Zealandia (/ziːˈlændiə/), also known as the New Zealand continent or Tasmantis, is an almost entirely submerged mass of continental crust that sank after breaking away from Australia 60–85 million years ago, having separated from Antarctica between 85 and 130 million years ago. It has variously been described as a continental fragment, a microcontinent, a submerged continent, and a continent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995. Zealandia's status as a continent is not universally accepted, but New Zealand geologist Nick Mortimer has commented that "if it wasn't for the ocean" it would have been recognized as such long ago.
The land mass may have been completely submerged about 23 million years ago, and most of it (93%) remains submerged beneath the Pacific Ocean. With a total area of approximately 4,920,000 km2 (1,900,000 sq mi), it is the world's largest current microcontinent, more than twice the size of the next-largest microcontinent and more than half the size of the Australian continent. As such, and due to other geological considerations, such as crustal thickness and density, it is arguably a continent in its own right. This was the argument which made news in 2017, when geologists from New Zealand, New Caledonia, and Australia concluded that Zealandia fulfills all the requirements to be considered a continent, rather than a microcontinent or continental fragment.
Zealandia supports substantial inshore fisheries and contains gas fields, of which the largest known is New Zealand's Maui gas field, near Taranaki. Permits for oil exploration in the Great South Basin were issued in 2007. Offshore mineral resources include iron sands, volcanic massive sulfides and ferromanganese nodule deposits.
Zealandia is largely made up of two nearly parallel ridges, separated by a failed rift, where the rift breakup of the continent stops and becomes a filled graben. The ridges rise above the sea floor to heights of 1,000–1,500 m (3,300–4,900 ft), with few rocky islands rising above sea level. The ridges are continental rock, but are lower in elevation than normal continents because their crust is thinner than usual, approximately 20 km (12 mi) thick, and consequently they do not float as high above the Earth's mantle.
About 25 million years ago, the southern part of Zealandia (on the Pacific Plate) began to shift relative to the northern part (on the Indo-Australian Plate). The resulting displacement by approximately 500 km (310 mi) along the Alpine Fault is evident in geological maps. Movement along this plate boundary has also offset the New Caledonia Basin from its previous continuation through the Bounty Trough.
Compression across the boundary has uplifted the Southern Alps, although due to rapid erosion their height reflects only a small fraction of the uplift. Farther north, subduction of the Pacific Plate has led to extensive volcanism, including the Coromandel and Taupo Volcanic Zones. Associated rifting and subsidence has produced the Hauraki Graben and more recently the Whakatane Graben and Wanganui Basin.
Volcanism on Zealandia has also taken place repeatedly in various parts of the continental fragment before, during and after it rifted away from the supercontinent Gondwana. Although Zealandia has shifted approximately 6,000 km (3,700 mi) to the northwest with respect to the underlying mantle from the time when it rifted from Antarctica, recurring intracontinental volcanism exhibits magma composition similar to that of volcanoes in previously adjacent parts of Antarctica and Australia.
This volcanism is widespread across Zealandia but generally of low volume apart from the huge mid to late Miocene shield volcanoes that developed the Banks and Otago Peninsulas. In addition, it took place continually in numerous limited regions all through the Late Cretaceous and the Cenozoic. However, its causes are still in dispute. During the Miocene, the northern section of Zealandia (Lord Howe Rise) might have slid over a stationary hotspot, forming the Lord Howe Seamount Chain.
Zealandia is occasionally divided by scientists into two regions, North Zealandia (or Western Province) and South Zealandia (or Eastern Province), the latter of which contains most of the Median Batholith crust. These two features are separated by the Alpine Fault and Kermadec Trench and by the wedge-shaped Hikurangi Plateau, and are moving separately to each other.
The case for Zealandia being a continent in its own right was argued by Nick Mortimer and Hamish Campbell in their book Zealandia: Our continent revealed in 2014, citing geological and ecological evidence to support the proposal.
