The Theory of Tectonic Plates
This theory states that the earth’s superficial crust is made of various broken pieces of the crust that are usually in constant motion. The broken pieces are always floating on top of the surface of the earth called the mantle. The mantle is liquid in nature and always generates the convectional currents that emanate from the epicenter of the universe called the core (Kusky, 2008). The core is deemed to be sweltering and hence having high temperatures that can even melt the rocks. The theory also states the movement that makes the plates be in constant motion is generated by the various conventional currents that emanate from the mantle. This movement occurs when the upper part of the mantle which is cooler and massive sinks and hot light inner part comes on top of the mantle (Silverstein, Silverstein, & Nunn, 2009). In this prospect, the movements that are seen in this advent make the tectonic plates be in continuous random movement.
There are two types of the tectonic plates, and these are the continental plates and the ocean plates. The oceanic plate is quite denser than the continental plates. In the event of the movements of the tectonic plates, various things happen at their boundaries. The boundaries can collide, move away from each other or simply move parallel to each other (Silverstein, Silverstein, & Nunn, 2009). These types of movements of the tectonic plates culminate into the emergence of various boundaries which leads to the formation of different sets of physical features that are deemed quite important to learn. Additionally, one of the determinant factors that would distinguish the feature that would be formed on a boundary is the type of tectonic plates that are involved then (Stein, & Mazzotti, 2007). There could be the boundaries of two continental plates, or two oceanic plates or a continental and oceanic plate’s movement.
Types of boundaries
As the tectonic plates are in constant motion, one of the changes that could happen is the collusion of the two tectonic plates. If the two tectonic plates collide, the resultant boundary that would be formed here is the convergent boundary. This collision can happen in three distinct ways. One of them could be the collision between two oceanic crusts (Kusky, 2008). This notion occurs in the sea and oceans. Two oceanic crusts under the random movement collide and form some physical feature such as the islands. For example, the islands that make the Philippines country was as results of the collusion of the Western Pacific oceanic crust. As the two oceanic crusts converged there emerged an upward force that pushed part of the oceanic crust upwards so that the islands could be formed (Gregersen, & Basham, 1989). Additionally, there could be a collision of the between the continental crusts’ plates within the continents which will eventually create mountains such as the Himalayas mountains. These movements are spearheaded by the high level of heat coming from the magma that would want to push the whole plates upwards.
Divergent boundaries form when the country tectonic plates move away from each other. In this movement can happen in two ways. One of them is the change where the two oceanic crusts move away from each other and causes various rifts in the ocean. The most prevalent physical feature that is formed here are the ocean trenches. The ocean trenches are some of the deepest areas in the sea (Silverstein, Silverstein, & Nunn, 2009). Furthermore, the divergent boundary can be seen within the continental crusts. Here tectonic plates made of the continental crust move away from each other and causes a rift and dangerous fault lines. The best example, in this case, is the rift valley that is found in the Eastern part of the African continent.
The last boundary that is formed is called a transformational edge. In this stance, the tectonic plates move parallel to each other. The movement is deemed to be quite constructive in nature. A closer look at the various prompts of this movement, as the plates move parallel to each other, they tend to form fault lines that would cause volcanic eruptions. These explosions happened in the oceans, and then they would create the islands while if they occur on the continental crust, then they are deemed to form the volcanic mountains (Kusky, 2008).
Putting Memphis Tennessee into context, the type of boundary that was created here was a divergent boundary. There was a continental drift of the North American plate. The flow was caused by the seismic waves that pushed the plates to moves asunder. The resultant effect was that there was the formation of the New Madrid Seismic zone for which earthquakes were very prevalent (Stille, 2007). The biggest earthquake happened in the year 1811-1812 with a magnitude of 6.6. This quake affected Memphis Tennessee a great deal. As the plates drifted, there was the formation of the faults, and this led to the inception of the valleys and frequent eruptions. There were also tsunamis in the nearby Atlantic Ocean. All these were the effects of the tectonic movement of the continental and the oceanic crust (Silverstein, Silverstein, & Nunn, 2009).
Stille, D. R. (2007). Plate tectonics: Earth’s moving crust. Minneapolis, Minn: Compass Point Books.
Silverstein, A., Silverstein, V. B., & Nunn, L. S. (2009). Plate tectonics. Minneapolis, MN: Twenty-First Century Books.
Kusky, T. M. (2008). Earthquakes: Plate tectonics and earthquake hazards. New York: Facts On File.
Stein, S., & Mazzotti, S. (2007). Continental intraplate earthquakes: Science, hazard, and policy issues. Boulder, Colo: Geological Society of America.
Gregersen, S., & Basham, P. W. (1989). Earthquakes at North-Atlantic Passive Margins: Neotectonics and Postglacial Rebound. Dordrecht: Springer Netherlands.