53-699: The Manawatū River is a major river of the lower North Island of New Zealand. The river flows from the Ruahine Ranges , through both the Manawatū Gorge and the city of Palmerston North , and across the Manawatū Plains to the Tasman Sea at Foxton . The river, along with the more northern Whanganui River , gives its name to the Manawatū-Whanganui region. The name of the river was given by
106-479: A high rate of compression and seismic activity due to the converging San Andreas Fault. As a result, the Ventura anticline rises at a rate of 5 mm/year with the adjacent Ventura Basin converging at a rate of about 7–10 mm/year. The anticline is composed of a series of sandstone rock beds and an impermeable rock cap under which vast reserves of oil and gas are trapped. Eight different oil bearing zones along
159-545: A mountain range. The river has formed a "water gap" across the mountains because it is older than the Ruahine and Tararua Ranges . Most rivers arise from an already-existing range of mountains or hills, but beginning about 3 million years ago the central North Island mountain ranges began to uplift across the Manawatū's current course. Because it drained a large catchment, the river had sufficient flow to keep pace with and erode
212-426: A single axial plane. An overturned anticline is an asymmetrical anticline with a limb that has been tilted beyond perpendicular , so that the beds in that limb have basically flipped over and may dip in the same direction on both sides of the axial plane. If the angle between the limbs is large (70–120 degrees), then the fold is an "open" fold , but if the angle between the limbs is small (30 degrees or less), then
265-709: A whole. During the Last Glacial Period when sea levels were over 100 metres lower than present day levels, the North and South islands were connected by a vast coastal plain which formed at the South Taranaki Bight . During this period, most of the North Island was covered in thorn scrubland and forest , while the modern-day Northland Peninsula was a subtropical rainforest . Sea levels began to rise 7,000 years ago, eventually separating
318-457: Is convex up in which the hinge or crest is the location where the curvature is greatest, and the limbs are the sides of the fold that dip away from the hinge. Anticlines can be recognized and differentiated from antiforms by a sequence of rock layers that become progressively older toward the center of the fold. Therefore, if age relationships between various rock strata are unknown, the term antiform should be used. The progressing age of
371-738: Is a large anticline in which a series of minor anticlinal folds are superimposed. Examples include the Late Jurassic to Early Cretaceous Purcell Anticlinorium in British Columbia and the Blue Ridge anticlinorium of northern Virginia and Maryland in the Appalachians, or the Nittany Valley in central Pennsylvania. Anticlines are usually developed above thrust faults, so any small compression and motion within
424-407: Is greatest, also called the crest . The hinge is also the highest point on a stratum along the top of the fold. The culmination also refers to the highest point along any geologic structure. The limbs are the sides of the fold that display less curvature. The inflection point is the area on the limbs where the curvature changes direction. The axial surface is an imaginary plane connecting
477-465: Is in the North Island", "my mother lives in the North Island". Maps, headings, tables, and adjectival expressions use North Island without "the". According to Māori mythology , the North and South Islands of New Zealand arose through the actions of the demigod Māui . Māui and his brothers were fishing from their canoe (the South Island) when he caught a great fish and pulled it right up from
530-562: Is mud and silty sand. In its meandering and frequent shifting of course it has created oxbow lakes , lagoons , and swamps . Sediment deposited along its course has created levees, higher than the surrounding plain; when the river is in flood it overflows these and creates wetlands. The Manawatū reaches the Tasman Sea at Foxton Beach , on the west coast of the North Island, creating the Manawatu Estuary . Major tributaries of
583-474: Is one of the two main islands of New Zealand , separated from the larger but less populous South Island by Cook Strait . With an area of 113,729 km (43,911 sq mi), it is the world's 14th-largest island , constituting 43% of New Zealand's land area. It has a population of 4,077,800 (June 2024), which is 76% of New Zealand's residents, making it the most populous island in Polynesia and
