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In New Zealand there are 3 major
volcano types: the cone volcano, the volcanic field,
and the caldera volcano.
An example of a cone volcano is Mount Ruapehu which
is located at the Taupo Volcanic Zone’s southern
end, the area most often active. This region
encompasses an area stretching from Ruapehu to White
Island. Frequently active, Ruapehu is one of New
Zealand’s biggest active volcanoes. In the past, Mt.
Ruapehu has erupted many times; 2 times in the 1800s
and 7 times in the 1900s. The latest eruptions
happened in 1995 and 1996. |
New Zealand’s North Island regions are covered by volcanic
activity from Whangarei, he Bay of Islands, White Island,
Auckland, Egmont, and Ruapehu. The Taupo Volcanic Zone is
the most active encompassing the region from Taupo to White
Island.
The volcanoes which are cone-shaped create consecutive
eruptions close to the vent, thus forming a big cone. The
area of eruptions in the future can then be predicted with
logical precision.
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Okataina and Taupo, the world’s 2 most prolific
caldera volcanoes are located in the Taupo Volcanic
Zone. The caldera type volcano is usually so big
that the earth’s surface collapses or falls into the
cavern that it leaves in its wake. The humungous
hole filled by Lake Taupo is the result of two
explosions which occurred approximately one thousand
eight hundred to two thousand six hundred years ago,
and was reportedly witnessed in skies as far as
China.
The North Island is where most volcanic activities
occur. The areas that suffered the most from past
volcanic episodes were the coast of the Bay of
Plenty and the region of the Tongariro National
Park. Inside the Tongariro National Park is located
the mountains of Ngauruhoe, Ruapehu, and Tongariro. |
Tongariro, Ruapehu, Ngauruhoe, Mount Tarawera, and
White Island are the North Island’s currently active
volcanoes. Although Rangitoto and Mount Taranaki
(a.k.a. Mount Egmont) are classified as sleeping or
dormant, they are still regarded as hazardous.
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Auckland City is a volcanic field. Within a volcanic
field, a small volcano is created by every eruption
which does not erupt for a second time.
Nevertheless, another eruption may happen in a
different part of the field, and these eruptions are
unpredictable practically until the actual point of
explosion.
Volcanic eruptions in the region of
Auckland started approximately a hundred and fifty
thousand years ago. The last major eruption was that
of Rangitoto which took place just six hundred years
ago.
Even though small earthquakes are somewhat common in
New Zealand, its seismic activity is comparatively
moderate. |
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Aside from the Northland peninsula, the chief seismic area
of the country extends over the entire North Island. On the
night of June 9, 1886, following a sequence of continuous
quakes ever since midnight, a fierce eruption happened close
to the Rotorua township. The peak of neighboring Mount
Wahanga was totally blown off, creating a thick dark cloud
covering the area from Paeroa to Taheke. It then turned into
an accumulation of thunder and lightening which went on
continuously through the night. Soon after, close by Mount
Tarawera and Ruawahia , its twin cone, burst into action,
spewing fire.
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