In 2017, a team of eleven geologists from New Zealand, New Caledonia, and Australia concluded that Zealandia fulfills all the requirements to be considered a drowned continent, rather than a microcontinent or continental fragment. This was widely covered by news media.
New Caledonia lies at the northern end of the ancient continent, while New Zealand rises at the plate boundary that bisects it. These land masses are two outposts of the Antarctic Flora, including Araucarias and Podocarps. At Curio Bay, logs of a fossilized forest closely related to modern Kauri and Norfolk Pine can be seen that grew on Zealandia about 180 million years ago during the Jurassic period, before it split from Gondwana. These were buried by volcanic mud flows and gradually replaced by silica to produce the fossils now exposed by the sea.
During glacial periods, more of Zealandia becomes a terrestrial rather than a marine environment. Zealandia was originally thought to have no native land mammal fauna, but the discovery in 2006 of a fossil mammal jaw from the Miocene in the Otago region shows otherwise.
The total land area (including inland water bodies) of Zealandia is 286,655 km2 (110,678 sq mi). Of this, New Zealand comprises the majority, at 267,988 km2 (103,471 sq mi, or 93%) which includes the mainland, nearby islands, and most outlying islands including the Antipodes Islands, Auckland Islands, Bounty Islands, Campbell Islands, and Chatham Islands (but not the Kermadec Islands or Macquarie Island (Australia), which are part of the rift).
New Caledonia and the islands surrounding it comprise some 18,576 km2 (7,172 sq mi or 7%) and the remainder is made up of various territories of Australia including Lord Howe Island Group (New South Wales) at 56 km2 (22 sq mi or 0.02%), Norfolk Island at 35 km2 (14 sq mi or 0.01%), as well as Elizabeth and Middleton Reefs (Coral Sea Islands Territory) with 0.25 km2 (0.097 sq mi).
The total human population of Zealandia today is about 5 million people.
Zealandia or Tasmantis, with its 3.5 million square km territory being larger than Greenland, ...
We cannot categorically say that there has always been land here. The geological evidence at present is too weak, so we are logically forced to consider the possibility that the whole of Zealandia may have sunk.
The continuous rifted basement structure, thickness of the crust, and lack of seafloor spreading anomalies are evidence of prolongation of the New Zealand land mass to Gilbert Seamount.
The Chatham Rise is an area of ocean floor to the east of New Zealand, forming part of the Zealandia continent. It stretches for some 1,000 kilometres (620 mi) from near the South Island in the west, to the Chatham Islands in the east. It is New Zealand's most productive and important fishing ground, as well as important habitat for whales.Relative to the rest of the Pacific Ocean waters around New Zealand, the Chatham Rise is relatively shallow, no more than 1,000 metres (3,300 ft) deep at any point. This shallowness is made more remarkable by the depth of the ocean immediately to the north and south. To the northeast, the Hikurangi Trench, an extension of the much deeper Kermadec Trench, drops to below 3,000 m (9,800 ft) close to the New Zealand coast, and further from the coast the Rise borders on the Hikurangi Plateau. To the south, similar depths are achieved in the Bounty Trough. Past the eastern end of the rise, the sea floor drops away to the abyssal plain.Fort Zeelandia (Taiwan)
Fort Zeelandia (Chinese: 熱蘭遮城; pinyin: Rèlánzhē Chéng; Pe̍h-ōe-jī: Ji̍at-lân-jia Siâⁿ) was a fortress built over ten years from 1624 to 1634 by the Dutch East India Company (VOC), in the town of Anping (now wholly subsumed as Anping District of Tainan) on the island of Formosa in present-day Taiwan, during their 38-year rule over the western part of the island. The site had been renamed several times as Orange City (奧倫治城), Anping City (安平城), and Taiwan City (臺灣城); the current name of the site in Chinese is Anping Fort (安平古堡).
