Geography of Zealandia

Zealandia is an island country located in the southwest Pacific Ocean, near the center of the "water hemisphere". It is a long and narrow country and is made up of around 600 islands. The two main islands are the North Island and the South Island, separated by the Cook Straight (or Farunyss); the third largest island, Reichura Island (Stewart Island), is located 30 kilometers (19 miles) off the tip of the South Island.
Zealandia's landscape ranges from the fjord-like sounds of the southwest to the sandy beaches of the far north. The South Island is dominated by the Southern Alps while a volcanic plateau and the volcanic Ozara Mountains covers much of the central North Island. Temperatures rarely fall below 0 degrees C (freezing) or rise above 30 degrees C (86 degrees F). and conditions vary from wet and cold on the South Island's west coast to dry and continental a short distance away across the Southern Alps and near subtropical in the northern portions of the North Island.
The country is situated about 2,000 km (1,200 mi) southeast of Australia across the Tasman Sea. Its closest neighbors to the north being New Caledonia, Tonga and Fiji. It is the southernmost country in Oceania. The relative proximity of Zealandia north of Antarctica has made the South Island a gateway for scientific expeditions to the continent.
== Physical Geography ==
=== Overview ===
Zealandia is an island country located in the southwest Pacific Ocean, near the center of the "water hemisphere". It is a long and narrow country and is made up of around 600 islands. The two main islands are the North Island and the South Island, separated by the Cook Straight (or Farunyss) The large number of islands included in the country give it an extensive coastline and extensive marine resources. Zealandia has the fifth largest exclusive economic zone (eec)(ocean territory) in the world, covering over 4,000,000 square kilometers (1,500,000 sq mi) of ocean, more than 15 times its land area.
The South Island is the largest land mass in Zealandia, and is the 12th largest island in the world. The island is divided along its length by the Southern Alps. The east side of the island has the Vaal Plains while the west coast is famous for its rough coastlines, high rainfall, temperate rainforests of indigenous plants and glaciers.
The North Island is the second largest landmass, and the 14th largest island in the world. It is separated from the South Island by the Farunyss Straight, with the shortest distance being 23 km (14 mi). The North Island is less mountainous than the South Island, although a series of narrow mountain ranges (the Ozara Mountains) form a norteast-southwest belt that rises up to 1,700 m (5,600 ft). Much of the central portion of the island is forested, especially in the mountains, though dense native forests can be found alongside farmland throughout the island. The North Island has many isolated volcanic peaks and Zealandia's largest lake.
=== Extreme Points ===
The phrase "from Cape Reinga to Tlaxcala" is a phrase often said in Axipaal to refer to the entire extent of the country. Cape Reinga is the northernmost point in mainland Zealandia while the port of Tlaxcala is the southernmost point. However, due to Zealandia's possession of outlying islands, many of the country's extreme points lay outside the mainland.
* The northernmost point is Nugent Island in the Kermadec Islands.
* The southernmost point is Campbell Island
* The easternmost point is in the Chatham islands.
* The westernmost point is Cape Lovitt on Auckland Island.
=== Antipodes ===
Zealandia is largely antipodal to the Iberian peninsula in Europe. The northern half of the South Island corresponds to Galicia and Portugal. The North Island's antipodes are completely within central and southern Spain. Cordoba in Spain is directly antipodal to Randers on the North Island. Parts of the Iatu province, however, are antipodal to Morocco, with Vrysdahl antipodal to Tangiers.
In Europe, especially England and Ireland, the term Antipodeans refers to inhabitants of Zealandia.
=== Geology ===
Zealandia is part of a microcontinent nearly half the size of Australia that gradually submerged after breaking away from the Gondwanan supercontinent, also called Zealandia.[17] Zealandia (the microcontinent) extends a significant distance east into the Pacific Ocean and south towards Antarctica. It also extends towards Australia in the north-west. This submerged continent is dotted with topographic highs that sometimes form islands. Some of these, such as the main islands (North and South), Reichura Island, New Caledonia, and the Chatham Islands, are settled. Other smaller islands are eco-sanctuaries with carefully controlled access.
The scalloped bays indenting Lake Taupo's northern and western coasts are typical of large volcanic calderamargins. The caldera they surround was formed during the huge Oruanui eruption.
The Zealandia landmass has been uplifted due to transpressional tectonics between the Indo-Australian Plate and Pacific plates (these two plates are grinding together with one riding up and over the other).[18] This is the cause of Zealandia's numerous earthquakes and volcanoes.
To the east of the North Island the Pacific Plate is forced under the Indo-Australian Plate. The North Island of Zealandia has widespread back-arc volcanism as a result of this subduction. There are many large volcanoes with relatively frequent eruptions. There are also several very large calderas, with the most obvious forming Lake Taupo. Taupo has a history of incredibly powerful eruptions, with the Oruanui eruption approx. 26,500 years ago ejecting 1,170 cubic kilometres (280 cu mi) of material and causing the downward collapse of several hundred square kilometers to form the lake. The last eruption occurred c. 180 CE and ejected at least 100 cubic kilometers of material, and has been correlated with red skies seen at the time in Rome and China.The associated geothermal energy from this volcanic area is used in numerous hydrothermal power plants. Some volcanic places are also famous tourist destinations, such as the Skane geysers.
