Our world is an amazing thing. Scientists have strived to understand as much as possible about the nature of our Earth, including its changes. Plate tectonics is a relatively new idea explaining how our Earth's surface changes. Our Earth is constantly changing, with the first theories of plate tectonics having developed over the years; From Alfred Wegener's theory of continental drift to Harry Hess's theory of seafloor spreading, scientists have expanded their knowledge of the ever-changing Earth. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get the original essay The crust and mantle of our Earth are constantly in motion. Different pieces, or plates, move at different times. If we look at the Himalayan mountains, we can easily see how the earth's surface is changing. The mountain grows a few centimeters each year as the Eurasian and Indian plates collide. The magma closest to the center of the Earth is heated. As it approaches the surface, its heat decreases and falls; thus creating a convection cell. As the circle rotates, it pushes away from the Earth's surface. This is the cause of plate tectonics. The first idea of ​​plate tectonics came from scientist Alfred Wegener. Alfred Wegener had the idea of ​​Pangea, or super Earth. The idea of ​​Pangea is the concept that all of Earth's landmasses were once a super continent and that there was a giant ocean. Wegener believed that over time the continents dispersed. His concept was not widely accepted at the time, although he had three major pieces of evidence. The first is that the continents seemed to fit together like a puzzle. As we pointed out in class, this is probably his most important piece of evidence. His second piece of evidence is that mountain ranges and deserts correspond to where continents come together. His third piece of evidence is that similar fossils have been found in Africa and South America; this would imply that at one point the two continents were side by side. His idea was not popular but was eventually proven, just like Harry Hess's. Harry Hess came up with the idea of ​​seabed spreading. We studied the largest underwater mountain range. He discovered that the Mid-Atlantic Range is actually a large chain of constantly erupting underwater volcanoes. When magma pours out, it pushes up against the current seafloor and adds to it. He discovered that the sea floor was expanding. Rocks on the seafloor record the attraction exerted on them by the magnetic poles. The Earth changes its magnetic attraction every thousand years, so rocks attracted to the north or south pole are marked white or black, respectively. When he noticed the zebra lines and stripes, he concluded that the sea floor is newer in some parts than others. Keep in mind: this is just a sample. Get a personalized article from our expert writers now. Get a Custom Essay These two theories have become the modern concept of plate tectonics. Plate tectonics is still a relatively new field of study. Scientists are still trying to unravel the mysteries of plate tectonics. We know that the Earth is constantly moving and that mantle convection is the cause. Hess and Wegener must be appreciated for being pioneers in this new field of plate tectonics...