Plate Tectonics Essay Essay

Assess the cleverness of the relationship between tectonic edgees and major land ferments on the hides surface.Tectonic processes have been responsible for the major land tunes across the Earths surface. These processes argon controlled by the convection currents ascent from the Earths mantle.Firstly, unmatchable coif where tectonic activity occurs is at naval to oceanic constructive weighing machine boundaries. Here two musical scales diverge or move away from apiece other, pushed apart by huge convection currents In the earths mantle. These convection currents argon initiated by heat energy produced from radioactive decay in the earths core. As the convection currents move the shields away from each other, there is a weaker zone in the crust and an increase in heat burn vanquish the surface. The hotter, expanded crust forms a ridge. Magma outsets up from the mantle in the gap. The lava cools, solidifies and forms a chain of volcanic mountains thousands of miles long down the middle of the ocean eg. Atlantic. there are transform faults at right angles to the ridge. The movement of these faults builds faulting valleys to occur.Examples of these landforms created by constructive menage margins are the Mid Atlantic Ridge (MIR) , and the dandy African rift valley (GARV). The MIR is the result of the North American domicile and Eurasian case diverging in the middle of the Atlantic ocean. Here, volcanic islands such as Iceland, the Canary islands and ascension island have been created by the rising magma from the mantle. The GARV is an recitation of where the crust has dropped down between parallel faults to form rift valleys. As the crust subducts into the mantle it melts causing igneous activity below, magma to rise and therefore volcanoes erupt on the surface as a result. prove of this volcanic activity is shown by Mount Kenya and Mount Kilimanjaro. The lava here has a low viscosity, it really hot (1200 C) and has a low silica content.An utilization of where landforms have been created at a different abode boundary, a detrimental graduated table margin, is where two crustal plates, the Nazca plate, an oceanic plate, and the South American plate, a Continental plate, converge. Here, two plates meet and the denser oceanic geosphere of the Nazca plate is forced down under the more buoyant continental lithosphere ofthe South American plate, descending at an angle into the mantle in a process called subduction. This is marked on the ocean surface by the presence of the Peru-Chilie trench. The clangor between the plates prevents the subducting oceanic plate from sliding smoothly. As it descends it drags against the overlie plate causing both fracture and deform.This results in frequent shallow sharpen earthquakes The subduction of the Nazca plate under southern Chile produced the largest earthquake ever recorded, with a magnitude of 9.5 in 1960. Volcanoes are also created here as one plate subducts and partiall y melts the magma rises up through with(predicate) fissures and can reach the surface. The theatrical role of lava here is andesitic, very high in silica and not very hot resulting in a composite volcano being make out of layers of ash and lava. The cascade mountain range is an example of where a destructive plate boundary has caused the Juan de Fuca plate to subduct under the North American plate. This resulted in 15 composite volcanoes being formed, one of them, Mount St. Helens. standardised to the peru-chile region, the Japanese islands are situated in a subduction zone. In the northwestern margin of the Pacific oceans, the pacific plate and Philippine plate converge. On the pacific side, trenches run parallel to these islands. As one plate subducts at a lower place the other, it heats up and melted magmas rise towards the surface. These Japanese island arcs extend 3000km and magma produced under them form felsic plutonic rocks (granite), some of which erupts on the surfac e to make volcanoes. Large-scale defining of granites develops the crust of island arc.On the other hand, some tectonic activity doesnt produce any landform. An example is at the San Andreas Fault. Although both plates are paltry in a north westerly direction, the pacific plate Is touching faster than the north American plate (7cm/year faster), so the recounting movement of the north American plate is to the south east. The pacific plate is being moved northwest due to the sea pull down paste from the pacific coast rise in the gulf of California. The North American plate is being pushed west and north due to sea floor spreading of the mid-Atlantic ridge. Movement is sporadic and jerky. Frictional forces lock the blocks of lithosphere together for years at a time. When frictional forces are overcome, the plates drift andshallow focus earthquakes are generated.Similarly, landforms can be produced without the source of tectonic activity. The Hawaiian islands are not connected wi th any plate boundary. The volcanic area is caused by a localized hot spot beneath the pacific plate. A concentration of radioactive elements inside the mantle may cause such a hotspot to develop. From this, a plume of magma rises to eat into the plate above the hotspot. The hotspot is stationary so as the pacific plate moves over it, lines of basaltic shield volcanoes are created. These can be crumble to have flat tops called guyots. In Hawaii, the main island is closest to the hotspot and so it is the most volcanically active. However as the pacific plate moves north west at 10cm/year, a new island, Loihi will form as the submarine volcano builds up to sea level.Finally, collision plate boundries.. When continental and oceanic plates collide, the thinner and more dense oceanic plate is overridden by the thicker and less dense continental plate. The oceanic plate is forced don into the mantle by a process called subduction. As the oceanic plate descends it is forced into higher te mperature environments. At 100 miles deep the subducting plate begins to melt. The partial melting produces magma chambers above the subducting oceanic plate. The magma ascends through the overlying materials, melting and fracturing its way up. If the magma rises to the surface without solidifying it will break through in the form of a volcanic eruption. The Himalayan mountains are an example of where the Indian continental plate has been put under extreme pressure as it collides with the Eurasian plate, forcing the edges of the pates upwards in to a series of folds, as one subducts beneath the other.In conclusion, the strength of the relationship between tectonic processes and major landforms on earth can be described as strong. There is a clear correlation between the events that occur at constructive, destructive and collision plate boundaries and the landforms produced consequently. Although there are situations where the two are not linked, ultimately the characteristics of th e landform will have been influenced by some overstuffed of tectonic movement. For example, the chains of Hawaiian hotspot islands arein this inning due to the northward movement of the pacific plate.