Download Volcanoes

Volcano Presentation
Courtney Boyce, Justin Watkins
and Bridget Egan
What Is a Volcano
• A Volcano is an opening or rupture in
Earth’s surface or crust that allows ash,
magma and gases to escape from bellow
Earth’s surface.
3 Areas of Formation
• Hot Zones
• Spreading Centers
• Subduction Zones
Spreading Centers
• Area where tectonic plates are diverging
• Creates pathway for magma to flow to
surface
• Some of the magma from these centers
will spill out, however, most of the lava
cools internally below Earth’s Crust
• Mid Oceanic Ridges
Subduction Zones
• 2 tectonic plates converge and the more dense of the 2
is subducted.
• Usually occurs upon the convergence of an oceanic
plate and continental plate because the oceanic plate is
dense enough to be subducted.
• The descending plate is heated by the pressure and
Earth’s heat. This heat and pressure leads to the
formation of magma.
• Not much volcanic activity at 2 continental plates
because continental crust because continental crust is
not dense enough to be subducted.
Hot Zones
• Occur in the middle of Plates
• Formed by rising magma from deep in
Earth’s core so the they remain stationary
while plates above them move
• 50-100 known hot spots in world
• Hawaiian Islands
How Volcanoes are Classified
• Shape
• Materials they are built of
• The way the volcano erupts
Composite Volcano
(also known as the strato-volcano)
• Formed by alternating layers of lava and rock
fragments
• Usually they are very big, usually bigger than
2500m in height, 1000 sq km in surface area
and 400 km^3 in volume
• Usually erupt in an explosive way this is
caused by viscous magma which clogs the
volcano’s crater pipe locking gas in the
crater pipe, pressure builds up inside the
volcano which leads to an explosive eruption
Shield Volcano
• Shield Volcanoes are huge in size
• Built by many layers of runny lava
flows
• Lava spills out of a central vent or
group of vents and a broad, gently
sloping cone is formed
• This is because the basaltic lava that
flows out of it is very fluid and cannot
pile up into steep mounds
Shield Volcanoes (con’t)
• They can be produced by hot spots which lay
far away from the edges of tectonic plates or
along the mid-oceanic range where the seafloor is spreading is in progress and also
along subduction related to volcanic arcs
• Shield volcanos eruptions are non-explosive
some lava-fountaining occurs and forms
cinder cones or spatter cones at the vents
• Some of the most famous shielf volcanoes
are located in Hawaii
Cinder Cones
• steep conical hill formed above a vent
• eruptions usually don't cause any loss of life
• built from lava fragments called cinders. The lava
fragments are ejected from a single vent and
accumulate around the vent when they fall back to
earth.
• Cinder cones grow rapidly and soon approach their
maximum size. They rarely exceed 250m in height
and 500m in diameter.
• A great example of a cinder cone is Paricuitin
Mexico.It was born in February 20, 1943 in a corn
field and grew to 300 feet in 5 days.
Spatter Cones
• When hot erupting lava contains just enough
explosive gas to prevent the formation of a lava flow,
but not enough to shatter it into small fragments the
lava is torn by expanding gases into fluid hot clots,
ranging in size from 1cm to 50cm across, called
spatter.
• When the spatter falls back to Earth the clots weld
themselves together and solidify forming steepsided accumulations. These accumulations focused
on an individual vent are called spatter cones.
Mt. Vesuvius
• Stratovolcano
• Status: Active
• Location: Italy
– Latitude: 40 °49’14” E
– Longitude: 14°25’29” N
Mt. Fuji
• Stratovolcano
• Status: Active
• Location: Japan
– Latitude:35°21’5” N
– Longitude:135°45’1”E
Mt. St. Helens
• Stratovolcano
• Status: Active
• Location: Washington
– Latitude: 46.2° N
– Longitude: 122.21°W
Mt. Etna
• Stratovolcano
• Status: Active
• Location: Sicily
– Latitude:37°45.304′N
– Longitude: 14°59.715′E
Mt. Kilimanjaro
• Stratovolcano
• Status: Inactive
• Location: Tanzania
– Latitude:03°04′33″S
– Longitude:37°21′12″E
Hekla
• Stratovolcano
• Status: Active
• Location: Iceland
– Latitude:63°59′N
– Longitude: 19°42′W
Chimborazo
• Stratovolcano
• Status: Inactive
• Location: Ecuador
– Latitude:01°28′09″S
– Longitude: 78°49′03″W
Mount Cleveland
• Stratovolcano
• Status: Active
• Location: Alaska
– Latitude: 52°49′24″N,
– Longitude: 169°56′51″W
Mt. Mauna Loa
• Sheild
• Status: Active
• Location:Hawaii
– Latitude:9°28′46.3″N
– Longitude: 155°36′09.6″W
Volcano Questions
• 1. What are the three ways that Volcanoes
are classified?
• 2-4 Name 3 Famous Volcanos and What
type of Volcano they are
• 5. What are the four physical components
of a volcano??
Resources:
• http://www.teachersdomain.org/resources/ess05/sci/ess/
earthsys/volcanintro/index.html
• http://en.wikipedia.org/wiki/Chimborazo
• http://en.wikipedia.org/wiki/Mauna_loa
• http://en.wikipedia.org/wiki/Cleveland_Volcano
• http://en.wikipedia.org/wiki/Vesuvius
• http://en.wikipedia.org/wiki/Mt.Fuji
• http://en.wikipedia.org/wiki/Mount_Etna
• http://en.wikipedia.org/wiki/Mount_St._Helens
• http://en.wikipedia.org/wiki/Kilimanjaro
• http://en.wikipedia.org/wiki/Hekla