When you look at the world map, you have likely seen ridges around the perimeter of each continent. You might have noticed, that these ridges look like puzzle pieces. But why do the continents match together? It is because of the state of the Earth about 175 million years ago when all the continents formed together to create a supercontinent called Pangea. But what evidence leads scientists to believe this? Why did the continent form together? Who came up with this theory? Let's look at the facts.
The first question we will consider is, who came up with this theory? In 1912 a weatherman and meteorologist whose name was Alfred Wegner came up with a radical theory that suggested that the continents were all joined together and they had been ripped apart. He called this supercontinent Pangea which was an appropriate name because Pangea means whole earth in greek He went on to say that the continents are in fact moving. Many people thought that he was crazy but Alfred Wegner did not give up. He dedicated his whole career to finding evidence that proved his theory. But what evidence proves his theory?
The primary piece of evidence Alfred Wegner proposed was the one mentioned at the start. All the continents specifically the East coast of South America and the West coast of Africa appear to fit together like puzzle pieces. The second being that plants that grow only in tropical continents were found in polar ones. For example, coal is the result of compressed trees which are grown in tropical climates. But, coal was found in Antartica. This coal couldn't have walked and then swam through the Atlantic Ocean to get to Antartica. Antartica would have had to have been near the Equator at some point. Also, desert plants were found beneath the ice. The next piece of evidence Alfred Wegner proposed was that animals such as the megalosaurus had fossils that were found across the globe. This couldn't have been a coincidence and would have required the animals to have strong aerial and or aquatic abilities. The 4th piece of evidence was that rocks such as basalt which is usually grouped together were found across the globe very similair to the fossils. And finally, glacier scratches were found in Brazil meaning that Brazil was once a polar continent. But what causes the continents to drift?
Scientists believe that the continents are on tectonic plates. Tectonic plates are part of Earths lithosphere or upper mantle and they travel on the magma. Each continent travels independently but sometimes the collide. When they collide they cause either an earthquake, mountain or volcano. When an earthquake occurs, the colliding tectonic plates create seismic waves because of the amount of power released. Then the seismic waves cause the ground to rumble causing earthquakes. When a mountain is formed, the tectonic plates push against each other creating an arch. Try putting your fingertips on each hand together and then push up. That is the same science behind the tectonic plates. When a volcano occurs, the tectonic plates open a gap in the Earths crust creating a chance for magma to get out. Then it bursts out through a mountain opening a crater and turning the mountain into a volcano. Tectonic plate sizes do vary and they are in an irregular shape. Tectonic plates can disappear altogether too. That is, in fact, happening to the Juan de Fuca Plate which is a remnant of a rather large continent. It is sinking and soon will disappear altogether. There are nine plates in total. The Pacific is the largest of all the plates.
In conclusion, we can see that the continental drift caused a supercontinent to form. Also, it is the cause of some natural disasters. At first Alfred Wegner’s idea was rejected but now it is a fact. This proves that if we put our mind to something we will get it done. So then lets all work hard at what we do and we will see the results.
