EXTRAORDINARY VOLCANOES

Index

When and why did volcanoes erupt?
How are volcanoes made?
Where and when did the first volcanoe erupt?
Scheme
Video
Sources

Made by Isabella, Portesan on the 17th January 2023. Aged 11. Published on saturday 14th january 2023 11:40am.

Did you ever stoped and thought how volcanoes work and what do they do?

When and why do volcanoes erupt?

Volcanoes erupt when a type of rock called magma comes up to the surface. Magna forms when the Earth’s mantle melts. This magma is lighter than the rocks around it and so it rises upwards. Where the magma eventually reaches the surface we get an eruption and volcanoes form. Volcanic eruptions are one of the most dangerous phenomena in the hole world because they have lava in them so when they erupt they get the lava of the inside of the volcano to the outside and destroys everything because it is extremely hot. The lowest temperature of lava from a volcano in earth is 500-600 degrees Celsius. The highest temperature of lava from a volcano in earth is 1,250ºC. Volcanoes erupt when heat moves underneath the Earth. The top part of the Earth is made up of a number of hard pieces called tectonic plates. Magma and volcanoes often form where the plates are pulled apart or pushed together but we also find some volcanoes in the middle of tectonic plates. The shape of the volcano and how explosively it erupts depends largely on how “sticky” and how “fizzy” (how much gas) the magma is that is erupted.

How are volcanoes made?

Volcanoes are made by a mountain that is extremly hot and then it forms a “hole”. Then you have lots of water in them so you get lava from them and (as I explained before) they erupt when magma comes out to the surface. Another way volcanoes are formed is when magma, which is located at the centre of the Earth, pushes its way upwards through the Earth through a long shaft. Volcanoes are normally made on the pacific ocean and that is why scientist call it the hot spot of the world. We have 2 types of volcanoes: composite volcanoes and shield volcanoes. Composite volcanoes are formed like a triangle. The majority of volcanoes are composite volcanoes. At the bottom of a composite volcano we have magma chamber. The magma enters through the Earth's mantle up to the surface through a little line and erupts after a couple of years and not immediately because the little line opens less than 5cm per year. Eventually the pressure becomes so high that a volcano eruption forms. The magma exits the volcano by its crater. Some magma exit by a secondary vent or a secondary cone. Craters can eject 4 types of materials on to the atmosphere: lava (the name for magma out of the surface), volcanic bombs, thick ash and gas. Shield volcanoes are commonly found on constructive plate margins or in hot spots. This is because they are usually in the ocean and create first a mountain until they get to the surface and they erupt.

Where and when did the first volcano erupt?

The first volcano eruption was 3.825 billion years ago. It was a lot of years ago that I think not even dinosaurs existed! The oldest proof of a volcano found on Earth, near the village of Inukjuak, are 3.825 billion years old. These rocks are certainly the product of a volcanic eruption, but they were not the first volcanic rocks erupted on Earth. The Earth is 4.56 billion years old, but the first 700 million years of Earth history are poorly preserved. When we look at the full moon, we can see light and dark areas. The dark patches are covered by extensive lava flows from lunar volcanoes that erupted 3.1 to 4.3 billion years ago. The moon is less geologically active than Earth, so old lunar lavas are better preserved than those on Earth. During historic times, not a year has pass without a volcanic eruption somewhere on Earth. At least once a year there is going to be 1 volcano eruption (minimum). This is such an incredible fact because, did you know that the maximum volcanoes that had erupted in one year was 400 and even more!