How do volcanoes erupt?
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Because it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through vents and fissures in the Earth’s surface. A volcanic eruption occurs! Magma that has erupted is called lava. Some volcanic eruptions are explosive and other are not. How explosive an eruption is depends on how runny or sticky the magma is. If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. Lava flows rarely kill people because they move slowly enough for people to get out of their way. Lava flows, however, can cause considerable destruction to buildings in their path. If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode.
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Because it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through vents and fissures in the Earth’s surface. A volcanic eruption occurs! Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. How explosive an eruption is depends on how runny or sticky the magma is. If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. Lava flows rarely kill people because they move slowly enough for people to get out of their way. Lava flows, however, can cause considerable destruction to buildings in their path. If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode. In this type of eruption, the magma blasts into the air and breaks apart int
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Because it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through vents and fissures in the Earth’s surface. A volcanic eruption occurs! Magma that has erupted is called lava. Some volcanic eruptions are explosive and other are not. How explosive an eruption is depends on how runny or sticky the magma is. If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. Lava flows rarely kill people because they move slowly enough for people to get out of their way. Lava flows, however, can cause considerable destruction to buildings in their path. If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode. In this type of eruption, the magma blasts into the air and breaks apart into
The magma chamber is surrounded by solid rocks. The weight of the overlaying rock presses on the chamber. This pressure causes the magma which is filled with gas to rise and melt its way through a fractured or weak part of the rock. As the magma continues to rise, it creates an opening called central vent. It may also branch out into smaller channels. Most of the magma and other volcanic materials come out to the earth’s surface through the central vent. These materials pile up around the vent. A crater is formed at the top of a volcano after its eruption has stopped.
