Why Do Volcanoes Erupt?
Volcanic eruptions occur almost the same way volcanoes are formed. As volcanoes form, a magma chamber is created underneath the volcano, where magma just sits there. If enough pressure is created when the earth's plates interact, that magma can ooze or shoot up through a tunnel in the volcano called a vent. And, when a volcano blows its top due to this pressure, a crater, or basin, is created at the top.
Volcanoes can be labeled as active, dormant, or extinct. Active volcanoes have the potential to erupt any time. Dormant volcanoes haven't erupted in a longer period of time but are not yet labeled as extinct. And extinct volcanoes will probably never erupt again.
How Do Volcanoes Differ?
Volcanoes look different, mostly based on what happens to the lava as it flows out. There are four different types: cinder cones, shield volcanoes, composite volcanoes, and lava volcanoes.
Cinder cones look the most circular, and the lava flows from a single vent. Shield volcanoes look like shields and are made from a special kind of lava called basalt lava. Composite volcanoes are the steepest ones and are made from many layers of cooled-off lava, rock, and ash. Finally, lava volcanoes look like domes and are made from a build-up of much thicker lava that has difficulty flowing down the volcano.
More Facts About Volcanoes
How does a volcano apologize? It says, 'I'm sorry for being so hot-headed.' Okay, that's a silly joke, not a fact. But there are a lot of interesting facts related to volcanoes. For example, there are over 1,500 active volcanoes on Earth, in addition to more than a million undiscovered volcanoes potentially sitting undersea. These active volcanoes can release lava and high-nutrient ash that's great for the soil and often used for growing plants.
Another well-known fact is that a big tourist destination, the Hawaiian Islands, was created due to activity in volcanic hot spots under the ocean. These islands are located in an area of Earth called the Ring of Fire, where 75% of Earth's volcanoes are found.
Lesson Summary
Let's take a few moments to review what we've learned. Volcanoes are special types of mountains that have an opening that spews out hot fluid from inside the Earth. They're formed when magma (hot molten rock) from the Earth's mantle comes up through the crust, which is made up of huge pieces of rock called plates. This usually happens when the Earth's plates interact with each other. Volcanoes can be active, dormant, or extinct. Active volcanoes have the potential to erupt any time. Dormant volcanoes haven't erupted in a longer period of time but aren't yet labeled as extinct, and extinct volcanoes will probably never erupt again.
There are four types of volcanoes: cinder cones, shield volcanoes, composite volcanoes, and lava volcanoes. Cinder cones look the most circular, and the lava flows from a single vent. Shield volcanoes look like shields and are made from a special kind of lava called basalt lava. Composite volcanoes are the steepest ones and are made from many layers of cooled-off lava, rock, and ash. Finally, lava volcanoes look like domes and are made from a build-up of much thicker lava that has difficulty flowing down the volcano. Now you should be aware of the different types of volcanoes, so next time you see a picture of one, you can identify it and tell your family or friends what it means when it's called active, dormant, or extinct.
