Describe and classify types of volcanoes.
Extinct: has not had an eruption for at least 10,000 years and is not expected to erupt
again in a comparable time scale of the future.
Dormant: hasn't erupted in the past 10,000 years, but which is expected to erupt again.
Active: is a volcano that has had at least one eruption during the past 10,000 years.
Volcanoes can also be classified by type. The formation and composition determine a
volcano’s type. Shield volcanoes are low, dome-shaped mountains formed by lava that
flows smoothly and covers an extensive area. Cinder cone volcanoes are the most
simplistic form; they erupt from a single vent and normally have a bowl-shaped crater at
the summit. Composite, or strata, volcanoes are the most prevalent type; they are tall
mountains with sheer sides, having alternating inner layers of rock and magma.
Volcanologists rank eruptions based on the Volcanic Explosivity Index, which includes
the debris that ejects during the eruption and runs from 0 to 8. classifications of
volcanoes based on the type of eruption they produce: Explosive eruptions are
produced by the buildup of gasses under highly viscous magma ensnared deep within
the volcano. Eruptions are fast and furious, often spitting lava, ash, and tephra high into
the air.
Quiet eruptions usually emit great quantities of lava along a long fissure or fracture. This
Lava typically has a low viscosity so the gases are not restricted from easily escaping.
Shield Volcanoes: largest of all the volcanoes on earth with a wide diameter the lava
that flows from these types of volcanoes is low in Viscosity volcanoes are not steep their
eruptions are not as volatile they're more like a fountain
Composite Volcanoes made of several elements or multiple eruptions
lava flows
form a thin crust resulting in a cone shape the lava that comes out of these volcanoes is
more viscous eruptions are explosive and contain large amounts of pyroclastic material
Caldera: these are the most explosive Volcanoes their eruptions cause them to collapse
on themselves rather than building any tall structure the depression created by the claps
of the volcanos structure causes a depression called a caldera. The magnitude of the
explosions indicates the magma chamber is closer to the surface of the earth.
Flood Basalt provinces: Outpour of Highly fluid lava that flows for long distances
Mid-ocean Ridge Volcanoes: Underwater mountain range formed by plate tectonics
divergent plate boundaries cause these volcanoes
Cinder cones: the most common type of volcano. A cinder cone has a cone shape, but
is much smaller than a composite volcano. Cinder cones rarely reach 300 meters in
height but they have steep sides. Cinder cones grow rapidly, usually from a single
eruption cycle
Supervolcano: Where are extremely volatile volcanoes cause catastrophic damage to
their massive eruption