Why, when, and how do volcanoes erupt?
Question: Why do volcanoes erupt? Answer: When rock inside the Earth becomes hot enough it melts. This molten rock, or magma, is less dense than the surrounding solid rock. Just as an object that is less dense than water will float on water, the relatively low density of the magma causes it to rise to the surface of the Earth. If the magma contains water and dissolved gasses, when the magma reaches the surface the water and dissolved gasses will suddenly expand into steam and gas, causing a violent eruption. This is like shaking a coke can and then popping the tab.
How: There are two different kinds of eruptions: quiet eruptions, and explosive eruptions. Quiet eruptions are when lava just oozes out of the volcano. Explosive eruptions occur when thick magma plugs up the conduit (pipe) of the volcano, and pretty soon gases build up. . . until the volcano has to let it out–BOOM! Why: The “how” volcanoes erupt is a lot like “why” volcaones erupt. Like I said, explosive eruptions are caused by thick magma plugging up the volcano’s pipe. Quiet eruptions can be caused by pressure in the pipe, but it is not that high, like in an explosive eruption. When: There is not a specific time when a volcano erupts. Sometimes, there is always volcanic activity going on, and it can erupt a lot. There are also dormant volcanoes, that are not currently active, but are likely to erupt soon. And extinct means that they are probably never going to erupt. So, when a volcano will erupt can never be predicted, but like how and why the eruptions are caused, the volcano will
