Volcanoes

A volcano is an opening in the Earth’s crust through which magma, ash and gases escape. The magnitude (strength) of the eruptions are measured used a Volcanic eruptions have both primary effects and secondary effects. One way of reducing the effects of volcanic eruptions is by predicting, planning, and preparing for them.

Volcanoes occur either at the unstable boundaries of tectonic plates or in the middle of plates where the crust is thin or where there is a particularly hot spot in the mantle.

There are two types of volcano:

People live near volcanoes for a number of reasons:

• Many people can visit the area, creating a tourism industry

• The soil around volcanoes is rich in minerals, and so is great for agriculture

• Geothermal energy can be harnessed, providing cheaper energy for locals

Primary effects of a volcanic eruption:

• When the volcano erupts, ash, lava, and pyroclastic flow are spewed out of it, causing damage to habitats and property

• Pyroclastic flow is made of super-heated gas and ash, and travels quickly at hundreds of kilometres an hour

• Ash fall from volcanoes can land on roofs of buildings, causing them to collapse.

Secondary effects of a volcanic eruption:

• Volcanic eruptions can lead to climate change. This is because the carbon dioxide released contributes to global warming

• Roads can become blocked by lava flows, making it difficult to travel around

• Ash from the volcano can act as a fertiliser for soils.

Some methods used for predicting volcanic eruptions are: