The volcanism of New Zealand has been responsible for many of the country's geographical features, especially in the

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-larges ...

and the country's outlying islands. While the land's

volcanism Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called a ...

dates back to before the

Zealandia Zealandia (pronounced ), also known as (Māori) or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago.Gurnis, M., Hall, C.E., and Lavier, L.L., ...

microcontinent

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-grabe ...

ed away from

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final sta ...

60–130 million years ago, activity continues today with minor eruptions occurring every few years. This recent activity is primarily due to the country's position on the boundary between the

Indo-Australian all of this entry re immigration is a complete fabrication Indian Australians or Indo-Australians are Australians of Indian ancestry. This includes both those who are Australian by birth, and those born in India or elsewhere in the Indian ...

and

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and I ...

s, a part of the

Pacific Ring of Fire The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur. The Ring ...

, and particularly the

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

of the Pacific Plate under the Indo-Australian Plate. New Zealand's rocks record examples of almost every kind of volcanism observed on Earth, including some of the world's largest eruptions in geologically recent times. None of the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

's volcanoes are active. map new zealand volcanoes

Major eruptions

New Zealand has been the site of many large explosive eruptions during the last two million years, including several of

supervolcano A supervolcano is a volcano that has had an eruption with a Volcanic Explosivity Index (VEI) of 8, the largest recorded value on the index. This means the volume of deposits for such an eruption is greater than 1,000 cubic kilometers (240 cubi ...

size. These include eruptions from

Macauley Island Macauley Island is a volcanic island in New Zealand's Kermadec Islands, approximately halfway between New Zealand's North Island and Tonga in the southwest Pacific Ocean. It is part of a larger submarine volcano that features a wide underwate ...

and the

Taupō Taupō (), sometimes written Taupo, is a town on the north-eastern shore of Lake Taupō, New Zealand's largest lake, in the central North Island. It is the largest urban area of the Taupō District, and the second-largest urban area in the Wa ...

, Whakamaru, Mangakino,

Reporoa Reporoa is a rural community in Rotorua Lakes within the Waikato region of New Zealand's North Island. It is located within the Reporoa Caldera, a caldera in the Taupo Volcanic Zone containing the Deer Hill, Kairuru and Pukekahu rhyolitic ...

Rotorua Rotorua () is a city in the Bay of Plenty region of New Zealand's North Island. The city lies on the southern shores of Lake Rotorua, from which it takes its name. It is the seat of the Rotorua Lakes District, a territorial authority encomp ...

, and Haroharo

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

s. Two relatively recent eruptions from the Taupō Volcano are perhaps the best known. Its Oruanui eruption was the world's largest known eruption in the past 70,000 years, with a Volcanic Explosivity Index (VEI) of 8. It occurred around 26,500 years ago and deposited approximately 1,200 km³ of material.

Tephra Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they r ...

from the eruption covered much of the central North Island with

ignimbrite Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surro ...

up to 200 metres (650 feet) deep, and most of New Zealand was affected by ash fall, with even an 18 cm (7 inch) ash layer left on the

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about t ...

, away. Later erosion and sedimentation had long-lasting effects on the landscape, causing the Waikato River to shift from the Hauraki Plains to its current course through the Waikato to the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer ...

. New Zealand's largest lake,

Lake Taupō Lake Taupō (also spelled Taupo; mi, Taupō-nui-a-Tia or ) is a large crater lake in New Zealand's North Island, located in the caldera of the Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's n ...

, fills the

formed in this eruption. Taupō's most recent major eruption, the Taupō or

Hatepe eruption The Hatepe eruption, named for the Hatepe Plinian pumice tephra layer, sometimes referred to as the Taupō eruption or Horomatangi Reef Unit Y eruption, is dated to 232 CE ± 10 and was Taupō Volcano's most recent major eruption. It is tho ...

