title: Xherdan Shaqiri

text: Shaqiri made his debut for Switzerland under-21s on 11 November 2009 in a 3–1 win against Turkey in a 2011 UEFA European Under-21 Championship qualifier. He scored his first goal for them on 11 June 2011 in the 2011 UEFA European Under-21 Championship opening game against Denmark.


title: Xherdan Shaqiri

text: Shaqiri was promoted to the Switzerland senior team in 2010, making his debut on 3 March 2010 in a 3–1 friendly loss against Uruguay. He was included in the 2010 World Cup squad, after receiving a surprise call-up from manager Ottmar Hitzfeld. Shaqiri scored his first goal for them on 7 September 2010, a long range left-footed shot, in a 1–3 loss against England in a Euro 2012 qualifier. He netted a hat-trick in another Euro 2012 qualifier on 6 September 2011, as Switzerland came from behind to beat Bulgaria 3–1. Switzerland also tried to select him to participate in the 2012 Olympic Football tournament, but he opted to stay at his new club for pre-season training.


title: Xherdan Shaqiri

text: On 11 September 2012, Shaqiri did not sing the Swiss national anthem in a World Cup qualifier against his ancestral Albania in Lucerne, and did not celebrate when he scored the opening goal of a 2–0 win. He wore boots with the flags of Kosovo, Albania and Switzerland for the match.


title: Xherdan Shaqiri

text: In June 2014, Shaqiri was named in Switzerland's squad for the 2014 FIFA World Cup. In the team's opening match, Shaqiri was named man of the match by FIFA as the "Nati" defeated Ecuador. He earned the same title ten days later in Switzerland's third group match, for scoring a hat-trick against Honduras, which included a bending strike from 30 yards, and ensuring Switzerland a spot in the knockout stage. They were eliminated following a 1–0 loss against Argentina in the last 16.


title: Xherdan Shaqiri

text: Shaqiri scored three times in Switzerland's successful qualification campaign for UEFA Euro 2016, with all of his strikes coming against Lithuania. He recorded a brace on 15 November 2014 in a 4–0 win over them in St. Gallen, and in the reverse fixture the following 14 June, he netted an 84th-minute winner in a 2–1 victory. In the final tournament in France, he started all four of Switzerland's matches as they reached the last 16, equalising with a bicycle kick from the edge of the penalty area as they drew 1–1 with Poland in Saint-Étienne; he scored again in the penalty shootout but the Poles won nonetheless.


title: Xherdan Shaqiri

text: Following Switzerland's first game at Euro 2016, Shaqiri declared he would switch allegiance to Kosovo if their manager would make him captain, in reaction to Switzerland manager Vladimir Petković's decision to omit him from that position. Although already an international for Switzerland, FIFA rules would permit Shaqiri to represent Kosovo, who joined the federation earlier that year. However, since Shaqiri continued to play for Switzerland after Kosovo had become a member of FIFA, it also ruled out the possibility of Shaqiri's eligibility to Kosovo.


title: Xherdan Shaqiri

text: Shaqiri was included in Switzerland's 23-man squad for the 2018 FIFA World Cup, held in Russia. In the group stage, he scored the winning goal as Switzerland came from behind to defeat Serbia 2–1. He and fellow goalscorer Granit Xhaka, who is also of Kosovar descent, celebrated their goals by making an eagle gesture, a symbol of ethnic Albanians. Switzerland captain Stephan Lichtsteiner, who is not of Albanian origin, did the same gesture to celebrate Shaqiri's goal, and defended both players after the match. FIFA fined Xhaka and Shaqiri 10,000 Swiss francs "for unsporting behaviour contrary to the principles of fair-play", while Lichtsteiner paid 5,000 Swiss francs. Additionally, with the goal he equalled Stéphane Chapuisat's tally of 21 in internationals and entered Switzerland's top ten scorers of all time.


title: Xherdan Shaqiri

text: Shaqiri was part of Switzerland's squad at the 2019 UEFA Nations League Finals in Portugal. He was named in the Team of the Tournament.


