Volcanoes are one of the world’s most fascinating natural features. Although they are majestic and breathtaking, their beauty comes with destruction.
Volcanoes have a lot going on outside and inside of them. Volcanologists study seismic data, ground deformation, and minerals in erupted lava to determine the classification of volcanoes. For example, a ‘fissure and rift volcano’ is a linear crack in the Earth from which magma has erupted. A ‘rift volcano’ is caused by eruptions that alternate from side to side.
When rock deep inside Earth melts, it forms a hot fluid-material called magma. Magma collects in underground chambers. Here, water and gases separate into bubbles. Pressure from layers of rock above, magma coming up from below, and these gases eventually cause magma to burst through Earth's crust as lava or volcanic ash, in a process known as eruption.
There are different types of eruptions, depending on the combination of lava, gases and pyroclasts, formally known as rock fragments, involved. Characteristics that help determine the type of eruption are magma accumulation, magma temperature, composition, and presence of water. Volcanologist recognize two main types of eruptions: effusive and explosive. Effusive volcanoes occur when lava gently flows from a crack in the rock. Explosive is the exact opposite; violent, huge clouds of material shout from the volcano and distribute much lava and ash.
Volcanoes can be so destructive and violent that they can destroy entire cities, as in Mt. Vesuvius, which buried an entire ancient city. Another historic eruption is Mt. St Helens. Once it erupted, it caused two months of earthquakes afterwards.
Volcanoes have mysterious and mesmerizing features, but I wouldn’t even want to be near one.
[Source: Volcanoes and Earthquakes]