Tectonic Plate Movements

Plate Tectonics and Earth’s Movements

Plate tectonics is a scientific theory that explains how the earth’s plates move and grind together. According to the idea, the world is made up of a hard crust known as the lithosphere, divided into seven continental-sized layers that rotate relative to one another (Nemeth, 2012). These continental plates will converge, diverge, or grind along their borders, according to Nemeth (2012). Major earth formations and destructions, such as mountain formations, ocean formations, volcanoes, and earthquakes, are caused by these movements. This paper examines a news article from The New York Times about the earthquake that struck Mexico City on September 19, 2017. The relationship between this occurrence and plate tectonics is that earthquakes are among the most common natural disasters. “The relationship between this event and plate tectonics is that earthquakes are among the various geographical events caused by the movements and grinding of the earth’s plates. In the past less than sixty days, the world has been hit by numerous earthquakes in different countries with magnitudes of between 3 and 6. However, Mexico recorded a higher magnitude of 7.1, leading to a huge destruction.

The Mexico Earthquakes and Plate Tectonics

According to Semple (2017), this earthquake was the second in less than a fortnight in Mexico. It was, however of a lesser magnitude from the previous which had a magnitude of 8.1. Coincidentally the earthquake hit on the 32nd commemoration of the greatest and most disastrous earthquake in Mexico. Semple (2017) explains that both earthquakes happened approximately 400 miles apart by occurred in a region where the earth’s plates are sliding beneath each other hence causing massive impacts to the earth’s surface. He, however, adds that it cannot be confirmed whether the two are connected although they recorded different magnitudes.

The Impact of Plate Tectonics on Earth’s Geography

Plate tectonics is responsible for a number of the earth’s formations and geography such as the rising of mountains when the plates converge. When the plates diverge there is the formation of oceans or the spreading of the coastal floor (Parks, 2016). Earthquakes, majorly occur along belts coinciding with boundaries of tectonic plates. Parks (2016), explains that the most important belt is the Circum-pacific Belt which affects most coastal regions along the Pacific Ocean such as New Zealand, Japan, Alaska and part of the north and south America particularly the west coast (Parks, 2016).

The Different Types of Plate Boundaries

When the earth’s plates come together to form convergent boundaries, the earth crumbles and rises into mountains such as the Himalaya which happened more than 55 million years ago (Parks, 2016). The convergent boundaries can also occur during a subduction. This is when an oceanic plate dives beneath a land mass hence forming ranges. The event can also lead to the melting of the diving plate leading to volcanic eruptions (Nemeth, 2012). In the instance two ocean plates converge, they form deep trenches in the ocean or form underwater volcanic eruptions to form islands (Parks, 2016). When the earth’s plates diverge in the ocean, Magma from the earth’s mantle rise pushing apart the two plates to form volcanic mountains along the seam. A new ocean floor is made and a widened basin (Parks, 2016). Divergent boundaries on Earth cause giant troughs, for example, the Great Rift Valley in Africa.

The Role of Transform Boundaries in Earthquakes

The third kind of boundaries brought about by tectonic plate movements are the transform boundaries. The article acknowledges that the Mexico earthquakes were as a result of this kind of boundary. The boundary is formed when two lithospheric plates move or grind past each other. These boundaries cause a sudden release of energy which can be in form of an elastic strain, gravity or chemical reaction. Parks (2016) argues that earthquakes are as a result of the release of the earth’s stored energy through the elastic strain. He adds that tectonic earthquakes occur when the restrained energy in the rocks exceed the capability of the rocks to hold it. This leads to the fracturing of the rock and exceeding several miles along the same line of weakness. According to the New York Times article, the earthquake covered a distance of 55 kilometers and with a strong shaking of about 20 seconds. It leads to the death of more than 220 people and thousands of others homeless.

Earthquakes and Faults

A single fault can be the cause of several other earthquakes in the past and future. It is, however not always clear whether all the energy released is as a result of a single fault plane. According to Semple (2017), Scientists are still trying to figure out the connection between the two earthquakes in Mexico, one with a 7.1 magnitude and the other with an 8.1 magnitude. It is assumed that they both experienced an energy release from a similar fault. Geological faults have relative displacements in distances of hundreds of kilometers over geological time but sudden slips generate seismic waves that vertically range from a few centimeters to tens of meters (Parks, 2016).

The Impact of the Mexico Earthquake

The article ends with an explanation as to the massive damage and loss of lives by the earthquake despite being of a lower magnitude than the previous one which recorded lesser damage. Semple (2017), states that the epicenter of the September 19th Earthquake was closer to the city hence affecting a larger population and causing more infrastructural damage.

Conclusion

Plate tectonics events and in our case, earthquakes have detrimental effects. If the latest frequency of this event is to go by, there will be more destructions, deaths, and casualties from these disasters. Plate tectonics, however, are natural geographic occurrences that cannot be controlled by man. The only human effort to avert such destruction is by limiting the number of infrastructures and population living along the identified faults and possible areas of plate grinds and slips.

References

Nemeth, J. D. (2012). Plate tectonics. New York: PowerKids Press.

Parks, P. J. (2016). The importance of plate tectonic theory. San Diego: ReferencePoint Press, Inc

Semple K. (2017). Mexico Earthquake Kills Hundreds, Trapping Many Under

Rubble. Nytimes.com. Retrieved 9 November 2017, from

https://www.nytimes.com/2017/09/19/world/americas/mexico-earthquake.html

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