During the seventeenth century, when Europeans from many countries sailed to Asia to develop trade, Formosa became one of East Asia's most important transit sites, and Fort Zeelandia an international business center. As trade at the time depended on "military force to control the markets", the value of Formosa to the Dutch was mainly in its strategic position. "From Formosa the Spanish commerce between Manila and China, and the Portuguese commerce between Macao and Japan could by constant attacks be made so precarious that much of it would be thrown into the hands of the Dutch, while the latter's dealings with China and Japan would be subject to no interruptions."On behalf of the VOC, ships departing from Formosa could head north to Japan, west to Fujian, or south to Vietnam, Thailand, Indonesia, India, Iran or Europe.Geography of New Caledonia
The geography of New Caledonia (Nouvelle-Calédonie), an overseas collectivity of France located in the subregion of Melanesia, makes the continental island group unique in the southwest Pacific. Among other things, the island chain has played a role in preserving unique biological lineages from the Mesozoic. It served as a waystation in the expansion of the predecessors of the Polynesians, the Lapita culture. Under the Free French it was a vital naval base for Allied Forces during the War in the Pacific.
The archipelago is located east of Australia, north of New Zealand, south of the Equator, and just west of Fiji and Vanuatu. New Caledonia comprises a main island, Grande Terre, the Loyalty Islands, and several smaller islands. Approximately half the size of Taiwan, the group has a land area of 18,575.5 square kilometres (7,172.0 square miles). The islands have a coastline of 2,254 km (1,401 mi). New Caledonia claims an exclusive fishing zone to a distance of 200 nmi or 370 km or 230 mi and a territorial sea of 12 nmi (22 km; 14 mi) from shore.
New Caledonia is one of the northernmost parts of an almost entirely (93%) submerged continent called Zealandia which rifted away from Antarctica between 130 and 85 million years ago (mya), and from Australia 85–60 mya. (Most of the elongated triangular continental mass of Zealandia is a subsurface plateau. New Zealand is a mountainous above-water promontory in its center, and New Caledonia is a promontory ridge on the continent's northern edge.) New Caledonia itself drifted away from Australia 66 mya, and subsequently drifted in a north-easterly direction, reaching its present position about 50 mya. Given its long stability and isolation, New Caledonia serves as a unique island refugium—a sort of biological 'ark'—hosting a unique ecosystem and preserving Gondwanan plant and animal lineages no longer found elsewhere.Geology of New Zealand
The geology of New Zealand is noted for its volcanic activity, earthquakes and geothermal areas because of its position on the boundary of the Australian Plate and Pacific Plates. New Zealand is part of Zealandia, a microcontinent nearly half the size of Australia that broke away from the Gondwanan supercontinent about 83 million years ago. New Zealand's early separation from other landmasses and subsequent evolution have created a unique fossil record and modern ecology.
New Zealand's geology can be simplified into three phases. First the basement rocks of New Zealand formed. These rocks were once part of the super-continent of Gondwana, along with South America, Africa, Madagascar, India, Antarctica and Australia. The rocks that now form the, mostly submerged, continent of Zealandia were then nestled between Eastern Australia and Western Antarctica. Secondly New Zealand drifted away from Gondwana and many sedimentary basins formed, which later became the sedimentary rocks covering the geological basement. The final phase is represented by the uplift of the Southern Alps and the eruptions of the Taupo Volcanic Zone.HMS Zealandia
HMS New Zealand was a King Edward VII-class battleship of the Royal Navy. Like all ships of the class (apart from HMS King Edward VII) she was named after an important part of the British Empire, namely New Zealand. The ship was built by Portsmouth Dockyard between 1903 and 1905. Armed with a battery of four 12-inch (305 mm) and four 9.2 in (234 mm) guns, she and her sister ships marked a significant advance in offensive power compared to earlier British battleship designs that did not carry the 9.2 in guns.
