KNOWLEDGE WORLDS
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Nature & Animals / Reading Samples
What happens during a volcanic eruption?
Magma rising to within a few kilometres depth can accumulate in caverns before being hurdled to the earth´s surface through a volcanic vent.
Igneous rock also develops kilometres deep in the earth and gushes to the surface. This can happen slowly or explosively.
When magma reaches the earth´s surface and pours forth, it is called lava. The origin of lava follows the same rules that govern the creation of magma from plutonic rock: Radioactivity, increasing temperature or pressure discharge create a molten mass which rises from the depth. Often hollow cavities filled with liquid rock form close the surface, the so-called magma chambers. From these lava is lifted during a volcanic eruption. This can occur through a more or less round chimney such as at the volcano Etna; in Iceland, however, also from fissures up to 100 kilometres in length.
Magma rising to within a few kilometres depth can accumulate in caverns before being hurdled to the earth´s surface through a volcanic vent.
Igneous rock also develops kilometres deep in the earth and gushes to the surface. This can happen slowly or explosively.
When magma reaches the earth´s surface and pours forth, it is called lava. The origin of lava follows the same rules that govern the creation of magma from plutonic rock: Radioactivity, increasing temperature or pressure discharge create a molten mass which rises from the depth. Often hollow cavities filled with liquid rock form close the surface, the so-called magma chambers. From these lava is lifted during a volcanic eruption. This can occur through a more or less round chimney such as at the volcano Etna; in Iceland, however, also from fissures up to 100 kilometres in length.
 | Band 45: Minerals and Rocks Would you like to know more? Then click here |
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