WorksheetsClassifying Volcanoes
Total questions: 13
Worksheet time: 17mins
What causes a volcano to erupt?
Pressure builds up in the magma chamber, forcing magma up through the main vent.
Movement along a fault line opens the crust and forces magma out of the main and side vents
Convection currents in the mantle push magma out of the vents
Volcanoes can be: (Choose 3)
Dormant
Closed
Active
Extinct
Open
This type of volcano is low to the ground and very wide. Their eruptions involve low viscosity lava that flows for many miles.
Stratovolcano
Shield
Cindercone
Type of volcano that is tall and mountainous. It's height is caused by a highly viscous magma that rises and cools before exiting unto Earth's surface. It's also called a composite volcano.
Stratovolcano
Shield
Cindercone
These volcanoes are usually small and have a large crater. They are made from short-lived eruptions where lava and rock are blown into the air, cool, and fall back down unto the volcano's sides.
Shield
Cindercone
Stratovolcano
This volcano is most likely which type of volcano?
Felsic
Composite
Shield
Cinder cone
Name the volcano type pictured:
cinder cone
stratovolcano
shield volcano
caldera
How do changes in a volcano's surface warn of an impending eruption?
Caving in near the crater shows that magma has moved toward the main vent
Inflation can show magma close to the surface
The crater sinking down shows that magma is moving to the side vents
How does seismic activity warn of an eruption? (Choose 2)
Major earthquakes can trigger an eruption
Increased minor earthquakes can warn of magma moving beneath the surface
A sudden decrease in seismic activity can warn of a build up in pressure, meaning an eruption is coming soon
Afterschocks following a major earthquake can trigger an eruption
What is a steam eruption?
When gasses such as water, carbon dioxide, and sulfur dioxide are released into the air
When underwater volcanoes erupt, causing the magma to heat up ocean water
When magma rises toward the surface, causing the groundwater to boil and releasing steam
Rank the volcanic stages from LEAST likely to MOST likely to erupt.
active, dormant, extinct
extinct, dormant, active
dormant, extinct, active
dormant, active, extinct
How do gas emissions warn us of an upcoming eruption?
The presence of increased CO2 or SO2 can show that magma is close to the surface
Gas emissions are present anytime a volcano is not dormant or extinct
The presence of decreased CO2 or SO2 can show that magma is close to the surface
Recent history of eruptions, likely to erupt again
Have not erupted for a very long time, but may erupt at a future time
Not expected to erupt anymore, magma chamber closed off
