Chapter 7 - Section 3 - Volcanic Eruptions Flashcards
What are the main parts of a volcano?
crater
vent
pipe
side vent
lava flow
magma chamber
As a volcano erupts, what force pushes magma out of a volcano onto the surface?
expanding gases
What are the two main kinds of volcanic eruptions?
quiet
explosive
What properties of magma help to determine the type of eruption?
A volcano erupts quietly if its magma is low in silica
A volcano erupts explosively if its magma is high in silica.
What are the three stages of volcanic activity?
active
dormant
extinct
Name 3 hazards of volcanic eruptions.
Volcanic ash can:
- bury entire towns.
- cause roofs to collapse.
- stall the engine of a plane.
Eruptions can cause landslides and avalanches of mud, melted snow, and rock
magma chamber
The pocket beneath a volcano where magma collects.
pipe
A long tube through which magma moves from the magma chamber to Earth’s surface.
vent
The opening through which molten rock and gas leave a volcano.
lava flow
The area covered by lava as it pours out of a volcano’s vent.
crater
A bowl-shaped area that forms around a volcano’s central opening.
pyroclastic flow
The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption.
dormant volcano
A volcano that is not currently active, but may become active in the future.
extinct volcano
A volcano that is no longer active and is unlikely to erupt again.
What happens to the pressure in magma as the magma rises toward the surface?
it decreases
When an explosive eruption hurls out a mixture of hot gases, ash, cinders, and bombs, it is called a
pyroclastic flow
what do geologists use to monitor volcanos?
tiltmeter
gases escaping from the volcano
underground water temperature