, took place around 232 CE, and is New Zealand's largest eruption since Oruanui. It ejected some 120 km³ of material (rating 7 on the VEI scale), with around 30 km³ ejected in just a few minutes. It is believed that the eruption column was high, twice as high as the eruption column from Mount St. Helens in 1980. This makes it one of the most violent eruptions in the last 5000 years (alongside the Tianchi eruption of Baekdu at around 1000 and the 1815 eruption of Tambora). The resulting

ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

turned the sky red over Rome and China.

Mount Tarawera Mount Tarawera is a volcano on the North Island of New Zealand within the older but volcanically productive Ōkataina Caldera. Located 24 kilometres southeast of Rotorua, it consists of a series of rhyolitic lava domes that were fiss ...

's eruption around 1310 CE, while not nearly as large, was still substantial, producing 2.5 km³ of

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or ...

and 5 km³ of tephra (VEI 5). Because its deposits, stretching from Gisborne to the Bay of Islands, were emplaced around the time that

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

permanently settled New Zealand, they have provided a useful archaeological marker. Tarawera erupted again on 10 June 1886, spewing ash and debris over , destroying the

Pink and White Terraces The Pink and White Terraces ( and ), were natural wonders of New Zealand. They were reportedly the largest silica sinter deposits on earth. Until recently, they were lost and thought destroyed in the 1886 eruption of Mount Tarawera, while new hy ...

and three villages, including Te Wairoa, and claiming the lives of perhaps 120 people. Approximately 2 km³ of tephra was erupted (VEI 5).

Hazards

As well as the direct effects of explosions,

, and

pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...

s, volcanoes pose various hazards to the New Zealand populace. These include

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater exp ...

s, break-out floods and

lahar A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extr ...

s from volcanically dammed lakes,

ashfall The Ashfall Fossil Beds of Antelope County in northeastern Nebraska are rare fossil sites of the type called lagerstätten that, due to extraordinary local conditions, capture an ecological "snapshot" in time of a range of well-preserved fossil ...

, and other far field effects. Ruapehu Crater Lake n

For instance, the Tangiwai disaster occurred on 24 December 1953 when the Tangiwai railway bridge across the Whangaehu River collapsed from a

in full flood, just before an express train was about to cross it. The train could not stop in time, and 151 people died. This was ultimately caused by Ruapehu's 1945 eruption, which had emptied the

crater lake Crater Lake ( Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fill ...

and dammed the outlet with tephra. Effects can be widespread even for eruptions of only moderate size. Ash plumes from Ruapehu's 1996 eruption forced the closure of eleven airports, including Auckland International Airport. Insurance against volcanic damage (along with other natural disasters) is provided by the country's Earthquake Commission.

Cultural references

The

had many myths and legends regarding the land's volcanic mountains. Perhaps the most well known regards the relative locations of

Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth D ...

, Tongariro and

Pihanga Pihanga is a andesitic volcanic peak in the North Island Volcanic Plateau, located to the north of Mount Tongariro, between Tongariro and Lake Taupo. Lake Rotoaira lies to the south-west of Pihanga, and the smaller Lake Rotopounamu is situate ...

. It holds that the two first-named volcanoes competed for the love of the beautiful Pihanga and, after Tongariro succeeded, the defeated Taranaki moved to its lonely location near

New Plymouth New Plymouth ( mi, Ngāmotu) is the major city of the Taranaki region on the west coast of the North Island of New Zealand. It is named after the English city of Plymouth, Devon from where the first English settlers to New Plymouth migrated. Th ...

Another legend recounts the exploits of

Ngātoro-i-rangi In Māori tradition, Ngātoro-i-rangi (Ngātoro) is the name of a tohunga (priest) prominent during the settling of New Zealand (Aotearoa) by the Māori people, who came from the traditional homeland Hawaiki on the '' Arawa'' canoe. He is the ...

