w
h
a
t
i
s
a
v
o
l
c
a
n
o
?
•Volcano is a cone – shaped mountainexplodes and lava comes out.
•The solid ground that we walk on is part ofthe earth’s crust and below this crust lies ahot layer knows as magma.
•When magma explodes through anopening in the earth’s crust and a volcanoerupts.
How are volcanos formed?
•Volcanoes are formed when a hot magmapushes to go to the earth’s crust.
•Earth’s crust is separated into differentpieces known as tectonic plates.
•These plates fit right together like a giantjigsaw puzzle.
Eruptions! Why do they erupt?
•As magma rises, gases expand and thewater becomes steam.
•This creates a huge pressure and whenthe pressure becomes too great, a volcanoerupts with a boom.
•Eruptions can be formed from gentleoozing and then to violent explosions.
A
f
t
e
r
t
h
e
e
r
u
p
t
i
o
n
.
•The volcano ashes are deadly it is hardand abrasive, like finely crushed glass.
•Gases spewed out from volcanic eruptionssuch as carbon dioxide and sulphurdioxide, are more deadly.
•Devastating mudflows, known as lahars,are caused by ashes, soil and rockcombining on volcanic slopes.
Types of volcano!
•There are three main types of volcanoesand it is composite, shield and cindercones.
•Composite volcanoes are formed by layersof lava and rock fragment.
•Cinder cone volcanoes erupt but don’tproduce much lava.
•Shield volcanoes erupt every few years,they create lava flows and fire fountains.
Types of erupting.
•Volcanoes can erupt in different ways.
•This also affects the surroundinglandscape and its people.
•Pompeii was buried by the eruption andkilled more than 2,000 people.
•Pompeii was buried for over 1500 years.
Mt. St Helen
•In 1980 on the 18th of May, Mt St Helen inWashington state, USA, erupted.
•The explosive eruption lasted for ninehours and resulted in the death of 57people.
•The number of trees blown down by thelateral blast of the eruption could havebuilt 300,000 homes.
Volcanic landscapes
•A
r
e
a
s
a
r
o
u
n
d
v
o
l
c
a
n
o
e
s
a
r
e
c
a
l
l
e
d
g
e
o
t
h
e
r
m
a
l
r
e
g
i
o
n
s
.
•G
e
y
s
e
r
a
r
e
h
o
t
s
p
r
i
n
g
e
r
u
p
t
i
n
g
f
r
o
m
v
e
n
t
s
i
n
t
h
e
g
r
o
u
n
d
.
•T
h
e
w
o
r
d
‘
g
e
y
s
e
r
’
c
o
m
e
s
f
r
o
m
I
c
e
l
a
n
d
i
c
r
e
g
i
o
n
a
n
d
m
e
a
n
s
t
o
‘
r
u
s
h
f
o
r
t
h
’
o
r
‘
t
o
g
u
s
h
’
.
Living with volcanoes!
•All around the world people and volcanoesexist side by side.
•Through volcanoes pose a threat, livingnear volcanoes also provides advantages.
•In 1992 an eruption of Mt. Etna threatenedto bury the village of lava.
W
o
r
k
i
n
g
w
i
t
h
v
o
l
c
a
n
o
e
s
.
•Volcanologists are scientists who studyvolcanoes.
•They try to find out how volcanoes formand predict when they might erupt.
•Scientists cannot prevent volcanoes fromerupting.
•Seismographs measure tremors in theEarth, which help scientist predict when avolcanoes might erupt.
Bibliography
•My bibliography was a book aboutvolcanoes from school.
•My other bibliography was Google,Wikipedia, Bing and encyclopedia.
•I also got some information of a bookcalled volcanoes but talks about Mt StHelens.