exam 4 volcanoes Flashcards
What are the 3 main types of volcanoes?
stratovolcano
cinder cone volcano
sheild volcano
What are the 2 kinds of tectonic plate boundaries that produce volcanoes?
convergent and divergent plate bounderies
What is the difference between magma and lava?
lava is above ground
magma is below ground
what is viscosity?
how thick or how runny a fluid is
How do high viscosity liquids flow vs low viscosity liquids?
high –> very thick / like tomato paste
low –> very runny / like syrup
What kind of viscosity magma produces highly explosive eruptions? What kind of volcano?
high viscosity
stratovolcano
What kind of viscosity magma produces quiescent eruptions? What kind of volcano?
low viscosity
sheild volcano
Pyroclastics (3)
Ash & dust – very fine
Lapilli – pea-sized bits of lava (cinders)
Lava bombs – Large blobs of lava
Volcanic gases
water vapor, carbon dioxide, sulfur dioxide
What are the general characteristic of a stratovolcano?
large cone shape with high, steep slopes
explosive eruptions
formed from convergent boundary / subduction zones
What are the main hazards of a stratovolcano?
lava flows - lease dangerous
lahar - dangerous
Pyroclastic flows - very dangerous
Ash clouds - dangerous to health
What are the general characteristics of a cinder cone?
small and numerous
Built from cinder-sized pyroclastic fragments / lava rock
May produce lava flows
What are the general characteristics of a shield volcano?
Dome-shaped with long, broad slopes
quiescent eruptions
Located on oceanic hot spots / divergent plate bounderies
hat are the main hazards of a shield volcano?
lava flows
Volcanic ash & gasses
What are some benefits that volcanoes provide people?
-Sources of valuable natural resources
-mined for construction materials, landscaping and abrasives
-Tourism
-Geothermal power
-the richest and most fertile soils
