The characteristics of the Tongariro Volcanic Environment
Introduction
Natural characteristics refer to landforms or relief, climate, soils and
vegetation. Characteristics is plural, and therefore you will need to fully
explain more than one characteristic with comprehensive supporting case
study evidence integrated throughout the description – e.g. when you describe
the climate, you must give specific examples of temperature, rainfall and
prevailing winds as well as the type of climates such as temperate or tropical.
You need to collect specific information on this environment you are studying.
You should be able to draw maps, diagrams and cross-sections to show each of
the elements of the natural environment – i.e. relief, climate, soils and
vegetation.
Suggested Answer
Large Natural Environment: Tongariro Volcanic Environment (Note:
Environment – not Tongariro National Park)
Explain, in detail, the location of your chosen large natural environment
The Tongariro Volcanic Environment (TVE) is located in the Central North Island
at the southern end of the Taupo Volcanic Zone and extends for 65km south –
southwest to Ohakune and contains the three active volcanoes of Tongariro,
Ngauruhoe and Ruapehu, as well as the ancient extinct volcanoes of
Kakaramea – Tihia (Massif) and Pihanga. The TVE lies between 39˚ and 39.5˚
south of the equator, between 50 and 100 km from the sea and between 500
and 2,797 m above sea level (ASL)
Map showing the location of the Tongariro Volcanic Environment
Guidelines : Show the alignment NE
– SW – watch size
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TIP: How to locate accurately the
Tongariro Volcanic Environment – is
using the ‘Squeezing the Zit’
method – using two fingers – one
from Taranaki, and the other from
Wellington – squeeze together – like
popping a zit.
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Natural Characteristics of Tongariro Volcanic
KEY
Tongariro Volcanic
Environment
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Environment
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50 million years ago, New Zealand was part
h of the super continent of
a
e on the coast. A rift valley began to
Gondwanaland, and sediment accumulated
form, separating New Zealand from the rest of the Gondwanaland.
2 million
q
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u
years ago was a major period of building,owith 100,000mm uplift
over 2 million
o
years. Made the relief very young and sharp
c looking. The Tongariro Volcanic
t
u oceanic Pacific Plate, sub-ducting
Environment (TVE) was caused by the heavy
e
m
beneath the Indo- Australian Plate, because of earth’s convection currents. The
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m
pressure built up, and andesitic magma flows up numerous volcanic vents,
producing numerous volcanic eruptions, which develop into the major
andesitic volcanic cones of the TVE, including Mount Ruapehu, Mount
Tongariro, and Mount Ngauruhoe. Deep seated earthquakes are still present
today. 100,000 years ago, the Ice Age began, forming numerous glaciers, such
as the former Mangatepopo Glacier. U-Shaped valleys, such as the
Mangatepopo Valley was formed from great weight of accumulated snow. The
Ice Age also formed Lake Rotoaira. 15,000 years ago, the Ice Age ended. Now
rivers are the main source of erosion of the TVE. The rivers flow from the
summits of the mountains, in a radial drainage pattern, eroding the landform
into V-Shaped Valleys, such as the Wairere Valley, flowing from Mount
Ruapehu. The Whangaehu River carries melt-water from the Whangaehu
Glacier, from Mount Ruapehu. Rivers carries sediment from the mountains,
depositing sediment across the TVE which creates the ring plains around the
mountains, such as the Mount Ruapehu ring plain. A single eruption can
deposit up to 10,000 m³ of tephra on the surrounding environment, however,
this is matched by fluvial erosion. Taranaki Falls is also the result of melt-water
flowing from the summit of Mount Ruapehu. Present day Rangipo Desert, is a
result of previous volcanic eruptions, and the rain shadow effect, with over
2,000mm of precipitation falling the western slopes of Mt Ruapehu each year,
while the easterly slopes, where Rangipo Desert is located, receives only 1,000
mm of precipitation every year, this is caused by Orographic Rainfall occurring
on the summits of the mountains. Plant succession occurs on the mountains
with Podocarp Forests (Beech Forest) covering the base of Mount Ruapehu,
tussock (grasses) above the forests, and ice, and snow on the summit.