After commissioning in July 1905, she served briefly with the Atlantic Fleet from October to March 1907 before transferring to the Channel Fleet. She then joined the Home Fleet in 1909. She was renamed HMS Zealandia in 1911. In 1912, she, along with her sister ships, was assigned to the 3rd Battle Squadron, part of the Home Fleet. That year, the squadron went to the Mediterranean Sea during the First Balkan War as part of an international blockade of Montenegro. In 1913, the ship returned to British waters.
When the First World War broke out, Zealandia was transferred back to the 3rd Battle Squadron, which was assigned to the Grand Fleet, the main British fleet during the war. Through 1914 and 1915, the ships frequently went to sea to search for German vessels, but Zealandia saw no action during this period. By the end of the year, the Grand Fleet stopped operating with the older 3rd Battle Squadron ships, and in November 1915, Zealandia was detached to serve in the Gallipoli Campaign. The campaign ended shortly thereafter, however, and so Zealandia returned to Britain in January 1916 and rejoined the 3rd Battle Squadron in March. Paid off in late 1917, the ship was converted into a gunnery training ship in early 1918, but she never served in that capacity. In 1919, she was used as a barracks ship before being sold in 1921 and broken up in 1923.Interstate 240 (North Carolina)
Interstate 240 (I-240) is a 9.1-mile (14.6 km) long Interstate Highway loop in the U.S. state of North Carolina. It serves as an urban connector for Asheville and runs in a half-circle around the north of the city's downtown district between exits 53B and 46B of Interstate 40. Between those points, I-40 continues in an east–west direction further south of the city, roughly parallel to the Swannanoa and French Broad rivers. The western segment of I-240 is now being co-signed with I-26 as part of a larger project extending I-26 from its former western terminus at I-40/I-240 to U.S. Route 23 (US 23) near Kingsport, Tennessee.
A planned construction project dubbed the I-26 Connector, is a $600-$800 million project to build the missing gap of I-26 through Asheville. Broken into three sections, they are all planned and funded in the 2016-2025 STIP. Section A, between Haywood Road and Brevard Road, will be a widening project with reconfiguration of ramps at Haywood, Amboy and Brevard. Section B, between north of Haywood Road to US 19/US 23/US 70, is the most expensive section of the project, at $332 million. After a review of various alternative designs, both state and federal agencies choose Alternative 4B, which will convert Patton Avenue along Bowen Bridges to local traffic and reroute I-240 along I-26 further north. Section C, the I-26/I-240/I-40 interchange, will be reconfigured to include missing ramp connects and a widening of I-40 through the area. The approximately 7-mile (11 km) project will begin right-of-way acquisition in 2019, with construction on all three sections in 2021. Additional plans for I-240 in west Asheville call for its expansion from 4 lanes to 8 lanes.Years prior to the loop's completion, I-240 was known as I-140; however, no signage was ever posted for I-140. The I-140 designation has now been given to a spur route in Wilmington.Kenn Plateau
The Kenn Plateau is a large piece of submerged continental crust off northeastern Australia that rifted from northeastern Australia about 63-52 mya, along with other nearby parts of the Zealandia continent.Lord Howe Rise
The Lord Howe Rise is a deep sea plateau which extends from south west of New Caledonia to the Challenger Plateau, west of New Zealand in the south west of the Pacific Ocean. To its west is the Tasman Basin and to the east is the New Caledonia Basin. Lord Howe Rise has a total area of about 1,500,000 square km, and generally lies about 750 to 1,200 metres under water. It is part of Zealandia, a much larger continent that is now mostly submerged, and so is composed of continental crust.Mount Lidgbird
Mount Lidgbird, also Mount Ledgbird and Big Hill, is located in the southern section of Lord Howe Island, just north of Mount Gower, from which it is separated by the saddle at the head of Erskine Valley, and has its peak at 777 metres (2,549 ft) above sea level.
