8 Volcanoes

VOLCANOES

Exploding Earth. There are thousands of volcanoes around the world. Some spray red-hot melted rock called lava. Others blast out clouds of ash. This is Mount Etna on Sicily shooting out lava.

A volcano forms. The Earth has an outer shell called the crust. Underneath this is a thick layer of hot rock called the mantle. The middle of the Earth is called the core. It is made of extremely hot metal.

There are cracks in the crust. Hot rock melts and pushes up into the cracks. The melted rock builds up and bursts out as lava. This is called an eruption. The lava hardens into rock. Layers of lava build up after many eruptions. Volcanoes are named after Vulcan, the Roman god of fire.

Fiery fountains. Some lava is runny, so gas inside it bubbles out easily. This creates gentle eruptions. This is Piton de la Fournaise, on the island of Réunion. Runny lava sprays out of it like a fountain.

Runny lava is like thin honey or hot wax. It gushes down the sides of the volcano. The lava spreads a long way before it cools and hardens. A volcano with gently sloping sides slowly builds up. The tallest lava fountain ever was five times higher than the Eiffel Tower in Paris.