, a tohunga (priest) who arrived from the ancestral Māori homeland, Hawaiki, on the Arawa waka (canoe). Travelling inland and then looking southward from

, he decided to climb the mountains he saw there. He reached and began to climb the first mountain along with his slave Ngāuruhoe, who had been travelling with him, and named the mountain Tongariro (the name literally means 'looking south'), whereupon the two were overcome by a blizzard carried by the cold south wind. Near death, Ngātoro-i-rangi called back to his two sisters, Kuiwai and Haungaroa, who had also come from Hawaiki but remained on Whakaari / White Island, to send him sacred fire, which they had brought from Hawaiki. This they did, sending the fire in the form of two taniwha (powerful spirits) named Te Pupu and Te Haeata by a subterranean passage to the top of Tongariro. The tracks of these two taniwha formed the line of geothermal fire that extends from the Pacific Ocean and beneath the Taupō Volcanic Zone, and is seen in the many volcanoes and

hot spring A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...

s extending from Whakaari to Tokaanu and up to the Tongariro massif. The fire arrived just in time to save Ngātoro-i-rangi from freezing to death, but Ngāuruhoe had already died by the time Ngātoro-i-rangi turned to give him the fire. For this reason the hole through which the fire ascended, the active cone of Tongariro, is now called Ngauruhoe. Eruptions in the North Island, such as the Kaharoa eruption of Mt Tarawera in 1314, have been used to help determine the approximate date of arrival of the early Polynesian colonists to about 1280. Fossilized footprints of perhaps second- or third-generation Polynesian colonists have been found in volcanic ash on islands in the Hauraki Gulf.

Volcanic areas

While there are remnants of volcanic activity throughout most of New Zealand, there are several areas where they are more obvious, and somewhere activity continues. Since Taranaki's last activity in 1854, all eruptions have been in the Taupō Volcanic Zone or the Kermadec Arc. VolcanicFeatures

Kermadec Arc

The

Kermadec Islands The Kermadec Islands ( mi, Rangitāhua) are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga. The islands are part of New Zealand. They are in total ar ...

are an active volcanic

island arc Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle alon ...

stretching north-northeast from New Zealand's North Island towards Tonga. While only a few volcanoes in the arc are tall enough to form islands, it includes about 30 sizeable

submarine volcano Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ri ...

es with many in the

South Kermadec Ridge Seamounts The South Kermadec Ridge Seamounts are a continuation of the volcanic island arc, formed at the convergent boundary where the Pacific Plate subducts under the Indo-Australian Plate. The subducting Pacific Plate created the Kermadec Trench, the s ...

at the New Zealand end of the chain. The largest island,

Raoul Island Raoul Island (''Sunday Island'') is the largest and northernmost of the main Kermadec Islands, south south-west of 'Ata Island of Tonga and north north-east of New Zealand's North Island. It has been the source of vigorous volcanic activity ...

, produced a large eruption around 2200 years ago with a VEI of 6. Its activity has continued intermittently since, with its latest eruption occurring in 2006.

Northland

The Northland region contains two recently active

volcanic field A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes ...

s, one centered around Whangarei, and the other is the Kaikohe-Bay of Islands volcanic field. The latest activity in the Kaikohe-Bay of Islands field, around 1300 to 1800 years ago, created four

scoria Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) '' ...

cones at

Te Puke Te Puke is a town located 18 kilometres southeast of Tauranga in the Western Bay of Plenty of New Zealand. It is particularly well-known for the cultivation of Kiwifruit. Te Puke is close to Tauranga, Mount Maunganui, Papamoa, and Maketu, ...

(near Paihia). Lion Rock, from North Piha

Earlier, during the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

, a mainly

andesitic Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomin ...

volcanic arc ran through Northland and neighbouring regions (including the Three Kings Ridge and northern Coromandel Peninsula), with western and eastern belts active between 25 and 15 million years ago and 23–11 million years ago respectively. Although this produced substantial volcanic edifices, including New Zealand's largest known

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

, the Waitakere volcano, most of these have been eroded away, buried, or submerged, especially in the west, where a series of volcanoes buried offshore stretches south almost to

. This is called the Northland-Mohakatino Volcanic Belt. Remnants of these two ancient volcano belts are still exposed in many places, including Whangarei Heads, the Hen and Chickens Islands, around Whangaroa Harbour,

Waipoua forest Waipoua Forest is a forest, on the west coast of the Northland Region of New Zealand's North Island. It preserves some of the best examples of kauri forest remaining in New Zealand. It is notable for having two of the largest living kauri t ...

