Vocabulary
This is a vent in the Earth's crust through which melted or molten rock flows.
Volcano
This is an area of earthquake and volcanic activity that surrounds the Pacific Ocean
Ring of Fire
True or False: When gases cannot easily escape from high viscosity lava, it leads to explosive eruptions.
True
True or False: A cinder cone volcano has steep sides
True
What two characteristics are used to classify volcanoes?
shape and size
This is molten rock below the earth's surface.
magma
True or False: Over many millions of years, a hot spot moves, but the plate above it stays still.
False
Complete this sentence: High viscosity magma leads to _______ volcanic eruptions.
explosive
This type of volcano results from explosive eruptions of andesitic and rhyolitic lava
composite volcano
Fill in the blanks: Slow-moving lava flows are _____ destructive and _____ deadly.
more, less
This is a large volcanic depression formed when a volcano's summit collapses or is blown away by explosive activity.
caldera
What are volcanoes called that are not associated with plate boundaries?
hot spots
What affects magma's viscosity?
The amount of silica in it
This type of volcano occurs at divergent plate boundaries and oceanic hot spots.
shield volcano
Fill in the blanks: Volcanoes can block _______ and ______ the atmosphere.
sunlight, cool
What is volcanic ash made of?
pulverized volcanic rock and glass
Where do most of Earth's volcanoes occur? Your answer should have the word(s) boundary or boundaries in it.
along convergent and divergent plate boundaries
What are three dissolved gases found in magma?
water vapor
carbon dioxide
sulfur dioxide, silica, or SiO2
Of the three that we studied, which volcano does NOT have basaltic lava.
Composite
What is pyroclastic flow?
A fast-moving cloud of hot gas, ash, and rock from an erupting volcano
What is the definition of viscosity? Give an example of a liquid with high viscosity and low viscosity.
Viscosity is a liquid's resistance to flow.
Low examples: water, milk, rubbing alcohol
High examples: honey, syrup
At convergent plate boundaries, the denser plate melts as it _______ beneath the less-dense plate. The resulting magma rises through cracks in the crust to form volcanoes.
subducts
Eruption style depends on these two factors.
magma's viscosity (amount of silica) and the amount of dissolved gases in the magma.
This type of volcano occurs at convergent plate boundaries.
composite
List 3 risk factors for volcanic eruptions
*Earthquake activity
*changes in the shape of the volcano
*past eruptive history of the volcano
*gas emissions