Welcome to Science 10/25
Today’s Schedule
1. Finish/Review Volcano Types Lab
2. Outline/Notes Volcanic Eruptions
3. Yokum Construction Co. will be open for business to sell building materials.
• Volcano Types
Shield, Cinder-Cone, and Composite.
What causes these different types of volcanoes to form?
The different ways in which they _______________________and the
different________________________________ that are erupted.
•
Volcanic Eruptions Section. 3
I. Kinds of Volcanic Eruptions
Eruptions are classified as either _______________________ or __________________________________.
How a volcano erupts depends on the gasses, silica, and viscosity of the magma.
_________________________-similar to sand, one of the key components of magma
____________________________________- the resistance of a liquid to flow
II. How the Eruption Works
A volcanic eruption is similar to an exploding pop can.
_________________________ inside the volcano build up. As gas builds up, so does the _________________________.
When the pressure is too great, the volcano erupts.
III. Quiet Eruptions
Magma has ______________ silica, ___________________ viscosity, and _________________ gasses so it flows easily.
Hawaiian Islands were made this way.
What type of volcano is formed by quiet eruptions? ___________________________
IV. Explosive Eruptions
Magma has ______________-silica and _______________ viscosity, making it thick and sticky. High Gas.
1. Magma does not flow. 2. Builds up in the pipe like a cork in a bottle. 3. Pressure builds up until the volcano
explodes.
V. Explosive Eruptions
Explosive eruptions break lava into fragments that quickly cool into pieces of different sizes.
Large pieces = __________________ Small pieces = ____________________________
__________________________________________- mixture of hot gas, ash, cinders, and bombs
VI. Stages of Volcanic Activity
Active, dormant, or extinct?
__________________________- erupting or shows signs of erupting.
__________________________- may awaken in the future.
__________________________- unlikely to erupt again
Is a volcano ever really extinct?
No, at anytime a volcano thought to be extinct could reawaken.
Directions: Color and label the diagram below. Make it look realistic. Answer the questions below using pages 222-226.
1. Is a non-explosive eruption more likely to produce lava or pyroclastic material? Explain.
2. If a volcano contained magma with small proportions of water and silica, would you predict a nonexplosive eruption
or an explosive one?
3. What is the primary force that pulls the pyroclastic flow down from the sky and down the sides of a volcano?