Table of Contents
What causes magma to erupt out of a volcano?
Volcanoes erupt when molten rock called magma rises to the surface. Magma is formed when the earth’s mantle melts. If magma is thick, gas bubbles cannot easily escape and pressure builds up as the magma rises. When the pressure is too much an explosive eruption can happen, which can be dangerous and destructive.
What is magma called when it comes out of a volcano?
Magma is extremely hot liquid and semi-liquid rock located under Earth’s surface. This magma can push through holes or cracks in the crust, causing a volcanic eruption. When magma flows or erupts onto Earth’s surface, it is called lava.
What does magma do in a volcano?
Magma moves up to the surface from deep within the Earth, and is ejected as lava. The magma carries crystals and fragments of unmelted rock. In addition, volatile compounds in the magma may separate from it as bubbles of gas. Some liquids in the magma may solidify and crystallize as they cool.
Why does magma from the center of the Earth go up a volcano and come out the top?
Magma rises up through volcanoes because of the pressure of the colliding plates. It rises up through rift valleys to fill the space that the rift creates. See this graphic for more information on these boundaries. As lava explodes from volcanoes or seeps up to fill rifts, it can seem inexhaustible.
What causes lava?
Lava is molten rock. It is created deep beneath Earth’s surface (often 100 miles or more underground), where temperatures get hot enough to melt rock. When magma erupts onto Earth’s surface and begins to flow, scientists then call it lava. Explosive eruptions can throw lava great distances.
Why lava is called lava?
The word lava comes from Italian and is probably derived from the Latin word labes, which means a fall or slide. Its first known use in connection with extrusion of magma from below the surface was in a short account of the 1737 eruption of Vesuvius written by Francesco Serao.
How does magma flow?
When magma reaches the surface of the earth, it is called lava. Since it its a liquid, it flows downhill in response to gravity as a lava flows. Different magma types behave differently as lava flows, depending on their temperature, viscosity, and gas content.
How does magma rise in the Earth?
The magma rises and collects in chambers within the crust. As magma fills the chamber, pressure grows. If the pressure gets high enough, the magma can break through the crust and spew out in a volcanic eruption. Most explosive volcanoes occur above subduction zones.
Why is there magma inside the Earth?
Differences in temperature, pressure, and structural formations in the mantle and crust cause magma to form in different ways. Decompression melting involves the upward movement of Earth’s mostly-solid mantle. This reduction in overlying pressure, or decompression, enables the mantle rock to melt and form magma.