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80-575: The Upper Waitematā Harbour is an estuary of the Waitematā Harbour in the Auckland Region of New Zealand. It flows south-east from the town of Riverhead , and was historically the border between Waitakere City and North Shore City in Auckland. The Upper Waitematā Harbour is an estuary of the Waitematā Harbour , which flows into the central Waitematā Harbour through a narrow outlet. Much of

160-471: A body harness , if only as a backup for an ankle attachment. Body harnesses generally derive from climbing equipment rather than parachute equipment. Milad tower bungee jumping with a height of 280 meters is the highest jumping platform in the world In August 2005, AJ Hackett added a SkyJump to the Macau Tower , making it the world's highest jump at 233 metres (764 ft). The SkyJump did not qualify as

240-530: A catenary rope, from a cliff, across a Sydney-area river, braking with carpet, releasing mid-river, and swimming to an accessible river bank. The first modern bungee jumps were made on 1 April 1979 from the 76-metre (250 ft) Clifton Suspension Bridge in Bristol , England, by David Kirke and Simon Keeling, members of the Oxford University Dangerous Sports Club , and Geoff Tabin,

320-519: A "Guide cable" system that limits swing (the jump is very close to the structure of the tower itself) but does not have any effect on the speed of descent, so this still qualifies the jump for the World Record. Kushma Bungee Jump is the world's second-highest bungee jump with a height of 228 metres (748 ft). It is located in the gorge of Kaligandaki River and world-first natural canyon bungee jump. Another commercial bungee jump currently in operation

400-462: A building or crane, a bridge across a deep ravine , or on a natural geographic feature such as a cliff. It is also possible to jump from a type of aircraft that has the ability to hover above the ground, such as a hot-air-balloon or helicopter . The thrill comes from the free-falling and the rebound. When the person jumps, the cord stretches and the jumper flies upwards again as the cord recoils, and continues to oscillate up and down until all

480-436: A harness. Those bungee cords are linked to steel cables along which they can slide due to stainless pulleys. The participants bicycle, sled or ski before jumping. SCAD diving (Suspended Catch Air Device) is similar to bungee jumping in that the participant is dropped from a height, but in this variation there is no cord; instead the participant free-falls into a net. Untrained SCAD divers use a special free fall harness to ensure

560-573: A harsh environment for organisms. Sediment often settles in intertidal mudflats which are extremely difficult to colonize. No points of attachment exist for algae , so vegetation based habitat is not established. Sediment can also clog feeding and respiratory structures of species, and special adaptations exist within mudflat species to cope with this problem. Lastly, dissolved oxygen variation can cause problems for life forms. Nutrient-rich sediment from human-made sources can promote primary production life cycles, perhaps leading to eventual decay removing

640-529: A number of coastal water bodies such as coastal lagoons and brackish seas. A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the tidal limit or the salt intrusion limit and receiving freshwater runoff; however the freshwater inflow may not be perennial, the connection to the sea may be closed for part of the year and tidal influence may be negligible". This broad definition also includes fjords , lagoons , river mouths , and tidal creeks . An estuary

720-730: A number of jumps from bridges and other structures (including the Eiffel Tower ), building public interest in the sport, and opening the world's first permanent commercial bungee site, the Kawarau Bridge Bungy at the Kawarau Gorge Suspension Bridge near Queenstown in the South Island of New Zealand. Hackett remains one of the largest commercial operators, with concerns in several countries. Several million successful jumps have taken place since 1980. This safety record

800-940: A professional climber who tied the ropes for the jump. The students had come up with the idea after discussing the " vine jumping " ritual of Vanuatu . The jumpers were arrested shortly after, but continued with jumps in the US from the Golden Gate Bridge and the Royal Gorge Bridge . The last jump was sponsored by and televised on the American programme That's Incredible , spreading the concept worldwide. By 1982, Kirk and Keelling were jumping from mobile cranes and hot air balloons. Colorado climbers Mike Munger and Charlie Fowler may have bungee-jumped earlier in Eldorado Springs, CO in 1977. Both were cutting-edge alpinists, preparing for

880-611: A second Upper Harbour Bridge was constructed parallel to the 1975 bridge. Estuary Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bays , harbors , lagoons , inlets , or sounds , although some of these water bodies do not strictly meet

