The inside of a volcano has one or more vents through which gas and lava flow during eruptions. Below the vent is the magma, which is the molten rock that flows upward due to the divergence or convergence of tectonic plates in the Earth's crust. The number of vents and shape of the buildup of magma inside the magma chamber depends upon the type of volcano.Know More
Cinder cone volcanoes have single vents. Their bowl-shaped craters form from particles of cooling lava. Lava does not always flow from the tops, but the discharge of particles may cause lava fountains. Stratovolcanoes, or composite volcanoes, may have one or a cluster of vents. These volcanoes consist of cones formed from multiple layers of lava flows. Magma flows upward from a deep magma reservoir and flows out through breaks in the wall of the crater and cracks and fissures on the sides.
Shield volcanoes may have one or a group of vents through which lava flows. They usually have broad slopes spread out over a large area. The fluid lava flows not only through the vents but from rift zones that open on the flanks. Lava domes are formed by the accumulation of highly viscous lava within a vent chamber. These buildups can cause explosive eruptions or collapse to cause deadly pyroclastic currents of swift-flowing lava.Learn more about Volcanoes
A volcano that has recently erupted and may erupt again soon is categorized as an active volcano. Dormant and extinct are also categories of volcanoes.Full Answer >
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.Full Answer >
The eruption of Mt. Vesuvius in 79 A.D. destroyed the Roman city of Pompeii and the volcano continues to threaten the inhabitants of modern-day Naples and neighboring communities in southern Italy. The 1st-century eruption buried the inhabitants and buildings of Pompeii and nearby Roman towns in hot ash and pyroclastic flows in only a matter of a few seconds. The speed of the destruction left behind casts of the victims' bodies which have provided archaeologists with a rare glimpse of how people lived during Roman times.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 >