The main features of a volcano include a vent, a summit crater and a magma chamber. The vent is an opening through which volcanic material is erupted. Volcanoes can have more than one vent. The summit crater is the large concave opening that holds the central vent at the top of the volcano. The magma chamber is the large pool-like structure inside the volcano that holds the magma.Continue Reading
When a volcano erupts, the magma is spewed from its chamber through the main vent. Lava, rocks, ash and other debris shoot out or roll over the volcano's sides. The volcano's actual structure accretes over time. After each eruption, the lava and other volcanic material cools around the volcano and creates a hard layer of rock.
Volcanoes can have more than one opening around the main vent. These are called cones and fumaroles. These are fractures in the volcano that open up to also release volcanic material and volcanic rocks.
Volcanoes are further classified by their shapes, their composition and their eruption patterns. The three main types are stratovolcanoes, shield volcanoes and scoria cones. Stratovolcanoes have steep upward slopes with a small crater at the top. Shield volcanoes are slightly sloped hills. Scoria cones are the most common type of volcano. They are short, hilly formations with steep slopes and a large crater at the top.Learn more about Volcanoes
A volcano forms when magma rises through weakened areas of the crust from a magma reservoir many miles deep within the earth, pushing itself up through a vent. This vent acts as a release valve for pressure building up below, and when the new volcano erupts, thousands or millions of pounds of ash and molten rock slowly accumulate, forming a volcanic mountain.Full Answer >
A volcanic neck, also called a lava neck or volcanic plug, is a cylindrical-shaped volcanic landform created when magma hardens inside the vent of a volcano, according to the University of Wisconsin. Examples of volcanic necks include Devil's Tower in Wyoming, Lizard Head in Colorado and Morro Rock in California.Full Answer >
The chief difference between a volcano and a mountain is that a volcano forms around a vent that allows magma to reach the surface of the Earth, while a mountain can be formed by a variety of different geological processes. Most mountains form as the result of plate tectonics, although some were formed by magma welling up from the mantle without breaking through the surface.Full Answer >
A volcanic eruption is caused by the injection of magma into a full magma chamber, the buoyancy of magma and the pressure exerted by the gases in the magma. The volcano simply acts as an opening through which magma and dissolved gases are discharged.Full Answer >