, and the

Waitākere Ranges The Waitākere Ranges is a mountain range in New Zealand. Located in West Auckland between metropolitan Auckland and the Tasman Sea, the ranges and its foothills and coasts comprise some of public and private land. The area, traditionally kno ...

Auckland volcanic field

The

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...

Auckland volcanic field The Auckland volcanic field is an area of monogenetic volcanoes covered by much of the metropolitan area of Auckland, New Zealand's largest city, located in the North Island. The approximately 53 volcanoes in the field have produced a diverse a ...

is a

monogenetic volcanic field A monogenetic volcanic field is a type of volcanic field consisting of a group of small monogenetic volcanoes, each of which erupts only once, as opposed to polygenetic volcanoes, which erupt repeatedly over a period of time. The small monogeneti ...

underlying much of the

Auckland Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The most populous urban area in the country and the fifth largest city in Oceania, Auckland has an urban population of about I ...

metropolitan area. The field's many vents have produced a diverse array of explosion craters,

cones, and

flows. The largest and most recent is Rangitoto in the

Hauraki Gulf The Hauraki Gulf / Tīkapa Moana is a coastal feature of the North Island of New Zealand. It has an area of 4000 km2,Dormant volcano, dormant, the field is likely to erupt again within the next "hundreds to thousands of years" (based on past events), a short timeframe in geologic terms.Beca Carter Hollings & Ferner (2002).
Contingency Plan for the Auckland volcanic field
',

Auckland Regional Council The Auckland Regional Council (ARC) was the regional council (one of the former local government authorities) of the Auckland Region. Its predecessor the Auckland Regional Authority (ARA) was formed in 1963 and became the ARC in 1989. The ARC ...

Technical Publication 165. Accessed 12 May 2008. Auckland's residents, however, face more danger from volcanoes farther south. Auckland's volcanoes are believed to be the latest product of an unusual magma source related to local

tectonics Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...

which is not a classic hot spot, as the earlier volcanic fields are to the south, the opposite expected from movement of the Australian plate over a stationary mantle plume source.

Waikato and South Auckland

Three volcanic fields erupted between 2.7 and 0.5 million years ago, migrating northwards from

Mount Pirongia Mount Pirongia is an extinct stratovolcano located in the Waikato region of New Zealand's North Island. It rises to 959 metres and is the highest peak in the Waikato region. It was active in the late Pliocene and early Pleistocene times. Pir ...

to the

Bombay Hills The Bombay Hills are a range of hills to the south of Auckland, New Zealand. Though only a small and seemingly insignificant range of hills, they lie at the southern boundary of the Auckland region, and serve as a divide between Auckland and th ...

. The earliest of these fields formed the Alexandra Volcanics which is distinguished by large arc volcano tholeiitic cones but did have associated Okete Volcanics which were traditionally more akaline and oxidised and were in the

pattern seen in the later fields. The distinction between the Alexandra and Okete volcanics is not necessarily clear cut and is still being studied.

Alexandra Volcanic Group The Alexandra Volcanic Group (also known as Alexandra volcanic lineament or Alexandra Volcanics) is a chain of extinct calc-alkalic basaltic stratovolcanoes that were most active between 2.74 to 1.60 million years ago but is now known to have ha ...

rocks (mostly basalt) cover about 450 km² amounting to 55 km³ from at least 40 vents.

and Mount Karioi are part of the main

lineament ''See also Line (geometry)'' A lineament is a linear feature in a landscape which is an expression of an underlying geological structure such as a fault. Typically a lineament will appear as a fault-aligned valley, a series of fault or fold-alig ...

in the group. The later fields are the smallest Ngatutura Volcanics which comprises about 16 volcanoes south of Port Waikato on the west coast and the

