How Do Volcanoes Occur?
The earth beneath our feet is not entirely solid. In fact the earth’s crust floats on a sea of molten substance known as the mantle. Volcanoes are points where this mantle of molten lava breaks through to the surface of the earth. The reason that there are points where the mantle comes pouring through, is due to the fact that the earth’s crust is made up of tectonic plates. In other words, the crust of the earth is not smoothly continuous, but instead, it is made up of plates that push against, or pull away from, one another. If you live at the junction of two plates, such as in Japan or Iceland, then you will be living in an area prone to earthquakes and volcanoes. Volcanoes can be either extinct, active or dormant. An extinct volcano has not been known to be active in the whole of human history, in fact the Scottish capital of Edinburgh is built upon just such an extinct volcano. An active volcano is one that still gives out hot ash and lava, and Japan has a number of these. A dorman
