Volcanos Flashcards
what are the landforms volcanos create ?
Ocean Ridges
Rift valleys
Deep see trenches
Island arcs
Young fold mountains
Fault lines
Hot spots
what is an ocean ridge
constrictive boundary
sea floor spreads via magma plumes
magma rises
new crust created
basaltic lave - low viscosity
Mid Atlantic ridge
Rift valley characteristics
constructive boundary
crust moves apart
crust stretches & gets thinner
magma rises, breaks crust & creates new crust
Great African rift valley
deep sea trench
destructive boundary
subduction zone
oceanic crust melts and rises up through the crust
andesitic lava - vicious and explosive
Mariana Trench
Island arc
destructive boundary
subduction zone
oceanic crust melts and rises up through the crust
andesitic lava - vicious and explosive
Young fold mountains
collisional boundary
2 continental crusts meet and push upwards
Himalayas
Fault Lines
conservative boundary
2 plates move parallel and create stress
the surface breaks as a result
san Andreas fault
Hot spots
the core causes magma to become radioactive
magma plumes eat at crust
basaltic lava
breaks through crust
Hawai
How many types of volcanos are there
5
Fissure
Shield
Dome/composit
Ash&cinder
Caldera
Fissure volcano
Constructive
Ridges and valleys
Basaltic lava ejected through fissures
Shield
Constructive
Basaltic lava flows from central vent
Travels before solidifying
Forms layers
Genuinely sloped
Dome/composit
Destructive boundary Andesitic lava from central vent
Solidifies quick
Forms layers
Steep sided
Ash & cinder
Fine ash and cinder ejected from central vent
Builds up & creates layers
Caldera
Gas builds in chamber and explodes
Creates sides collapse
Depression can be filled with water
What are the volcanic hazards
Pyroclastic flow
Nuee ardent
Tephra
Lava flow
Lahar/mudflow
Acid rain