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960-621: A stop. The designer engineer suggested that for safety the ground below "be covered with eight feet of feather bedding". The proposal was declined by the Fair's organizers. The word "bungee" originates from West Country dialect of the English language, meaning "Anything thick and squat", as defined by James Jennings in his book "Observations of Some of the Dialects in The West of England" published 1825. In 1928,

1040-474: A trip to Monte Fitzroy in Patagonia by simulating long falls onto a springy, 46-metre (150 ft) nylon climbing rope. They scrambled up to a large tree at the top of the 210 m (700 ft) wall, above a severely overhanging climb appropriately named "Diving Board", and tied one end of the rope into the tree. With a piece of flat seat belt webbing around his waist and some homemade leg loops, Mike tied into

1120-408: A type of ecosystem in some estuaries that have been negatively impacted by eutrophication. Cordgrass vegetation dominates the salt marsh landscape. Excess nutrients allow the plants to grow at greater rates in above ground biomass, however less energy is allocated to the roots since nutrients is abundant. This leads to a lower biomass in the vegetation below ground which destabilizes the banks of

1200-550: A well-mixed water column and the disappearance of the vertical salinity gradient . The freshwater-seawater boundary is eliminated due to the intense turbulent mixing and eddy effects . The lower reaches of Delaware Bay and the Raritan River in New Jersey are examples of vertically homogeneous estuaries. Inverse estuaries occur in dry climates where evaporation greatly exceeds the inflow of freshwater. A salinity maximum zone

1280-436: A wholly marine embayment to any of the other estuary types. The most important variable characteristics of estuary water are the concentration of dissolved oxygen, salinity and sediment load. There is extreme spatial variability in salinity, with a range of near-zero at the tidal limit of tributary rivers to 3.4% at the estuary mouth. At any one point, the salinity will vary considerably over time and seasons, making it

1360-470: A wide effect on the surrounding water bodies.  In turn, this can decrease fishing industry sales in one area and across the country. Production in 2016 from recreational and commercial fishing contributes billions of dollars to the United States' gross domestic product (GDP). A decrease in production within this industry can affect any of the 1.7 million people the fishing industry employs yearly across

1440-420: A world's record for the longest bungee jump from a fixed structure. In "Catapult" (Reverse Bungee or Bungee Rocket), the jumper starts on the ground. The jumper is secured and the cord is stretched, then released and shooting the jumper up into the air. This is often achieved using either a crane or a hoist attached to a (semi-)perma structure. This simplifies the action of stretching the cord and later lowering

1520-455: Is a dynamic ecosystem having a connection to the open sea through which the sea water enters with the rhythm of the tides . The effects of tides on estuaries can show nonlinear effects on the movement of water which can have important impacts on the ecosystem and waterflow. The seawater entering the estuary is diluted by the fresh water flowing from rivers and streams. The pattern of dilution varies between different estuaries and depends on

1600-432: Is already significant at the cord's natural length. This gives a harder, sharper bounce. The braided cover also provides significant durability benefits. Other operators, including A. J. Hackett and most southern-hemisphere operators, use unbraided cords with exposed latex strands. These give a softer, longer bounce and can be home-produced. Accidents where participants became detached led many commercial operators to use

1680-656: Is at the Royal Gorge Bridge in Colorado. The height of the platform is 321 metres (1,053 ft). However, this jump is rarely available, as part of the Royal Gorge Go Fast Games—first in 2005, then again in 2007. Previous to this the record was held in West Virginia, USA, by New Zealander Chris Allum, who bungee jumped 251 metres (823 ft) from the New River Gorge Bridge on "Bridge Day" 1992 to set

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1760-399: Is attributable to bungee operators rigorously conforming to standards and guidelines governing jumps, such as double checking calculations and fittings for every jump. As with any sport, injuries can still occur (see below), and there have been fatalities. A relatively common mistake in fatality cases is to use a cord that is too long. The cord should be substantially shorter than the height of

1840-509: Is derived from the Latin word aestuarium meaning tidal inlet of the sea, which in itself is derived from the term aestus , meaning tide. There have been many definitions proposed to describe an estuary. The most widely accepted definition is: "a semi-enclosed coastal body of water, which has a free connection with the open sea, and within which seawater is measurably diluted with freshwater derived from land drainage". However, this definition excludes

1920-411: Is formed, and both riverine and oceanic water flow close to the surface towards this zone. This water is pushed downward and spreads along the bottom in both the seaward and landward direction. Examples of an inverse estuary are Spencer Gulf , South Australia, Saloum River and Casamance River , Senegal. Estuary type varies dramatically depending on freshwater input, and is capable of changing from

