Volcanoes

A volcano is a structure containing a publicize or cluster fed by magma rising accountability off from great depth within the earth. The level of hazardousness of a volcano can be determined by both(prenominal) human and physical factors. Physical factors include viscousness of lava, collection musical scale margins and lawsuit 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 refuse the density and the more easily it go out flow. te dioxide content; the mellower the silica content, the more viscous the lava exit be. Amount of gases; the greater the amount of dissolved gases, the more molten the lava. Two types of lava are basalti c (basic) and andesitic (acidic) lava. Basaltic lava which is produced by up journeyment of material from drapery 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 move on of the oceanic plate. It has a higher silica content, high viscosity and flows slowly.

An fashion model 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 po wer of volcanoes and how hazardous it can be! come. Plate margins can affect the type of eruption, thus, causing some volcanoes to be more hazardous. Volcanoes are by and large found along two types of plate margins reconstructive and destructive. At constructive plate margins, upwelling of magma cause overlying plates to move obscure 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 essential to get a full essay, order it on our website: OrderCustomPaper.com

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