title: Xherdan Shaqiri

text: Shaqiri was named in the 26-man Swiss squad for the postponed UEFA Euro 2020. On 20 June 2021, he scored twice in the 26th and 68th minutes against Turkey in a group stage match. On 2 July 2021, he scored in the quarter final of the tournament against Spain. The match ended 1–1 and went to a penalty shoot-out, in which Spain progressed to the semi-finals.


title: Xherdan Shaqiri

text: On 15 November 2021, Shaqiri became only the fifth Swiss player to reach 100 caps when he started Switzerland's final 2022 World Cup qualifier against Bulgaria.


title: Xherdan Shaqiri

text: Shaqiri primarily plays as a right winger and FIFA's official website describes him as "unpredictable on the ball, adept with both feet, clinical in front of goal and possessing excellent vision." He was described in "The Daily Telegraph" as "stocky and powerful" with a "wand of a left foot". He is nicknamed "the Alpine Messi" and "the magic dwarf". Also capable of playing as an attacking midfielder, a 2011 scouting profile by Jamie Sanderson of "The Independent" described Shaqiri with the following words: "Diminutive, agile and pacy across the turf, Shaqiri boasts excellent technique and balance. He's left footed, but comfortable and equally effective on either wing or as a classic play-maker, boasting good vision and almost zero back lift in his passing and shooting." He also added that Shaqiri's "tricks," "direct running style," and "composure," made him "a player who's dangerous in almost any attacking area." However, while he acknowledged the young winger's promising talent and potential to become a top player, he also noted that he had a poor work rate and lacked maturity.


title: Xherdan Shaqiri

text: Shaqiri is a Muslim but celebrates Christmas, despite it being a mainly Christian holiday. This is due to his family who celebrated it in his childhood. In 2014, he cited the Christmas tree as the reason for it, saying "So we don't celebrate it so much, but my little sister loves to have a Christmas tree, so we always get one of those." Shaqiri was chosen to be on the cover of the "FIFA" video game "FIFA 15" in Switzerland next to Lionel Messi. Shaqiri is sponsored by sportswear and equipment supplier Nike. He wears Nike Mercurial Vapor boots, and at the 2018 World Cup he had the flags of Switzerland and Kosovo embroidered on each heel.


title: River Thames

text: The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn.


title: River Thames

text: The river rises at Thames Head in Gloucestershire, and flows into the North Sea near Tilbury, Essex and Gravesend, Kent, via the Thames Estuary. From the west it flows through Oxford (where it is sometimes called the Isis), Reading, Henley-on-Thames and Windsor. The Thames also drains the whole of Greater London.


title: River Thames

text: In August 2022, the source of the river moved five miles to beyond Somerford Keynes due to the heatwave in July 2022.


title: River Thames

text: The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock. Its tidal section includes most of its London stretch and has a rise and fall of . From Oxford to the Estuary the Thames drops by 55 metres. Running through some of the drier parts of mainland Britain and heavily abstracted for drinking water, the Thames' discharge is low considering its length and breadth: the Severn has a discharge almost twice as large on average despite having a smaller drainage basin. In Scotland, the Tay achieves more than double the Thames' average discharge from a drainage basin that is 60% smaller.


title: River Thames

text: Along its course are 45 navigation locks with accompanying weirs. Its catchment area covers a large part of south-eastern and a small part of western England; the river is fed by at least 50 named tributaries. The river contains over 80 islands. With its waters varying from freshwater to almost seawater, the Thames supports a variety of wildlife and has a number of adjoining Sites of Special Scientific Interest, with the largest being in the North Kent Marshes and covering .


title: River Thames

text: According to Mallory and Adams, the Thames, from Middle English "Temese", is derived from the Brittonic name for the river, "Tamesas" (from *"tamēssa"), recorded in Latin as "Tamesis" and yielding modern Welsh "Tafwys" "Thames". The name may have meant "dark" and can be compared to other cognates such as Russian темно (Proto-Slavic *"tĭmĭnŭ"), Lithuanian "tamsi" "dark", Latvian "tumsa" "darkness", Sanskrit "tamas" and Welsh "tywyll" "darkness" and Middle Irish "teimen" "dark grey". The origin is shared by many other river names in Britain, such as the River Tamar at the border of Devon and Cornwall, several rivers named Tame in the Midlands and North Yorkshire, the Tavy on Dartmoor, the Team of the North East, the Teifi and Teme of Wales, the Teviot in the Scottish Borders and a Thames tributary the Thame.


