Volcanoes
Volcanoes are any vent in the crust of the Earth
or other planet or satellite, from which molten rock, pyroclastic debris, and
steam issue. Volcanism is the name given to the processes and phenomena
associated with the surgical discharge of such material from volcanoes,
geysers, and fumaroles. Volcanism is a profound process resulting from the
thermal evolution of planetary bodies. Heat does not easily escape from large
bodies by conduction or radiation. Instead, partial melting and buoyant rise of
magma are major contributors to the process of heat flux from the Earth’s
interior. Volcanoes are the surface manifestation of this thermal process,
which has its roots deep inside the earth and which hurls its ashes high into
the atmosphere. The term volcano can either mea the vent from which magma
erupts to the surface or it can refer to the landform created by the solidified
lava and fragmental volcanic debris that accumulate near the vent. Volcanoes
affect humankind in many ways. Their destructiveness is awesome, but the risk
involved can be reduced by assessing volcanic hazards and forecasting volcanic
eruptions. Volcanism provides fertile soils, valuable mineral deposits, and
geothermal energy. Over geologic time, volcanoes recycle the Earth’s
Hydrosphere and atmosphere, and explosive eruptions can affect climate.
