2006-11-26 22:12:44 · 6 answers · asked by joseph a 1 in Science & Mathematics ➔ Earth Sciences & Geology
It erupts out.
2006-11-26 22:17:12 · answer #1 · answered by gen Xer 2 · 0⤊ 0⤋
Technically, Lava comes out of a volcano from an eruption. Magma is inside the Earth.
2006-11-27 04:11:02 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The build up of pressure from far below the surface forces the magma our through the volcano which is really a giant vent in the crust of the Earth.
2006-11-26 22:15:09 · answer #3 · answered by Isis 7 · 0⤊ 0⤋
There are several ways. All the molten rock in the centre of the Earth is the same but as it rises through the Earths crust, depending on how long it takes, different parts of the magma seperate out. Basalt magma is rich in iron. It is much more liquid and flows rapidly over the Earth's surface if it finds a fissure that will allow it to rise. This is the classic lava flow. Common in Hawaii and Iceland. Lava flows are more common below the ocean than they are on land. Lava that is rich in quartz cools to form granite. It it much more viscuos and floats on the basalt lava. Granite gradually rises through the Earth's crust. Usually it cools and solidifies below the surface but sometimes a stiff body of granite lava will extrude from the Earth like, a turd from a dog's butt (sorry couldn't think of a different analogy). This will set to form a volcanic plug. As well as flowing lava rock and dust is ejected from volcanoes in PYROCLASTIC events. That is when bits of dust, ash, molten lava and gases are violently blasted into the air. Where these materials fall and solidify they form a rock called tuff. This is a simplified version of igneous geology.
2006-11-26 22:37:04 · answer #4 · answered by Anonymous · 0⤊ 1⤋
No. No magma comes from the middle. some volcanoes produce lava that is sourced as deep because of the fact the middle-mantle boundary, yet those warm spot volcanoes are the exception, not the rule of thumb. maximum volcanism is pushed by making use of melting interior the better mantle or deep lithosphere (that's comparatively shallow in comparison to the middle).
2016-12-17 16:58:25 · answer #5 · answered by ? 3 · 0⤊ 0⤋
when the pressure inside the earth builds up,the magma is forced up.it erupts only in the case that pressure is very high.it first sends out poisonous gases throwing rocks all over and then the lava erupts out
2006-11-26 22:25:34 · answer #6 · answered by jerry 2 · 0⤊ 0⤋