Which common plate boundary type is associated with volcanoes?
convergent
100
What is a caldera?
a large depression in a volcano
200
Low silica magma tends to have what quality?
Fluidity, flows easily, low viscosity
200
What is another name for tephra?
Pyroclastic Materials
200
Which volcanoes have gentle lava flows? Why does it not experience explosions?
Shield because lava is so fluid, there is no pressure buildup or clogs in vents
200
How do volcanoes form away from plate boundaries?
Hot mantle plume rises -- hotspots
200
What is a real life example of a caldera?
Crater Lake, Oregon
300
Dissolved gases are found in higher concentrations what type of magma? (silica/viscosity?)
High silica viscous magma
300
Sequence hard/firm tephra fragments by decreasing size.
Block, lapilli, ash
300
Contrast cinder and composite volcanoes
Cinders are only made of pyroclastic materials so smaller than composite, while composite has both pyroclastic materials and lava.
Cinders are only explosive. Composites have explosive, destructive phases and gentle, constructive phases.
300
What type of igneous process occurs at divergent boundaries?
Mantle rises and fills rift where plates separate
300
How do lava plateaus form?
lava flows out of a fissure or crack
400
Order the following liquids by most to least viscous:
corn oil, water, hair gel, syrup, ketchup
Ketchup, Hair Gel, Syrup, Corn Oil, Water
400
Which lava flow is associated with high viscosity?
aa
400
Volcano type with steepest angles. Explain why
Composite because it builds off of lava and pyroclastic materials.
400
At an ocean-continent convergent boundary, which plate melts?
Continental plate
400
How does a volcanic neck form?
when volcanic pipe remains after most of cinder cone volcano has eroded
500
What effect does increased temperature have on magma?
decreased viscosity
500
What causes a volcanic explosion?
viscous magma clogs vents which creates pressure
explosion is release of pressure and energy
500
What type of magma/lava is associated with shield volcanoes?