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#1732780971873636-525: Is reduced and the river cuts down into the terrace, forming a gorge. This cycle has created four distinct terraces between the Manawatū Gorge and Palmerston North. The Manawatū Plain was seabed 5 to 6 million years ago, and as it was raised above water by the action of the Australian and Pacific Plates it buckled, forming five long and low ridges (or anticlines ) parallel to the mountains, which impede
689-606: Is the El Dorado anticline in Kansas. The anticline was first tapped into for its petroleum in 1918. Soon after the site became a very prosperous area for entrepreneurs following World War I and the rapid popularization of motor vehicles . By 1995 the El Dorado oil fields had produced 300 million barrels of oil. The central Kansas uplift is an antiform composed of several small anticlines that have collectively produced more than 2.5 million barrels of oil. Another notable anticline
742-548: Is the Tierra Amarilla anticline in San Ysidro, New Mexico. This is a popular hiking and biking site because of the great biodiversity, geologic beauty and paleontological resources. This plunging anticline is made up of Petrified Forest mudstones and sandstone and its caprock is made of Pleistocene and Holocene travertine. The anticline contains springs that deposit carbon dioxide travertine that help to contribute to
795-765: Is trapped and stored in reservoir rock such as sandstone or porous limestone. The oil becomes trapped along with water and natural gas by a caprock that is made up of impermeable barrier such as an impermeable stratum or fault zone. Examples of low-permeability seals that contain the hydrocarbons, oil and gas, in the ground include shale , limestone , sandstone , and rock salt. The actual type of stratum does not matter as long as it has low permeability. Water, minerals and specific rock strata such as limestone found inside anticlines are also extracted and commercialized. Lastly, ancient fossils are often found in anticlines and are used for paleontological research or harvested into products to be sold. Ghawar Anticline, Saudi Arabia,
848-448: The 28th-most-populous island in the world. Twelve main urban areas (half of them officially cities) are in the North Island. From north to south, they are Whangārei , Auckland , Hamilton , Tauranga , Rotorua , Gisborne , New Plymouth , Napier , Hastings , Whanganui , Palmerston North , and New Zealand's capital city Wellington , which is located at the south-west tip of the island. The island has been known internationally as
901-532: The Manawatū Gorge , between the Ruahine and Tararua Ranges . Beyond the gorge it joins with the Pohangina River at Ashhurst and turns south-west, flowing through the city of Palmerston North . At this stage the river is still flowing swiftly and carrying gravel from the mountains. After Opiki , it slows and has a lower gradient, meandering over the Manawatu Plains ; its bed at this point
954-639: The Ministry for the Environment ranked 76 New Zealand sites for water clarity and E. coli levels. Using those measures, they found only four other New Zealand rivers rate worse than the Manawatū (the Waitara , Whanganui , Waipā and Rangitīkei ). North Island The North Island ( Māori : Te Ika-a-Māui [tɛ i.kɐ ɐ mɑː.ʉ.i] , lit. 'the fish of Māui', officially North Island or Te Ika-a-Māui or historically New Ulster )
1007-566: The North Island for many years. The Te Reo Māori name for it, Te Ika-a-Māui , also has official recognition but it remains seldom used by most residents. On some 19th-century maps, the North Island is named New Ulster (named after Ulster province in northern Ireland) which was also a province of New Zealand that included the North Island. In 2009 the New Zealand Geographic Board found that, along with
1060-463: The structural trap for the largest conventional oil field in the world. The Weald–Artois Anticline is a major anticline which outcrops in southeast England and northern France. It was formed from the late Oligocene to middle Miocene , during the Alpine orogeny . Anticlines can have a major effect on the local geomorphology and economy of the regions in which they occur. One example of this
1113-585: The tohunga Haupipi-a-Nanaia, a descendant of Haunui-a-paparangi. Haupipi-a-Nanaia or Hau, travelled down the west coast in pursuit of his wife Wairaka, who had eloped. When Hau reached what is now known as the Manawatū River, he is said to have stopped and clutched his chest, horrified at the prospect of crossing so mighty an expanse of water. Therefore the river's name comes from the Māori words manawa (heart) and tū (stand still). In this context, when said together,
