Raymundo, Maria Carina 2010-20226Dec. 11, 2013

Dynamic EarthFor the past few weeks, we have been studying plate tectonics and the documentary which was presented summed our lectures and discussions. The documentary first discussed the history of the theory of plate tectonics and how Alfred Wegener came up with the idea that parts of the earth are moving in his Continental Drift Theory, unfortunately he was not able to show enough evidences for his theory thus, he did not live to see the day that his theory will become widely accepted. In his arguments, he questioned fit of the continents, the presence of coal deposits normally found in tropical climates in the North Pole, the glaciation patterns in Africa and the similar fossils in different continents. Decades later, with better equipment and an improved body of knowledge, new evidences started to piece together the whole story. One evidence that was presented was the surprising fit of the worlds continents into Pangaea. This argument is one of the most convincing pieces of evidence, however, for me, there is still a question of how do they know which patches of land were originally included in the Pangea and which land is newer or formed after the drifting. As we can see from the theory, it has only visibly taken into account Africa, Eurasia, America, South America and Antartica. However, I believe that my argument can be easily answered by the dating of land and the formulation of an updated Continental Drift demonstration showing the appearance of new forms of land as well as the movement of the continents.Another solid evidence is the presence of similar fossils across continents separated by vast bodies of water. Some of the examples include the fossils of Lystrosaurus, Mesosaurus, Cynognathus and Glossopteris. It is amazing to think that at one time, a creature could walk from Africa to America. They also used the age and features of several mountain ranges to match separate countries with another such as mountain ranges in South Africa and those in Argentina as well as the USA with parts of the United Kingdom. Correlating these geological features which are several thousand or million miles away is a feat and I believe that there are still similar cases in other parts of the world.It was also found that millions of years ago, the continents were in a very much different place than they are right now. It has been said that Antarctica used to contain more life forms, thus it may have been in a different place than its current location to support life. Fossils of corals have also been found in places in North America and Eurasia even though coral reefs can only be found near the equator. Also, grooves made by the movement of ice can be observed in South America, Africa, India and Australia, indicating that they may have been in a different location millions of years ago. Another evidence is that of paleomagnetism where it was found that layers of rock had different magnetisms indicating that there may have been several time when the world has shifted its magnetic pole. What is amazing with this theory is that it is both a story of heartbreak and triumph. While Wegener may have felt horrible when his colleagues rejected his theory, hes probably the one laughing at them now. It is amazing how different evidences from different fields such as geology and biology support each other. After a hundred years, the theory of plate tectonics has finally become multi-sectoral and universal.