title: River Thames

text: Kenneth H. Jackson proposed that the name of the Thames is not Indo-European (and of unknown meaning), while Peter Kitson suggested that it is Indo-European but originated before the Britons and has a name indicating "muddiness" from a root "*tā-", 'melt'.


title: River Thames

text: Indirect evidence for the antiquity of the name 'Thames' is provided by a Roman potsherd found at Oxford, bearing the inscription "Tamesubugus fecit" (Tamesubugus made [this]). It is believed that Tamesubugus' name was derived from that of the river. Tamese was referred to as a place, not a river in the Ravenna Cosmography (c. AD 700).


title: River Thames

text: The river's name has always been pronounced with a simple "t" /t/; the Middle English spelling was typically "Temese" and the Brittonic form "Tamesis". A similar spelling from 1210, "Tamisiam" (the accusative case of "Tamisia", see Kingston upon Thames#Early history), is found in the Magna Carta.


title: River Thames

text: The Thames through Oxford is sometimes called the Isis. Historically, and especially in Victorian times, gazetteers and cartographers insisted that the entire river was correctly named the Isis from its source down to Dorchester on Thames and that only from this point, where the river meets the Thame and becomes the "Thame-isis" (supposedly subsequently abbreviated to Thames) should it be so called. Ordnance Survey maps still label the Thames as "River Thames or Isis" down to Dorchester. Since the early 20th century this distinction has been lost in common usage outside of Oxford, and some historians suggest the name "Isis" is nothing more than a truncation of "Tamesis", the Latin name for the Thames. Sculptures titled "Tamesis" and "Isis" by Anne Seymour Damer can be found on the bridge at Henley-on-Thames, Oxfordshire (the original terracotta and plaster models were exhibited at the Royal Academy, London, in 1785. They are now on show at the River and Rowing Museum in Henley).


title: River Thames

text: Richard Coates suggests that while the river was as a whole called the Thames, part of it, where it was too wide to ford, was called *"(p)lowonida". This gave the name to a settlement on its banks, which became known as Londinium, from the Indo-European roots *"pleu-" "flow" and *"-nedi" "river" meaning something like the flowing river or the wide flowing unfordable river.


title: River Thames

text: The river gives its name to three informal areas: the Thames Valley, a region of England around the river between Oxford and West London; the Thames Gateway; and the greatly overlapping Thames Estuary around the tidal Thames to the east of London and including the waterway itself. Thames Valley Police is a formal body that takes its name from the river, covering three counties. In non-administrative use, the river's name is used in those of Thames Valley University, Thames Water, Thames Television, publishing company Thames & Hudson, Thameslink (north–south rail service passing through central London) and South Thames College. An example of its use in the names of historic entities is the Thames Ironworks and Shipbuilding Company.


title: River Thames

text: The administrative powers of the Thames Conservancy to control river traffic and manage flows have been taken on with some modifications by the Environment Agency and, in respect of the Tideway part of the river, such powers are split between the agency and the Port of London Authority.


title: River Thames

text: The marks of human activity, in some cases dating back to Pre-Roman Britain, are visible at various points along the river. These include a variety of structures connected with use of the river, such as navigations, bridges and watermills, as well as prehistoric burial mounds.


title: River Thames

text: The lower Thames in the Roman era was a shallow waterway winding through marshes. But centuries of human intervention have transformed it into a deep tidal canal flowing between 200 miles of solid walls; these defend a floodplain where 1.5 million people work and live.


title: River Thames

text: A major maritime route is formed for much of its length for shipping and supplies: through the Port of London for international trade, internally along its length and by its connection to the British canal system. The river's position has put it at the centre of many events in British history, leading to it being described by John Burns as "liquid history".