The trek to the summit is for expert climbers only. Ropes are needed to scale the cliffs and slippery, steep terrain. In comparison, Mount Gower is an easy hike. Halfway up the mountain is Goat House Cave, a former shelter for 19th-century Kentia palm gatherers. From this spot, visitors can see nesting masked boobies and numerous red-tailed tropicbirds.New Zealand Subantarctic Islands
The New Zealand Subantarctic Islands comprise the five southernmost groups of the New Zealand outlying islands. They are collectively designated as a UNESCO World Heritage Site. Most of the islands lie near the southeast edge of the largely submerged continent centred on New Zealand called Zealandia, which was riven from Australia 60–85 million years ago and from Antarctica between 130 and 85 million years ago.
Until 1995, scientific research staff were stationed permanently at a meteorological station on Campbell Island. Since then, the islands have been uninhabited, though they are periodically visited by researchers and tourists. The islands are:
The Snares: Northeast Island, High Island, Broughton Island, Alert Stack, Tahi, Rua, Toru, Wha, and Rima, plus minor rocks
Bounty Islands: two small groups of islets, the Western Group and the Eastern Group, plus minor rocks
Antipodes Islands: main island, plus Bollons Island, the Windward Islands, Orde Lees Island, Leeward Island, and South Islet, plus minor rocks
Auckland Islands: Auckland Island, Adams Island, Disappointment Island, Enderby Island, Ewing Island and Rose Island, plus minor rocks
Campbell Island group: Campbell Island, the main island, plus several minor rocks and small islets surrounding Campbell Island, including New Zealand's southernmost point, Jacquemart IslandThey share some features with Australia's Macquarie Island to the west.
New Zealand also has territorial claims, held in abeyance under the Antarctic Treaty System, over several islands close to the Antarctic mainland, including:
Ross Island and the rest of the Ross Archipelago
Balleny Islands: Young Island, Buckle Island, and Sturge Island, plus several smaller islets
Scott Island and Haggits PillarOf these, Ross Island is inhabited by the scientific staff of several research stations, notably at McMurdo Sound and Scott Base.
Protection of reserves were strengthened in 2014, becoming the largest natural sanctuary in the nation.Norfolk Ridge
The Norfolk Ridge is a long submarine ridge running between New Caledonia and New Zealand, about 1300 km off the east-coast of Australia.
It is part of a complex region of ridges between the crust of the Pacific Basin and the continental crust of Australia. Little is known about the Norfolk Ridge; however, it generally lies about 2000 m below sea level and consists of Late Cretaceous continental crust. It is part of Zealandia, a submerged continent that sank 60-85 million years ago.Pohokura field
The Pohokura field is an oil and gas field located 4 km offshore of north Taranaki in New Zealand, in approximately 30 m of water. The field was discovered in 2000 by Fletcher Challenge and has ultimate recoverable reserves (1P) of 1,227 Bcf (1435 PJ) of gas and 61 mmbbls of oil and condensate.The field has 6 offshore and 3 onshore wells, with the production station located on shore, adjacent to the Motunui methanol plant. The production station is unmanned, and is operated from a control room in New Plymouth. The first commercial production was in September 2006.
In 2009, Pohokura was the largest gas-producing field in New Zealand, producing 42% of total production.Pohokura is owned by OMV (74%) and Todd Energy (26%), and is operated by OMV.Puysegur Trench
The 6,300-metre (20,700 ft) deep Puysegur Trench is a deep cleft in the floor of the south Tasman Sea formed by the subduction of the Indo-Australian Plate under the Pacific Plate to the south of New Zealand. Immediately to its east lies a ridge, a northern extension of the Macquarie Ridge, which separates the Puysegur Trench from the Solander Trough. To the west is the expanse of the Tasman Basin, which stretches most of the distance to Australia. To the north of the trench lies the Fiordland Basin, which can be considered an extension of the trench. The Puysegur Trench mirrors the Kermadec Trench and Tonga Trench north of New Zealand.
