The theory of plate tectonics states that the plates on which the continents reside move steadily over the planet’s surface as a result of their residence upon a substratum of magma (Dictionary.com, 2012). Continental drift is the term that is used to describe the lateral continental movement which occurs as a result of the movement of crustal plates (Dictionary.com, 2012). It is this movement of the plates that creates the cause and effect nature of continental drift and earthquakes; as one plate moves, it shifts into another plate, causing either the two plates to hit directly, causing one plate to slide underneath the other, or causing the two plates to scrape past each other, like two ships in the night.
Originally, the landmasses of the world were all present in one area, a landmass that is referred to today as Pangaea. During the Jurassic period this supercontinent started to break up, starting the basis for the theory of continental drift, originally proposed in 1912 by Alfred Wegener (Encyclopaedia Brittanica, 2013). These continents reside on separate plates, working to move apart at oceanic ridges and coming together, providing the shifting effect discussed previously, in subduction zones and other areas.
What most people consider to be solid ground, the ground that all creatures on the planet walk upon, is actually the top of the continental crust of the Earth itself. The lower portion of this crust is made up of older rocks that have a lower density than those upon the surface of the earth itself, and this lower density works to allow them to float on the mantle; the solid crust and the upper part of the mantle itself are referred to as the lithosphere, comprised of fourteen separate tectonic plates, and it is those plates which reside on the substratum of magma (San Andreas Fault, 2010).
The effects of continental drift may be seen throughout the globe, though the earthquakes that they cause are not always immediately noticeable, as is the case in New Zealand, where silent earthquakes occurring deep under the country are working to push parts of the lower North Island out of shape (Bevan, 2006); between 2002 and 2006 alone there were seven different silent earthquakes, causing geologists to state, back in 2006, that a crack which opened up in 2005 may eventually stretch until it reaches the Red Sea, working to isolate much of Ethiopia and Eritrea from the rest of Africa (New Ocean, 2006).
Earthquakes are typically only reported by major news media outlets when a great loss of life occurs as a direct result of an earthquake, though these events happen on a daily basis; most people fail to realize how much of an everyday occurrence earthquakes truly are, coming about as a result of the process of continental drift. Though these earthquakes may not be reported by news media outlets, they are tracked by geophysicists who are working to determine not only the effects of continental drift and earthquakes on the resulting landmasses surrounding the epicenter, but they are also working to see if they are able to determine any specific patterns, or gain an increased ability to predict said occurrences. For example, when a pattern of earthquakes presenting in either shallow, intermediate, or deep focus occurs on the same angle as, or a similar angle to, the descending plate, inclined steeply toward the continent behind the trench, the pattern enables the geophysicists to trace the plate that is descending to depths between 600 and 700 kilometers, a level at which temperatures are believed to be in a range between 1,800 degrees Fahrenheit and 3,600 degrees Fahrenheit (Subduction Zone, 2010).
When these two plates work to cause an earthquake, this is done as a result of what is known as a lateral slipping movement, when the force and the pressure created by the collision causes the earthquake itself to happen. Lateral slipping movement occurs when two plates that are next to each other slide along this bed of magma, brushing against each other. The best way to explain this type of movement would be to look at the type of movement that a person makes when attempting to walk with their shoes tied together. The feet are close to each other and the shoes scrape against each other in a north south orientation; in plate tectonics this may occur in any orientation, between two touching plats. They may shift up to down, left to right, or even diagonally.
Plate tectonics and the subsequent continental drift that they cause, combined with the resulting earthquakes, are a part of our planet’s daily life; there are geologists and seismologists who make their living, and their careers based on studying the resulting patterns and working to attempt to predict when the next earthquake will occur. The theory of plate tectonics, which, as mentioned, includes the theory of continental drift, provides the basic framework for studying the geology of the earth itself. It causes volcanos, tsunamis, and earthquakes, and it serves to provide, through a change in the landmasses and climate, pushes for the evolution of various species. As it may be seen there are many different effects that originate as a result of continental drift, of which earthquakes are one such example.
The ground below our feet is not solid, and it is important for all individuals to be aware that the ground that they walk on is as much in motion as their feet are, and those motions work together in a cause and effect symbiosis to create this system of motion. Through an understanding of this process of cause and effect, individuals will be better able and better equipped to understand the different changes and variances which occur in the world around them, regardless of whether or not it is an earthquake so miniscule that it is barely felt, if it is felt at all, or if it is an earthquake so large that an entire city, or more, is destroyed in its wake.
