scie volcano Flashcards
The word ‘volcano’ comes
from the island _____ which is a volcanic island in
Italy.
Vulcano
This is the outer layer of the
earth. It varies in thickness
from 0 – 60km thick. It is not
even and is made up of pieces
which overlap to cover the
entire planet. These pieces are
called ‘tectonic plates’.
The Crust
is approximately
2897km thick and is made of
a solid, rocky substance
called molten rock or
magma. This is what
escapes when a volcano
erupts.
The Mantle
is a liquid layer
made out of molten iron and nickel.
This liquid metal creates the earth’s
magnetic field.
The Outer Core
This is a solid layer and is made of
iron and nickel. It is the hottest
part of the earth and can reach
temperatures of up to 5500oC!
The Inner Core
a volcano that has erupted recently, and there is the possibility
that it may erupt again.
Active
one that has not erupted for a long time, however, it may
still erupt in the future.
Dormant
one which has erupted
thousands of years ago, but it will
probably never erupt again.
Extinct
The movement causes ___
which causes earthquakes and
volcanic eruptions near the edges of
the plates.
friction
A cloud of ash. It is
formed by volcanic
explosions
ash cloud
The mouth of a volcano. It
surrounds the vent.
crater
The entrance of a
volcano. It ejects lava
and volcanic ash.
throat
A large underground pool
of liquid rock found
beneath the surface of the Earth
magma reservoir
An underground
passage which magma
travels through.
conduit
An opening in the
surface of the Earth
through which volcanic
materials, such as
magma, can escape.
vent
is an important material
in a volcanic activity. Volcanic
eruptions are influenced by the
type of magma, which also
influences the resulting type of
cone formed.
Magma
Different Types of Magma
- Basaltic
- Andesitic
- Granitic
Types of Eruption
●Phreatic
●Vulcanian
●Strombolian
●Pelean
●Phreatomagmatic
●Plinian
Hazards Posed by Active Volcanoes
●Blasts
● Dome growth
●Gases
● Lahar flow
●Pyroclastic flow
●Pyroclastic surges
● Tephra falls
(fragments of rock)
● Tsunami
driven by steam produced when groundwater is heated due to an underlying heat source.
Phreatic
Results from the release of large quantities of accumulated magmatic gas
Vulcanian
Egg shaped
Strombolian
ejection of magmatic gases and steam produced by the conversion of groundwater to steam by ascending magma
Phreatomagmatic
Occurs when gas-rich pasty lava accumulates and forms a dome on the volcano edifice or beneath its surface
Pelean
the release of gas-rich siliceous magma is commonly accompanied by the collapse of the top of the volcanic cone or by the collapse of a broader region
Plinian
Types of volcano
composite cone
cinder cone
shield volcanos
Form by less viscous basaltic lava flows
shield volcanos
built from ejected lava fragments
Cinder cone volcanos
produced when viscous lava of andesitic composition flows out over a long time.
Composite cone volcanos
is the fast movement of a turbulent mass of fragmental volcanic materials (ash and rocks) mixed with hot gases down the slope at speeds of more than 60 km/h. The high temperature of pyroclastic flows can burn everything along their path.
Pyroclastic flow
is a streamlike flow of incandescent, molten rock materials erupted from a volcano. Areas that are buried by lava flow will be unusable for long
periods of time as the lava solidifies.
Lava flow
is a shower of fine-to coarse-grained volcanic materials and other airborne products of a volcanic eruption. Ashfall distribution or dispersal is dependent on the prevailing wind direction. When inhaled, these fine ash particles can cause respiratory problems. The accumulation of ashfall can result in the collapse of residential roofs.
Ashfall, or tephra fall
s a rapid-flowing thick mixture of volcanic material and water, usually created along river channels by extreme rainfall. Its deposits can bury areas with volcanic debris several meters thick.
Lahar
refer to the high-temperature mixture of water vapor, hydrogen sulfide, sulfur dioxide, carbon monoxide, hydrogen chloride, and hydrogen fluoride released into the atmosphere. Volcanic gases are harmful to health.
Volcanic gases
