volcanoes called hill, detached over the canals and fissures in the crust, which are displayed on the surface of the deep magma chambers eruption products.They have the shape of a cone with a crater at the top.Crater of the volcano - is the channel that connects the center with the ground.
products that enter the Earth's surface are different in size and composition.In addition, a volcanic eruption can occur with varying intensity and duration.In view of these characteristics is made the most common types of classification activity.It should be noted that a single volcanic eruption may take one or the other character.
Plinian type is named for Pliny the Elder.Roman scholar died during the eruption of Mount Vesuvius in 79 AD.e.Plinian type is of particular intensity.Eruption at the same time accompanied by the release of a large amount of ash to a height of about twenty to fifty kilometers, and can last for several hours or sometimes even days.Products emissions propagate over a large area, and their volume is from 0.1 to 50 and more cubic kilometers.Plinian Eruption of type can result in collapse of the hill and the formation of the caldera.In some cases, scorching clouds are formed, but lava flows do not always occur.In this type of volcano erupted Heles St. (in the US) in 1980.
Peleysky type is characterized by the presence of viscous lava.It solidified to yield, thus forming one or more extrusive domes.Since the volcano erupted Montagne Pelee (in Martinique) in 1902.
Vulcan different type of short activity.Eruptions at the same time can take several minutes or hours.However, they are resumed within a few months after a number of days or weeks.Eruptions of this type are characterized by the presence of fluid magma, forming lava flows.Structures formed from lava and pyroclastic material.The volume of stratovolcanoes is from ten to one hundred cubic kilometers.Extrusive dome and ash emissions are not always observed.By Vulcan type erupts in Guatemala Fuego volcano.
Strombolian type is called in honor of the Mediterranean island of Stromboli.For this type of eruption is characterized by a continuous eruptive activity for a few months (sometimes years).In this post eruptive rarely rises above ten kilometers.Some eruptions form cinder cones.They consist of basalt (predominantly) andesite or (rarely) the slag.The cones are usually formed at one eruption and volcanoes themselves are called monogenic.
emissions of Hawaiian type are characterized by the release of liquid lava.Fountains of faults and fractures may reach one, sometimes two thousand meters in height.When there is only one crater, lava diverges radially.This elevation formed shield with very gentle slopes (up to ten degrees).These elevations are added and the layers do not contain ash.Shields is the largest volcano in the world Manua Loa (Hawaii).Its height - 4103 m.This elevation has a length of one hundred and twenty, and fifty kilometers width.Streams of lava spread it on the island area of more than five thousand square kilometers.Of the forty-two thousand five hundred cubic kilometers of volume more than eighty percent is below sea level.
There are other types of eruptions.However, they rarely occur.For example, a submarine eruption in 1965 in Iceland volcanic island Surtsey was formed.
