Where do volcanoes occur?

Volcanoes are found all over the world, from freezing cold Antarctica to under the ocean! But did you know they are also found in outer space? In fact, the biggest volcano in our entire solar system is not found on Earth at all, but on planet Mars. It’s 17 miles tall and is called Olympus Mons.

Most volcanoes on Earth are found around the Pacific Ocean along the ‘Ring of Fire’ and 10% of the world’s active volcanoes are found in Japan.

Types of volcanoes

Shield volcanoes: these volcanoes are formed from layers of lava that have built up from continuous eruptions. They are shaped like shields with wide flat slopes.

Stratovolcanoes or composite volcanoes: these volcanoes are tall with steep slopes. These volcanoes can grow into huge mountains like Mount Fuji and Mt.Vesuvius.

Caldera volcanoes: these volcanoes are shaped like a cauldron. They are formed when the top of a stratovolcano blows its top off. 

Cinder cones: these are straight, steep volcanoes that are usually no taller than 1000 feet.

Volcanic eruptions

When we think of volcanoes we normally think of huge eruptions, lava shooting high up into the sky and smoke covering everything, but guess what? Not all volcanoes erupt! Some volcanoes quietly pour lava through their openings.

Volcanic eruptions happen when pressure builds up inside the volcano. When the pressure is so high, gases and rocks shoot up through the opening called a vent. Lava then runs over burning everything it touches! Many volcanoes have a main vent and other vents branching off the sides.

The good, the bad and the ugly

A volcano isn’t really something you would want to live next to right? Well, believe it or not, 1 in 20 people actually live near an active volcano! 

Volcanoes can be very dangerous and destructive, triggering avalanches, mudslides, tsunamis and earthquakes. But volcanoes also produce rich, fertile soil which is great for growing crops! 

Basalt, granite and pumice are formed from hardened lava. They’re used for all kinds of useful things. 

Rocks that are formed from hardened lava are called igneous rocks.

Can volcanoes be prevented?

There’s nothing people can do to stop volcanoes from erupting but scientists have learnt how to predict when the next eruption will come. Scientists who study volcanoes are called volcanologists.

Satellites, radars and infrared instruments are used to detect the pressure of a volcano as it gets ready to erupt. Gases and clouds of ash can also be detected.

Did you know?

• The Hawaiian islands were formed from underwater volcanic eruptions.
• If you used a glass thermometer to measure the temperature of lava, it would melt.
• Maleo birds bury their eggs near the soil of volcanoes. The heat from the volcanoes acts like an incubator and when the babies are ready to hatch they claw their way up to the surface.

• In 1883 a volcano in Southeast Asia called Krakatau erupted. It was the loudest sound ever reported in history. 
• Volcanic eruptions can shoot ash over 30km (17 miles) into the sky.