Research into the theory of plate tectonics first began around 1920. This research was spearheaded by Alfred Wegner, a German meteorologist and geophysicist. His work presented the theory that today’s continents once were joined as one to form a huge supercontinent commonly referred to as Pangaea today. Wegner’s theory stated that the super continent broke up and the pieces (today’s continents) drifted over time into their current positions, he called this “Continental Drift”. Wegener's theory also provided an alternate explanation for the formation of mountains (orogenesis).
The underlying ideas that Wilson built his theory on were proposed by Alfred Wegener in 1912 with his Theory of Continental Drift. Tuzo Wilson was able to provide a way to explain how the continents were able to move apart that Wegener could not explain when he had proposed his idea. Scientists had believed that based on the evidence Wegener had provided it did appear that all of the present day continents had somehow been connected together. The way that the coasts of Africa and South America appear to fit together nicely in addition to fossil evidence of large tortoises and other animals being found near the edges of the continents. Alfred could not explain how the huge masses of land could have moved so far.
Plate tectonics was first suggested as a theory by the geologist Alfred Wegener in 1915 when he proposed the concept of continental drift. Back in the geological past, what is now South America, Africa, Australasia and Antarctica fitted together into a supercontinent known as Gondwanaland; with North America, Europe and Asia fitting into another supercontinent known as Laurasia. (OCR AS/A2 Geology, Mugglestone et al, 2008). These were once believed to be joined to form one major central global landmass known as Pangaea (Introducing Geology, Graham Park). But now due to the global distribution of these major plates it has been proposed by Wegener and his successors that convection currents in the mantle are the cause of the movement of plates.
Theory of continental drift The hypothesis that the continents had once formed a single land mass before breaking apart and drifting to there present locations was first presented by Alfred Wenger. He believed that the continents were once joined in a super continent that scientists now call Pangaea. Over a vast period of time the continents drifted apart due to the earth’s rotation. In 1915 he published a book about his theory. His main evidence was the continents appear to have a jigsaw like fit, the west coast of Africa and South America have the same pattern of rock layers and have the same plant and animal fossils; some of these animals are only found in those parts of the world and their fossils show they could not swim.
How to predict an volcanic eruption Ground Deformation Ground deformation is the change in shape that happens before during or after a volcanic eruption. This happens because the sides of the volcano change shape because the magma in many ways to measure the change of shape of the volcano, like leveling, triangulation and more recently using continuous Global Positioning System (CGPS). It is also possible to use lakes as large tilt meters. Tilt meters measure the tiny degrees of tilt or slope on land. This is one of the oldest methods of knowing when ground deformation was caused because of rising lava.
He named the supposed single land mass on Earth “Pangaea”, meaning All-earth. “Scientists still do not appear to understand sufficiently that all earth sciences must contribute evidence toward unveiling the state of our planet in earlier times, and that the truth of the matter can only be reached by combing all this evidence (Wegener, 1915)”. Continental drift was a theory that became the precursor to plate tectonics. Wegener held a Ph.D. in astronomy; he worked as a professor of meteorology. He had always been interested in geophysics, developing fields of meteorology, and climatology.
Along the coast of south America, the Nazca plate is moving towards the south American plate. The Nazca plate is oceanic, hence denser; therefore it is subducted underneath the continental crust into the mantle. As the Nazca plate bends down into the mantle it forms a deep oceanic trench. This is made up of long, deep gorges in the sea bed that occur around the edges of some oceans including the Pacific Ocean. The force of one plate being dragged under another causes intense friction and the pressure increases.
It wasn’t until Alfred Wegener (1912) presented his theory of continental drift that a reasonable explanation was available. As this theory gained acceptance, although slowly at first, through the 20th century geologists were able to gather evidence to produce maps showing the arrangement of the Earth’s major continents at different periods of its history. These paleo-maps are of great importance for those who study evolution, as the presence and break-up of so called ‘super-continents’ in the past offered an explanation to the disjointed distributions of many terrestrial animals, both extant and fossils. Scientists pre-Wegener postulated that sister clades somehow travelled across large oceans, via land-bridges that are geologically improbable, to explain their presence in both Africa and S. America. What was now a possibility is that these animals were simply on the opposite sides of one continent as it split down the middle to form the Atlantic Ocean.
Even though the coastlines didn’t match perfectly (maybe due to erosion/weathering), he later found that the continental shelves matched more closely which matched the theory that those continents were once together. The strongest evidence for continental movement is the study of paleomagnetism. The study of the intensity and orientation of the Earths magnetic field is preserved in the magnetic orientation of certain minerals found in rocks formed throughout geologic time. A study of the ocean floors have demonstrated that the orientation of the earths
The reason for the movement is convection currents originating in the core caused by radioactive decay. Knowing the theory of plate tectonics is a useful tool in understanding the distribution of earthquakes and volcanoes as they correlate very closely. If we map out the location of major earth quakes, location of active volcanoes and a map of general plat tectonic, the 3 would overlap. This gives us a general idea of locations and correlations. Each boundary between 2 plates have the capability of being a different type of boundary.