volcanoes in general Flashcards
what is magma
molten rock found in mantle
what is lava
molten rock found at earths surface
example of composite volcano
mt etna
what is a composite volcano
larger classic volano with alternating layers of ash and lava
violent and gentle eruptions
example of culdera
santorini
what is a culdera
build up of gasses blows top off volcano and clears magma chamber sides of volcano subside - lagoon can form in middle
what is ash cinder cone volcano
ash and cynder build up to form a cone
ash cinder cone example
mount fuji japan
dome volcano example
mt pelee
what is a dome volcano
lava quickly solidifies when exposed to air
steep spine can form
shield volcano example
mauno loa
what is a shield volcano
lava out of central vent
gentle sides
many layers of basaltic lava
fissure example
iceland = heimay eruption
what is a fissure
two plates move apart , lava ejected through linear volcanic vent rather than one central vent
types of basaltic lava
Aa Aa lava
Pahoehoe lava
what the three main types of lava
basaltic
andesitic
rhyolitic
order types of lava in viscosity
basaltic > andesitic > rhyolitic
lowest highest
how hot is basaltic lava
1100-1200
what is frequency and magnitude of basaltic eruptions
eruptions frequent but gentle
where do basaltic lava usually occur
constructive plate
what sort of slopes does basaltic produce
gentle
what is AaAa lava texture and why
rough texture as when it cools it fractures
pahoe hoe texture
flows and solidifies smoothly
temp of andesitic lava
800 degrees
speed of lava for andesitic
slow
type of eruption for andesitic
violent
sort of sides andesitic produced
steep
where does andesitic lava usually founded
destructive plate boundary
temp of rhyolitic lava
700
eruption type for rhyolitic lava
very explosive
how fast is rhyolitic lava
very slow to none
gas content of rhyolitic lava
high gas content
examples of volcanic gases
water co2 so2
what was the invisible killer volcano
lay nyos gas eruption
how many people were killed in lake nyos eruption
1700
how were people killed in lake nyos murder
co2 and water mixed making it denser than 02 so it hugged ground
tephra
rock fragments ejected into the air
pyroclastic flows
dense destructive mass of hot ash flows at great speed
lahars
mudflow that originates from volcano sides
how to manage volcano
manage
prepare
protect
adapt
how to monitor volcano
use drones, monitor land swells , monitor gas emmisions look at past records
how to prepare
hazard mapping
evacuation practice
food and water supplies
protection against volcano
dig trenches
build barriers
gas mask
water systems to slow flow
how to adapt
timber homes so that they can be moved
stonger rooves to withstand ash