Hot melted rocks collect under the Earth's surface and when the pressure becomes too hard, the Earth's skin breaks, and a volcano erupts. The melted rock inside the Earth is called magma, but when it comes out in an eruption, it is called lava.Know More
Plates are like the Earth's skin. They are called the Earth's mantle, and they float on the magma. Sometimes the plates separate, and that creates even more red-hot liquid rock. The Earth has to relieve the pressure in the form of a volcanic eruption. After the eruption, the lava spreads out, cools down and hardens into rock, but hot magma remains under the surface.
In the Pacific Ocean, 75 percent of all volcanoes are located in an area called the Ring of Fire, where two of the Earth's plates meet. Some volcanoes are cone-shaped mountains, some are flat-topped like mountain plateaus, some have fissure vents, which are cracks where the lava escapes, and others bulge like domes. There are even volcanoes on the ocean floor and under the icecaps in Iceland.
Volcanoes also happen on other planets in the solar system. On Mars there is a volcano called Olympus Mons, and it is 373 miles wide and 13 miles high. The most volcanic activity in the solar system is on one of Jupiter's moons.Learn more about Volcanoes
A volcano forms when magma pushes up through the Earth's crust from below, depositing lava on the surface. This lava cools, creating volcanic rock. Over time, repeated eruptions of lava build a cone-shaped mountainous structure, producing a volcano.Full Answer >
The opening at the top of a volcano is called a vent and is where lava flows from erupting volcanoes. Volcanic vents usually sit inside craters, which are circular depressions in the ground.Full Answer >
While many volcanoes are mountains, it is possible for a volcano to erupt from a vent in any type of land form. Over time, volcanoes become mountains by depositing their discharge around them in ever-increasing layers. Not all mountains are volcanoes.Full Answer >
A Cascade Range volcano is one that is part of a series of mountains in western North America that includes an arc of volcanoes. The Cascade Range extends from British Columbia through Washington and Oregon to northern California.Full Answer >