Volcanic crater facts for kids
A volcanic crater is a bowl-shaped dip in the ground. It is made by a volcano when it erupts. Craters are usually round and can be very deep.
Inside an active crater, there are openings called vents. Through these vents, hot magma (melted rock) comes out. It can erupt as gases, liquid lava, or pieces of rock and ash called ejecta.
Sometimes, during very big eruptions, a volcano's underground magma chamber (where magma is stored) can become empty. When this happens, the ground above it might sink down. This large, sunken crater is called a caldera.
Contents
What is a Volcanic Crater?
A volcanic crater is like a big, round hole at the top of a volcano. Think of it as the volcano's mouth. When a volcano erupts, all the hot stuff like lava, ash, and gases comes out of this opening.
How do Craters Form?
Craters form when a volcano explodes or when lava flows out. The force of the eruption blasts away rock, making a bowl shape. Over time, more eruptions can make the crater bigger or change its shape.
Types of Volcanic Craters
There are different kinds of craters. Some are simple, just a single hole. Others are more complex, with smaller craters inside bigger ones.
- Summit craters: These are the most common type. They are found at the very top of a volcano.
- Flank craters: Sometimes, craters form on the sides of a volcano, not just at the top. These are called flank craters.
- Maar craters: These are special craters formed by explosive eruptions when hot magma meets groundwater. They are often wide and shallow, and can fill with water to become lakes.
Craters and Calderas
It is easy to mix up a crater and a caldera. While both are dips in the ground made by volcanoes, they are different in size and how they form.
What is a Caldera?
A caldera is a much larger depression than a crater. It forms when a volcano's magma chamber empties out after a huge eruption. Without the support of the magma, the ground above the chamber collapses inward. This creates a massive basin, often many kilometers wide.
How are they Different?
- Size: Craters are usually smaller, from a few meters to a kilometer wide. Calderas are much larger, often several kilometers across.
- Formation: Craters are formed by explosions or lava flows from the vent. Calderas form when the ground collapses after a large eruption empties the magma chamber.
- Location: Craters are typically at the summit or flanks of a volcano. Calderas often replace the entire top of a volcano.
Famous Volcanic Craters and Calderas
Many famous volcanoes have craters or calderas. These natural features can be very beautiful, sometimes even filling with water to form lakes.
- Crater Lake, USA: This is a famous caldera in Oregon, USA. It formed about 7,700 years ago when Mount Mazama collapsed after a huge eruption. It is now the deepest lake in the United States.
- Diamond Head, Hawaii: This is a well-known volcanic crater (or tuff cone) in Honolulu, Hawaii. It is an extinct volcano, meaning it is no longer active.
- Kerið, Iceland: This is a volcanic crater lake in Iceland, known for its striking red volcanic rock and blue-green water.
Related pages
Images for kids
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Craters on Mount Cameroon
See also
In Spanish: Cráter volcánico para niños
