Study guide - flash card answers
Terms
Definitions
a vent or fissure in the
Earth's surface through
volcano
which magma and gases are
expelled
magma
molten rock below ground
magma that flows onto the
lava
Earth's surface
clouds of hot debris, ash and
gas rapidly shoot from a
volcano - cause molten rock to
be blown into tiny particles
what happens during an
that harden in the air - can
explosive volcanic eruption
blast millions of tons of lava
and rock - can demolish a
mountainside in a matter of
seconds
produce relatively calm flows
what happends during a nonof lava - can release hugh
explosive volcanic eruption
amounts lava
a body of molten rock deep
magma chamber
underground that feeds a
volcano
cracks in the Earths crust
vents
which the magma chamber is
attached and magma rises
high water conent in lava
an explosive eruption is likely
means
has a stiff consistency and
silica-rich magma
tends to harden a volcanoes
vents
aa, pahoehoe, pillow lava, and
name 4 types of lava
blocky lava
viscosity
how lava, or a liquid, flows
based on its flow - if it flows
how can you predict the silica
slower, it has a high silica
content based on viscosity
content
volcanic bombs - large blobs
of magma that harden in the
air, lapilli - means little stones
describe four types of
in Italian, pebble-like bits of
pyroclastic flow
magma, volcanic ash - form
when gases in still magma
expand rapidly, volcanic
blocks - the largest pieces
produced when enormous
amounts of hot ash, dust and
pyrolastic flow
gases are ejected from a
volcano
are built of layers of lava
released from repeated non
explosive eruptions - lava is
shield volcanoes
runny and spreads out over a
wide area - Mauna Kea in
Hawaii
are built from pyroclastic
cinder cone volcanoes
material during moderately
explosive eruptions - has steep
slopes - Paricutin in Mexico
are built from explosive
eruptions followed by quieter
flows of lava - most common
composite vocanoes
type of volcano - also called
stratovolcanoes - Mount Fuji
in Japan & Mount Hood in
the US
volcanic ash and gas spread
throughout the atmosphere
volcanic eruption affects
and can block out sunlight
climate change how
and cause global
temperatures to drop - Mount
Pinatubo in the Philippines
what type of lava flows from a runny lava - spreads out over
shield volcano
a wide area
describe the eruption of a usually erupt for only a short
cinder cone volcano
time
combination of both types of
eruptions form alternating
describe the eruption of a layers of pyroclastic material
composite volcano
and lava - have broad bases
and sides that get steeper
toward the top
a funnel shaped pit near the
crater
top of the central vent of a
volcano
a large semi-circle depression
caldera
that forms when the magma
chamber below a volcano
partially empties and causes
the ground above to sink
Destructive effects from
Can destroy crops, forests,
volcanoes
homes and lives.
caldera is usually bigger than
a crater because every time
size of a caldera to a crater
there is an eruption the
caldera gets bigger
when its temperature
increases or when the
when does rock melt
pressure on the rock
decreases
because it is not hot enough
why doesn’t rock of the
and there is not enough
mantel melt at Earth's surface
pressure
Sea Mounts
Submerged volcanic peaks
Chain of volcanoes formed
Volcanic arcs
from hot magma rising to the
surface
An area of deep cracks that
forms between two tectonic
rift zone
plates that are pulling away
from each other (Divergent
plate boundaries)
an underwater mountain
chain where new ocean floor
mid-ocean ridge
is formed - by lava that flows
underwater
how does magma form at a tectonic plates pull away and
divergent boundary
magma rises
- the movement of one
subduction
tectonic plate underneath
another
When oceanic crustal rock
melts near a subduction zone
why is magma near a
it is high in silicates which are
subduction zone more viscous
then released into the rising
than magma at a hot spot
magma making it more
viscous
a volcanically active area of
hot spot
Earth's surface far from a
tectonic plate boundary
study active and dormant
volcanoes, study small
earthquakes that occur before
an eruption, study volume
methods that scientists
and composition of volcanic
predict volcanoes
gases, use a tiltmeter to
measure small changes in the
angle of a volcanoes slope, use
satellite images
Scientist who studies
Volcanologist
volcanoes
Energy produced by the
steam rising from cracks in
Geothermal energy
the ground produced by
magma below. Produces
electricity.
Constructive effects from Geothermal energy, enriches
volcanoes
soil, creates hot springs and
beautiful landscapes, and
provides natural products
(basalt for cleaning agents,
chemical and industrial uses.
Floods create sandy beaches,
minerals in molten rock
(nickel, chromium, platinum)
60% of the volcanoes on earth
are…?
composite volcanoes
Real world example of a
Composite volcano
Mt. Fuji – Japan. Mt. St
Helens, Mt Rainer –
Washington State
Real world example of a
Shield volcano
Real world example of a
Cinder Cone volcano
Dormant Volcano
Active Volcano
Extinct Volcano
Erosion
Hawaiian Islands, Iceland
Red Hill, California –
Paricutin, Mexico
A volcano that has not
erupted in the past 10,000
years, but which is expected
to erupt again
A volcano that has erupted
sine the last ice age in the past
10,000 years
A volcano that nobody
expects to ever erupt again.
Although some have still
erupted.
The process of eroding or
being eroded by wind, water,
or other natural agents.
Breaking down