They can provide minerals for the ground. They can also create beautiful landforms.
100
What are the two types of eruptions?
Explosive and non-explosive
200
What is the difference between magma and lava?
Lava is magma after it reaches the Earth's surface.
200
True or false: Volcanoes start out looking like mountains.
FALSE: Eruptions over time create the mountain look due to ash and lava cooling on the sides.
200
Which type of lava is rope like and pillowy?
Pahoehoe
200
What is formed when magma hardens in the pipe of a volcano and then softer rock around the pipe erodes away?
Volcanic Necks
200
What is a quiet (non-explosive) volcanic eruption?
lava oozes quietly from the vent and flows
300
What is the definition of viscosity?
A liquid's resistance to flow.
300
Most volcanoes are found where? (two possible answers)
where two tectonic plates meet or the Ring of Fire
300
What is the hole in a volcano where lava escapes from called?
the vent
300
What type of energy can be derived from volcanoes? It is a way volcanoes are constructive to us.
Geothermal energy
300
What are the three things volcanoes can be?
Active, dormant, and extinct
400
What are the three types of magma?
Basaltic, Andesitic, and Rhyolite
400
What is the most common type of volcano in the world?
Composite
400
What type of volcano is created from low viscosity lava?
Shield volcano
400
True or false: Ash in the air from a big explosive volcano can lower temperatures around the world.
True
400
Why do most volcanoes form where two tectonic plates meet?
Earthquakes are causes where tectonic plates meet due to fault lines and friction. Earthquakes can cause volcanoes to erupt.
500
Which type of magma would flow the slowest and why?
Rhyolite has the highest viscosity because it contains the most silica. The more silica the magma has the slower it flows.
500
Volcanoes can also be found in places OTHER than where plates diverge and converge. Sometimes, volcanoes are found on places on the earth called what?
Hot Spots
500
How does the viscosity change when magma turns to lava?
Lava starts to cool so the viscosity is higher.
500
What is the mixture of hot rocks, gases, ash, and cinders called that comes from an explosive volcano?
Pyroclastic flow
500
Explain why a volcano erupts.
Magma contains gases. As the magma starts to rise, the pressure on the magma is decreased which allows the gases to expand. When the gases expand they push the magma up which causes the eruption.