South Auckland volcanic field The South Auckland volcanic field, also known as the Franklin Volcanic Field, is an area of extinct monogenetic volcanoes around Pukekohe, the Franklin area and north-western Waikato, south of the Auckland volcanic field. The field contains at ...

with over 80 volcanoes. The magma body that created the Auckland volcanic field is considered to have been related to these outpourings also. Unlike typical hot spots such as the one underlying Hawaii, it does not seem to have stayed still, but instead is migrating northward at a faster pace than the surrounding Indo-Australian Plate. Its motion has been explained as the tip of a propagating crack produced by the twisting of the North Island's crust.

Coromandel Volcanic Zone

The extinct Coromandel Volcanic Zone (CVZ) was a volcanic arc stretching from Great Barrier Island in the north, through the

Coromandel Peninsula The Coromandel Peninsula ( mi, Te Tara-O-Te-Ika-A-Māui) on the North Island of New Zealand extends north from the western end of the Bay of Plenty, forming a natural barrier protecting the Hauraki Gulf and the Firth of Thames in the ...

, to

Tauranga Tauranga () is a coastal city in the Bay of Plenty region and the fifth most populous city of New Zealand, with an urban population of , or roughly 3% of the national population. It was settled by Māori late in the 13th century, colonised by ...

and the southern Kaimai Ranges in the south. Activity began in the north around 18 million years ago, and was primarily andesitic until around 9–10 million years ago, when it changed to a bimodal basaltic/rhyolitic pattern. Eruptive centres gradually migrated southward, where they transitioned into early activity in the Taupō Volcanic Zone. Later activity in the CVZ and its interface with the Taupō Volcanic Zone is obscured by subsequent events and is not fully understood, but continued in the south until perhaps 1.5 million years ago in the Tauranga Volcanic Centre. Together with the extinct undersea Colville Ridge, the CVZ formed a precursor to the modern Taupō Volcanic Zone and Kermadec Ridge.

Mayor Island / Tūhua

Mayor Island / Tūhua Mayor Island / Tūhua is a dormant shield volcano located off the Bay of Plenty coast of New Zealand's North Island. It lies north of Tauranga and covers . Geography The island is quite steep along its coast and rises to above sea level. A ...

is a peralkaline shield volcano with a caldera partly formed in a large eruption some 7000 years ago. It has exhibited many eruptive styles, and its last eruption may have occurred only 500–1000 years ago. The island's Maori name, ''Tuhua'', refers to the obsidian they found on the island and prized for its sharp cutting edge.

Taupō Volcanic Zone

About 350 kilometres long by 50 kilometres wide, the

Taupō Volcanic Zone The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward throu ...

(TVZ) is the world's most productive area of recent

silicic Silicic is an adjective to describe magma or igneous rock rich in silica. The amount of silica that constitutes a silicic rock is usually defined as at least 63 percent. Granite and rhyolite are the most common silicic rocks. Silicic is the grou ...

volcanic activity, with the highest concentration of young

rhyolitic Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals ( phenocrysts) in an otherwise fine-grained groundmass. The ...

volcanoes.

Mount Ruapehu Mount Ruapehu (; ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within the Tongari ...

marks its southwestern end, and it continues up through

Ngauruhoe Mount Ngāuruhoe (also spelled Ngauruhoe; Māori: ''Ngāuruhoe'') is a volcanic cone in New Zealand. It is the youngest vent in the Tongariro stratovolcano complex on the Central Plateau of the North Island and first erupted about 2,500 ...

, Tongariro,

, the Whakamaru, Mangakino, Maroa,

, and

s, the Okataina Volcanic Complex (including

) and 85 kilometres beyond Whakaari / White Island to the submarine Whakatāne Seamount. The TVZ also contains numerous smaller volcanoes, along with

geyser A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only i ...

s and geothermal areas. Volcanic eruptions began here around two million years ago, with silicic eruptions starting around 1.55 million years ago, as activity shifted southeast from the Coromandel Volcanic Zone.