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#17327809718731166-590: The 2023 census, 63.1% of North Islanders identified as European ( Pākehā ), 19.8% as Māori , 10.6% as Pacific peoples , 19.3% as Asian , 1.9% as Middle Eastern/Latin American/African, and 1.1% as other ethnicities. Percentages add to more than 100% as people can identify with more than one ethnicity. Māori form the majority in three districts of the North Island: Kawerau (63.2%), Ōpōtiki (66.2%) and Wairoa (68.5%). Europeans formed
1219-805: The Manawatū River. In 2009, the Cawthron Institute found that the river had the highest gross primary production (GPP) compared to 300 rivers and streams in the Western world. High GPP rates are an indication of poor ecological health and can lead to various environmental issues . In 2011, the Horizons Regional Council laid blame with the Palmerston North City Council for "considerable" and "sustained" breaches of one of its discharge consents, and some degree of non-compliance with two others. A report by
1272-499: The North Island is provided by fifteen District Health Boards (DHBs) . Organised around geographical areas of varying population sizes, they are not coterminous with the Local Government Regions . Anticline In structural geology , an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline
1325-519: The South Island, the North Island had no official name. After a public consultation, the board officially named it North Island, or the aforementioned Te Ika-a-Māui, in October 2013. In prose, the two main islands of New Zealand are called the North Island and the South Island , with the definite article. It is also normal to use the preposition in rather than on , for example "Hamilton
1378-437: The South Island, this is solely due to the North Island having higher natural increase (i.e. births minus deaths) and international migration; since the late 1980s, the internal migration flow has been from the North Island to the South Island. In the year to June 2020, the North Island gained 21,950 people from natural increase and 62,710 people from international migration, while losing 3,570 people from internal migration. At
1431-462: The South Island, with the country's largest city, Auckland, and the capital, Wellington, accounting for nearly half of it. There are 30 urban areas in the North Island with a population of 10,000 or more: The sub-national GDP of the North Island was estimated at NZ$ 282.355 billion in 2021 (78% of New Zealand's national GDP). Nine local government regions cover the North Island and its adjacent islands and territorial waters. Healthcare in
1484-693: The Tokomaru River, which covered 22000 acres; and Taonui Swamp on the north side of the river. The main vegetation in the swamps was harakeke and raupō : harakeke in the drier parts, raupō in the wetter. The Manawatū river mouth and estuary was listed under the Ramsar Convention as a Wetland of International Importance in 2005. The Manawatū River flooded in February 2004, displacing over 3000 people (primarily from Marton and Feilding ) and damaging over 1000 Manawatū farms. The cost of
1537-411: The circumnavigation of New Zealand. The maps described the North Island as " Ea Heinom Auwe " and " Aeheinomowe ", which recognises the "Fish of Māui" element. Another Māori name that was given to the North Island, but is now used less commonly, is Aotearoa . Use of Aotearoa to describe the North Island fell out of favour in the early 20th century, and it is now a collective Māori name for New Zealand as
1590-451: The conclusion of the Otago gold rush in the 1860s, New Zealand's European population growth has experienced a steady 'Northern drift' as population centres in the North Island have grown faster than those of New Zealand's South Island. This population trend has continued into the twenty-first century, but at a much slower rate. While the North Island's population continues to grow faster than
1643-399: The different types of rock within each layer. During the formation of flexural-slip folds, the different rock layers form parallel-slip folds to accommodate for buckling . A good way to visualize how the multiple layers are manipulated, is to bend a deck of cards and to imagine each card as a layer of rock stratum. The amount of slip on each side of the anticline increases from the hinge to
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1696-401: The fault including both shortening and extension of tectonic plates, usually also deforms strata near the fault. This can result in an asymmetrical or overturned fold. An antiform can be used to describe any fold that is convex up. It is the relative ages of the rock strata that distinguish anticlines from antiforms. The hinge of an anticline refers to the location where the curvature
