Plate techtonics

Running head: PLATE TECTONICS PLATE TECTONICS: Affiliation September 2008 The hypothesis plate tectonics clarifies the movement of the Earths plates. The name plate tectonics tell us how the Earths exterior is composed up of plates. In geology science, a plate is a big block of rock, whereas the tectonics is a word of Greek that has the meanings to build ThinkQuest(2008). The assumption of plate tectonics turned out to be generally established by scientists of the 1960s and 1970s era. It transformed our perception of the Earth and combined the Earth sciences, from the learning of paleontology (fossils study) to the science of earthquakes which is also known as seismology. According to this theory, the Earths crust is composed up of about a dozen plates or big rock slaps on which the continents and oceans lies. Plate tectonics explains the big scale movements of Earths lithosphere. The theory comprises the developed beliefs of continental drift, urbanized throughout the initial half of the 20th century, and seafloor scattering, understood during the 1960s Wiki (2008). The furthest part of the Earths center comprises two layers: top layer is the lithosphere which surrounds the coating and the inflexible topmost part of the layer. Inferior the lithosphere the asthenosphere lies. While the hard, the asthenosphere has comparatively small thickness and shear potency and is able to stream like a liquid on geological time scales. The inner deeper layer under the asthenosphere is extra rigid yet again due to the higher stress / pressure ThinkQuest(2008).
The lithosphere is divided tectonic plates, if we talk about the Earth; there are 7 main and important plates and many small/ minor plates. These plates are frequently shifting their position because the surface under them, the boiling, hot, soft layer, is changing position gradually similar to a conveyor strap/ belt, determined by heat and other forces at work in the Earths core/ center. These plates or slaps are changing their positions or moving at speed of approximately a centimeter (0. 5 inch) to 15 cm (6 inch) per year in diverse directions. In scientific notations this movement is called as “ cross motion of the plates is naturally at rate of 50-100 mm/a” Wiki (2008).
Now we talk about the main and big plates of earth. As we have discussed earlier there are seven main plates. Listed below from Earth Science Enterprise (2004).
Figure 1 Earth main plates Source [Zoomschool. com]
The main plates are
African Plate
cover Africa [it is a Continental plate ]
Antarctic Plate
cover Antarctica – [it is a Continental plate ]
Australian Plate
cover Australia – [it is a Continental plate]
Indian Plate
cover Indian subcontinent and few parts of the Indian Ocean- [it is a Continental plate ]
Eurasian Plate
cover Asia and Europe – [it is a Continental plate ]
North American Plate
cover North America and north-east Siberia -[it is a Continental plate]
South American Plate
cover South America – [it is a Continental plate]
Pacific Plate
cover the Pacific Ocean – [it is a Oceanic plate ]
Famous small plates include the: Earth Science Enterprise (2004).
Arabian Plate
the Caribbean Plate
the Juan de Fuca Plate
the Cocos Plate
the Nazca Plate,
the Philippine Plate
the Scotia Plate
The lithospheric plates lie on the asthenosphere. These plates change their positions or move in relation to each other at one of three kinds of plate borders or boundaries:
Crash boundaries
Dispersal boundaries
Changed boundaries
Earthquakes, volcanic exploit, mountain formation, and oceanic exhaust configuration happens because of plate boundaries.
Now we talk about the Continental drift. It is the movement of or change in the position of the Earths continents compared to one another. The idea that continents drift was originally proposed by Abraham Ortelius in 1596 and was fully urbanized by Alfred Wegener in 1912. However it is fully developed after the advancement of the assumption of plate tectonics in the 1960s that is an adequate geological clarification of that movement was understood (louie, 1996).
Alfred Wegener argued that today’s continents were fashioned from a sole landmass, to which he given name Pangaea.  It ruined into parts due to the weak spots in the earths crust as they were composed up of less thick materials, which move smoothly centimeter by centimeter over millions of years and they reached at where they are present now. It is probable for the plates to shift appropriate to the convection currents in the mantle (louie, 1996).
The motion of plates can be explained with an example of water and cattle. The motion of these currents is comparable to the motion of convection currents in cattle of boiling water.
Boiled water inflates and increases the surface of the cattle.  In the same way, the magma nearer the core increases and goes upward. Water that has increased the surface of the cattle spreads out crossways the outside, cools and goes down to the base.  Similarly, the magma that has increased spreads out under the plates.  As the magma spreads out side, the plates are pulled next to and they shift away from each one other.  This is known as the sea-floor spreading (louie, 1996).
When the magma goes down, the plates are drawn towards one another.  This is the procedure of subduction.  The frequent warming and rising of the magma locates up nonstop convection currents in the mantle, reasoning the plates to move. So this is the all the process of Continental drift (louie, 1996)
REFERENCES
1. Earth Science Enterprise. (2004). Retrieved on September 29, 2008. Retrieved from: http://kids. earth. nasa. gov/
2. Louie, J. (1996). Retrieved on September 29, 2008. Retrieved from: http://www. seismo. unr. edu/ftp/pub/louie/class/100/seismic-waves. html
3. ThinkQuest. (2008). Retrieved on September 29, 2008. Retrieved from : http://library. thinkquest. org/17457/platetectonics/1. php
4. Wikipedia The free Encyclopedia. (2008). Retrieved on September 29, 2008. Retrieved from: http://en. wikipedia. org/