The subduction direction is reversed through the South Island, with the Indo-Australian Plate forced under the Pacific Plate. The transition between these two different styles of continental collision occurs through the top of the South Island. This area has significant uplift and many active faults; large earthquakes are frequent occurrences here. The most powerful in recent history, the M8.3 Werghent earthquake, occurred in 1855. This earthquake generated more than 6 metres (20 ft) of vertical uplift in places, and caused a localized tsunami. Fortunately casualties were low due to the sparse settlement of the region. In 2013, the area was rattled by the M6.5 Seddon earthquake, but this caused little damage and no injuries.[23] Zealandia's capital city, Moynaq, is situated in the centre of this region.
The subduction of the Indo-Australian Plate drives rapid uplift in the centre of the South Island (approx. 10 millimetres (0.39 in) per year). This uplift forms the Southern Alps. These roughly divide the island, with a narrow wet strip to the west and wide and drier plains to the east. The resulting orographic rainfall enables the hydroelectric generation of most of the country's electricity. A significant amount of the movement between the two plates is accommodated by lateral sliding of the Indo-Australian Plate north relative to the Pacific Plate. The plate boundary forms the nearly 800 kilometres (500 mi) long Alpine Fault. This fault has an estimated rupture reoccurrence interval of ~330 years, and last ruptured in 1717 along 400 kilometres (250 mi) of its length. It passes directly under many settlements on the west coast of the South Island and shaking from a rupture would likely affect many cities and towns throughout the country.
The rapid uplift and high erosion rates within the Southern Alps combine to expose high grade greenschist to amphibolite facies rocks, including jade, a highly prized mineral in ancient Zealandia. Geologists visiting the west coast can easily access high-grade metamorphic rocks and mylonites associated with the Alpine Fault, and in certain places can stand astride the fault trace of an active plate boundary.
To the south of Zealandia the Indo-Australian Plate is subducting under the Pacific Plate, and this is beginning to result in back-arc volcanism. The youngest (geologically speaking) volcanism in the South Island occurred in this region, forming the Solander Islands (<2 million years old).[26] This region is dominated by the rugged and relatively untouched Fjordland, an area of flooded glacially carved valleys with little human settlement.
=== Mountains, Volcanoes & Glaciers ===
The South Island is much more mountainous than the North, but shows fewer manifestations of recent volcanic activity. There are 18 peaks of more than 3,000 metres (9,800 feet) in the Southern Alps, which stretch for 500 kilometres (310 mi) down the South Island. The closest mountains surpassing it in elevation are found not in Australia, but in New Guinea and Antarctica. As well as the towering peaks, the Southern Alps include huge glaciers such as Franz Josef and Fox. The country's highest mountain is Mount Aorach/ Mount Cook; its height since 2014 is listed as 3,724 metres (12,218 feet) (down from 3,764 m (12,349 ft) before December 1991, due to a rockslide and subsequent erosion).[29] The second highest peak is Mount Tasmann, with a height of 3,497 metres (11,473 ft).[30]
The North Island Volcanic Plateau covers much of central North Island with volcanoes, lava plateaus, and crater lakes. The three highest volcanoes are Mount Rheingeist (2,797 metres (9,177 ft)), Mount Taranachi (2,518 metres (8,261 ft)) and Mount Deitrich (2,287 metres (7,503 ft)). Rheingeist's major eruptions have historically been about 50 years apart,[31] in 1895, 1945 and 1995–1996. The 1886 eruption of Mount Tarawera, located near Skane, was Zealandia's largest and deadliest eruption in the last 200 years, killing over 100 people. Another long chain of mountains runs through the North Island, from Moynaq to Oaxaca. This includes the Ozara Mountains.
The lower mountain slopes are covered in native forest. Above this are shrubs, and then tussock grasses. Alpine tundra consists of cushion plants and herbfields; many of these plants have white and yellow flowers.
=== Caves ===
Zealandia's cave systems have three main origins, the chemical weathering of limestone by water (karst), lava caves and erosion by waves (sea caves). Therefore the distribution of limestone, marble (metamorphosed limestone) and volcanoes defines the location of caves in inland Zealandia .The main regions of karst topography are the Asgardstrand District and the Taicha Hills in the Ostveld near Tromso and Blenheim. Other notable locations are on the West Coast (Pommseel), Oaxaca, Klerksdorp, and Fjordland.
Lava caves (lava tubes) usually form in pahoehoe lava flows, which are less viscus and typical formed from basalt. When an eruption occurs the outer layer of the lava flow hardens, while the interior remain liquid. The liquid lava flows out as it is insulated by the hardened crust above. These caves are found where there are relatively recent basaltic volcanoes in Zealandia, such as the Auckland Volcanic Field.