title: River Thames

text: Two broad canals link the river to other river basins: the Kennet and Avon Canal (Reading to Bath) and the Grand Union Canal (London to the Midlands). The Grand Union effectively bypassed the earlier, narrow and winding Oxford Canal which also remains open as a popular scenic recreational route. Three further cross-basin canals are disused but are in various stages of reconstruction: the Thames and Severn Canal (via Stroud), which operated until 1927 (to the west coast of England), the Wey and Arun Canal to Littlehampton, which operated until 1871 (to the south coast), and the Wilts and Berks Canal.


title: River Thames

text: Rowing and sailing clubs are common along the Thames, which is navigable to such vessels. Kayaking and canoeing also take place. Major annual events include the Henley Royal Regatta and the Boat Race, while the Thames has been used during two Summer Olympic Games: 1908 (rowing) and 1948 (rowing and canoeing). Safe headwaters and reaches are a summer venue for organised swimming, which is prohibited on safety grounds in a stretch centred on Central London.


title: River Thames

text: The usually quoted source of the Thames is at Thames Head (at ). This is about north of Kemble parish church in southern Gloucestershire, near the town of Cirencester, in the Cotswolds.


title: River Thames

text: However, Seven Springs near Cheltenham, where the Churn (which feeds into the Thames near Cricklade) rises, is also sometimes quoted as the Thames' source, as this location is farthest from the mouth, and adds some to the river's length. At Seven Springs above the source is a stone with the Latin hexameter inscription "Hic tuus o Tamesine pater septemgeminus fons", which means "Here, O Father Thames, [is] your sevenfold source".


title: River Thames

text: The springs at Seven Springs flow throughout the year, while those at Thames Head are only seasonal (a winterbourne). With a length of , the Thames is the longest river entirely in England. (The longest river in the United Kingdom, the Severn, flows partly in Wales.) However, as the River Churn, sourced at Seven Springs, is longer than the section of the Thames from its traditional source at Thames Head to the confluence, the overall length of the Thames measured from Seven Springs, at , is greater than the Severn's length of . Thus, the "Churn/Thames" river may be regarded as the longest natural river in the United Kingdom.


title: River Thames

text: The stream from Seven Springs is joined at Coberley by a longer tributary which could further increase the length of the Thames, with its source in the grounds of the National Star College at Ullenwood.


title: River Thames

text: The Thames flows through or alongside Ashton Keynes, Cricklade, Lechlade, Oxford, Abingdon-on-Thames, Wallingford, Goring-on-Thames and Streatley, Pangbourne and Whitchurch-on-Thames, Reading, Wargrave, Henley-on-Thames, Marlow, Maidenhead, Windsor and Eton, Staines-upon-Thames and Egham, Chertsey, Shepperton, Weybridge, Sunbury-on-Thames, Walton-on-Thames, Molesey and Thames Ditton. The river was subject to minor redefining and widening of the main channel around Oxford, Abingdon and Marlow before 1850, since when further cuts to ease navigation have reduced distances further.


title: River Thames

text: Molesey faces Hampton, and in Greater London the Thames passes Hampton Court Palace, Surbiton, Kingston upon Thames, Teddington, Twickenham, Richmond (with a famous view of the Thames from Richmond Hill), Syon House, Kew, Brentford, Chiswick, Barnes, Hammersmith, Fulham, Putney, Wandsworth, Battersea and Chelsea. In central London, the river passes Pimlico and Vauxhall, and then forms one of the principal axes of the city, from the Palace of Westminster to the Tower of London. At this point, it historically formed the southern boundary of the medieval city, with Southwark, on the opposite bank, then being part of Surrey.


title: River Thames

text: Beyond central London, the river passes Bermondsey, Wapping, Shadwell, Limehouse, Rotherhithe, Millwall, Deptford, Greenwich, Cubitt Town, Blackwall, New Charlton and Silvertown, before flowing through the Thames Barrier, which protects central London from flooding by storm surges. Below the barrier, the river passes Woolwich, Thamesmead, Dagenham, Erith, Purfleet, Dartford, West Thurrock, Northfleet, Tilbury and Gravesend before entering the Thames Estuary near Southend-on-Sea.


