Transcript Jamie - Science A 2 Z

Volcanoes!!!
By: Jamie Stephenson
What is a Volcano?
• A volcano is a landform (usually a
mountain) where liquid rock erupts
through the surface of the planet.
• In simple terms a volcano is a mountain
that opens downward to a pool of
molten rock (magma) below the surface
of the earth. It is a hole in the Earth
from which molten rock and gas erupt.
Did You Know The name "volcano" gets its
origin from the name of
Vulcan, a god of fire in Roman
mythology.
What causes volcanoes to
erupt?
• The Earth's crust is made up of huge slabs
called plates, which fit together like a
jigsaw puzzle. These plates sometimes move.
• Between the Earth's crust and the mantle is
a substance called magna which is made of
rock and gases.
• When two plates collide, one section slides
on top of the other, the one beneath is
pushed down. Magma is squeezed up
between two plates.
In Other Words • Volcanoes are like giant safety valves
that release the pressure that builds
up inside the Earth.
What is the difference between
lava and Magma?
• Magma is liquid rock inside a volcano.
• Lava is liquid rock (magma) that flows
out of a volcano. Fresh lava ranges
from 1,300° to 2,200° F (700° to 1,200°
C) in temperature and glows red hot
to white hot as it flows.
The different parts of a
Volcano
•
•
•
•
•
•
•
•
•
•
•
•
Magna - Molten rock beneath Earth's
surface.
Parasitic Cone - A small cone-shaped
volcano formed by an accumulation of
volcanic debris.
Sill - A flat piece of rock formed when
magma hardens in a crack in a volcano.
Vent - An opening in Earth's surface
through which volcanic materials
escape.
Flank - The side of a volcano.
Lava - Molten rock that erupts from a
volcano that solidifies as it cools.
Crater - Mouth of a volcano surrounds a volcanic vent.
Conduit - An underground passage
magma travels through.
Summit - Highest point; apex
Throat - Entrance of a volcano. The
part of the conduit that ejects lava
and volcanic ash.
Ash - Fragments of lava or rock smaller
than 2 millimeters in size that are
blasted into the air by volcanic
explosions.
Ash Cloud - A cloud of ash formed by
volcanic explosions.
The 3 Different Types of
Volcanoes
• There are 3 different types
of volcanos:
• Active - eruptions can be
anytime and often.
• Dormant - has been a while
since it has erupted, but
could at anytime.
• Extinct, meaning it hasn't
erupted in a very long, long
time so it probably won't
ever again.
Shapes of Volcanoes
• shield volcanoes
• composite
volcanoes
• cinder cones
• lava domes
Volcanic Eruptions Can
Trigger:
tsunamis
flashfloods
earthquakes
mudflows
rock falls
Volcanoes can have a very serious
effect on the lands and people
around them when they erupt
• Buildings are destroyed and people are made
homeless.
• People are killed.
• Clouds of ash cover plants making them inedible.
• Poisonous gases kill people and animals.
• Dust causes pneumonia and illnesses to the
survivors.
• Dark skies, severe winds and heavy rains may follow
an eruption for months afterwards.
Where are There Active
Volcanoes Today?
Active volcanoes in the U.S. are found
mainly in Hawaii, Alaska, California, Oregon
and Washington. The greatest chance of
eruptions near areas where many people live
is in Hawaii and Alaska. The danger area
around a volcano covers about a 20-mile
radius. In May 18, 1980, Mount St. Helens
erupted in Washington state. It killed 58
people and caused more than $1 billion in
property damage.
Works Cited
• http://images.google.com/images?hl=en&um=
1&q=images+of+erupting+volcanoes&sa=N&st
art=108&ndsp=18
• http://www.woodlandsjunior.kent.sch.uk/Homework/mountains/vo
lcanoeruptions.html
• http://images.google.com/images?hl=en&um=1&
sa=1&q=images+of+shield+volcanoes&aq=f&oq
=
• http://www.fema.gov/kids/volcano.htm