New Zealand Volcanoes

The White Island Volcano in New Zealand is an active Stratovolcano that is 70% under water.

One of the most interesting volcanoes in New Zealand is the White Island Volcano. This particular volcano has been active for at least 150,000 years; and for the last 40 years it is known as the most active volcano in New Zealand. This volcano is considered a composite cone volcano, because it’s built from multiple eruptions throughout thousands of years forming composite cones out of layers of andesite lava flows and pyroclastic deposits (tephra). “Although andesitic composite cones are built mostly of fragmental debris, some of the magma intrudes fractures within the cones to form dike or sills. In this way, multiple intrusive events build a structural framework of dikes and sills that knits together the voluminous accumulation of volcanic rubble.” (http://volcanology.geol.ucsb.edu/volcano.htm)

Basic illustration of how a Composite Volcano is formed.

 “Andesite magma can generate strong explosive eruptions to form pyroclastic flows and surges and enormous eruption columns”. (http://volcano-pictures.info/glossary/andesite.html) Later, andesite turns into a grey to black volcanic rock.

But what really makes this volcano interesting is that 70% of this Stratovolcano is submerged under the sea. It was formed by the subduction of the Pacific Plate below the Australian Plate. With the help of a few cameras on the island, the country is able to monitor the active volcano and keep an eye out for the occasional ash, gas, and lava bombs. A lava bomb is a mass of molten rock that is ejected from the volcano during eruption.

The gas this volcano produces is actually very bad for human contact because it’s a mix of carbon dioxide and sulphur dioxide. When they mix, “the gasses dissolve in the magma escape and rise towards the surface where they mix with, and heat the groundwater beneath the crater floor.” (http://www.gns.cri.nz/Home/Learning/Science-Topics/Volcanoes/New-Zealand-Volcanoes/White-Island) When this happens, a white steam forms above White Island. Otherwise known as an acidic cloud that can sting the eyes and skin and affect your breathing.

In order for you to visit the volcano, they require you to wear a gas mask because of the toxic gas it produces.

http://ebrondoherty.files.wordpress.com/2013/02/wi19.jpg

Creation of New Zealand's Landscape

New Zealand is on the border between both the Australian-Indian Plate and the Pacific plate.  The boundary between them is called the Alpine fault. Since New Zealand is between these two plates, lots of mountains, glaciers, volcanoes, earthquakes, and oceanic trenches are formed depending on when and how the plates shift.

Mountains, such as Aoraki/Mount Cook or Mount Tasman, were created when these two plates converged with each other.

Tectonic Plate Map of New Zealand 

Volcanoes, like Mount Tongariro in New Zealand, result from the divergence (the action of spreading apart) of these two plates. These volcanoes are just a couple of the many volcanoes you can find in New Zealand due to the pacific plate, where most of the worlds most active volcanoes are found due to the ring of fire.

White Island Volcano (above) is one of the most active volcanoes in New Zealand. Which is also the backdrop used in Lord of the Rings

When these plates converge they do not only make New Zealand’s infamous mountains and volcanoes, but also can create spectacular geothermal areas with hot springs and mud pools; these areas are also used for providing electricity.

Because these two plates are right under New Zealand, the island gets frequent, big earthquakes that are caused by the plates shifting side by side; which is known as transformation. However some of the largest earthquakes in the world are subduction earthquakes.

Unlike other parts of the world, New Zealand is special because it sits on this border between the Australian-Indian Plate and the Pacific plate. Thus giving it the geological experience of all three plate boundaries: transformation, diverging, and converging.

The island of New Zealand and all the many little islands you see around it can either be formed from the tectonic plates moving away from each other splitting the land mass, diverging. Or they can be created from oceanic crusts colliding with each other resulting in one plate descending (subducting) beneath another.

http://sciencelearn.org.nz/Contexts/Earthquakes/Science-Ideas-and-Concepts/Plate-tectonics

http://www.teara.govt.nz/en/map/4398/plate-boundary-through-new-zealand

http://www.newzealand.com/us/feature/new-zealand-geography-and-geology/

http://www.earthonlinemedia.com/ebooks/tpe_3e/tectonics_landforms/tectonics_introduction.html

http://www.gns.cri.nz/Home/Learning/Science-Topics/Volcanoes/New-Zealand-Volcanoes/White-Island

Introduction to New Zealand and Me

My name is Holly Kattau, I am a marketing major at CU Denver, and I will be doing my blogs on New Zealand this semester. I chose New Zealand because this spring I will be studying abroad there and thought this wold be a great opportunity to learn about the country. This way I will know what to look for when I get there and what landmarks would be worth visiting during my time abroad. I will be living there for 6 months, so I'll have to do some research on my temporary home one way or another. This way I am knocking two birds out with one stone and will be one of the most educated visitors during my time there! I can not wait to enjoy this experience!

This is a photo of Milford Sound which is SW of the southern island. The Milford Sound was carved by glaciers in the ice ages and has breathtaking views throughout the year.

http://www.aptouring.com/Destinations/new-zealand