Taihape Area School L1 Science Internal Assessment
Achievement Standard 90952 v 1
Demonstrate understanding of the formation of surface features in
New Zealand
1
Taihape Area School L1 Science Internal Assessment
Achievement Standard 90952 v 1
Subject Reference: Science 1.13
Student Name:
Demonstrate understanding of the formation of surface features in New Zealand
Level
1
Credits
4
Assessment
Internal
This achievement standard involves demonstrating understanding of the formation of surface
features in New Zealand.
Achievement Criteria
Achievement
Achievement with Merit
Achievement with Excellence
 Demonstrate
understanding of the
formation of surface
features in New Zealand.
 Demonstrate in-depth
understanding of the
formation of surface
features in New Zealand.
 Demonstrate comprehensive
understanding of the formation of
surface features in New Zealand.
Demonstrate understanding:
Demonstrate in-depth
understanding:
Demonstrate comprehensive
understanding:

describe selected
external and/or internal
processes and the
formation of surface
features in New
Zealand using
information, visual
representations and
data.

explain selected external
and/or internal processes
and the formation of
surface features in New
Zealand using
information, visual
representations and data.


explaining thoroughly links selected
external and/or internal processes to
the formation of surface features in
New Zealand using information, visual
representations and data.
It may involve elaborating, applying,
justifying, relating, evaluating,
comparing and contrasting, and
analysing.
This is a study of the surface features of the local area and is focused around the volcanic plateau
and the mangatepopo valley.
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Surface features may include one or more local features such as:
 volcanoes and/or volcanic features
 landslides
 glacial features and valleys
2
External processes may be selected from:
 erosion and weathering as caused by ice.
3
Internal processes studied:
 formation of volcanoes or mountains due to collisions between the Pacific plate and Australian
plates
 movement along fault lines, folding, faulting, and uplift
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Formation of surface features in New Zealand
This workbook is designed to help you prepare to write a report on the formation of Earth’s
surface features focusing on the Mangatepopo Valley. Being able to describe the internal
and external processes that helped form the chosen features clearly is essential. You MUST
have photographs and sketches collected on the field trip and you MUST use these photos,
along with diagrams and annotations, to show your understanding of how the processes
lead to the shape of the land we see today.
To achieve with excellence you must also:



link internal and external processes and compare how different were features
formed by different processes OR
Explain in depth HOW the internal and/or external processes shaped the features
chosen, demonstrating good scientific understanding of those processes. OR
Justifying WHY you think the processes were involved in shaping the land based on
observed evidence.
Internal Processes
Convection Currents and Plate tectonics
Learning Objective: Understand the cause of plate tectonic movement according to
current theory
Click on the link below to watch a short clip.
View the clip as often as you need to and use the following pages to write a clear explanation of how
convection currents work under the surface of the Earth to cause plate tectonic movement.
You need to use terms like:
heat, radioactive, less dense, more dense, expand, rise, sink, subduction, sea-floor spreading,
constructive boundary, destructive boundary,
http://youtu.be/ryrXAGY1dmE
1
Explanation and diagram:
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Plate tectonics
Tectonic plates
The crust of the Earth is divided into tectonic plates. The plates are less dense than the mantle
(due to containing more silicon and aluminium) and float on it. On the surface some plates
are spreading apart, some are colliding and some are stationary. The edges of the plates are
called plate boundaries.
Figure 4.3: Earth’s tectonic plates
Continents
A continent is a large land mass, often on its own tectonic plate. The land part of the tectonic
plate is less dense and floats high enough to be above sea level. However, the edge of a
continent may be below sea level.
Plate boundaries
Some tectonic plates are moving, driven by convection currents in the mantle below them.
The edges of the plates, where they meet, are called plate boundaries. At a divergent plate
boundary two
plates are moving apart, causing a crack in the crust. Magma splits the
diverging plate, oozes through the crack from the mantle and then hardens. This becomes a
series of long mid-oceanic ridges and underwater volcanoes.
This type of boundary usually occurs where the tectonic plates are thin, in the ocean. The
thinner part of a tectonic plate is called an oceanic plate (the thicker part is called a continental
plate).
The oceanic plate is denser than the continental plate, so it is below sea level. When
covered in sediment it forms the floor of the oceans. New ocean floor is slowly being formed
at these boundaries and spreads outwards, a process called sea-floor spreading.
Science for the New Zealand Curriculum Years 9 and 10
© Donald Reid, Catherine J. Bradley, Des Duthie, Catherine Low, Matthew McLeod, Colin Price 2010
Published by Cambridge University Press www.nzscience.co.nz www.cambridge.edu.au
5
Occasionally the mid-oceanic ridges at divergent plate boundaries protrude above the
oceans, forming volcanic islands. The fiery, red, fast-flowing basalt lava flows of Hawaii and
Iceland are examples.
Figure 4.4: Divergent
plate boundary showing
sea-floor spreading
At a transform fault boundary, two plates alongside each other are passing, which may
cause earthquakes as they rub roughly together.
At a collision plate boundary, two thick continental plates are colliding with one another.
Parts of the plates are forced up, resulting in large fold mountains. An example of this is the
Himalayan mountain range which has over 100 mountains higher than 7200 m. These peaks
are the result of a 50 million year long collision between the Indian and Eurasian plates.
Because these plates have not stopped moving, earthquakes in this region are fairly common.
Figure 4.5: Transform fault boundary
Figure 4.6: Collision plate boundary
From:
Science for the New Zealand Curriculum Years 9 and 10
© Donald Reid, Catherine J. Bradley, Des Duthie, Catherine Low, Matthew McLeod, Colin Price 2010
Published by Cambridge University Press www.nzscience.co.nz www.cambridge.edu.au
6
At a subduction plate boundary, (see next page) one plate is diving below the other. In most
cases, a thinner oceanic plate is forced underneath a thicker, less dense continental plate. As
the oceanic plate gets pushed down towards the hot mantle it melts, becoming magma again.
However, the magma will be a mixture of continental crust (rich in silicon and aluminium),
oceanic crust (basalt) and water. This mixture creates a superheated fluid that is under great
pressure and rises to the surface to produce explosive, unpredictable volcanoes along the
subduction zone.
See page 63 for the evidence for plate tectonics.
oceanic plate Thinner, more dense part of a tectonic plate
continental plate Thicker, less dense part of a tectonic plate
sea-floor spreading The formation of new oceanic plates at a divergent plate boundary
transform fault boundary Where two tectonic plates are passing alongside each other
collision plate boundary Where two tectonic plates are colliding with one another
subduction plate boundary Where one tectonic plate is diving below another
Science for the New Zealand Curriculum Years 9 and 10
© Donald Reid, Catherine J. Bradley, Des Duthie, Catherine Low, Matthew McLeod, Colin Price 2010
Published by Cambridge University Press www.nzscience.co.nz www.cambridge.edu.au
Plate tectonics and New Zealand Landforms
Important:
If you want an excellence, comparing and contrasting internal processes and how they
form different surface features, or analysing one feature and being able to describe in
depth how it formed will help you.
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Learning Objective: Distinguish between the Taupo and Ruepehu vonanoes.
Formation of the Taupo Volcanic Zone
Click on the following links and watch them as often as you need to gain an understanding
of the processes that formed the New Zealand land mass. You will need this information to
answer the following questions.
1
Zealandia was a large piece of continental landmass that broke off from Gondwana
more than 40 million years ago. It is not very buoyant so it slowly sank below the ocean with
only small islands showing above the surface.
http://youtu.be/S_Ohu8KHkBs
2
New Zealand landmass has been under the ocean a number of times in its history.
Land was then pushed up by both hot spots and subduction. You need to know the
difference between the two and which areas of NZ they apply to.
http://youtu.be/E6Nyr78Mqyg
The following diagrams show New Zealand in relation to the other tectonic plates on the
surface of Earth and the process that produced the Taupo volcanic region and Mt Taranaki:
Notice that the land mass under
Ruapehu is also being pushed up.
This is significant as Ruapehu forms
quite a complex volcanic system.
The land has been forced up then
cracked and faulted forming the
Taupo Graben.
See pg 18 of Anderson’s Tongariro,
a Volcanic Environment
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The tectonic plates:
See also pgs 15 – 18
Anderson’s Tongariro, a
Volcanic Environment
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Volcanic Eruptions
Volcanoes can erupt in many ways but it is very difficult to classify them as they tend to end
up having different eruptions with different characteristics.
The two major factors which affect the eruptions are:


