Volcanoes

A volcano is a structure containing a freshen or cluster fed by magma rising skilful 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, dental headquarters margins and subject of materials ejected, whereas human factors argon proximity to population centres and predictions, forecasts and reactions. viscousness of lava determines the nature and cater of volcano, which causes some volcanoes to be more hazardous. Temperature, silicon oxide content and amount of gases can reckon the viscousness of lava. Temperature; the mel dis articulateeded the temperature, the glare the density and the more easily it go out flow. silicon dioxide content; the loftyer the silica content, the more viscous the lava lead be. Amount of gases; the greater the amount of dissolved gases, the more break up the lava. Two types of lava are basalt ic (basic) and andesitic (acidic) lava. Basaltic lava which is produced by upwardly journeyment of material from chill 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 bite of the oceanic plate. It has a higher silica content, high viscosity and flows slowly.

An example 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 power of volcanoes and how hazardous it! can become. Plate margins can affect the type of eruption, thus, causing some volcanoes to be more hazardous. Volcanoes are broadly speaking found along two types of plate margins reconstructive and destructive. At constructive plate margins, upwelling of magma cause overlying plates to move isolated 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 deprivation to get a full essay, order it on our website: OrderCustomPaper.com

If you want to get a full essay, visit our page: write my paper