2000-617: Is just 13 metres (43 ft) smaller, at 220 metres (720 ft). This jump, made without guide ropes, is from the top of the Verzasca Dam near Locarno, Switzerland. It appears in the opening scene of the James Bond film GoldenEye . The 216-metre (709 ft) Bloukrans Bridge Bungy in South Africa and the Verzasca Dam jumps are pure freefall swinging bungee from a single cord. Guinness only records jumps from fixed objects to guarantee

2080-560: Is less restricted, and there is a slow but steady exchange of water between the estuary and the ocean. Fjord-type estuaries can be found along the coasts of Alaska , the Puget Sound region of western Washington state , British Columbia , eastern Canada, Greenland , Iceland , New Zealand, and Norway. These estuaries are formed by subsidence or land cut off from the ocean by land movement associated with faulting , volcanoes , and landslides . Inundation from eustatic sea-level rise during

2160-515: Is the Colorado River Delta in Mexico, historically covered with marshlands and forests, but now essentially a salt flat. Bungee jumping Bungee jumping ( / ˈ b ʌ n dʒ i / ), also spelled bungy jumping , is an activity that involves a person jumping from a great height while connected to a large elastic cord . The launching pad is usually erected on a tall structure such as

2240-426: Is the most frequently reported complication. Impaired eyesight secondary to retinal haemorrhage may be transient or take several weeks to resolve. In one case, a 26-year-old woman's eyesight was still impaired after 7 months. Whiplash injuries may occur as the jumper is jolted on the bungee cord and in at least one case, this has led to quadriplegia secondary to a broken neck. Very serious injury can also occur if

2320-639: Is the whitefish species from the European Alps . Eutrophication reduced the oxygen levels in their habitats so greatly that whitefish eggs could not survive, causing local extinctions. However, some animals, such as carnivorous fish, tend to do well in nutrient-enriched environments and can benefit from eutrophication. This can be seen in populations of bass or pikes. Eutrophication can affect many marine habitats which can lead to economic consequences. The commercial fishing industry relies upon estuaries for approximately 68 percent of their catch by value because of

2400-719: The Holocene Epoch has also contributed to the formation of these estuaries. There are only a small number of tectonically produced estuaries; one example is the San Francisco Bay , which was formed by the crustal movements of the San Andreas Fault system causing the inundation of the lower reaches of the Sacramento and San Joaquin rivers . In this type of estuary, river output greatly exceeds marine input and tidal effects have minor importance. Freshwater floats on top of

2480-595: The Mandovi estuary in Goa during the monsoon period. As tidal forcing increases, river output becomes less than the marine input. Here, current induced turbulence causes mixing of the whole water column such that salinity varies more longitudinally rather than vertically, leading to a moderately stratified condition. Examples include the Chesapeake Bay and Narragansett Bay . Tidal mixing forces exceed river output, resulting in

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2560-628: The Mid-Atlantic coast, and Galveston Bay and Tampa Bay along the Gulf Coast . Bar-built estuaries are found in a place where the deposition of sediment has kept pace with rising sea levels so that the estuaries are shallow and separated from the sea by sand spits or barrier islands. They are relatively common in tropical and subtropical locations. These estuaries are semi-isolated from ocean waters by barrier beaches ( barrier islands and barrier spits ). Formation of barrier beaches partially encloses

2640-702: The Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border. The width-to-depth ratio of these estuaries is typically large, appearing wedge-shaped (in cross-section) in the inner part and broadening and deepening seaward. Water depths rarely exceed 30 m (100 ft). Examples of this type of estuary in the U.S. are the Hudson River , Chesapeake Bay , and Delaware Bay along

2720-478: The black-tailed godwit , rely on estuaries. Two of the main challenges of estuarine life are the variability in salinity and sedimentation . Many species of fish and invertebrates have various methods to control or conform to the shifts in salt concentrations and are termed osmoconformers and osmoregulators . Many animals also burrow to avoid predation and to live in a more stable sedimental environment. However, large numbers of bacteria are found within

2800-413: The jumping platform to allow it room to stretch. When the cord becomes taut and then is stretched, the tension in the cord progressively increases, building up its potential energy . Initially the tension is less than the jumper's weight and the jumper continues to accelerate downwards. At some point, the tension equals the jumper's weight and the acceleration is temporarily zero. With further stretching,