The Puysegur Trench stretches for over 800 kilometres south from the southwesternmost point of the South Island's coast, its southernmost extent being 400 kilometres due west of the Auckland Islands. It is named after Puysegur Point.SS Zealandia (1910)
SS Zealandia, nicknamed "Z" (or "Zed"), was an historically significant Australian cargo and passenger steamship. She served as a troopship in both World War I and World War II. Zealandia transported the Australian 8th Division. Her crew were the last Allied personnel to see HMAS Sydney, which was lost with all hands in 1941. Zealandia was sunk in the air raids on Darwin of 19 February 1942.Zealandia, Saskatchewan
Zealandia is a town in the Canadian province of Saskatchewan. It is one of the smallest communities in the province to be designated as a town.Zealandia (newspaper)
Zealandia was a New Zealand tabloid newspaper owned, and published weekly for 55 years, by the Catholic Bishop of Auckland. Its first issue is dated 10 May 1934 and its last is dated 23 April 1989. It was founded by the seventh Catholic Bishop of Auckland, James Michael Liston and even though its focus was on Catholic religious matters, well-known New Zealand writers were published in its columns such as James K. Baxter and John Reid. Its editors included Cardinal McKeefry and Bishop Owen Snedden (as they later became), the historian Father Ernest Simmonds, Pat Booth, the newspaper's first lay editor, and the later prominent traditionalist priest, Father Denzil Meuli.
The Catholic Diocese of Auckland holds an archive of publications, including those of its replacement publication New Zealandia.Zealandia (personification)
Zealandia is a national personification of New Zealand. In her stereotypical form, Zealandia appears as a woman who is similar in dress and appearance to Britannia, who is said to be the mother of Zealandia.Zealandia (wildlife sanctuary)
Zealandia, formerly known as the Karori Wildlife Sanctuary, is a protected natural area in Wellington, New Zealand, the first urban completely fenced ecosanctuary, where the biodiversity of 225 ha (just under a square mile) of forest is being restored. The sanctuary was previously part of the water catchment area for Wellington, between Wrights Hill (bordering Karori) and the Brooklyn wind turbine on Polhill.
Most of New Zealand's ecosystems have been severely modified by the introduction of land mammals that were not present during the evolution of its ecosystems, and have had a devastating impact on both native flora and fauna. The sanctuary, surrounded by a pest-exclusion fence, is a good example of an ecological island, which allows the original natural ecosystems to recover by minimising the impact of introduced flora and flora.
The sanctuary has become a significant tourist attraction in Wellington and is responsible for the greatly increased number of sightings of species such as tui and kākā in city's suburbs.
Sometimes described as the world's first mainland island sanctuary in an urban environment, the sanctuary has inspired a raft of similar projects throughout New Zealand, with predator-proof fences now protecting the biodiversity of many other areas of forest. Examples include the 7.7 hectare lowland podocarp forest remnant of Riccarton bush/ Putaringamotu, the 98 hectare Bushy Park and, the 3500 hectare Maungatautari Restoration Project enclosing an entire mountain.Zealandia Bank
Zealandia Bank, also known as Farallon de Torres or Piedras de Torres in Spanish, or Papaungan in Chamorro, consists of two rocky pinnacles about 1.5 kilometers apart, in the Northern Mariana Islands in the Pacific Ocean. One reaches a height of approximately 1 meter (3.3 ft) at low tide; the other does not normally broach the surface. They are located 11 nautical miles (20 km) north-northeast from Sarigan, in between Sarigan and Guguan, but because of their small size, they are not listed in most maps. Zealandia Bank is one of 18 units within the Mariana Arc of Fire National Wildlife Refuge, (a.k.a. Volcanic Unit) of the Marianas Trench Marine National Monument.Zealandia Bank is the exposed portion of the peak of an eroded underwater volcano. In 2004, a survey by NOAA discovered active fumaroles, including possible volcanic activity.
Zealandia Bank was named in 1858 after the British barque Zealandia. The area is part of the United States Commonwealth of the Northern Mariana Islands.
Oceanic features of Zealandia
|Plateaux, ridges, and rises|
|Troughs and trenches|