title: River Thames

text: Sediment cores up to 10 m deep collected by the British Geological Survey from the banks of the tidal River Thames contain geochemical information and fossils which provide a 10,000-year record of sea-level change.<ref name=" The application of δ13C, TOC, C/N geochemistry to reconstruct Holocene relative sea levels and paleoenvironments in the Thames Estuary, UK."></ref> Combined, this and other studies suggest that the Thames sea-level has risen more than 30 m during the Holocene at a rate of around 5–6 mm per year from 10,000 to 6,000 years ago. The rise of sea level dramatically reduced when the ice melt nearly concluded over the past 4,000 years. Since the beginning of the 20th century, rates of sea level rise range from 1.22 mm per year to 2.14 mm per year.


title: River Thames

text: The Thames River Basin District, including the Medway catchment, covers an area of . The river basin is a mixture of urban through to rural in the east and northern parts while the western parts of the catchment are predominantly rural with many towns to a suburban layout such as, archetypically Swindon. The area is among the driest in the United Kingdom. Water resources consist of groundwater from aquifers and water taken from the Thames and its tributaries, much of it stored in large bank-side reservoirs.


title: River Thames

text: The Thames itself provides two-thirds of London's drinking water while groundwater supplies about 40 percent of public water supplies in the total catchment area. Groundwater is an important water source, especially in the drier months, so maintaining its quality and quantity is extremely important. Groundwater is vulnerable to surface pollution, especially in highly urbanised areas.


title: River Thames

text: Brooks, canals and rivers, within an area of , combine to form 38 main tributaries feeding the Thames between its source and Teddington Lock. This is the usual tidal limit; however, high spring tides can raise the head water level in the reach above Teddington and can occasionally reverse the river flow for a short time. In these circumstances, tidal effects can be observed upstream to the next lock beside Molesey weir, which is visible from the towpath and bridge beside Hampton Court Palace. Before Teddington Lock was built in 1810–12, the river was tidal at peak spring tides as far as Staines upon Thames.


title: River Thames

text: In descending order, non-related tributaries of the non-tidal Thames, with river status, are the Churn, Leach, Cole, Ray, Coln, Windrush, Evenlode, Cherwell, Ock, Thame, Pang, Kennet, Loddon, Colne, Wey and Mole. In addition, there are occasional backwaters and artificial cuts that form islands, distributaries (most numerous in the case of the Colne), and man-made distributaries such as the Longford River. Three canals intersect this stretch: the Oxford Canal, Kennet and Avon Canal and Wey Navigation.


title: River Thames

text: Its longest artificial secondary channel (cut), the Jubilee River, was built between Maidenhead and Windsor for flood relief and completed in 2002.


title: River Thames

text: The non-tidal section of the river is managed by the Environment Agency, which is responsible for managing the flow of water to help prevent and mitigate flooding, and providing for navigation: the volume and speed of water downstream is managed by adjusting the sluices at each of the weirs and, at peak high water, levels are generally dissipated over preferred flood plains adjacent to the river. Occasionally, flooding of inhabited areas is unavoidable and the agency issues flood warnings. Due to stiff penalties applicable on the non-tidal river, which is a drinking water source before treatment, sanitary sewer overflow from the many sewage treatment plants covering the upper Thames basin should be rare in the non-tidal Thames. However, storm sewage overflows are still common in almost all the main tributaries of the Thames despite claims by Thames Water to the contrary.


title: River Thames

text: Below Teddington Lock (about upstream of the Thames Estuary), the river is subject to tidal activity from the North Sea. Before the lock was installed, the river was tidal as far as Staines, about upstream. London, capital of Roman Britain, was established on two hills, now known as Cornhill and Ludgate Hill. These provided a firm base for a trading centre at the lowest possible point on the Thames.


title: River Thames

text: A river crossing was built at the site of London Bridge. London Bridge is now used as the basis for published tide tables giving the times of high tide. High tide reaches Putney about 30 minutes later than London Bridge, and Teddington about an hour later. The tidal stretch of the river is known as "the Tideway". Tide tables are published by the Port of London Authority and are available online. Times of high and low tides are also posted on Twitter.


