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Litton Reservoirs

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34-401: Litton Reservoirs (also known as Coley Reservoirs ) ( grid reference ST590553 ) are two reservoirs near the village of Litton , Somerset , England . They are operated by Bristol Water . They lie on the boundary between Bath and North East Somerset and Mendip districts. The individual lakes are called Lower Litton and Upper Litton. The former is 8 acres (32,000 m) in size,

68-623: A transverse Mercator projection with an origin (the "true" origin) at 49° N , 2° W (an offshore point in the English Channel which lies between the island of Jersey and the French port of St. Malo ). Over the Airy ellipsoid a straight line grid, the National Grid, is placed with a new false origin to eliminate negative numbers, creating a 700 km by 1300 km grid. This false origin

102-496: A grid index where the tens denote the progress from West to East and the units from South to North. In the north of Scotland, the numbering is modified: the 100 km square to the north of 39 is numbered N30; the square to the north of 49 is N40, etc. The grid is based on the OSGB36 datum (Ordnance Survey Great Britain 1936, based on the Airy 1830 ellipsoid ), and was introduced after

136-542: A steep sea cliff situated about halfway between Whitby and Scarborough on the coast of North Yorkshire in northeastern England. Beast Cliff is at the southern end of a coastal region designated as a Special Area of Conservation and Site of Special Scientific Interest . Bordering the eastern edge of the North York Moors national park, the Cleveland Way runs at the head of the cliffs. In terms of its position on

170-447: A wide variety of flora. Scrub and woodland grow on a moderately sloping intermediate plateau part way down the main cliff. This plateau separates lower and upper steeper cliffs. The undercliff is some 45 metres (148 ft) high and it consists of two steep slopes with a near-vertical face in between which varies in height around about 5 metres (16 ft). The 75-metre (246 ft) upper cliff slopes at about 45°. The total height of

204-464: Is an abbreviated alphanumeric reference where the letters are simply omitted, e.g. 166712 for the summit of Ben Nevis. Unlike the numeric references described above, this abbreviated grid reference is incomplete; it gives the location relative to an OS 100×100 km square, but does not specify which square. It is often used informally when the context identifies the OS 2-letter square. For example, within

238-595: Is called the Helmert datum transformation , which results in a typical 7 m error from true. The definitive transformation from ETRS89 that is published by the Ordnance Survey is called the National Grid Transformation OSTN15. This models the detailed distortions in the 1936–1962 retriangulation, and achieves backwards compatibility in grid coordinates to sub-metre accuracy. The difference between

272-576: Is generally for rainbow ( Oncorhynchus mykiss ) and brown trout ( Salmo trutta ). Fish breeding takes place in the netted area immediately below the upper dam is the site for fish breeding. Ordnance Survey National Grid The Ordnance Survey National Grid reference system ( OSGB ), also known as British National Grid ( BNG ), is a system of geographic grid references , distinct from latitude and longitude , whereby any location in Great Britain can be described in terms of its distance from

306-477: Is located south-west of the Isles of Scilly. In order to minimize the overall scale error, a factor of 2499/2500 is applied. This creates two lines of longitude about 180 km east and west of the central meridian along which the local scale factor equals 1, i.e. map scale is correct. Inside these lines the local scale factor is less than 1, with a minimum of 0.04% too small at the central meridian. Outside these lines

340-619: Is now the preferred coordinate reference system across Ireland. ITM is based on the Universal Transverse Mercator coordinate system (UTM), used to provide grid references for worldwide locations, and this is the system commonly used for the Channel Islands . European-wide agencies also use UTM when mapping locations, or may use the Military Grid Reference System (MGRS), or variants of it. The first letter of

374-587: Is on the west coast of Scotland and the greatest in Kent . These two datums are not both in general use in any one place, but for a point in the English Channel halfway between Dover and Calais , the ED50 longitude lines are about 20 m east of the OSGB36 equivalents, and the ED50 latitude lines are about 150 m south of the OSGB36 ones. Beast Cliff Beast Cliff is

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408-562: The British Isles : this article describes the system created solely for Great Britain and its outlying islands (including the Isle of Man ). The Irish grid reference system is a similar system created by the Ordnance Survey of Ireland and the Ordnance Survey of Northern Ireland for the island of Ireland. The Irish Transverse Mercator (ITM) coordinate reference system was adopted in 2001 and

