Kids why do volcanoes erupt

My name is Vera and I would like to tell you a bit more about volcanoes. The name volcano comes from Vulcan, the Roman god of fire! The molten rock and ash solidify as they cool, forming the distinctive volcano shape shown here. As a volcano erupts, it spills lava that flows downslope. Hot ash and gases are thrown into the air. Some volcanoes are covered with snow and ice. If they erupt, melted snow and ice mixes with mud and volcanic ash and flows down mountain.

Volcanic flows are called lahars. Volcanoes are made of unique rocks called extrusive igneous rocks. The plate tectonic theory is supported by a wide range of evidence that considers the earth's crust and upper mantle to be composed of several large, thin, relatively rigid plates that move relative to one another.

The plates are all moving in different directions and at different speeds. Sometimes the plates crash together, pull apart or sideswipe each other. When this happens, it commonly results in earthquakes. Continental Drift: To see this animation again, just refresh this page! This animation shows you what our planet looked like millions of years ago and what it looks like now!

Cinder cones are circular or oval cones made up of small fragments of lava from a single vent that have been blown into the air, cooled and fallen around the vent. Composite volcanoes are steep-sided volcanoes composed of many layers of volcanic rocks, usually made from high-viscosity lava, ash and rock debris.

Rainier and Mount St. This is not ash like you get after a barbecue or fire, it does not crumble away in your fingers. It is very sharp and is dangerous to breathe in. Some explosive volcanoes can send ash high up into the sky and it can travel around the world over different countries.

If aeroplanes travel through an ash cloud from a volcano it can cause a lot of damage to the engine. Other explosive eruptions create fast-moving, hot clouds of volcanic ash, gas and rocks that travel down the sides of the volcanoes and destroy pretty much everything in their path. Despite the great damage they can cause, volcanoes also help us to live.

Volcanic ash provides food for the soil around volcanoes which helps us grow plants to eat. You can find some more information about different types of volcanoes here and here. Read more: Curious Kids: Do most volcanologists die from getting too close to volcanoes? Some volcanic eruptions are explosive. Lava shoots into the sky. Gas and hot pieces of rock and ash are also released. Lava oozes slowly from the volcano. The intensity of an eruption depends on a few factors. The amount of gas trapped within the magma is also an important factor.

Mount Saint Helens, one of the most destructive volcanic eruptions in U. It runs from the southern tip of South America and up the west coast of North America. The ring sits along the outline of several tectonic plates. Most volcanoes form at the edges of tectonic plates. These huge plates are constantly shifting. Sometimes, the plates pull apart or slide into each other. When this happens, magma rises to fill in the space. Strong pressure and intense heat force the magma upward.

It squeezes upward like toothpaste through a tube. Volcanoes can be dangerous—especially to the millions of people around the world who live near one. When a volcano erupts, lava, hot ash, steam, and rocks are released. In addition, volcanic eruptions can cause other natural disasters. These include landslides, mudslides, earthquakes, and tsunamis. The most destructive volcanic event in U.

The eruption destroyed entire forests. It killed 57 people.