Montserrat's Soufriere Hills volcano erupted because the underlying pressures beneath the rock grew too high and exploded. A pyroclastic surge was observed, which is a mixture of hot gas and rock that flows at high speeds down the sides of the blown volcano. The presence of this flow means Montserrat experienced a thick lava flow that was impeded, built up and collapsed into a fast-moving pyroclastic surge.Know More
Volcanic eruptions occur when magma from deep beneath the Earth's surface escapes to the top and emerges as lava. If the magma contains dissolved gases like hydrogen, carbon dioxide and sulfur dioxide, the sudden release of pressure at the less dense surface results in a massive explosion. When the magma is deep within the Earth, the pressure keeps the magma semi-solid and the contents very hot.
The Earth's mantle is beneath the crust and on top of the radioactive iron core. This radioactivity partially melts the mantle, and heat transfer by convection occurs because the lower mantle is warmer than the upper mantle. Warm substances rise and cooler substances fall, so convection cells arise and the mantle becomes a constantly-roiling mass. This motion causes plate tectonics and magma breaks through weak layers of rock above, forming a volcano.Learn more in Volcanoes
Volcanoes erupt due to pressure that the weight of the rocks puts on the magma and forces it to the surface out any available vent or exit provided to it. The magma is in a reservoir like area under the surface and the pressure from the rocks causes the less dense magma to move into any available crack or fissure that it can reach to try to release in some fashion. The magma can even melt its way to the surface if no exit is available for it at the time.Full Answer >
A volcano erupts when the pressure of a subterranean pool of magma becomes great enough to crack the earth's crust. Whether the eruption results in a violent explosion or a slow seepage depends on several different factors, according to How Stuff Works.Full Answer >
A volcano is a place where molten rock seeps or erupts from beneath the crust. Most volcanoes develop in the oceans, but some occur on land. When the molten rock, which is called lava, erupts with force, large, cone-shaped mountains form, which are also called volcanoes.Full Answer >
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 >