title: River Thames

text: The principal tributaries of the River Thames on the Tideway include the rivers Crane, Brent, Wandle, Ravensbourne (the final part of which is called Deptford Creek), Lea (the final part of which is called Bow Creek), Roding, Darent and Ingrebourne. At London, the water is slightly brackish with sea salt, being a mix of sea and fresh water.


title: River Thames

text: This part of the river is managed by the Port of London Authority. The flood threat here comes from high tides and strong winds from the North Sea, and the Thames Barrier was built in the 1980s to protect London from this risk.


title: River Thames

text: The Nore is the sandbank that marks the mouth of the Thames Estuary, where the outflow from the Thames meets the North Sea. It is roughly halfway between Havengore Creek in Essex and Warden Point on the Isle of Sheppey in Kent. Until 1964 it marked the seaward limit of the Port of London Authority. As the sandbank was a major hazard for shipping coming in and out of London, in 1732 it received the world's first lightship. This became a major landmark, and was used as an assembly point for shipping. Today it is marked by Sea Reach No. 1 Buoy.


title: River Thames

text: The River Thames contains over 80 islands ranging from the large estuarial marshlands of the Isle of Sheppey and Canvey Island to small tree-covered islets like Rose Isle in Oxfordshire and Headpile Eyot in Berkshire. They are found all the way from the Isle of Sheppey in Kent to Fiddler's Island in Oxfordshire. Some of the largest inland islands, for example Formosa Island near Cookham and Andersey Island at Abingdon, were created naturally when the course of the river divided into separate streams.


title: River Thames

text: In the Oxford area the river splits into several streams across the floodplain (Seacourt Stream, Castle Mill Stream, Bulstake Stream and others), creating several islands (Fiddler's Island, Osney and others). Desborough Island, Ham Island at Old Windsor and Penton Hook Island were artificially created by lock cuts and navigation channels. Chiswick Eyot is a landmark on the Boat Race course, while Glover's Island forms the centre of a view from Richmond Hill.


title: River Thames

text: Islands of historical interest include Magna Carta Island at Runnymede, Fry's Island at Reading, and Pharaoh's Island near Shepperton. In more recent times Platts Eyot at Hampton was the place where Motor Torpedo Boats (MTB)s were built, Tagg's Island near Molesey was associated with the impresario Fred Karno and Eel Pie Island at Twickenham was the birthplace of the South East's R&B music scene.


title: River Thames

text: Westminster Abbey and the Palace of Westminster (commonly known today as the Houses of Parliament) were built on Thorney Island, which used to be an eyot.


title: River Thames

text: Researchers have identified the River Thames as a discrete drainage line flowing as early as 58 million years ago, in the Thanetian stage of the late Palaeocene epoch. Until around 500,000 years ago, the Thames flowed on its existing course through what is now Oxfordshire, before turning to the north-east through Hertfordshire and East Anglia and reaching the North Sea near present-day Ipswich.


title: River Thames

text: At this time the river-system headwaters lay in the English West Midlands and may, at times, have received drainage from the Berwyn Mountains in North Wales.


title: River Thames

text: About 450,000 years ago, in the most extreme Ice Age of the Pleistocene, the Anglian, the furthest southern extent of the ice sheet reached Hornchurch in east London, the Vale of St Albans, and the Finchley Gap.


title: River Thames

text: It dammed the river in Hertfordshire, resulting in the formation of large ice lakes, which eventually burst their banks and caused the river to divert onto its present course through the area of present-day London.


title: River Thames

text: The ice lobe which stopped at present-day Finchley deposited about 14 metres of boulder clay there. Its torrent of meltwater gushed through the Finchley Gap and south towards the new course of the Thames, and proceeded to carve out the Brent Valley in the process.


title: River Thames

text: The Anglian ice advance resulted in a new course for the Thames through Berkshire and on into London, after which the river rejoined its original course in southern Essex, near the present River Blackwater estuary. Here it entered a substantial freshwater lake in the southern North Sea basin, south of what is called Doggerland. The overspill of this lake caused the formation of the Channel River and later the Dover Strait gap between present-day Britain and France. Subsequent development led to the continuation of the course that the river follows at the present day.


