Download The Nature of Volcanoes and Types updated.notebook

The Nature of Volcanoes and Types updated.notebook
The Nature of
Volcanoes and Types
September 24, 2013
Key Concepts you will be able to
answer:
* What determines the type of volcanic eruption?
* What materials are ejected from volcanoes?
EES Essential Standard:
2.1.1.
* What are the three main types of volcanoes?
* What other landforms are associated with volcanic
eruptions?
Created by:
Christy Dion
Paulding County High School
Dallas, Georgia
Jan 21­12:20 PM
Jan 21­12:20 PM
Why do some volcanoes erupt
violently while others are
relatively quiet?
Mt. Kilauea, in
Hawaii: click on
gases: during eruptions gases provide
the image to Dissolved
the
right to see a mild
volcanic eruption.
Vicosity
Magma's viscosity whether thick, runny, or
The primary factors that determine whether a volcano
erupts explosively or quietly include characteristics of the
magma and the amount of dissolved gases.
Magma that has reached the surface is known as lava.
Gases
Mt Saint Helens: click on the image to the
left to watch one of the most explosive
volcanic eruptions ever in North America.
What factors affect
eruptions?
Think about the two videos you just watched, how
are they different? Why are they different?
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Jan 21­12:20 PM
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The Nature of Volcanoes and Types updated.notebook
Viscosity: Factors
that affect it
Chemical Composition
Temp.
Magma from a violent eruption can be thousands of times
more viscous than magma from a quiet eruption.
Basaltic lava: not as viscous
Rhyolitic lava: more
viscous,like toothpaste
plops when squeezed.
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May 20­3:40 AM
Volcanic Material
Basaltic
Dissolved Gases: Affect
on Eruptions
Dissolved gases are mostly water vapor and carbon dioxide.
As magma moves toward the surface, pressure is greatly
reduced in the magma. This reduction in pressure allows the
gases to release suddenly.
Lava Flows
Depending on the type of eruption, volcanoes may produce
lava flow or eject pyroclastic materials, or both. All types
of volcanic eruptions, emit large amounts of gas.
Gases
Pyroclastic Materials
Rhyolitic
panding gases to
September 24, 2013
Identify the types of pyroclastic materials in the
gif image above.
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The Nature of Volcanoes and Types updated.notebook
September 24, 2013
Identify the volcano materials?
Types of Volcanoes
Click on the flashing images to begin.
The three main types of volcanoes are shield, cinder
cones, and composite cones.
How a Volcano forms:
1) A crack or fissure develops in the Earth's crust as magma is
pushed up.
2) The magma collects in a pocket called a magma chamber.
3) The magma rises in the chamber until it reaches a vent in the
Earth's surface.
4) Repeated eruptions of lava and pyroclastic materials eventually
form a volcano.
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Shield Volcano
Cinder Cone Volcanoes
Fragments that build
These are formed by an accumulation of basaltic fluids.
Shape
Ejected fragments that are harden in the
air form a cinder cone.
Magma
From
Examples
of a single eruption that occurs over a few weeks. Once the Shape
eruption is complete the magma solidifies and it sometimes Mt. Kilaeua in Hawaii is a shield volcano.
Click above to see how it was formed.
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Parachutin Cinder Cone Volcano in Mexico.
Click on the image to see how it was
formed.
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The Nature of Volcanoes and Types updated.notebook
Composite Cone Volcanoes
Earth's most dangerous and beautiful volcanoes
are composite cones, also known as
stratovolcanoes.
What is it?
Other Volcanic Landforms
Volcanic landforms include lava
plateaus, calderas, and volcanic necks.
A caldera is a large depression left in a volcanic mountain.
A volcanic neck is a landform
made of magma that hardened
in the pipe and was later
exposed by erosion.
Magma
Location
Mt. Vesuvius, in Naples Italy. Click to
watch a short clip.
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Volcanic Hazards
Hazards include lava flows, volcanic
ash, pyroclastic flows, and mudflows.
Lava flow
September 24, 2013
A lava plateau forms from multiple erosions where lava flows over a wide area and forms layer on top of layer.
Jan 21­12:20 PM
Identify the volcanic hazards in the images below.
Click on the flashing images to begin.
Note: You must understand that volcanoes that are
active or dormant can erupt at anytime even thousands
of years after their last eruption.
Volcanic ash
Pyroclastic Flow
Mudflows
Click on the image above to watch a clip of volcanic hazards and preventions.
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Feb 25­12:34 PM
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The Nature of Volcanoes and Types updated.notebook
Apr 24­5:07 AM
September 24, 2013
May 20­3:40 AM
Resources
1) Youtube.com
2) Wikipedia.org
3) Tarbuck & Lutgens, Prentice Hall "Earth
Science". 2009. Pearson Education, Inc.
4) Gifsoup.com
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