place

Looking similar to a hydrothermal trap, geothermal regions consist of a source, aquifer, and impermeable rock.

• The heat source is the region where heat is produced, like the earth core, or magma which is undergoing the cooling processes. These sources are hot and execute enough heat so that water reaching the place gets vaporized.
• An aquifer is a place that has pores within, and acts as a purifier, as the water gets purified while circulating with the pores. Geologically formed, such places have several pores associated within, which allows the water to get stored within. 
• An impermeable layer of cover rock also plays an essential role in the whole process, which acts as a trap. Water after covering thousands of kilometers gets trapped within porous rocks due to the impermeable layer of rocks, which do not allow it to flow further. This layer of rock works as a cover plate, and as a result, as the water is further heated it gets vaporized. 

A similar process can be created artificially, as there are the requirements of three major things, which are a heat source, cover plate, and space where water can be stored and evaporation can take place.   

Conclusion 

Water travels a long distance from the surface to the inner core of the earth, passing through cracks and faults that have been created within rocks. However, a barrier gets created while traveling through due to the impermeable layer. This impermeable layer of rock does not allow the water to pass through, and it gets stored within porous rocks. This amount of water can attain a temperature even more as compared to the temperature which can be attained on the surface. However, a source producing heat, which can be the inner temperature of earth or cooling magma that helps in vaporization process to take place within. The vapors which are created get stored and circulate within the porous rocks. Further, they are either dug or naturally come out to the surface due to internal pressure caused. These spots of hot water springs are utilized for generating electricity and are found in several parts of the world.