The development and background of plate tectonics
Plate tectonics arises from two words; plate and tectonic. Plate in geological terms implies a sizable slab of hard rock as tectonics in Greek implies’ to build’. Therefore’ plate tectonic should be defined as how the earth’s builds on transferring the plate. It may possibly also be well-defined for a phase for the Earth’s lithosphere which is rigid moves distinctively from those people bordering it (Rodger, 1993).
Idea of plate tectonics states that the lithosphere within the earth is constructed up of individual plates that fragmented into multiple considerable and compact pieces of strong rock. The plates move future to each other along with the lessen mantle to develop numerous types of plate borders that have shaped the Earth’s landscape around many decades. (Oreske & Legrand, 2001).
Alfred Wegener, a populous meteorologist, is known to be the founder of the plate tectonic theory. He noticed the coastline of East South America and that with the west coast of Africa seemed to fit together in a jigsaw manner like to form a bigger plate. He then proposed an idea that all plates (continents) connected to a single giant plate called Pangaea which gradually began to drift apart about 300 million many years ago (Rodger, 1993).
More scientific research on the plates’ coastline revealed that all the plate of earth’s continent somehow fit together. The principle, commonly known as continental drift idea, and Wegener became the founder for the theory on which scientist have based on their research.find here
However, Alfred Wegener plate tectonics principle could not ascertain how exactly the continents drifted away from every other. He proposed the earth’s rotations and the centrifugal forces towards the equator as one in the possible mechanism for continental drift. He said that Pangaea started at South Pole and earth’s rotation finally caused it to break up, sending continents toward the equator. His theories were discarded by the scientific community (Rodger, 1993).
Arthur Holmes, (1929), a British geologist, came up with the idea of thermal convection to explain the gradual drift from the Earth’s continents. He based on heating and cooling cycle from the Earth’s mantle that caused the continents to shift. The Wegner’s idea being borrowed by scientist community in their quest for earth’s shape.
Today scientist have researched and analyzed past pieces of evidence and findings by geologist and scientist to expound and come up with a better ways of explaining plate tectonic concept and forces that were behind the drifting on the plates. It is believed and proofed using geological evidence that earth’s plate at one time was one big supercontinent called Pangaea. Due to three main driving forces namely, mantle convection, gravity, and the Earth’s rotation led to the drifting away for the a multitude of plate from the main one. Some major plates (continents) formed which include North America, South America, Eurasia, Africa, Indo-Australian, Pacific, and Antarctica.
Expounding on the three main driving forces for the movement within the Earth’s tectonic plates; Mantle convection is the most extensively studied technique of tectonic plate movement. It was widely discussed by Holmes in 1929, in his principle. The large convection current of molten material in the Earth’s upper mantle produces a lot of energies which is transferred to cheaper mantle. The decreased mantle material finds their way to the crust causing the embedded rock to shift away and out from the ridge thus going the plate. Evident of this is present in mid-ocean ridges.
Gravity evidenced by the mid-ocean ridges where the elevation is higher than the bordering ocean floor. Convection currents within the Earth cause lessen mantle material to rise and spread away from the ridge, causing the older material to flow toward the ocean floor due to gravity and aid in the movement within the plates. Then lastly earth rotation is caused by centrifugal forces as the earth rotates (Oreskes $ Legrand, 2001).
Plates build different kinds of the boundaries as they interact with their movement. Some on the boundaries established include the Divergent boundaries form when a plate breaks along certain lines of weakness and go away from every other forming a new crust, for instance, Mid-ocean ridges. The other boundary is called Convergent boundaries and created when two plates collide with one another causing the sinking of one plate below the other. Transform boundaries forms at the location where new crust created and without destroying it.
Today, through research, scientists have come up with shreds of evidence proving that earth plates were once super plate that split into the current Continent. One belonging to the evidence is the jig-saw fitting within the East coast of South America, west coast of Africa appear to fit into one another. Also, Fossils remains of plants and animals collected by scientist around the world showed similarities that were cumbersome to explain unless continents had once joined. For instance, Cynognathus was a land reptile; its Fossils remain present both Africa and South America. Thus proving that the two continents joined as one, millions of decades ago, (Oreskes $ Legrand, 2001). Scientists have also found out from the evidence of earthquakes happened continually and occurred along certain lines, near the boundaries between tectonic plates.
As Wegener’s ideas form the basis why the landscape within the earth is the way it is, scientist community has advanced the methodology of studying the plate tectonic concept currently. They use the satellite to study evidences of plate tectonic where they position it several kilometers away from the earth surface. From the satellite statistics, it is evidenced which the plates move linearly and away from every other at the speed of 10mm to 100mm per year. Thus proving that plate tectonic principle that could be earth was once one plate that gradually drifted apart greater than millions of decades back to form the current continents.