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Lava Rock Types | Stages of Volcanic Activity | Volcano Types

A volcano is a location on the surface of the Earth where magma has erupted out of the interior of the planet. Magma is molten rock, which has melted from the extreme heat (2200 degrees Celsius to 5000 degrees Celsius) and pressure that exists inside the Earth. Once molten rock has erupted onto the Earth's surface, it is called lava. As lava spreads out on the surface, it cools and becomes solid rock again. The buildup of lava forms hills and mountains on land, and it forms islands if the volcano began on the ocean floor. The Hawaiian Islands, for example, exist because of volcanoes. There are many stages of volcanic activity, types of lava rocks, and volcano types.