Download Volcanoes Day 1 - NVHSEarthScienceOlsen

Volcanoes
Day 1
October 6, 2010
Objectives
• I will be able to identify what makes _______
_____________________________________
• I will be able to compare _______ _______
that come out of a volcano.
• I will be able to compare the different
_______ _______ _______ _______ _______
Key Points
• A magma’s viscosity is directly related to its silica content.
• A lava flow with a surface of rough, jagged blocks and sharp,
angular projections is called aa flow.
• As the temperature of lava increases, the viscocity decreases.
• Highly explosive volcanoes tend to have magma with high silica,
high viscosity, and higher gas content.
• The particles produced in volcanic eruptions are called
pyroclastic material.
• Pyroclastic materials include ash, cinders and lapili.
• The most abundant gas associated with volcanic activity is
water vapor.
• A cinder cone is a type of volcano that is built almost entirely
from ejected lava fragments.
• The pipe is the hollow center of the volcano.
Factors Affecting Eruption
• Volcanoes can erupt _______ _______ or
_____ _______ __. They can erupt with lots of
lava spewing out or slowly oozing out of the
mouth. Some volcanoes erupt ash and dust
with no lava at all. So what makes all of them
so unique?
• Let's watch!
• Let’s take a look at the factors that affect the
eruption of a volcano.
Factors Affecting Eruption
Viscocity - _______ _______ _______ _______
_______ _______ _______ _______ ______.
– This means that something that has a high
viscosity does not flow easily. A substance with a
high viscosity would be honey. A substance with
a low viscosity would be water.
– If the lava of a volcano has _______ _______, the
_______ of a volcano will be _______ _______.
– There are three factors that affect the viscocity of
lava: ___ _______ ____ _______, _______
content, and _______.
Factors Affecting Eruption
1. Silica – the more silica in lava, the more _______
it has. A magma’s viscosity is directly related to its
silica content.
2. Gas content - the more _______ in lava, the
_______ viscocity it has.
3. Temperature – as temperature in lava increases,
_______ _______ _______ _______ _______.
• Example: heating up syrup.
***Bottom line: _______ _______ _______ volcanoes
tend to have magma with high _ _______ ______,
_______ _______ viscosity, and higher _______
content.
Volcanic Material
There are three main types of materials that come out of
volcanoes: ___ _______ ____, _______, and _______
_______ _______.
Lava flows:
1.aa flow (AH ah): A lava flow with a surface of _______,
jagged _______ and sharp, angular _______.
view here! Think “ow!” it hurts to step on!
1.pahoehoe flow: lava flows that flow _______ forming
flows that look like twisted braids in ropes.
view here!
Gases:
The most abundant gas associated with volcanic activity is
_______ _______.
Volcanic Material
Pyroclastic Material – _______ _______
_______ _______ _______ _______ _______
_______ _______ _______ _______ _______
• Pyroclastic materials include _______, ___
_______ _______ ____ and _______.
• These particles can range in _______ from fine
dust to pieces that weigh several tons!
Types of Volcanoes
Anatomy of a volcano
• While there are several different types of
volcanoes, each have a “typical” anatomy with
the following parts:
A. _______
B. _______
C. _______
D._______
Types of Volcanoes
• The three main types of volcanoes are
_______ cones, _______ volcanoes and
_______ _______ cones.
• _______ _______ _______ plays a major part
in determining the _______ of a volcano.
Types of Volcanoes
• When you think about a typical volcano, what
do you see?
• Usually a cinder cone – highly explosive lava.
1.A cinder cone is a type of volcano that is built
almost entirely from _______ _______
_______ _______ _______.
– This give it a cone shape over time.
– Learn more here!
Cinder Cone Volcano
Cinder Cone from Pu'u'O'o eruption of Mount Kilauea
Types of Volcanoes
2. Composite Cones – a _______, symmetrical
volcano composed of both _______ and
_______ _______ deposits.
About Composite Cone Volcanoes
Composite Volcano
Mt. Shasta
Types of Volcanoes
3. Shield Volcano – have the shape of a broad,
slightly _______ structure.
• Most shield volcanoes grow up from the
_______ _______ – like the islands of Hawaii
or Iceland.
More about shield volcanoes
Shield Volcano
Iceland