Several factors trigger volcanic eruptions, including the buoyancy of magma, a build-up of pressure from the gases in the magma and an injection of new magma into a full magma chamber.
When a part of the earth's upper mantle or lower crust melts, magma forms. A volcano is essentially an opening or a vent through which this magma and the dissolved gases it contains are discharged.
Volcanoes erupt because of density and pressure. The lower density of the
magma relative to the surrounding rocks causes it to rise (like air bubbles in
Aug 20, 2015 ... Volcanoes are channels that transfer molten rock from Earth's crust to the surface.
Here's why eruptions happen.
Deep within the Earth it is so hot that some rocks slowly melt and become a thick
flowing substance called magma. Because it is lighter than the solid rock ...
Jun 29, 2013 ... A quick and fun cartoon lesson about volcanoes. ... Why Volcanoes Erupt ... and
its due tomorrow. thanks to you it took half an hour less to do!
Find out what the earth make-up is, and how extreme pressure build up inside
the earth forces molten matter to be expelled out to the surface, causing a
An extinct volcano is one which has erupted thousands of years ago and there's
no possibility of eruption. Why do volcanoes erupt? The Earth's crust is made up
What disturbs the peaceful slumber of a volcano and makes it erupt? Find out the
answer and see images of erupting volcanoes on PlanetSEED today.
A volcano begins as melted rock (magma) which rises from deep inside the earth
toward the surface. As the gas-filled magma rises ...
Aug 5, 2015 ... Some people believe volcanic eruptions are caused by fate. Others believe a
volcanic eruption is a sign that a mountain is upset because ...