Why Did the Continents Drift Apart?
One of the most convincing explanations of why the continents drifted apart is that the earth expanded considerably after its creation. This theory can be illustrated by imagining earth as a balloon and the continents as pieces of paper stuck on the outside. As the balloon is blown up the pieces of paper will grow farther apart. Other theories suggest that the continents only appeared to drift apart because masses of land were drowned under volcanic waters.
But it has been demonstrated that land masses are, in fact, made to drift, by the heat generated from the earth’s interior and from earthquakes. Probably a combination of various theories may be necessary to provide a complete explanation.
Alfred Wegener’s theory of continental drift states that the existing continents of the earth were once glued together forming a super landmass. Over time, the landmass broke and drifted away and is still drifting to this day. In his proposal, he stated that the super continent, which he named Pangaea, meaning ‘’all earth” once existed. The supercontinent was surrounded by water bodies, mainly oceans, and seas.
As a result of movement of the supercontinent, Pangaea split into two super landmasses namely Laurasia and Gondwanaland. Laurasia, makes up the northern continents of today. The northern continent consists of Europe, North America, and Asia. Gondwanaland makes up the southern continents of today. The southern continent consists of South America, Antarctica, Australia, India, and Africa. While making this claim, he had a collection of evidence to support it.
The causes of continental drift are perfectly explained by the plate tectonic theory. The earth’s outer shell is composed of plates that move a little bit every year. Heat coming from the interior of the earth triggers this movement to occur through convection currents inside the mantle. Over the course of millions of year ago, this gradual movement caused the once combined supercontinent to separate into 7 continents you witness in the present day.
Almost all plate movement occurs in boundaries which lie between different plates. When plates drift away from each other, there is formation of new crust at divergent boundaries. On the other hand, tectonic movement destroys crust during interaction of the plates. Destruction happens when one plate moves below the other at convergent boundaries. However, the crust is never destroyed when plates move past one another horizontally at transform boundaries.
Continental drift has impacted the universe in many ways. It has affected the global climate, the world’s geographical positions and the evolution of animals. Continental drift also comes along with grave effects such as Volcanoes, Earthquakes, and Tsunamis. Through the theory of continental drift, humans have been able to figure out how the earth’s crust moves and the causes of volcanoes, earthquakes, oceanic trenches, formation of mountain ranges and other geological occurrences.