2880-573: The kinetic energy is dissipated. The land diving ( Sa : Gol ) of Pentecost Island in Vanuatu is an ancient ritual in which young men jump from tall wooden platforms with vines tied to their ankles as a test of their courage and passage into manhood. Unlike in modern bungee-jumping, land-divers intentionally hit the ground, but the vines absorb sufficient force to make the impact non-lethal. The land-diving ritual on Pentecost has been claimed as an inspiration by A. J. Hackett , prompting calls from

2960-520: The rohe of Te Kawerau ā Maki . The traditional Māori name for the estuary is Te Wairoa-ō-Kahu ("The Great River of Kahu"), referring to the ancestor Kahumatamomoe , a second generation descendant of the crew of the Te Arawa migratory waka. The harbour was an important trading route for Tāmaki Māori peoples, due to Te Tōangaroa, the overland canoe portage which linked the Kaipara Harbour with

3040-400: The United States. Estuaries are incredibly dynamic systems, where temperature, salinity, turbidity, depth and flow all change daily in response to the tides. This dynamism makes estuaries highly productive habitats, but also make it difficult for many species to survive year-round. As a result, estuaries large and small experience strong seasonal variation in their fish communities. In winter,

3120-608: The Upper Waitematā Harbour area contains mangrove forests, and areas of mangrove forest that transitions into forests. Major tributaries of the Upper Waitematā Harbour include the Brigham Creek, Rangitopuni Stream, Paremoremo Creek, Lucas Creek, and Oruamo or Hellyers Creek . During the Last Glacial Maximum (known locally as the Ōtira Glaciation) when sea-levels were significantly lower, the Upper Waitematā Harbour

3200-515: The Upper Waitematā Harbour was administered by the Waitemata County . In 1974, the western shores of the estuary became a part of Waitemata City , with the remaining areas split between Rodney County and local government authorities on the North Shore . With the 1989 New Zealand local government reforms , the Upper Waitematā Harbour became the border between the newly formed Waitakere City in

3280-461: The Waitematā Harbour. The portage could be travelled to across either Rangitōpuni ( Riverhead ) in the north, or at Pitoitoi (Brigham Creek) in the south. The shores of the estuary had numerous kāinga (unfortified villages), and the area was known for its diverse seafood resources. The channel between Greenhithe and Herald Island was known as Wainoni. By the first half of the 19th century,

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3360-513: The above definition of an estuary and could be fully saline. Many estuaries suffer degeneration from a variety of factors including soil erosion , deforestation , overgrazing , overfishing and the filling of wetlands. Eutrophication may lead to excessive nutrients from sewage and animal wastes; pollutants including heavy metals , polychlorinated biphenyls , radionuclides and hydrocarbons from sewage inputs; and diking or damming for flood control or water diversion. The word "estuary"

3440-493: The accuracy of the measurement. John Kockleman however recorded a 670-metre (2,200 ft) bungee jump from a hot air balloon in California in 1989. In 1991 Andrew Salisbury jumped from 2,700 metres (9,000 ft) from a helicopter over Cancun for a television program and with Reebok sponsorship. The full stretch was recorded at 962 metres (3,157 ft). He landed safely under parachute. One commercial jump higher than all others

3520-452: The bottom where they are harmless. Historically the oysters filtered the estuary's entire water volume of excess nutrients every three or four days. Today that process takes almost a year, and sediment, nutrients, and algae can cause problems in local waters. Some major rivers that run through deserts historically had vast, expansive estuaries that have been reduced to a fraction of their former size, because of dams and diversions. One example

3600-625: The cliffs at Greenhithe to erode from a height of 30.5m to 18.3m. In 1972, work began on a bridge to connect West Auckland with the North Shore. In November 1975, the Upper Harbour Bridge was opened, leading to a population boom in Greenhithe . The bridge was used in 1986 used by A. J. Hackett for the first jumps testing the equipment for what was to eventually become the world's first commercial bungee jumping company. From 1876 until 1974,

3680-437: The correct falling position. Free-style SCAD divers do not use harnesses. The landing into the huge airtube framed net is extremely soft and forgiving. The SCAD was invented by MONTIC Hamburg, Germany in 1997. Bungee jumping injuries may be divided into those that occur after jumping secondary to equipment mishap or tragic accident, and those that occur regardless of safety measures. In the first instance, injury can happen if

