Why do volcanoes erupt?
Why do volcanoes erupt? It's not that hard to understand. The Earth is like a big furnace, full of hot magma. But the magma is normally held down by the Earth's crust, so it can't get out. If there is too much pressure on the crust, or if there is a crack, the magma will take advantage of the opportunity to pour out, and this is the beginning of a volcanic eruption.
The Earth's internal structure is very complex, and the deeper you go, the higher the temperature and the higher the pressure. Under such extreme conditions, rocks are melted into magma, which is constantly surging and gathering, always looking for a chance to break through the boundaries of the earth's crust.
The Earth's surface is divided into so many big pieces like a jigsaw puzzle; these are the plates. The plates sometimes collide, separate, or slide together, and when they do, the Earth's crust tends to crack, and the magma runs out along the cracks.
When plates collide with each other, they generate tremendous forces that cause the crust to deform and break. It's as if two cars collide violently and the shells of the cars crack. The separation of plates, on the other hand, causes the Earth's crust to thin and magma to rise to the surface more easily.
There's also a lot of gas in the magma, like the bubbles in a soda. As the magma rises to the surface, more and more gas is released, and then the magma and gas are released with a bang. The heat of the magma is so great that it melts the rocks around it, and the gas expands with it, and when it finds an exit, it erupts violently.
Volcanoes erupt in different ways, some sprayed very violent, a lot of magma, rocks, ash are out; some just slow flow of magma. It depends on the composition of the magma and the amount of gas.
Generally speaking, the silica-rich magma is relatively viscous, the gas is not easy to escape, it is easy to trigger violent eruptions; while the basal magma is relatively thin, the eruption will be more moderate.
Ejected magma flow down the mountainside, cold into a new stone, slowly piled up a volcanic cone, each eruption to the volcano to add some material.
Over time, the cone will become higher and higher, bigger and bigger, becoming a unique landscape on the surface of the earth.
Some volcanoes after the eruption will sleep, may be hundreds of years, thousands of years are not moving, but maybe when it wakes up, so scientists have to keep an eye on them, so as to know in advance when to erupt again.
Volcanic eruptions are dangerous, but there are also beautiful places. Like Hawaii's volcanic eruption, lava flow can be beautiful; Iceland's volcano sprayed on the snow, the scene is also very strange, many people run to see.
However, volcanic eruptions are really dangerous, hot lava, toxic gases, falling rocks and thick ash, can destroy houses, bad crops, but also hurt people's lives.
The good thing is that scientists can use seismometers, satellites, and other tools to know in advance that the volcano is going to erupt, and can detect earthquakes, crustal changes, and magma movement, so that people can rush to get out of the way.
After a volcano erupts, the soil chilled by the lava can be fertilized and grow good crops. The geothermal heat next to the volcano also generates electricity, a clean energy source.
In many cultures, volcanoes are mysterious and sacred. For example, Hawaiians believe that volcanoes are the home of the goddess Pele, and there are stories about volcanoes all over the world.
Some volcanoes that have been sleeping for a long time suddenly erupt again, which is called a “reactivated volcano”, leaving people defenseless and showing that the power of nature is elusive.
Scientists in order to understand the volcano, and is to take magma samples, and is to analyze the gas, but also the amount of crustal changes, so that we can better know how the volcano, how to reduce the harm.
Volcanoes show us that the Earth is a dynamic planet with a lot of energy inside. We have to respect nature and get along with it.
In the future, as technology becomes more and more powerful, we will know more about volcanoes, and we may be able to accurately know in advance of the eruption, and also be able to use the energy of volcanoes more safely. The secrets and power of volcanoes will continue to fascinate us.