442-607: The Ordnance Survey and which adjoins NZ , SE and TA at their quadripoint . Indeed, OV0000 is also the only United Kingdom land within the 500-kilometre square with the prefix letter O, which is otherwise occupied by the North Sea (and a small part of Norway , if the grid is extended). Geograph Britain and Ireland is a project which is progressively publishing photographs of every one-kilometre square in Great Britain, based on grid references – only areas of land are included. Geograph has developed its own terminology whereby

476-485: The Ordnance Survey National Grid system of geographical mapping, Beast Cliff is mostly in the one-kilometre grid square TA0099 but at its northern end it extends into OV . That point is the only area of land in the entire 100-kilometre national grid square of OV , adjoining NZ , SE and TA . Beast Cliff is formed from rocks of Jurassic sandstone and shale and is highly vegetated with

510-726: The retriangulation of 1936–1962 . It replaced the Cassini Grid which had previously been the standard projection for Ordnance Survey maps. The Airy ellipsoid is a regional best fit for Britain; more modern mapping tends to use the GRS80 ellipsoid used by the Global Positioning System (the Airy ellipsoid assumes the Earth to be about 1 km smaller in diameter than the GRS80 ellipsoid, and to be slightly less flattened). The British maps adopt

544-507: The 100-kilometre squares are called myriads and 500-kilometre squares are pentads. Traditionally there has been competition to publish the first photograph taken from within any given one-kilometre square. In the case of the first uploaded photograph of OV0000, taken by Peter Standing on 15 July 2006 and published two days later, it turned out to create another new record. In the Geograph discussion forums there had been interest in which would be

578-561: The British National Grid is derived from a larger set of 25 squares of size 500 km by 500 km, labelled A to Z, omitting one letter (I) (refer diagram below), previously used as a military grid. Four of these largest squares contain significant land area within Great Britain: S, T, N and H. The O square contains a tiny area of North Yorkshire , Beast Cliff at OV 0000 , almost all of which lies below mean high tide. For

612-569: The OSGB 36 lines in South Cornwall , the difference diminishing to zero in the Scottish Borders , and then increasing to about 50 m north on the north coast of Scotland . (If the lines are further east , then the longitude value of any given point is further west . Similarly, if the lines are further south, the values will give the point a more northerly latitude.) The smallest datum shift

646-688: The OSGB36 National Grid location for Ben Nevis is at 216600, 771200. Grid references may also be quoted as a pair of numbers: eastings then northings in metres, measured from the southwest corner of the SV square. 13 digits may be required for locations in Orkney and further north. For example, the grid reference for Sullom Voe Oil Terminal in the Shetland islands may be given as HU396753 or 439668,1175316 . Another, distinct, form of all-numeric grid reference

680-526: The area is also designated as a 265-hectare (650-acre) Special Area of Conservation , "Beast Cliff–Whitby (Robin Hood's Bay)". The Natura 2000 improvement plan for the site involves extending its boundaries to allow geomorphological processes to take place undisturbed; preventing inappropriate drainage and coastal defences; and permitting appropriate grazing. On 10 February 1923, the Grimsby steam trawler FV Premier

714-445: The cliff is about 160 metres (520 ft). The cliffs are geologically unstable and frequent landslides intrude upon the woodland, which is therefore constantly renewed with young trees. Mosses and ferns cover sandstone boulders. The woodland is flourishing with juvenile ash and birch growing through a lush understorey, and with alder and willow near pools of water. The Cleveland Way long-distance footpath follows along at

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748-433: The context of a location known to be on OS Landranger sheet 41 (which extends from NN000500 in the south-west to NN400900 in the north-east) the abbreviated grid reference 166712 is equivalent to NN166712. If working with more than one Landranger sheet, this may also be given as 41/166712. Alternatively, sometimes numbers instead of the two-letter combinations are used for the 100×100 km squares. The numbering follows

782-560: The coordinates on different datums varies from place to place. The longitude and latitude positions on OSGB 36 are the same as for WGS 84 at a point in the Atlantic Ocean well to the west of Great Britain. In Cornwall , the WGS 84 longitude lines are about 70 metres east of their OSGB 36 equivalents, this value rising gradually to about 120 m east on the east coast of East Anglia . The WGS 84 latitude lines are about 70 m south of

