Volcanoes Flashcards
Not associated with any plate boundary:
Hot spots
A large and steep sided, occurs along convergent boundaries, and results from explosive eruptions
Composite Volcano
Have gentle slopes of basaltic lava: they are commonly located along divergent plate boundaries and ocean hot spots:
Shield Volcano
Is small and steep sided, and it erupts basaltic lava
Cinder Cone
Is molten rock beneath Earth’s surface
Magma
Molten rock that flows along Earth’s surface
Lava
When magma erupts explosively, it can send particles of rock and glass, or____ into the air:
Volcanic Ash
Magma’s resistance to flow:
Viscosity
Magma contains ____ gases, including carbon dioxide and sulfur dioxide
dissolved
A vent in Earth’s crust through which molten rock flows
Volcano
Volcanos form along 2 boundaries:
Convergent and Divergent
Geologists theorize that hot spots form over ____, which are places where hot magma rises due to convection currents in the mantle
plume
Most volcanoes occur along:
plate boundaries
The ____ is the area of earthquake and volcanic activity that surrounds the
Ring of Fire
Most volcanos in the US occur near the ____ coast
Pacific
A fast moving avalanche of hot gas, ash, and volcanic rock
Pyroclastic Flow
Viscosity of lava is higher when magma has a high ____ content
Silica
The release of a large amount of volcanic ash can affect Earth’s climate by blocking _____
sunlight
Magma that has low silica content forms:
basalt
Magma that is rich in silica content forms when the mantle mixes with:
Continental Crust
What type of volcano is Mt. Saint Helens?
Composite
Magma can form when:
there is a sinking tectonic plate
Volcano that makes up the Hawaii Islands:
Shield
Sign that a volcano will soon erupt:
temp. of lakes nearby