title: River Thames

text: Most of the bedrock of the Vale of Aylesbury comprises clay and chalk that formed at the end of the ice age and at one time was under the Proto-Thames. At this time the vast underground reserves of water formed that make the water table higher than average in the Vale of Aylesbury.


title: River Thames

text: At the height of the last ice age, around 20,000 BC, Britain was connected to mainland Europe by a large expanse of land known as Doggerland in the southern North Sea Basin. At this time, the Thames' course did not continue to Doggerland but flowed southwards from the eastern Essex coast where it met the waters of the proto-Rhine–Meuse–Scheldt delta flowing from what are now the Netherlands and Belgium. These rivers formed a single river – the Channel River ("Fleuve Manche") – that passed through the Dover Strait and drained into the Atlantic Ocean in the western English Channel.


title: River Thames

text: Upon the valley sides of the Thames and some of its tributaries can be seen other terraces of brickearth, laid over and sometimes interlayered with the clays. These deposits were brought in by the winds during the periglacial periods, suggesting that wide, flat marshes were then part of the landscape, which the new rivers proceeded to cut into.


title: River Thames

text: The steepness of some valley sides indicates very much lower mean sea levels caused by the glaciation locking up so much water upon the land masses, thus causing the river water to flow rapidly seaward and so erode its bed quickly downwards.


title: River Thames

text: The original land surface was around above the current sea-level. The surface had sandy deposits from an ancient sea, laid over sedimentary clay (this is the blue London Clay). All the erosion down from this higher land surface, and the sorting action by these changes of water flow and direction, formed what is known as the Thames River Gravel Terraces.


title: River Thames

text: Since Roman times and perhaps earlier, the isostatic rebound from the weight of previous ice sheets, and its interplay with the eustatic change in sea level, have resulted in the old valley of the River Brent, together with that of the Thames, silting up again. Thus, along much of the Brent's present-day course, one can make out the water-meadows of rich alluvium, which is augmented by frequent floods.


title: River Thames

text: After the river took its present-day course, many of the banks of the Thames Estuary and the Thames Valley in London were partly covered in marshland, as was the adjoining Lower Lea Valley. Streams and rivers like the River Lea, Tyburn Brook and Bollo Brook drained into the river, while some islands, e.g. Thorney Island, formed over the ages. The northern tip of the ancient parish of Lambeth, for example, was marshland known as "Lambeth Marshe", but it was drained in the 18th century; the street name Lower Marsh preserves a memory.


title: River Thames

text: The East End of London, also known simply as the East End, was the area of London east of the medieval walled City of London and north of the River Thames, although it is not defined by universally accepted formal boundaries; the River Lea can be considered another boundary. Most of the local riverside was also marshland. The land was drained and became farmland; it was built on after the Industrial Revolution.


title: River Thames

text: Canvey Island in southern Essex (area ; population 40,000) was once marshy, but is now a fully reclaimed island in the Thames estuary, separated from the mainland of south Essex by a network of creeks. Lying below sea level, it is prone to flooding at exceptional tides, but has nevertheless been inhabited since Roman times.


title: River Thames

text: Various species of birds feed off the river or nest on it, some being found both at sea and inland. These include cormorant, black-headed gull and herring gull. The mute swan is a familiar sight on the river but the escaped black swan is more rare. The annual ceremony of Swan Upping is an old tradition of counting stocks.


title: River Thames

text: Non-native geese that can be seen include Canada geese, Egyptian geese and bar-headed geese, and ducks include the familiar native mallard, plus introduced Mandarin duck and wood duck. Other water birds to be found on the Thames include the great crested grebe, coot, moorhen, heron and kingfisher. Many types of British birds also live alongside the river, although they are not specific to the river habitat.


title: River Thames

text: The Thames contains both sea water and fresh water, thus providing support for seawater and freshwater fish. However, many populations of fish are at risk and are being killed in tens of thousands because of pollutants leaking into the river from human activities. Salmon, which inhabit both environments, have been reintroduced and a succession of fish ladders have been built into weirs to enable them to travel upstream.


