“Volcanic and seismic events are major components of evidence to proving that the plate tectonic theory is valid” Talk about the extent to which you agree with this statement (40). The theory of plate tectonics explains the structure and motion with the Earth’s lithosphere. The theory claims that the Globe’s crust is usually split into large sections known as tectonic dishes, and these types of move in accordance with one another creating boundaries where the dishes converge, diverge or move forward from each other.
These discs are both continental or oceanic and are powered simply by convection power, which is the circular motion of accozzaglia that comes from in the mantle. These currents are powered by the core, which heats the magma, triggering it to increase, cool and fall back off. This spherical motion causes the china, which float on the mantle, to move. In 1912, Alfred Wegener, a German meteorologist, was the 1st man to convey that the continents were once joined in a super continent named Pangaea, on the other hand he could not explain so why and so what happened to trigger the discs to move a part.
He primarily based his theory on the incredible fit with the South American and Africa continent coastlines. Notably the eastern border of South America and the traditional western edge of Africa revealed very similar geological features suggesting that sooner or later in the Earth’s history the landmasses were joined with each other. Another sign that the regions were once distributed in another way was geological evidence of glaciations in India – it truly is unlikely that glaciers would ever be able to reach this kind of low latitudes, but this challenge can easily be the result of the theory of continental wander.
Fossil circulation also provided some of the earliest evidence intended for plate tectonics. Interestingly, flower and creature fossils were found on the matching coastlines of South America and Africa. These are now widely separated by the Atlantic Water, therefore he reasoned that is physically not possible for most of those organisms to obtain swum or have been transferred across the wide oceans. Out of this he advised that the china were when connected. Sadly, at the time of Wegner’s work lots of the geophysical equipment that are used today did not are present making the idea much more hard to support.
Because the original theory in 1912, newer evidence has made an appearance which helps the theory. In 1962 Hess studied the age of rocks about the mid-Atlantic shape. He learned that the newest rubble were closest to the ridge and the most well-known were towards USA and Caribbean. He therefore reasoned that the globe’s crust was expanding over the oceanic ridges, so it has to be shrinking elsewhere. According to Hess, the Atlantic Water was increasing while the Pacific Ocean was downsizing. The old oceanic crust was consumed inside the trenches causing new magma to rise and erupt over the spreading side rails to form a fresh crust.
This individual explained so why the earth does not get bigger with sea flooring spreading and why there is so little sediment accumulation within the ocean ground, and so why oceanic rubble are so very much younger than continental types. Paleomagnetism is one of the strongest items of evidence pertaining to plate tectonic theory and was developed to convince experts of the ideas validity. Basalt lava forms volcanoes because it rises towards the surface, cools and then varieties land. When new crust is formed specific minerals line-up themselves with all the Earth’s magnet field.
Fascinatingly, new technology indicates that the permanent magnet field from the Earth is recognized to reverse every single few hundred thousand years. Which means this implies fresh material is constantly being created and the ocean floor is usually spreading. However , as the planet earth is certainly not changing in proportions, material is being destroyed consist of areas which are called subduction zones, and the position with the Earth’s crust must be constantly changing. Seismic activity could also tell us a good deal about plate tectonics. Plotting the locations of large earthquakes allows us to discover where they will most frequently occur.
Earthquakes result from the activity of tectonic plates. The plates move past each other that causes friction triggering pressure to build up resulting in unexpected jolts. This kind of only occurs on plate boundaries which means areas that lie on them experience the many intense earthquakes. The fact that earthquakes come in connected lines as opposed to clusters is good evidence for the theory of global dish tectonics. Scenic events can also be useful because they provide very good evidence intended for the theory of plate tectonics.
Similarly to earthquakes, plotting the locations of active volcanoes on a map of the world will also be useful since it will show a similar pattern. The three main places that volcanoes are set up are at subduction zones, constructive plate restrictions and in hotspots, with around 75% in the world’s volcanoes being located on the ‘Pacific Band of Fire’. The area wherever two plates converge is named a subduction zone, in this article one menu is pushed underneath the other because of differing in density. This kind of results in accozzaglia rising approximately form volcanoes or scenic island couronne.
At beneficial plate limitations, new materials is created by simply magma rising through the split. The fact that volcanoes in some areas have different types of eruption provides good proof for menu tectonic theory. All the above reasons suggest that the idea is valid. However , there are several anomalies which will go against the theory. Not all volcanoes occur in plate limitations, some occur on hot spots which are locations where the layer is particularly sizzling, causing this to rise and create volcanoes on the brown crust area above.
This suggests that dish tectonics theory may not be valid as volcanoes can can be found without the theory being right. Hawaii is actually a notable sort of an active killer spot – the hawaiian islands are scenic yet rest in the middle of the Pacific platter. It is component to a chain of extinct volcanic islands inside the Pacific Ocean which in turn decrease in both equally age and size whenever you move north-west. Since the hotspot is created by underlying layer this shows that the crust is going over this hotspot meaning the volcanoes eventually turn into extinct and eroded away.
Since Wegener’s first theory, there is now a lot of evidence to aid the theory of plate tectonics. Seismic and volcanic incidents can provide a lot of evidence to support the theory, even though much of it will require tools that were not available when the theory was initially developed such as accurate techniques of mapping earthquakes. This managed to get difficult to prove the theory of plate tectonics as there were no hard facts. Though others may well disagree, you will find large amounts of evidence to prove the idea and so in my opinion the theory is a valid approach.