by 
Mackenzie Patel
Because I think anything related to our natural environment is appealing, I decided to discuss the fascinating topic of plate tectonics and how it differs from continental drift (another landmass theory). Both attempt to explain how our landmasses are situated the way they are today and why. They also are enmeshed with the lithosphere, the region of the Earth that contains the crust and the solid upper mantle. To start, the landmasses of our Earth were all bunched together in a supercontinent, Pangaea, millions of years ago. However, how have Africa and South America separated as well as Alaska and Russia? Simply feed your eyes and brain by reading the rest of this article.
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| Plate tectonics |
Plate tectonics is the movement of the earth’s crust (the upper portion of the lithosphere). The crust and major plates shift over time and separate to form new landmasses. The plates move in the first place because of the dispersed heat that is generated in the center of Earth by the liquid mantle rock. There are seven major plate boundaries on Earth: Antarctic, Indo-Australian, Pacific, South American, North American, African, and Eurasian. It is the boundaries between the plates that cause many natural disasters in today’s world. Take tsunamis for example: because of a convergent plate boundary, the giant waves are able to generate. At an oceanic-continental meeting of two plates, one plate (the oceanic) subducts under the continental plate. However, instead of a smooth subduction, the two plates catch/rub on each other, and friction occurrs. Once the continental plate finally snaps over the oceanic plate, a massive release of energy ensues and the tsunami is able to form. Once the energy is transferred to the ocean, the waves are able to rear their ugly heads and move quickly outward towards land. The water forms a wall over the land and crashes over it, inundating coastal beaches, businesses, and homes.
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| Continental Drift |
The other prevailing (but less accurate) theory is that of continental drift. It was proposed by the industrious Alfred Wegener in the early 1900s (c. 1915). Continental drift is the theory that the landmasses of Earth were all connected into one supercontinent, Pangaea. Over time, the large landmass separated and formed the continents we know today. This happened because of heat within the Earth’s mantle. Wegener cited evidence for continental drift (i.e. similar coastlines and organisms of South America and Africa), but it was generally weaker compared to the evidence for plate tectonics today. Plate tectonics is only considered a fact because it adequately explains the formation of volcanoes, trenches, mountain ranges, etc. Continental drift is vaguer and only talks about landmasses floating on top of the Earth’s surface.
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| Mariana Trench http://en.wikipedia.org/wiki/Mariana_Trench |