Volcanoes

A volcano is a structure containing a air out or cluster fed by magma rising indemnify off from great depth within the earth. The level of perilousness of a volcano can be determined by both(prenominal) human and physical factors. Physical factors include viscosity of lava, crustal collection plate margins and quality of materials ejected, whereas human factors argon proximity to population centres and predictions, forecasts and reactions. viscousness of lava determines the nature and former of volcano, which causes some volcanoes to be more hazardous. Temperature, silica content and amount of gases can reckon the viscosity of lava. Temperature; the mel dis articulateeded the temperature, the land the density and the more easily it go out flow. te dioxide content; the steeper the silica content, the more viscous the lava allow for be. Amount of gases; the greater the amount of dissolved gases, the more melt the lava. Two types of lava are basaltic (basic) and andesitic (acidic) lava. Basaltic lava which is produced by upwardly journeyment of material from cerement is usually at divergent plate boundaries and hotspots. It is low in silica content, has low viscosity and high fluidity. Andesitic lava is produced by the subduction of oceanic crust into asthenosphere, found at the raciness of the oceanic plate. It has a higher silica content, high viscosity and flows slowly.

An poser of a basaltic lava volcano (shield volcano) is Mauna Loa in Hawaii. An example of andesitic lava volcano is Mt St Helens in USA. Thus, we know that the viscosity of lava affects the p ower of volcanoes and how hazardous it can b! ecome. Plate margins can affect the type of eruption, thus, causing some volcanoes to be more hazardous. Volcanoes are in the main found along two types of plate margins reconstructive and destructive. At constructive plate margins, upwelling of magma cause overlying plates to move aside from one another. Basaltic lava is thus produced by the partial(p) melting of the mantle deep below the surface. Therefore, it has a low viscosity and is associated...If you destiny to get a full essay, order it on our website: OrderCustomPaper.com

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