Download volcanoreview

Volcanic Activity
Volcanoes, explosions and more!
Intrusions
Igneous __________classified
by shape, size, and orientation
Magma Source

Areas Where Magma Forms







Upper mantle
depths of 50 to 250 km
High temps (800-1100 C), medium
pressure
Rocks melt, or partially melt
Divergent plate boundaries
Above subduction zones
Hot spots
Major Volcanoes Around the World
Wahalua Visitors’ Center Aflame in Hawaii
Source: Photograph by J.D. Griggs, USGS Photo Library, Denver, CO.
Ruins of the Visitors’ Center After Lava Cooled
Source: Photograph by J.D. Griggs, USGS Photo Library, Denver, CO.
There are three types of
volcanic cones:



Cinder – explosive eruptions, small but
______
steep slopes, pyroclastics (like ash)
Shield – nonexplosive eruptions, fluid
_______
basaltic lava, gentle broad slopes
Composite – alternating between lava
_________
and pyroclastics, explosive and
nonexplosive eruptions, steep and tall
A common type of volcano is called a
cinder
cone
_____ _____,
these can explode like
a bottle pop due to high pressure
Kilauea on Hawaii is a good example of
shield
a _______
cone, with less explosive
eruptions and less viscous lava.
Mt Rainier and Mt St Helens are good
examples of __________
composite cones, with
explosive eruptions and erupted materials
such as ash, bombs, and blocks.
Mt St Helens
Mt Rainier
Crater Lake in Oregon is a __________formed
caldera
from the collapse of the gigantic volcano Mount
Mazama.
Famous Volcanic Disasters

Pompeii was destroyed and completely
buried during a long catastrophic
eruption of the volcano Mount Vesuvius
spanning two days in 79 AD. The
eruption buried Pompeii under 4 to 6
meters of ash and pumice, and it was
lost for over 1,500 years before its
accidental rediscovery in 1599.