The viscosity of the magma (how sticky it is)
The amount of gas and water trapped in the magma (high gas content means an
eruption will be more explosive. The more gas builds up, the more explosive the
eruption)
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2
Explain the differences between the eruptions of Ngauruhoe and Taupo.
(one is rhyolitic and the other is andesitic)
Refer to pgs 15 – 17 of Anderson’s Tongariro, a Volcanic Environment
You should use as many of the following terms: silica content, gas,
andesitic, rhyolitic, subduction.
Remember you are comparing/contrastiong so use link words like both
have, both are, Taupo is … while Ngauruhoe is …, They are different in
that…
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External Processes
Learning Objective: List the broad internal and external processes that shaped New
Zealand surface features
1
Construct a table of two columns (internal and external processes) and
place the following processes into the appropriate columns:
biological weathering, chemical weathering, earthquakes, faulting, folding, gravity,
human impact, ice erosion, physical weathering, sea level changes, uplift, volcanism,
water erosion, wind erosion.
Internal processes
External processes
Learning Objective: Explain how glacial action has modified the landscape to form the
Mangatepopo valley
We are going to focus on weathering and erosion caused by water and changes in
temperature.
As the land surface of the central plateau area has been raised by volcanic processes, the
increased altitude causes cycles of low temperatures and high temperatures which
causes water to freeze and then thaw regularly. This causes weathering.
Glaciers have formed in the past, during ice ages but are not apparent on Ngauruhoe in our
time as they have melted as the climate has warmed.
The mangatepopo valley was formed by a large glacier, then its base was covered with
layers of erupted volcanic material (lava, ash and scoria).
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1
Briefly describe how freezing and thawing causes weathering.
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Morains:
Clearly explain what is meant by moraine, lateral moraine and terminal
moraine
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3
Briefly describe the process of glacial erosion (weathering,
transportation, deposition)
Weathering
Transportation
Deposition
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4
The picture below is of the mangatepopo valley. Label the lateral and
terminal morianes and where lava and other volcanic debris have
overlayed where the head of the glacier would have been.
Composite cone (Ngauruhoe)
Glacial Bluffs
Mangatepopo Valley
Outwash where Mangatepopo stream
has eroded terminal moraine.
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1
Describe the sequence of possible events that lead to the shape of
Ngauruhoe today.
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3
On the picture below draw the possible shape of proto-Ngaurahoe that
the shape of the land suggests.
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