TECTONIC LANDSCAPES-Test 1
What do you need to be able to
do to achieve A+?
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1-Be able to describe the distribution of earthquakes
and volcanoes.
Volcanoes and earthquakes occur in narrow belts
(overall distribution). The largest belt runs around the
Pacific Ocean, along the edge of continents.
Why can’t you use plate
boundaries to describe the
distribution of earthquakes
and volcanoes on THIS
map?
2
Other bands are found in the middle of oceans
such as the belt that extends down the entire
length of the mid-Atlantic Ocean.
3
Another major belt travels through the
continents of Europe and Asia and Eastern
Africa.
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1- Volcanoes occur in narrow
belts along plate boundaries.
2-The largest belt runs around the
Pacific Ocean, near convergent
boundaries.
3-Many volcanoes are found either along
the edge of the North American and South
American continents or form volcanic
islands in the Pacific Ocean.
4-There are some volcanoes along the
northern part of the Mid-Atlantic Ridge.
5-Some volcanoes are located far from plate boundaries such as the
Hawaiian hotspot in the Pacific Ocean
5
Be able to explain why
earthquakes, volcanoes and fold
mountains occur where they do.
6
Why do plates move?
Learn the name
and the location
of the layers of
the Earth.
Crust
Inner core
Huge convection currents occur in the mantle.
The cause of these currents is heat from the
interior of the core. Plates move due to these
convection currents.
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Depending on the direction of the
convection currents, the plates can
move
• Towards each other (convergent)
• Away from each other (divergent)
• Slide past each other (transform)
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Know the names of the major
tectonic plates.
Pacific Plate
Pacific
Plate
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Plates are made of two types of crust which have
different characteristics.
Older, lighter, cannot
sink and is permanent.
Younger, heavier,
can sink and is
constantly being
destroyed and
replaced.
It is the differences between the two types of
crust that account for the variation of activity at
plate boundaries
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Be able to name the features produced at each
type of boundary and to explain how they are
formed.
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Divergent or constructive boundaries
6-Earthquakes
are caused by
volcanic
eruptions or by
plates moving
apart.
5-Submarine
volcanoes appear
along the ridge. Some
may grow to form
islands, e.g. Iceland.
Oceanic crust
3-As the plates move apart,
magma from the mantle rises to
fill the gaps and forms new
oceanic crust.
4-A mid-ocean ridge is
formed by the new crust.
2-This leads to
a gap being
formed in the
crust.
Oceanic crust
1-Convection
currents pull
plates apart.
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Describe and explain the characteristic features
of a constructive boundary. (4)
What are the features? Mid-ocean ridges, volcanic
islands and earthquakes are the features of a
constructive boundary.
The question asks for an explanation , i.e. the reasons for
these features.
You may answer this question using the ‘case study’, i.e.
located example, of the Mid-Atlantic constructive
boundary.
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Destructive/Convergent
boundaries
A- Oceanic-continental boundaries
B- Continental-continental boundaries
C- Oceanic-oceanic boundaries
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Ocean-to-continent boundary
7-The collision causes
folding and uplift of
rocks which form fold
mountains.
1-The Nazca
Plate and the
South
American Plate
move towards
each other due
to convection
currents.
6-The Peru-Chile
trench
forms where the
oceanic plate is
being
subducted.
5-The melting plate
creates lighter
magma that rises
towards the surface
to form volcanoes.
Andes fold mountains
Pacific
Ocean
Trench
Volcano
South American
Plate (Continental)
Nazca Plate
(Oceanic)
Mantle
2-The Nazca Plate
(oceanic) is being
subducted below
the South
American Plate
(continental).
Subduction
zone
Earthquakes
3-Friction and pressure
cause earthquakes to
occur along the subduction
zone
4-The heat from
the mantle causes
the oceanic plate
to be destroyed.
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b- Continental-to-continental boundary
4- However,
earthquakes
occur due to the
collision of the
plates.
2- This results in
intense folding and
uplift and leads to
the formation of
fold mountains.
3- There is no
subduction. Therefore,
there are no volcanoes.
1- When two
continental plates
meet at a
destructive
boundary, a slow
collision takes place
as both plates have
a low density.
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Ocean-to-ocean boundaries
4- As the Philippine plate
begins to melt, magma
escapes to the surface to
form volcanoes, a few
kilometres from the
trench.
5- After several eruptions, these
volcanoes break the ocean surface to
form islands
Ryuku Islands (Japan)
Eurasian Plate
Philippine Plate
Subduction zone
1- Due to convection
currents in the mantle,
the two oceanic plates
collide.
6- When several
volcanic islands form
together they are
called an island arc.
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3- As it is subducted, friction and
pressure cause earthquakes
along the subduction zone.
2-The Philippine Plate is
subducted beneath the
Eurasian Plate.
Conservative [transform] boundaries
Plates just slide past each other with crust neither created nor
destroyed.
Friction builds up and energy is released when the plates move
forward, causing earthquakes.
The San Andreas Fault in
California marks the
junction of the North
American and Pacific plates.
Both plates are moving
north-west but at different
speeds. Instead of slipping
smoothly past each other,
they tend to ‘stick’. The
pressure builds up until
suddenly the plates move
forward and an earthquake
occurs.
There is no volcanic action
because the crust is not being
destroyed.
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