http://www.youtube.com/thinkingcaptain - To understand how a volcano erupts, we’ll first need to take a look at the structure of the Earth. Earth has different layers which include the inner and outer core, the mantle and the crust. We’ll focus on the mantle and crust as this is where all the volcanic action takes place. The crust is the outermost layer, as well as the thinnest layer on Earth. Right below the crust is the mantle, where temperatures can reach up to 1000 degrees Celsius. Due to the high temperatures and the increased pressure in the mantle, rocks can melt to form molten rock or magma.
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