3760-578: The dam later makes an appearance as a Roadblock task in the 14th season of the reality competition series The Amazing Race . A fictional proto-bungee jump is a plot point in the Michael Chabon novel The Amazing Adventures of Kavalier and Clay . In the film Selena , in which Jennifer Lopez plays Selena Quintanilla-Perez, her character is shown bungee jumping at a carnival. This actual event took place shortly before Selena's murder on 31 March 1995. In Valiant (comics) #171 (January 8, 1966),

3840-409: The dissolved oxygen from the water; thus hypoxic or anoxic zones can develop. Nitrogen is often the lead cause of eutrophication in estuaries in temperate zones. During a eutrophication event, biogeochemical feedback decreases the amount of available silica . These feedbacks also increase the supply of nitrogen and phosphorus, creating conditions where harmful algal blooms can persist. Given

3920-401: The effects of modifying the estuarine circulation. Fjord -type estuaries are formed in deeply eroded valleys formed by glaciers . These U-shaped estuaries typically have steep sides, rock bottoms, and underwater sills contoured by glacial movement. The estuary is shallowest at its mouth, where terminal glacial moraines or rock bars form sills that restrict water flow. In the upper reaches of

4000-595: The estuary impacted by human activities, and over time may shift the basic composition of the ecosystem, and the reversible or irreversible changes in the abiotic and biotic parts of the systems from the bottom up. For example, Chinese and Russian industrial pollution, such as phenols and heavy metals, has devastated fish stocks in the Amur River and damaged its estuary soil. Estuaries tend to be naturally eutrophic because land runoff discharges nutrients into estuaries. With human activities, land run-off also now includes

4080-424: The estuary, the depth can exceed 300 m (1,000 ft). The width-to-depth ratio is generally small. In estuaries with very shallow sills, tidal oscillations only affect the water down to the depth of the sill, and the waters deeper than that may remain stagnant for a very long time, so there is only an occasional exchange of the deep water of the estuary with the ocean. If the sill depth is deep, water circulation

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4160-771: The estuary, with only narrow inlets allowing contact with the ocean waters. Bar-built estuaries typically develop on gently sloping plains located along tectonically stable edges of continents and marginal sea coasts. They are extensive along the Atlantic and Gulf coasts of the U.S. in areas with active coastal deposition of sediments and where tidal ranges are less than 4 m (13 ft). The barrier beaches that enclose bar-built estuaries have been developed in several ways: Fjords were formed where Pleistocene glaciers deepened and widened existing river valleys so that they become U-shaped in cross-sections. At their mouths there are typically rocks, bars or sills of glacial deposits , which have

4240-609: The fish community is dominated by hardy marine residents, and in summer a variety of marine and anadromous fishes move into and out of estuaries, capitalizing on their high productivity. Estuaries provide a critical habitat to a variety of species that rely on estuaries for life-cycle completion. Pacific Herring ( Clupea pallasii ) are known to lay their eggs in estuaries and bays, surfperch give birth in estuaries, juvenile flatfish and rockfish migrate to estuaries to rear, and anadromous salmonids and lampreys use estuaries as migration corridors. Also, migratory bird populations, such as

4320-400: The great biodiversity of this ecosystem. During an algal bloom , fishermen have noticed a significant increase in the quantity of fish. A sudden increase in primary productivity causes spikes in fish populations which leads to more oxygen being utilized. It is the continued deoxygenation of the water that then causes a decline in fish populations. These effects can begin in estuaries and have

4400-625: The headlands of Oruamo and Lucas Creek were some of the most densely settled areas of the North Shore by Tāmaki Māori. During the 1820s, most of the Te Kawerau people in the area fled for temporary refuge during the events of the Musket Wars , returning to the Waitākere Ranges and Te Henga / Bethells Beach years later. Early European sources refer to the estuary as the Waitemata River. In

4480-420: The impacts do not end there. Plant death alters the entire food web structure which can result in the death of animals within the afflicted biome . Estuaries are hotspots for biodiversity , containing a majority of commercial fish catch, making the impacts of eutrophication that much greater within estuaries. Some specific estuarine animals feel the effects of eutrophication more strongly than others. One example

4560-476: The islanders' representatives for compensation for what they view as the unauthorised appropriation of their cultural property . A tower 1,200 metres (4,000 ft) high with a system to drop a "car" suspended by a cable of "best rubber" was proposed for the Chicago World Fair, 1892–1893. The car, seating two hundred people, would have been shoved from a platform on the tower and then would have bounced to

