Plate Tectonics
Introduction.
Alfred Wegener made a proposition in 1912, which stated that a number of the continents seemed to neatly fit into a sort of jig saw puzzle thus implying that these continents were once a single land mass-which he called “pangaea”.geological studies of these continents in the past-refered to as continental plates-have revealed that indeed they fit together as well as the plates under seas and oceans to form a continous land mass that probably existed billions of years back during the formation of the planet earth. These plates were perhaps separated due to various tectonic forces, however; at times they still impact each other through occasional movements that cause earthquakes, volcanic eruptions as well as other natural phenomenon such as tsunamis (ETE, n.pag).
These plates exist side by side and they are separated by fault lines which create different types of boundaries between the plates. These fault lines are planar fractures that create discontinuities in rocks that make up the continetal or teutonic plates. They occur in places where diplacements of a significant size have occured. These faults are a result of tectnic forces acting on the continetal plates. There are three types of basic plate boundary lines created by fault lines. These include divergent boundaries, convergent boundaries and transform bounadaries. Divergent boundaries occur in fault lines where plates separate further from each other laeding to the development of new earth crust along the faultline. Convergent boundaries occur in fault lines where two teutonic plates approach one another in a form of collision which causes one plate to dive under another plate. Finally, transform bounadries occur on fault lines where there is no new crust formation, and all that happens is the sliding of one plate parallel to the other (Gardiner, n.pag).
Teutonic plates, faults and plate boundaries
These teutonic plates are in actual sense made up of two major layers that form up what is termed as the earth crust. The two major layers are the crust (the upper most earth layer) and the mantle (the layer beneath the lithosphere). The plates constitute of the crust (upper most earth part) and the mantle layer below the crust and their combination forms the lithospehere which is approximately 80 kilometres deep. These gigantic plates move occasionally while sliding over a semi-solid layer of molten rock beneath them (Gardiner, n.pag). This semi solid layer is what is termed as the asthenospehere. This semi solid layer is ductile and it can deform and get pushed like putty as it responds to the heat of the earth and other forces. The churing motion of teh molten interiror of teh earth causes stresses that cause the asthenosphere to move. The flowing layer beneath teh mantle actually carries the continenatl plates on its upper layers (USGS, n.pag).
Generally, the lithosphere is more solid, cooler and on the upper most part of the earth, whereas; the asthenosphere is beneath the lithosphere’s mantle and it has semi-solid and hot form that is flowy. Unlike the asthenospehere the lithosphere is not flowy and it is relatively static, but its occasional motion is determined by the asthenosphere (ETE, n.pag).
Conclusion
The earth is made up of continental plates whose solid part made up of the crust and mantle layer. This part is termed as the lithosphere and it floats on top of a flowy and at times turbulent asthenosphere which is semic solid in nature. The flow of this asthenosphere determines the coccasional movement of the lithosphere and hence the tectonic plates. The resultant motions may make plates to collide, move further apart or move in a parallel shear motion. All these movemnts result in various happening such as eathquakes, volcanic eruption and many more.
Works Cited
Exploring the Environment (ETE). Plate tectonics, 2005. Retrieved on 18th February 2011from http://www.cotf.edu/ete/modules/msese/earthsysflr/plates2.html, 2005. Web
Gardiner, Lisa. The earth’s crust, Lithosphere and athenosphere; Windows to the universe.org, 2008. Retrieved on 18th February 2011 from http://www.windows2universe.org/earth/interior/earths_crust.html, 2008. Web
USGS, Understanding plate motions, USGS.gov, 1999. Retrieved on 18th February 2011 from http://pubs.usgs.gov/gip/dynamic/understanding.html, 1999. Web
Is this your assignment or some part of it?
We can do it for you! Click to Order!
