The theory of tectonics has been brought forward by many scientists in the world, but all of them have come to one conclusion. Plate tectonics is the study of how the planet plates (earth plates) are shaped and driven by geographical forces which are found in the earth, and it is a result of these forces that keep these plates at constant motion on the earth’s surface. “The outermost layer of the earth is made up of a solid shell and these solid shells are crack into many large pieces and these pieces are called earth plates and they are usually 50 miles (80km) thick” (Naomi, 2003).
“In history, this theory was told by many geological scientists, but the first comprehensive plate tectonic theory was formulated by the scientist from Germany know as Alfred Wegener and this was in 1912” (Naomi, 2003). “In his hypothesis, he declares that the earth seven continents are made up of lighter rocks which rest on heavier materials, and these materials are sometimes called crustal material and lighter materials usually float on the heavier crustal material” (Naomi 2003), this can be compared to icebergs floating on the water at sea. The theory of Plate tectonics states that the earth was made up of one continent millions of years ago, but this one continent broke down into many continents and they drifted from one another forming several continents and these continents are today; Africa, Australia, Europe, Antarctic, Asian, South and North America. While several small earth plates exist apart from these 7 major ones and these are Arabian plates, Nazca plate, and Philippines plate. Also, this theory explains how major earth’s features like mountains, volcanic eruptions and how they were formed and similar animals found in the earth could have lived on the earth continent when it was one block and on what is now widely seen as the seven continents which are found in the earth.
The theory of plate tectonics can be explained in two methods and the first method is spreading. In this method, the two tectonic plates are spreading apart forming cracks that will be found on the earth’s crust. These cracks will be filled with lava (molten rocks) and this lava will erupt if pressure from the earth surface builds up and as a result of that it will form new land, an example of a feature formed due to the spreading method is the rift valley which spread from Asia continent down to East Africa. The second method is called subduction, in this method, two tectonic plates move toward each other and the denser plate will be forced under the lighter plate which is found in the earth crust. “Deep trenches have been formed in the ocean and sea as a result of subduction and this sometimes will give rise to earthquakes which are mostly found in places like Japan” (Naomi, 2003).
Many geology scientists don’t agree with the hypothesis brought forward by Alfred Wegener in the year 1912 but there is a general theory that is acceptable to all geology scientists. According to this general theory on plate tectonics they believe- the scientist- the earth surface has been broken down into many plates or shifting slabs and they are 50 miles in thickness, these plates are in constant motion which is relative to the individual tectonic plate and they are found above a hot layer know as the earth core. Most of the active volcanoes are found along shifting plates on the earth’s surfaces but sometimes these active volcanic mountains are not connected with the plate boundaries of the earth’s surface.
References
Naomi, C. (2003).Plate tectonics: an insider’s history of the modern theory of the Earth. London: Westview Press.