Volcano Eruption:-
A volcanic eruption occurs when hot materials from the earth's interior are thrown out of a volcano. Lava, rocks, dust and gas compounds are some of these "ejects".
Eruptions can come from side branches or from the top of the volcano. Some eruptions are terrible explosions that throw out huge amounts of rock and volcanic ash and kill many people. Some are quiet outflows of hot lava. Several more complex types of volcanic eruptions have been described by volcanologists. These are often named after famous volcanoes where that type of eruption has been seen. Some volcanoes may show only one type of eruption during a period of activity.
Volcano eruptions happen when magma erupts from beneath the Earth's crust. When a volcano erupts, the magma becomes lava and shoots into the air, eventually running down the side of the volcano.
To understand how and why volcanoes erupt, we must first understand the different layers of our planet.
The Layers of Planet Earth:-
1. Core
2. Mantle
3. Crust
Earth is made of three layers: the core, the mantle, and the crust. The core is comprised of inner and outer sections. The mantle has lower and upper mantle areas, too. The crust, though, consists of one main layer.
The Crust:-
The Earth's Crust is like the skin of an apple. It is very thin in comparison to the other three layers. The crust is only about 3-5 miles (8 kilometers) thick under the oceans and about 25 miles (32 kilometers) thick under the continents. The temperatures of the crust vary from air temperature on top to about 1600 degrees Fahrenheit (870 degrees Celcius) in the deepest parts of the crust. You can bake a loaf of bread in your oven at 350 degrees Fahrenheit , at 1600 degrees F. rocks begin to melt.
The crust of the Earth is broken into many pieces called plates. The plates "float" on the soft, plasticmantle which is located below the crust. These plates usually move along smoothly but sometimes they stick and build up pressure. The pressure builds and the rock bends until it snaps. When this occurs an Earthquake is the result.
The Mantle:-
The mantle is the layer located directly under the sima. It is the largest layer of the Earth, 1800 miles thick. The mantle is composed of very hot, dense rock. This layer of rock even flows like asphalt under a heavy weight. This flow is due to great temperature differences from the bottom to the top of the mantle. The movement of the mantle is the reason that the plates of the Earth move! The temperature of the mantle varies from 1600 degrees Fahrenheit at the top to about 4000 degrees Fahrenheit near the bottom.
Outer Core:-
The core of the Earth is like a ball of very hot metals. (4000 degrees F. to 9000 degrees F.) The outer core is so hot that the metals in it are all in the liquid state. The outer core is located about 1800 milesbeneath the crust and is about 1400 miles thick. The outer core is composed of the melted metals nickel and iron.
Inner Core:-
The inner core of the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move about like a liquid, but are forced to vibrate in place as a solid. The inner core begins about 4000 miles beneath the crust and is about 800 miles thick. The temperatures may reach 9000 dgrees F. and the pressures are 45,000,000 pounds per square inch. This is 3,000,000 times the air pressure on you at sea level
