how do volcanos erupt?

Question

I like volcanos.

Answer 1

Well usually it's because they're mad at the sky.
Sometimes an argument ensue between them and then, bam Alice, to the moon!

But really, there's a couple of different ways.
The Hawaiian island chain is the result of the tectonic plate moving over a "hot spot" in the crust. The "hot spot" shoot magma directly to the surface as the tectonic plate moves over it.
Other volcanoes erupt because of sub-surface activity that results in a magma chamber being formed. As the activity increases and seismic events continue, the earth above the chamber is disturbed. Remember the magma is under unbelievable pressure. If the seismic events coupled with the intense pressure produce a rapid release of pressure holding the magma in the chamber occurs, the gases in the magma literally explode when released. Just life St. Helens, Pinatubo and other volcanoes.
tc

Answer 2

EXPLANATION OF THE ERUPTION MODEL
THE MAGMA COLUMN -- Eruptions are fed from a magma column that exists below the point source of the eruption. The magma column contains two critical pressure surfaces:
(1) The exsolution surface occurs in the magma reservoir beneath the volcano. It separates a zone of magma containing dissolved volatiles from an overlying zone of magma containing exsolved gas bubbles

(2) The fragmentation surface occurs at the top of the magma column. It separates the zone of magma containing exsolved gas from the overlying eruption column. Fragmentation of the magma is generated by rapid gas expansion and bubble explosion.

The exsolution of gas from magma (or "boiling") is called vesiculation. These gas bubbles (vesicles) begin to form at the exsolution surface. Vesiculation is promoted by decompression of magma as it rises upward (where the confining pressure is less than the dissolved gas pressure). Fragmentation of the bubble walls then begins at the fragmentation surface; here, the gas bubbles grow during ascent until they become unstable and explode. This occurs when the volume of bubbles is about 75% of the total volume of the magma column. Gas release is confined to the diameter of the magma column, and the eruption velocity is controlled mainly by the gas content. The low strength of surface rocks and the high initial exit pressure commonly results in vent erosion, so that a flared vent shape develops which enhances velocity. This marks an upward transition from subsonic to supersonic flow.

THE ERUPTION COLUMN --The fragmentation surface is the point source of the eruption. The region of hot gas and broken pyroclastic particles above the fragmentation surface is called the eruption column. It transports pyroclastic materials from the ground into the atmosphere. Common observed heights for plinian eruptive columns are between 2 and 45 km. The eruption column for the 1994 eruption of the Klyuchevskoi volcano in Kamchatka is shown here.
VR

Answer 3

Volcanoes hot.

Answer 4

You like it eh?? Tell me it again when you are standing near volcano that is erupting!

Answer 5

If you love it read about it:

http://en.wikipedia.org/wiki/Volcano
http://www.pbs.org/wnet/savageearth/animations/volcanoes/index.html
http://www.learner.org/exhibits/volcanoes/
http://pubs.usgs.gov/gip/volc/eruptions.html
http://www.eri.u-tokyo.ac.jp/VRC/vrc/erup/erup.html

Answer 6

earth pressure build up