One of the most famous volcanic eruptions in history is that of Mount Vesuvius in the year 79. Rivers of lava ran down the volcano after erupting through its vent, engulfing the nearby human settlements of Pompeii and Herculaneum, whose locations were lost until they were accidentally discovered in the 18th century. The eruption, though unfortunate for the inhabitants of the time, became a fortunate event for archaeologists, who were later on offered an interesting glimpse into the past when the buried towns were unearthed.
Under the Earth’s thin crust lie many layers reaching to the core of the planet; hot gases and magma lying underneath the plates, coming up to the surface from time to time through the vents of volcanoes. Volcanoes tend to exist along the edges between tectonic plates; around 90% of all volcanoes exist within the “Ring of Fire” along the edges of the Pacific Ocean.
When there is a large build up of pressure from molten rock, there is no way of releasing that energy except through erupting from volcanoes. With every eruption, a volcano gets bigger and bigger; when the magma flows out onto the surface it becomes lava, and as it slides down the sides of the volcano, it cools down and solidifies adding to the size of the volcano. Basically, volcanoes are what remain after the material spewed during eruptions has collected and hardened around the vent, this can happen over a period of weeks or millions of years.
Scientists have categorized volcanoes into three main categories: active, dormant, and extinct. An active volcano is one that has recently erupted and there is a possibility that it may erupt soon. A dormant volcano is one that has not erupted in a long time but there is a possibility it can erupt in the future, while an extinct volcano is one that erupted thousands of years ago and there is almost no possibility of it erupting again.
Even though the dangers of living near a volcano are apparent to all, many still do. A large eruption can be extremely dangerous; flows of searing lava, which can reach 1250°C or more, can be released, burning everything in its way. Large pieces of hardening lava can shower down on nearby villages and towns. Eruptions cause snow to melt quickly, which can result in mud flows that can strip mountains and valleys bare and bury towns in its wake. All the ash and toxic gases that are released into the atmosphere can lead to lung damage and other problems; still, people ignore all of that for the gain of farming the fertile soil of volcanoes.
Erupting in 2010, Icelandic Eyjafjallajökull maybe the most notorious volcano of recent years. Despite not being that big of an eruption, the disruption it caused impacted many people. There was enormous disruption to air travel across Europe over an initial period of six days, as ash clouds covered large areas of northern Europe; about 20 countries closed their airspace, hundreds of thousands of travelers were left stranded and disgruntled at airports. Still, this is nothing compared to volcanic eruptions of yore, such as that of Mount Vesuvius.