volcanoes Flashcards
where volcanoes occur
divergent and convergent boundaries
viscosity
easily flow, more viscous
if a magma is highly viscus then its flow is
does this oen cause more deaths
very low, does NOT flow easily
yes, becasue it blows the top off themoutain
if a magma is LOWLY viscus then its flow is
flows VERY easily
factors that effect viscosity
cold temperture, composition (high temeperture/viscosity)
amt eof disolved gas
what would inc the amt of gas in magma do?
more displved gass= hoighere the viscodsity
ehat sahape does a basalt/mafic volcano make
shielt, basalt, cinder cones
intermediate volcanoes shapes
composite cones
this kind of lava has a ropey texture and is a basalt lava
pahoehoe
aa lava
has lots of gas
pillow lavas
lava comes up into water and nstachilled
lava tubes
cavelike tunnels carrying lava to the flows edge
describe the process fo volcanic activity beginning
a fissure is in the earths crust, gas mpoves through a conduit/pipelike openibg, the openigng enlargnesnto form a vent and make a cone shape volcano
fissue
condit vent
volcano
why are shield volcanoes the way they are?
what shape is it?
low viscosity lava, basalt lava
broad and flat
andescitic lava
cinder cones
shape? composition? personality?
steep but small, looks like a pimple hehehe
basalt lava, vairous pyroclastic material,
usuallly errupts ONLY once, lava flos from the base
strato volcanoes aka compositie volcanoes
shape? composition? where?
ex: mnt Fuji
narrow around paciific ocean, convergent plates
usually Andesitic low viscous lava, conical shape with sloping flanks due to large amounts of pyroclasitc ash
hot gasses/ash mizex with large lava fragments is
pyroclastic flow
how does pyroclasitic flow, flow?
gravity redices the friction btw ash/pumice making it avalanche
mudslide of volcanic ash mixed with water is called
lahar
fissure erruption
composition?
basalting lava
lava streaming out like a blanket from earth’s crust
lava fountains