Taranaki

Volcanism in the

region has migrated southeastward during the last two million years. Beginning in the

Sugar Loaf Islands The Sugar Loaf Islands (often Sugarloaf; mi, Ngā Motu, ) are a collection of five small uninhabited islands and several sea stacks near Port Taranaki, New Zealand. The largest, Moturoa Island, covers approximately . Motumahanga is the island f ...

, near

, activity then shifted to Kaitake (580,000 years ago) and Pouakai (230,000 years ago) before creating the large stratovolcano called

Mount Taranaki Mount Taranaki (), also known as Mount Egmont, is a dormant stratovolcano in the Taranaki region on the west coast of New Zealand's North Island. It is the second highest point in the North Island, after Mount Ruapehu. The mountain has a seco ...

, (former name Mount Egmont), which last erupted in 1854, and its satellite vent, Fanthams Peak. This southeastward migration is the continuation of the 25 million year activity of the Northland-Mohakatino Volcanic Belt that extends mainly under the present

from the west of Northland down to

Chatham Islands

The higher portions of the

are formed from volcanic rock that is up to 81 million years old, although

flows on the northern shore of Chatham Island date back only about five million years.K. S. Panter, J. Blusztajn, S. R. Hart, P. R. Kyle, R. Esser, W. C. McIntosh (2006)
The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands
/ref>

Banks Peninsula

Banks Peninsula Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately and encompasses two large harbours and many smaller bays and coves. The South Island's largest city, ...

comprises the eroded remnants of two large stratovolcanoes, Lyttelton, which formed first, and Akaroa. These formed by intraplate volcanism through

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called '' sial'' be ...

approximately eleven to eight million years ago (

). The peninsula formed as offshore islands, with the volcanoes reaching to about 1,500 m above sea level. Two dominant craters were eroded, then flooded, to form the Lyttelton and

Akaroa Akaroa is a small town on Banks Peninsula in the Canterbury Region of the South Island of New Zealand, situated within a harbour of the same name. The name Akaroa is Kāi Tahu Māori for "Long Harbour", which would be spelled in standard ...

Harbours. The portion of crater rim lying between Lyttelton Harbour and Christchurch city forms the Port Hills.

Oamaru

Small Surtseyan volcanoes on the submerged

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

formed the Waiareka-Deborah volcanic group in the area around

Oamaru Oamaru (; mi, Te Oha-a-Maru) is the largest town in North Otago, in the South Island of New Zealand, it is the main town in the Waitaki District. It is south of Timaru and north of Dunedin on the Pacific coast; State Highway 1 and the ra ...

around 35 to 30 million years ago.

Southern Alps

The Alpine Dyke Swarm of volcanic intusion took place about 25 million years ago and is located near

Lake Wanaka A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

in the

Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...

Dunedin

The

Dunedin Volcano The Dunedin Volcano is an extensively eroded multi-vent shield volcano that was active between 16 and 10 million years ago. It originally extended from the modern city of Dunedin, New Zealand to Aramoana about 25 km away. Extensive erosion has ...

formed during the Miocene, beginning with basaltic eruptions on the

Otago Peninsula The Otago Peninsula ( mi, Muaūpoko) is a long, hilly indented finger of land that forms the easternmost part of Dunedin, New Zealand. Volcanic in origin, it forms one wall of the eroded valley that now forms Otago Harbour. The peninsula lies sou ...

. Large central-vent structures formed, and then large domes, with seawater interacting explosively with erupting submarine magma. Antipodes Penguin

Solander Islands

The Solander Islands, a small chain of uninhabited islets close to the western end of the

Foveaux Strait The Foveaux Strait, (, or , ) separates Stewart Island, New Zealand's third largest island, from the South Island. The strait is about 130 km long (from Ruapuke Island to Little Solander Island), and it widens (from 14 km at Ruapuke ...

, are the emergent portions of a large extinct andesitic volcano that last erupted around 150,000 to 400,000 years ago. Caused by the subduction of the Australian Plate beneath the Pacific Plate, it is the only volcano associated with this subduction zone that protrudes above the sea.