1749-470: The flood in terms of insurance payouts was NZ$ 122 million. Further damage was prevented by the opening of the Moutoa floodgates , which intercept the river between Foxton and Shannon . In 2018 a case study on water quality in the Manawatū-Whanganui region was jointly commissioned by Horizons Regional Council and the Ministry for the Environment , the study was conducted by Land Water People (LWP) and
1802-445: The flow of the Manawatū, Rangitikei , and Oroua Rivers, forcing them to flow southwest rather than directly into the Tasman Sea. At the time of human arrival, the Manawatū Plains were covered with forest. Towards the foothills and the Manawatū Gorge grew black beech , turning into tawa forest at lower altitudes. Along the plains and terraces the forest was mixed podocarp and tōtara , changing to mixed tawa, tītoki , and māhoe in
1855-552: The fold is a "tight" fold . If an anticline plunges (i.e., the anticline crest is inclined to the Earth's surface), it will form V s on a geologic map view that point in the direction of plunge . A plunging anticline has a hinge that is not parallel to the earth's surface. All anticlines and synclines have some degree of plunge. Periclinal folds are a type of anticlines that have a well-defined, but curved hinge line and are doubly plunging and thus elongate domes . Folds in which
1908-408: The hinge of each layer of rock stratum through the cross section of an anticline. If the axial surface is vertical and the angles on each side of the fold are equivalent, then the anticline is symmetrical. If the axial plane is tilted or offset, then the anticline is asymmetrical. An anticline that is cylindrical has a well-defined axial surface, whereas non-cylindrical anticlines are too complex to have
1961-400: The inflection point. Passive-flow folds form when the rock is so soft that it behaves like weak plastic and slowly flows. In this process different parts of the rock body move at different rates causing shear stress to gradually shift from layer to layer. There is no mechanical contrast between layers in this type of fold. Passive-flow folds are extremely dependent on the rock composition of
2014-428: The inner crust can have large effects on the upper rock stratum. Stresses developed during mountain building or during other tectonic processes can similarly warp or bend bedding and foliation (or other planar features). The more the underlying fault is tectonically uplifted, the more the strata will be deformed and must adapt to new shapes. The shape formed will also be very dependent on the properties and cohesion of
2067-702: The interpretation is ‘heart standing still’ to represent how Hau felt when he first saw the river. However cross he did, and a few kilometres south of Paekākāriki, Hau overtook the fugitives and changed Wairaka into a rock. The Manawatū River has its headwaters northwest of Norsewood in the Tararua District , on the eastern slopes of the Ruahine Range on the North Island of New Zealand. It flows initially eastward before turning south-west near Ormondville , flowing 40 kilometres (25 mi) before turning north-west near Woodville . At this point it enters
2120-602: The islands and linking the Cook Strait to the Tasman Sea . The North Island has an estimated population of 4,077,800 as of June 2024. The North Island had a population of 3,808,005 at the 2023 New Zealand census , an increase of 213,453 people (5.9%) since the 2018 census , and an increase of 570,957 people (17.6%) since the 2013 census . Of the total population, 733,893 people (19.3%) were aged under 15 years, 743,154 (19.5%) were 15 to 29, 1,721,427 (45.2%) were 30 to 64, and 609,534 (16.0%) were 65 or older. Ever since
2173-401: The limbs dip toward the hinge and display a more U-like shape are called synclines . They usually flank the sides of anticlines and display opposite characteristics. A syncline's oldest rock strata are in its outer limbs; the rocks become progressively younger toward its hinge. A monocline is a bend in the strata resulting in a local steepening in only one direction of dip. Monoclines have
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2226-470: The plurality in the Auckland region (49.8%) and are the majority in the remaining 39 districts. The proportion of North Islanders born overseas at the 2018 census were 29.3%. The most common foreign countries of birth were England (15.4% of overseas-born residents), Mainland China (11.3%), India (10.1%), South Africa (5.9%), Australia (5.5%) and Samoa (5.3%). The North Island has a larger population than
2279-662: The results were reviewed by the National Institute of Water and Atmospheric Research (NIWA) and StatsNZ . Results showed that water quality for sediment and E. coli had improved over the previous seven to ten years in the Manawatū-Whanganui region. The report found strong statistical evidence of a connection between regional scale water quality improvements and local scale interventions. In 2006 Fonterra were criticised for an application to discharge 8,500 cubic metres (300,000 cu ft) of wastewater into
