Volcanic eruptions occur when magma builds up beneath the Earth's crust and forces its way to the surface. Natural vents in the crust allow magma passage to the surface, and eruptions occur when the magma that forms is less dense than the material above it, causing it to flow upward. In some cases, this flow is slow and steady, but it can also be rapid and violent.Know More
Explosive eruptions occur when pressure builds up in magma chambers beneath volcanoes. This is often due to different types of magma mixing in the chambers. Lighter, less-dense magma naturally rises, but if a bubble of lighter magma builds beneath a more dense, viscous reservoir of magma, the pressure can build up inside the chamber. Eventually, it becomes enough to force the heavier magma through the volcano's vent, causing an explosive eruption.
An eruption can also occur due to a collapse of the cinder cone of the volcano. Over time, lava flowing out of a volcano builds up more and more rock around the vent, and in some cases, that rock may become unstable. If enough collapses into the vent to block it and prevent magma and gases from reaching the surface, the pressure can build up to the point of explosive eruption.Learn more about Volcanoes
Volcanoes form when magma, a mixture of hot gas and molten rock, flows out of fissures in Earth's crust. The powerful eruption creates vents in the crust, and mountainous formations take shape above ground as molten rock spreads out in layers and gradually cools down. Each successive eruption occurs when more gas and magma accumulate in the vents, building pressure below the crust.Full Answer >
A volcano forms when magma pushes up through the Earth's crust from below, depositing lava on the surface. This lava cools, creating volcanic rock. Over time, repeated eruptions of lava build a cone-shaped mountainous structure, producing a volcano.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 >
Various factors trigger a volcanic eruption. The three predominant factors are the magma's buoyancy, the pressure from the gases that separate in the magma and the merger of a new batch of magma with a chamber already filled with magma.Full Answer >