Volcanoes

A volcano is an opening in the Earth's surface. Hot melted rock called magma comes up from deep inside the Earth. When it reaches the surface, it is called lava. Volcanoes can erupt with ash, gas, and rock. Some volcanoes are quiet for many years between eruptions.

How They Work

Deep inside the Earth, rock is so hot that it melts. This melted rock rises slowly through cracks. When pressure builds up, the volcano erupts. Lava flows down the sides of the mountain. Ash and smoke can fly high into the sky.

A long row of volcano craters in Iceland.
A long row of volcano craters in Iceland. (Juhász Péter / Wikimedia Commons)

Where They Are

Volcanoes are found all over the world. Many sit along a curve called the Ring of Fire in the Pacific Ocean. Some volcanoes are on land, and some are under the sea. Underwater volcanoes can even make new islands. Hawaii was formed by volcanoes long ago.

Fun Facts

  • Lava can be hotter than 2,000 degrees Fahrenheit.
  • There are over 1,500 active volcanoes on Earth.
  • The tallest volcano is Mauna Kea in Hawaii.

Did You Know?

Volcanic soil is full of minerals and very good for growing plants. Farmers often plant crops near old volcanoes.