2332-628: The rich diversity of microorganisms. This area also contains remains of fossils and ancient plants from the Jurassic period that are sometimes exposed through geological erosion. The Ventura Anticline is a geologic structure that is part of the Ventura oil fields , the seventh largest oil field in California that was discovered in the 1860s. The anticline runs east to west for 16 miles, dipping steeply 30–60 degrees at both ends. Ventura County has
2385-438: The rising mountains, eventually forming the Manawatū Gorge; other rivers were unable to and were diverted into the Manawatū instead. After exiting the Manawatū Gorge, the river carries rock and sediment down from the mountains. During glacial times, with the prevalence of ice, snow, and bare mountains, this erosion increases and forms a stony elevated terrace. During an interglacial, while the mountains are forested, gravel outwash
2438-548: The river include the Makakahi , Mangahao , Pohangina and Oroua Rivers . The Manawatū's total length is 180 kilometres (110 mi), making it only the 12th-longest in the country, but at 102 cubic metres per second (3,600 cu ft/s) it is one of New Zealand's greatest rivers in terms of flow, and second only to the Waikato River among North Island rivers. The river is crossed by 18 road bridges (not including
2491-427: The rock strata towards the core and uplifted center, are the trademark indications for evidence of anticlines on a geologic map . These formations occur because anticlinal ridges typically develop above thrust faults during crustal deformations. The uplifted core of the fold causes compression of strata that preferentially erodes to a deeper stratigraphic level relative to the topographically lower flanks. Motion along
2544-466: The sand dunes. Across the flood plain of the Manawatū and on the low-lying land bordering the river, the predominant vegetation was semi-swamp forest, mostly kahikatea and pukatea . Three major swamps bordered the Manawatū: Moutoa Swamp north of the river, towards the mouth, known as the "Great Swamp" in the 19th century; Makerua Swamp further inland, to the south of the Manawatū and north of
2597-486: The sea. While he was not looking, his brothers fought over the fish and chopped it up. This great fish became the North Island, and thus a Māori name for the North Island is Te Ika-a-Māui ("The Fish of Māui"). The mountains and valleys are believed to have been formed as a result of Māui's brothers' hacking at the fish. During Captain James Cook 's voyage between 1769 and 1770 , Tahitian navigator Tupaia accompanied
2650-567: The shape of a carpet draped over a stairstep. An anticline that has been more deeply eroded in the center is called a breached or scalped anticline . Breached anticlines can become incised by stream erosion, forming an anticlinal valley. A structure that plunges in all directions to form a circular or elongate structure is a dome . Domes may be created via diapirism from underlying magmatic intrusions or upwardly mobile, mechanically ductile material such as rock salt ( salt dome ) and shale (shale diapir) that cause deformations and uplift in
2703-408: The stratum and can typically occur in areas with high temperatures. Anticlines, structural domes, fault zones and stratigraphic traps are very favorable locations for oil and natural gas drilling. About 80 percent of the world's petroleum has been found in anticlinal traps. The low density of petroleum causes oil to buoyantly migrate out of its source rock and upward toward the surface until it
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#17327809718732756-509: The surface rock. The Richat Structure of the Sahara is considered a dome that has been laid bare by erosion. An anticline which plunges at both ends is termed a doubly plunging anticline , and may be formed from multiple deformations, or superposition of two sets of folds. It may also be related to the geometry of the underlying detachment fault and the varying amount of displacement along the surface of that detachment fault. An anticlinorium
2809-484: The under-construction Parahaki Island Bridge), 3 rail bridges and He Ara Kotahi walk/cycleway. The lowest and longest, Whirokino Trestle and Manawatū River Bridge, carry SH1 1.1 km (0.68 mi) over the Moutoa Floodway and 180 m (590 ft) over the river. It replaced the 1938 and 1942 bridges in February 2020, at a cost of $ 70m. The Manawatū is unique among New Zealand rivers in that it crosses
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