Subantarctic islands

The majority of New Zealand's widely separated subantarctic islands are primarily volcanic in origin, including Auckland Island, Campbell Island / Motu Ihupuku, and

Antipodes Island In geography, the antipode () of any spot on Earth is the point on Earth's surface diametrically opposite to it. A pair of points ''antipodal'' () to each other are situated such that a straight line connecting the two would pass through ...

. These are mainly

intraplate volcanoes with ages decreasing towards the northeast, although Antipodes Island may have been active during the last 20,000 years.

Older volcanism

Older remnants of volcanism are also found in several places around New Zealand. These were generally formed either when New Zealand still formed part of the

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which leav ...

, or while

was rifting away from the rest of Gondwana, although some have been emplaced in their current setting more recently. (New Zealand is the main part of the submerged

microcontinent Continental crustal fragments, partly synonymous with microcontinents, are pieces of continents that have broken off from main continental masses to form distinct islands that are often several hundred kilometers from their place of origin. Caus ...

of Zealandia that currently emerges above the sea.) A band of granitic intrusions covering over 10,000 km², the Median Batholith, stretches from

Stewart Island / Rakiura Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar ...

through

Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lake ...

, and again through the West Coast and Nelson after interruption by the Alpine Fault. This was produced between 375 and 105 million years ago in the course of subduction-related volcanism in a long mountain range along the Gondwanan coast somewhat like today's

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. Two more

batholith A batholith () is a large mass of intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, s ...

s, the Karamea-Paparoa and Hohonu Batholiths, are also found on the West Coast. Zealandia-Continent map en

Basaltic lava flows, dikes, and tuff from fissure eruptions between 100 million and 66 million years ago, during Zealandia's separation from Gondwana, are found in Marlborough, the West Coast and offshore further west. Ultramafic intrusions are found in Marlborough and north

Canterbury Canterbury (, ) is a cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour. The Archbishop of Canterbury is the primate of t ...

, including at the summit of Tapuae-o-Uenuku, the country's highest mountain outside the

Southern Alps / Kā Tiritiri o te Moana The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...

. Rhyolitic ignimbrite from 85 million years ago is found in

Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...

Shag Point / Matakaea Shag Point / Matakaea is a headland and township in East Otago, New Zealand. It is located close to State Highway 1 nine kilometres to the northeast of Palmerston, at the southern end of a long open bay known as Katiki Beach. The point itself ...

and in the

Kakanui Mountains The Kakanui Range is a range of high hills located inland from Oamaru in the South Island of New Zealand. The range forms a boundary between the valley of the Waitaki River to the north and the high plateau known as the Maniototo and the upper wa ...

. The Hikurangi Plateau is an

oceanic plateau An oceanic or submarine plateau is a large, relatively flat elevation that is higher than the surrounding relief with one or more relatively steep sides. There are 184 oceanic plateaus in the world, covering an area of or about 5.11% of the ...

on the Pacific Plate that attached to the Chatham Ridge after being partially subducted under it, and is now subducting under the

. It likely formed in one of the world's largest volcanic outpourings, the greater Ontong Java event.

Ophiolite An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level and often emplaced onto continental crustal rocks. The Greek word ὄφις, ''ophis'' (''snake'') is found ...

s, volcanic deposits from the ocean floor, have been incorporated into the continental basement of New Zealand in the Dun Mountain Ophiolite Belt, found at both ends of the

, and in Northland.

Notes

References

* Dench, Alison; ''Essential Dates: A Timeline of New Zealand History'', Auckland: Random House, 2005

External links

Geonet: NZ's geological hazard monitoring system

GNS Science: NZ Government research site

Earthquake Commission
{{DEFAULTSORT:Volcanism Of New Zealand * Geographic areas of seismological interest Articles containing video clips Back-arc basins Subduction volcanoes Volcanic belts + Rift volcanoes Rift volcanism Volcanoes of New Zealand