Since the earliest history, volcanoes have quite literally moved and shaped the earth! These mountainous giants plague nature and people to this day. At present there are a staggering 34 volcanoes that are erupting right now and there are about 50 volcanoes around the world that are active and that may erupt at any time.
A volcano is an opening on the surface of the earth. The opening acts like a window that can let out hot air trapped inside, but instead of hot air, it is lava, ash, rock and gases. When these materials escape, it causes an eruption. Eruptions can explode, which causes materials to shoot out forcefully, or it can be calmer, which causes materials to flow slowly from the opening. Volcanoes form mountains because of the rock, ash and lava pile-up that happens when they erupt.
Volcanoes form when magma (hot liquid rock and dissolved gases underground) erupts onto the earth’s surface (which then becomes lava, hot liquid rock on the surface).
The earth’s crust is five to 60 kilometres thick and it is made of tectonic plates. These plates float on a layer of magma. Magma is lighter than the solid rocks of the Earth’s crust and because of this it can easily force its way into spaces between rocks.
The movement of tectonic plates away from each other allows magma to fill the spaces and push its way up to the surface where it erupts. It can also rise when tectonic plates move toward each other. A part of the Earth’s crust then gets shoved deeper into the interior. This creates lots of heat and pressure, which forces the crust to melt and turn into magma. The magma becomes less dense and rises to cause an eruption.
WHEN TO GET OUTTA HERE!
Active volcanoes may erupt in many ways, but it is best to always keep a safe distance! Active volcanoes have pressure build up which can cause eruption at any time. Before eruption, magma builds up in a volcanic vent (a chimney-like tunnell leading to the opening) from a magma chamber (a huge space filled with hot magma). The pressure causes the magma to either burst out violently or slowly ooze out. It then turns into lava, which is about 1 200 degrees Celsius! It can melt anything in its path, but usually moves quite slowly. Eruptions can cause landslides or mudslides and avalanches in colder areas, and also tsunamis. It also releases a dense cloud of hot material, called pyroclastic flows, which are extremely dangerous as it moves very fast. Eruptions also create ash clouds and acid rain. So, best to have a healthy respect for these monsters of nature.
VOLCANOES KILL THE EARTH, OR DO THEY?
It is true that volcanic eruptions can cause irreparable damage to the environment. The gases that are released from these eruptions are harmful and can pollute the planet, but can also be deadly to living things as it causes asphyxiation.
But, these guys aren’t all bad... volcanoes also happen to fill the soil with rich nutrients, which is great for farming and agriculture. They also provide minerals like gold, silver and even diamonds. Volcanoes are responsible for creating hot springs (a tourist favourite in many countries!) and generate geothermal energy (a form of clean energy).
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