What makes a volcano erupt?
Stacey
and Nicole
Hi Stacey and Nicole,
A volcano will erupt when the pressure of the magma inside it is too strong and
it breaks its way to the surface. Most of the time the pressure increases
because there are gas bubbles within the magma and they are trying to expand
(like the bubbles that build up in a bottle of soda). When the pressure gets
too high, the rocks that make up the volcano break, and the magma escapes to the
surface to erupt.
In some volcanoes the supply from within the Earth is relatively constant so
there are lots of eruptions (such as at Kilauea). In other places it seems more
like the magma comes up in blobs every few, few 10's, few 100's or few 1000's of
years, and eruptions are much less frequent (such as at Mt. St. Helens or Pinatubo).
Hopefully this answers your question.
Sincerely,
Scott Rowland, University of Hawaii
Other Categories
Other Questions
To VolcanoWorld