4640-532: The jumper has an increasing upward acceleration and at some point has zero vertical velocity before recoiling upward. The Bloukrans River Bridge was the first bridge to be used as a bungee jump launch spot in Africa when Face Adrenalin introduced bungee jumping to the African continent in 1990. Bloukrans Bridge Bungy has been operated commercially by Face Adrenalin since 1997, and is the highest commercial bridge bungy in

4720-530: The jumper's neck or body gets entangled in the cord. More recently, carotid artery dissection leading to a type of stroke after bungee jumping has also been described. In the film GoldenEye and its associated videogame, James Bond makes a jump over the edge of a dam in Russia (in reality the dam is in Switzerland: Verzasca Dam , and the jump was genuine, not an animated special effect). The jump in

4800-556: The late 1830s and 1840s, settlers purchased many areas of the Upper Waitematā Harbour from Ngāti Whātua . One of the first wooden structures on the North Shore was the Retreat, a kauri mill and brewery established by Thomas Hellyer on Oruamo or Hellyers Creek in the late 1830s. In 1844, the township of Riverhead was established between at the headland of the Rangitōpuni Stream, where a kauri mill operated until 1856. After this date,

4880-525: The many chemicals used as fertilizers in agriculture as well as waste from livestock and humans. Excess oxygen-depleting chemicals in the water can lead to hypoxia and the creation of dead zones . This can result in reductions in water quality, fish, and other animal populations. Overfishing also occurs. Chesapeake Bay once had a flourishing oyster population that has been almost wiped out by overfishing. Oysters filter these pollutants, and either eat them or shape them into small packets that are deposited on

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4960-422: The marine environment, such as plastics , pesticides , furans , dioxins , phenols and heavy metals . Such toxins can accumulate in the tissues of many species of aquatic life in a process called bioaccumulation . They also accumulate in benthic environments, such as estuaries and bay muds : a geological record of human activities of the last century. The elemental composition of biofilm reflect areas of

5040-575: The marsh causing increased rates of erosion . A similar phenomenon occurs in mangrove swamps , which are another potential ecosystem in estuaries. An increase in nitrogen causes an increase in shoot growth and a decrease in root growth. Weaker root systems cause a mangrove tree to be less resilient in seasons of drought, which can lead to the death of the mangrove. This shift in above ground and below ground biomass caused by eutrophication could hindered plant success in these ecosystems. Across all biomes, eutrophication often results in plant death but

5120-486: The mill was repurposed to be used as a flour mill, which was the largest provider of flour in the Auckland Region in the 1850s and 1860s. During the 19th century, the river and its tributaries were the major means of transportation for communities in the area, including Albany (then known as Lucas Creek) and Beach Haven . In the 1920s, Winstone Ltd dredged the sandy Upper Waitematā Harbour near Greenhithe, which caused

5200-399: The name suggests, running along a track (often inflatable) with a bungee cord attached. One often has a velcro-backed marker that marks how far the runner got before the bungee cord pulled back. This activity can often be found at fairs and carnivals and is often most popular with children. Bungee jumping off a ramp. Two rubber cords – the "bungees" – are tied around the participant's waist to

5280-440: The now off-balance nitrogen cycle , estuaries can be driven to phosphorus limitation instead of nitrogen limitation. Estuaries can be severely impacted by an unbalanced phosphorus cycle, as phosphorus interacts with nitrogen and silica availability. With an abundance of nutrients in the ecosystem, plants and algae overgrow and eventually decompose, which produce a significant amount of carbon dioxide. While releasing CO 2 into

5360-537: The other end of the rope and, after no small amount of trepidation, he jumped. He then ascended the rope mechanically to the tree and untied. Then Charlie tied in and jumped. The total fall was about 40 m (130 ft). Organised commercial bungee jumping began with the New Zealander, A. J. Hackett , who made his first jump from Auckland 's Greenhithe Bridge in 1986. During the following years, Hackett performed

5440-460: The participant to the ground. "Bungy Trampoline" uses elements from bungy and trampolining. The participant begins on a trampoline and is fitted into a body harness, which is attached via bungy cords to two high poles on either side of the trampoline. As they begin to jump, the bungy cords are tightened, allowing a higher jump than could normally be made from a trampoline alone. "Bungee Running" involves no jumping as such. It merely consists of, as

