Magma from deep within the Earth's mantle can surge through a
volcano in a matter of months rather than thousands of years or
more, as previously thought, according to a study published
Wednesday in the journal Nature.  The molten lava that erupts
from volcanoes comes from the mantle, the portion of the Earth
that lies between the core in the center and the crust on top.
It periodically pumps hot magma into a volcano’s magma chamber,
filling it from below.  Scientists believed that these pulses of
magma mixed together in the chamber before climbing upward -- a
process estimated to take several thousands of years.  But
Columbia University volcanologists found that the eruption of
Costa Rica’s Irazu volcano in 1963 was likely triggered by magma
that took a nonstop route from the mantle over just a few
months.  The finding suggests that magma can spark an eruption
relatively quickly -- a potentially important factor to consider
when forecasting volcanic activity.  “There has to be a conduit
from the mantle to th