Transcript Violent volcanoes

Violent volcanoes
By Brandon Swain
About Magma
• Magma (from Greek "mixture") is a
mixture of molten or semi-molten
rock, volatiles and solids that is
found beneath the surface of the
Earth, and is expected to exist on
other terrestrial planets. Magma
often collects in magma chambers
that may feed a volcano or turn
into a pluton.
About lAvA’s temperAture
• Lava comes from the core in the middle
of the earth. When first erupted from a
volcanic vent, lava is a liquid at
temperatures from 700 to 1,200 °C
(1,292 to 2,192 °F). Up to 100,000 times as
viscous as water, lava can flow great
distances before cooling and solidifying
because of its thixotropic and shea
thinning properties.
About volcanoes that have
erupted
According to the Global Volcanism
Program at the Smithsonian Institute,
hundreds of volcanoes have erupted in
the last century, but most of these
eruptions were minor and did not garner
much worldwide attention. Twelve,
however, were large enough to cause
major disruptions to local citizens,
property damage or deaths.
About volcAnoes ‘s nAture
• Volcanoes are one of nature's deadliest killers.
Breathtakingly beautiful yet devastatingly fatal,
volcanoes have fascinated human beings since
time immemorial. They stand as permanent
reminders of the fragility of the human race—
constantly at the mercy of the unpredictable
ruthlessness of the natural world. Volcanic
eruptions create and destroy landscapes,
fascinate and terrify observers, and can even
control our climate. Explore the history of
volcanoes, revealed in the world's 10 greatest
eruptions.
Volcanoes
• Volcanoes are usually cone shaped.
• Magma rises through cracks or
weaknesses in the earths crust.
• Pressure builds up inside the earths.
• Over time, after several eruptions, the rock
builds up and a volcano forms.
• The lava from the eruption cools to form
new crust.