5520-435: The safety harness fails, the cord length is miscalculated, or the cord is not properly connected to the jump platform. In 1986, a man died during rehearsals for a bungee jumping stunt on a BBC television programme , because the cord sprang loose from a carabiner clip. Injuries that occur despite safety measures generally relate to the abrupt rise in upper body intravascular pressure during bungee cord recoil. Eyesight damage

5600-405: The same time, something that he has done hundreds of times since 2017. The elastic rope first used in bungee jumping, and still used by many commercial operators, is factory-produced braided shock cord. This special bungee cord consists of many latex strands enclosed in a tough outer cover. The outer cover may be applied when the latex is pre-stressed, so that the cord's resistance to extension

5680-427: The seawater in a layer that gradually thins as it moves seaward. The denser seawater moves landward along the bottom of the estuary, forming a wedge-shaped layer that is thinner as it approaches land. As a velocity difference develops between the two layers, shear forces generate internal waves at the interface, mixing the seawater upward with the freshwater. An examples of a salt wedge estuary is Mississippi River and

5760-411: The sediment which has a very high oxygen demand. This reduces the levels of oxygen within the sediment often resulting in partially anoxic conditions, which can be further exacerbated by limited water flow. Phytoplankton are key primary producers in estuaries. They move with the water bodies and can be flushed in and out with the tides . Their productivity is largely dependent upon the turbidity of

5840-456: The volume of freshwater, the tidal range, and the extent of evaporation of the water in the estuary. Drowned river valleys are also known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley. This is the most common type of estuary in temperate climates. Well-studied estuaries include

5920-453: The water and atmosphere, these organisms are also intaking all or nearly all of the available oxygen creating a hypoxic environment and unbalanced oxygen cycle . The excess carbon in the form of CO 2 can lead to low pH levels and ocean acidification , which is more harmful for vulnerable coastal regions like estuaries. Eutrophication has been seen to negatively impact many plant communities in estuarine ecosystems . Salt marshes are

6000-835: The water. The main phytoplankton present are diatoms and dinoflagellates which are abundant in the sediment. A primary source of food for many organisms on estuaries, including bacteria , is detritus from the settlement of the sedimentation. Of the thirty-two largest cities in the world in the early 1990s, twenty-two were located on estuaries. As ecosystems, estuaries are under threat from human activities such as pollution and overfishing . They are also threatened by sewage, coastal settlement, land clearance and much more. Estuaries are affected by events far upstream, and concentrate materials such as pollutants and sediments. Land run-off and industrial, agricultural, and domestic waste enter rivers and are discharged into estuaries. Contaminants can be introduced which do not disintegrate rapidly in

6080-534: The west and North Shore City in the east. The Upper Waitematā Harbour is the namesake of the Upper Harbour local government area, which was established in 2010, and the Upper Harbour parliamentary electorate, which was established in 2014. In 2007, the Upper Harbour Motorway was opened, creating a motorway connection between West Auckland and the North Shore via Greenhithe. As a part of this work,

6160-453: The word started to be used for a rubber eraser . The Oxford English Dictionary records early use of the phrase in 1938 relating to launching of gliders using an elasticated cord, and also as "A long nylon-cased rubber band used for securing luggage". "Bungy" is the usual spelling in New Zealand and other countries. In 1963, Jim Tyson, a Sydney, Australia commando , slid down

6240-579: The world's highest bungee as it is not strictly speaking a bungee jump, but instead what is referred to as a 'Decelerator-Descent' jump, using a steel cable and decelerator system, rather than an elastic rope. On 17 December 2006, the Macau Tower started operating a proper bungee jump, which became the "Highest Commercial Bungee Jump in the World" according to the Guinness Book of Records. The Macau Tower Bungy has

6320-452: The world. In 2008, Carl Dionisio of Durban performed a 30 meter bungy jump attached to a cord made of 18,500 condoms. He currently runs the only Ocean Touch bungy jump in the World at Calheta Beach in Madeira, Portugal, and claims to be the only person operating in the bungy industry single-handed. He holds the world record for being the only person to bungy jump while driving a tower crane at

6400-460: Was the source of a river that forms the modern Waitematā Harbour. The river flowed eastwards along the Waitematā Harbour, turning north-east along the Rangitoto Channel , and entering the ocean to the north of Great Barrier Island . Once sea-levels rose between 12,000 and 7,000 years ago, the Upper Waitematā Harbour was flooded, becoming an estuary . The Upper Waitematā Harbour area is within

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