How many times have you’ve seen something on T.V. about volcanoes and said, “what is a volcano?” Well, a volcano is a mountain that comes in many different shapes and sizes. The magma and lava come in many different types too. But not all volcanic eruptions are big and explosive. There’s more to volcanoes than you think.
What are volcanoes? Volcanoes are mountains that formed downward reaching a pool of molten rock. It goes in therefore, creating magma. It only erupts because of the pressure from the gas bubbles in the magma. It then comes out and turns into lava. Volcanoes also have four structures to it. The vent, pipe, crater, and cone. The vent is the opening of the volcano, and the pipe is the passageway for the magma to get out. The crater is where other materials are released, and the cone is solified lava, ash, and cinder.
There is not only one kind of volcano. In fact, there are three kinds of different volcanoes. Shield volcanoes, cinder cone volcanoes, and composite volcanoes. Shield volcanoes are big, but slope down on the sides. Shield volcanoes landform is basaltic. Cinder cone volcanoes are made of mostly solid fragments. Composite volcanoes are made of layers of lava and tephra. They make big, but quiet explosions. This happens because they are made with both basalt and granite.
There are also different types of magma and lava- basaltic and granitic. Basaltic magma is when it doesn’t contain a lot of silica. Basaltic lava pours down from the vent, and down the sides of the volcano. Granitic lava is when magma has a lot of silica. Granitic lava is slow, sticky, and lumpy. It also traps gases, so it has explosive eruptions.
Not every volcano has huge eruptions. It all depends on a little chemical called silica. Silica is the thing that controls how volcanic eruptions are. If magma has low silica, it’s thin and runny. If lava has a lot of silica, it’s thicker and slower. Gas and temperature also affects how a volcano erupts. So does viscosity. Viscosity is a physical property that describes the resistance to flow.
All in all, there is not only just one kind of volcano. Volcanoes come in many types. There is also different types of magma and lava. So next time think- “ What really is a volcano?”