Sometimes mountains are formed when boiling runny rock bursts from the ground and hardens. These mountains are called volcanoes. They can be made in a few days! Some explode without warning. Others will never explode again.
Volcanoes are found where the Earth’s crust is thin.
Volcanoes can also occur where the Earth’s plates meet. When one plate slides under another, the magma on which it lies erupts out of the Earth. The magma is called lava when it comes to the surface. Liquid lava cools and hardens to form mountain rock.
Living near an active volcano is dangerous. They may explode at any time!
Volcanoes often change shape — they can erupt suddenly or even collapse. In the 1980s, steam and ash unexpectedly erupted from Mount St Helens, USA. Some very old volcanoes are called dormant (or sleeping) volcanoes. Volcanoes that will never erupt again are called extinct.
When boiling hot rock is forced out of the Earth it can be thrown 600 metres into the sky!
When a volcano erupts, huge pieces of rock fly into the air and clouds of ash smother the land around. The suffocating ash or red hot lava can kill people. Volcanoes can also cause earthquakes, making the earth shake.
Picture Credit : Google