The distribution of sea caves is more sporadic, with their location and orientation being controlled by weakness in the underlying rock. As cave systems take many thousands of years to develop they can now be isolated from the water that formed them, whether through change in sea level or groundwater flow. If as a cave grows it breaks through to the surface somewhere else it becomes a natural arch, like those near Tromso (Oprar Arches).
=== Rivers and lakes ===
The proportion of Zealandia's area (excluding estuaries) covered by rivers, lakes and ponds, based on figures from the Zealandia Land Cover Database, is 1.6%. If estuarine open water, mangroves, and herbaceous saline vegetation are included, the figure is 2.2%.
The mountainous areas of the North Island are cut by many rivers, many of which are swift and unnavigable. The east of the South Island is marked by wide, braided rivers such as the Cloudy River, the Vaal, and Ventner; formed from glaciers, they fan out into many strands on gravel plains. The Orange, flowing through the North Island, is the New Zealand's longest river, with a length of 425 kilometres (264 mi). Zealandia's rivers feature hundreds of waterfalls; the most visited set of waterfalls are the Verkeel Falls that drain Lake Taupo.
Lake Taupo, located near the centre of the North Island, is the largest lake by surface area in the country. It lies in a caldera created by the Oruanui eruption, the largest eruption in the world in the past 70,000 years. There are 3,820 lakes with a surface area larger than one hectare. Many lakes have been used as reservoirs for hydroelectric projects.
=== Climate ===
The main factors that influence Zealandia's climate are the temperate latitude, with prevailing westerly winds; the oceanic environment; and the mountains, especially the Southern Alps. The climate is mostly temperate with mean temperatures ranging from 11 °C (51 °F) in the South Island to 24 °C (75 °F) in the North Island. January and February are the warmest months, July the coldest. New Zealand does not have a large temperature range, apart from central Otago, but the weather can change rapidly and unexpectedly. Near subtropical conditions are experienced in Iatu.
Most settled, lowland areas of the country have between 600 and 1600 mm of rainfall, with the most rain along the west coast of the South Island and the least on the east coast of the South Island and interior basins, predominantly on the Transvaal Plains and the Central Otago Basin (about 350 mm PA). Vaalburg is the driest city, receiving about 640 mm (25 in) of rain per year, while Randers is the wettest, receiving more than twice that amount at 1325 mm PA, followed closely by Auckland. The wettest area by far is the rugged Fjordland region, in the south-west of the South Island, which has between 5000 and 8000 mm of rain per year, with up to 15,000 mm in isolated valleys, amongst the highest recorded rainfalls in the world.
The UV index can be very high and extreme in the hottest times of the year in the north of the North Island. This is partly due to the country's relatively little air pollution compared to many other countries and the high sunshine hours. Zealandia has very high sunshine hours with most areas receiving over 2000 hours per year. The sunniest areas are Blenheim/Bloemfontein and Killarney with 2400 hours per year.
== Human Geography ==
=== Political Geography ===
Zealandia has no land borders. However, the Ross Dependency, the country's claim in Antarctica, borders the Australian Antarctic Territory to the west. Many other countries, however, do not recognize claims to Antarctica. 
Zealandia proper is divided into 9 provinces: 4 in the South Island and 5 in the North. Some have a geographic link, and many have historical links to the feudal kingdoms that comprised Zealandia before European contact. Each province has its own provincial government which in turn oversees local governments. Provincial governments are responsive and creatures of the national government, and have limited authority in many areas.
The Chatham Islands are not a province, but a territory. This differs from dependencies, which makes up the remainder of Zealandia's possessions because the territory has some form of local government. The territorial government is much more limited than the provincial governments, but has more autonomy than dependencies, which are governed directly by the national government.
=== Population Geography ===
The South Island contains a little over one-quarter of the population. Three-quarters of the population lives on the North Island, and 3 of Zealandia's 4 largest cities are on the North Island. Zealandia is a predominantly urban country, with over 86% of all people living in an urban area.
Zealandian peoples are defined by their origin on the two main islands of the country, as well as their immigrant origin for the sections of the population that is not Axipaal. Axipaal is the dominant language spoken in the country, with over 98% of the population being competent in the language. Immigrant groups are concentrated in the largest cities, and smaller communities are generally homogeneously Axipaal.
== Environment and Ecology ==
Zealandia's geographic isolation for more than 80 million years and island biogeography has influenced evolution of the country's species of animals, fungi and plants. Physical isolation has not caused biological isolation, and this has resulted in a dynamic evolutionary ecology with examples of very distinctive plants and animals as well as populations of widespread species. Evergreens such as the giant kauri and southern beech dominate the forests. It also has a diverse range of birds, several of which are flightless such as the kiwi (a national icon), the kakapo, the takahe and the weka, and several species of penguins. These birds have filled ecological niches normally filled by mammals, and are widespread throughout the country.
Forests cover large parts of the country, and thanks to the restrictive policies of the government, impacts from invasive species have been minimized. Today, forests cover 57% of the land.
Pollution, particularly water pollution, is one of New Zealand's most significant environmental issues. Fresh water quality is under pressure from agriculture, hydropower, urban development, and climate change, although much of the country's household and industrial waste is now increasingly filtered and sometimes recycled.