Volcanoes For Kids

Volcanoes are ruptures in the planet’s surface which allow magma, volcanic ash and gasses to escape from beneath the earth’s crust. They are commonly found where tectonic plates diverge or converge.

Diverging tectonic plates are moving away from each other, and converging plates are those that are moving towards each other.

Most land volcanoes are caused by converging tectonic plates, one of the plates forces the other one downwards into the earth’s mantle, which is very hot, this high temperature causes an increase in pressure which causes the rocks which form the tectonic plate to melt and form a magma reservoir shown in the image . When this magma reservoir’s pressure builds enough to break through the earth’s crust, this causes a volcanic eruption.

Volcanic eruptions can be very destructive, not only can they cause a lot of damage to areas near the volcano, but they can fill the sky with volcanic ash which can be a threat to aircraft. Volcanoes can also cause volcanic winters where volcanic ash and sulphuric acid can cause the earth’s temperature to drop, which can cause the death of both people and any other forms of life on a large scale.

History

In recorded history, around 650 volcanoes have erupted while in an average year around 60 are active and there are around 20 erupting at any given time. There have probably been millions of volcanoes in the earth’s history and it’s more likely most of them have been at the bottom of the sea rather than on land. This is because most areas with diverging tectonic plates are located in the sea.

The picture above shows a “conical” volcano, gasses and and molten lava coming from a crater at the top, which is the what most people usually picture when they think of volcanoes. This is only one of many types, however and most do not look like this. They can take many forms. Below are some pictures of recently erupted volcanoes.

 

 

 

 

 

 

 

5 interesting facts!

• The tallest known volcano is on Mars and is called “Olympus Mons”. It measures at roughly 27km tall, which is over 6 times taller than the tallest volcano on earth which is Mouna Kea (pictured above).

• If a volcano ejects more than 1000 cubic meters, it is known as a “super volcano”. Most historic eruptions are roughly 1/1000th the size of these.

• As well as on the ocean floor, sometimes volcanoes can form under icecaps, there are plenty of these to be found in iceland.

• Over 75% of the earth’s volcanoes can be found in the pacific ring of fire, an area around the pacific ocean. This is due to it being a large area of converging tectonic plates.

• The hot liquid rock beneath the earth’s surface is known as magma, however as soon as it leaves the volcano, it is then known as lava.