Outline the Relationship Between Plate Movement and Volcanic Activity

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Outline the relationship between plate movement and volcanic activity (10 marks) Volcanic activity mainly tends to occurs on the edge of plate margins, but could potentially occur at any location, such as Hawaii where the plate boundary is underneath a hot spot, which causes the Hawaiian chain islands. It is where the magma in the mantle breaks through the lithosphere to form extrusive landforms. Shield volcanoes can be formed due to subduction and they tend to start of as a submarine volcano (under water) at either an oceanic/ oceanic convergence or a hotspot. At a hotspot, the limited magma plumes rise and go in a circular motion due to the convection currents, this eventually lead to the plumes rising up through the mantle and break through the oceanic crust. Over a long period of time, the on-going movement of the plate i.e. Pacific plate and the stationary hotspot forms an chain of many volcanoes such as the Hawaiian Chain, where Hawaii being the youngest island currently formed. At a oceanic/ oceanic convergence, the subduction of the oceanic plate tends to increase pressure in the Benioff Zone, which leads to partial melting of the plate, this is similar to composite and calderas as O-O convergence is destructive along with calderas and composite. They tend to have gentle and predictable eruptions which can cause to build up a large amount of flows, where the lava is of low viscosity and is basaltic causing it to be 1200°C. Furthermore, fissure volcanoes tend to also have gentle and predictable eruptions along with shield volcanoes and are found at constructive margins and rifts. As the North American and Eurasian plates diverge, there is an oceanic ridge formed, such as the Mid-Atlantic ridge which is about 10,000 km (6,200 mi) long, and it connects to a series of oceanic ridges that encircle the entire planet, with a total length of about 40,000 km. Here the basaltic lava can leak through a crack forming gently sloping volcanoes such as the Heimaey in...
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