816-466: The digits is for the first coordinate and the second half for the other. The most common usage is the six figure grid reference , employing three digits in each coordinate to determine a 100 m square. For example, the grid reference of the 100 m square containing the summit of Ben Nevis is NN 166 712 . (Grid references may be written with or without spaces; e.g., also NN166712.) NN has an easting of 200 km and northing of 700 km, so

850-495: The first myriad to have every square photographed. Since OV0000 was the only land square in OV and no other myriads had been completed, it also won that "race". Since that time several photographs of the grid point have been uploaded to Geograph. Only the southwestern corner of OV0000, that is to say OV000000 and OV000001 , are occupied by land – there are only some 0.5 hectares (1 acre) of foreshore, with far less above high tide at

884-435: The head of the cliffs. At one time animals were lowered on ropes to the intermediate plateau for grazing. The whole stretch of coast between Maw Wyke and Beast Cliff around Robin Hood's Bay is a designated Site of Special Scientific Interest with an area of 365 hectares (900 acres). Beast Cliff itself, at the southern end of this area, is regarded as nationally important for its coastal and woodland vegetation. Part of

918-745: The latter 16 acres (65,000 m) and much deeper. They were built around 1850 by the Bristol Waterworks Company in conjunction with the "Line of Works" to bring water from the Mendip Hills to Bristol . A public footpath goes around the lakes and across the dam. The banks are home to a variety of flowers including primroses ( Primula vulgaris ), common bluebell ( Hyacinthoides non-scripta) , wood anemone ( Anemone nemorosa ), violets and red campion . Several species of birds are frequent visitors including moorhens , coots , mallards , mute swans and tufted ducks . Fishing (under permit)

952-473: The local scale factor is greater than 1, and is about 0.04% too large near the east and west coasts. Grid north and true north are only aligned on the central meridian (400 km easting) of the grid which is 2° W (OSGB36) and approx. 2° 0′ 5″ W ( WGS 84 ). A geodetic transformation between OSGB 36 and other terrestrial reference systems (like ITRF2000 , ETRS89 , or WGS 84 ) can become quite tedious if attempted manually. The most common transformation

986-503: The myriad OV, the first "activation" was on 8 September 1977. In 1987 a specially built ladder was fitted to the steepest part of the cliff below the intermediate plateau. From War Dike Gate, on the Cleveland Way at the top of the cliff, the ladder could be reached by scrambling down the upper part of the cliff, aided by ropes. More fixed ropes led from the foot of the ladder to the shore. An 8-metre (26 ft) radio mast, constructed on

1020-568: The origin (0, 0), which lies to the west of the Isles of Scilly . The Ordnance Survey (OS) devised the national grid reference system, and it is heavily used in its survey data, and in maps based on those surveys, whether published by the Ordnance Survey or by commercial map producers. Grid references are also commonly quoted in other publications and data sources, such as guide books and government planning documents. A number of different systems exist that can provide grid references for locations within

1054-440: The second letter, each 500 km square is subdivided into 25 squares of size 100 km by 100 km, each with a letter code from A to Z (again omitting I) starting with A in the north-west corner to Z in the south-east corner. These squares are outlined in light grey on the "100km squares" map, with those containing land lettered. The central (2° W) meridian is shown in red. Within each square, eastings and northings from

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1088-412: The south west corner of the square are given numerically. For example, NH0325 means a 1 km square whose south-west corner is 3 km east and 25 km north from the south-west corner of square NH. A location can be indicated to varying resolutions numerically, usually from two digits in each coordinate (for a 1 km square) through to five (for a 1 m square); in each case the first half of

1122-472: The very foot of the cliff. Worked all Britain is an amateur radio awards group established in 1969 to encourage geographical knowledge and improved radio transmission techniques for amateur radio operators. There are awards for operating a radio station from as many of the OS , Irish and UTM 100-kilometre squares ("large squares") as possible and also, likewise, for 10-kilometre squares. For OV00 , and hence

1156-518: Was wrecked after running aground and the lifeboat from Robin Hood's Bay rescued all nine crew. Later the fishing vessel broke up in heavy seas at the foot of Beast Cliff. At the northern end of Beast Cliff is a place that is unique in terms of the British National Grid system of geographical coordinates. The one-kilometre square OV0000 is the only square containing land in the entire 100 kilometre by 100 kilometre square labelled OV by

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