Volcanoes are incredible natural wonders that showcase the powerful forces at work deep within our planet. These amazing landforms can create new landscapes and also put on a spectacular display of Earth’s energy.
What is a Volcano?
A volcano is like a special kind of mountain or hill that has an opening, or vent, connecting to melted rock far beneath the Earth’s surface. This opening allows hot materials from inside the Earth to escape. Many volcanoes look like cone-shaped mountains with a bowl-shaped dip at the top, which is called a crater. However, some volcanoes can also be flat or have other shapes.
They grow bigger over time as eruptions add more layers of cooled rock and ash around the opening. This process shows how the Earth is always changing, even if we cannot always see it happening.
How Does a Volcano Erupt?
A volcanic eruption begins with super hot, melted rock called magma, deep inside the Earth. This magma often collects in large underground spaces known as magma chambers. The Earth’s crust, which is its outer layer, has weak spots or cracks where this magma can begin to rise.
As magma moves closer to the surface, gases trapped within it expand, building up immense pressure, similar to shaking a soda bottle. When this pressure becomes too great for the surrounding rock to hold, the magma forces its way up through a pathway, or vent, and bursts out of the volcano. This release of pressure results in the eruption.
What Comes Out of a Volcano?
During an eruption, several different materials can emerge from a volcano. One of the most recognizable is lava, which is what magma is called once it reaches the Earth’s surface and flows like a very hot, thick liquid. Lava can be extremely hot, with temperatures ranging from about 1,300 to 2,200 degrees Fahrenheit (700 to 1,200 degrees Celsius). It glows brightly as it flows and then cools down to form solid rock.
Another material released is volcanic ash, which is not like the ash from a campfire. Instead, it consists of tiny, sharp pieces of rock, minerals, and volcanic glass, smaller than two millimeters in diameter. This ash forms when gases violently shatter magma into small bits. Additionally, volcanoes release various gases, some of which are invisible but are a significant part of the eruption, such as water vapor, carbon dioxide, and sulfur dioxide. Along with ash and gases, larger rocks and other debris can also be thrown out during an eruption.