title: River Thames

text: On 5 August 1993, the largest non-tidal salmon in recorded history was caught close to Boulters Lock in Maidenhead. The specimen weighed and measured in length. The eel is particularly associated with the Thames and there were formerly many eel traps. Freshwater fish of the Thames and its tributaries include brown trout, chub, dace, roach, barbel, perch, pike, bleak and flounder. Colonies of short-snouted seahorses as well as tope and starry smooth-hound sharks have also recently been discovered in the river. The Thames is also host to some invasive crustaceans, including the signal crayfish and the Chinese mitten crab.


title: River Thames

text: Aquatic mammals are also known to inhabit the Thames. The population of grey and harbour seals numbers up to 700 in the Thames Estuary. These animals have been sighted as far upriver as Richmond. Bottlenose dolphins and harbour porpoises are also sighted in the Thames.


title: River Thames

text: On 20 January 2006, a northern bottle-nosed whale was seen in the Thames as far upstream as Chelsea. This was extremely unusual: this whale is generally found in deep sea waters. Crowds gathered along the riverbanks to witness the spectacle but there was soon concern, as the animal came within yards of the banks, almost beaching, and crashed into an empty boat causing slight bleeding. About 12 hours later, the whale is believed to have been seen again near Greenwich, possibly heading back to sea. A rescue attempt lasted several hours, but the whale died on a barge. "See River Thames whale".


title: River Thames

text: The River Thames has played several roles in human history: as an economic resource, a maritime route, a boundary, a fresh water source, a source of food and more recently a leisure facility. In 1929, John Burns, one-time MP for Battersea, responded to an American's unfavourable comparison of the Thames with the Mississippi by coining the expression "The Thames is liquid history".


title: River Thames

text: There is evidence of human habitation living off the river along its length dating back to Neolithic times. The British Museum has a decorated bowl (3300–2700 BC), found in the river at Hedsor, Buckinghamshire, and a considerable amount of material was discovered during the excavations of Dorney Lake. A number of Bronze Age sites and artefacts have been discovered along the banks of the river including settlements at Lechlade, Cookham and Sunbury-on-Thames.


title: River Thames

text: So extensive have the changes to this landscape been that what little evidence there is of man's presence before the ice came has inevitably shown signs of transportation here by water and reveals nothing specifically local. Likewise, later evidence of occupation, even since the arrival of the Romans, may lie next to the original banks of the Brent but have been buried under centuries of silt.


title: River Thames

text: Some of the earliest written references to the Thames () occur in Julius Caesar's account of his second expedition to Britain in 54 BC, when the Thames presented a major obstacle and he encountered the Iron Age Belgic tribes the Catuvellauni and the Atrebates along the river. The confluence of the Thames and Cherwell was the site of early settlements and the River Cherwell marked the boundary between the Dobunni tribe to the west and the Catuvellauni tribe to the east (these were pre-Roman Celtic tribes). In the late 1980s a large Romano-British settlement was excavated on the edge of the village of Ashton Keynes in Wiltshire.


title: River Thames

text: Starting in AD 43, under the Emperor Claudius, the Romans occupied England and, recognising the river's strategic and economic importance, built fortifications along the Thames valley including a major camp at Dorchester. Cornhill and Ludgate Hill provided a defensible site near a point on the river both deep enough for the era's ships and narrow enough to be bridged; Londinium (London) grew up around the Walbrook on the north bank around the year 47. Boudica's Iceni razed the settlement in AD 60 or 61 but it was soon rebuilt and, following the completion of its bridge, it grew to become the provincial capital of the island.


title: River Thames

text: The next Roman bridges upstream were at Staines on the Devil's Highway between Londinium and Calleva (Silchester). Boats could be swept up to it on the rising tide with no need for wind or muscle power.


title: River Thames

text: A Romano-British settlement grew up north of the confluence, partly because the site was naturally protected from attack on the east side by the River Cherwell and on the west by the River Thames. This settlement dominated the pottery trade in what is now central southern England, and pottery was distributed by boats on the Thames and its tributaries.


title: River Thames

text: Competition for the use of the river created the centuries-old conflict between those who wanted to dam the river to build millraces and fish traps and those who wanted to travel and carry goods on it. Economic prosperity and the foundation of wealthy monasteries by the Anglo-Saxons attracted unwelcome visitors and by around AD 870 the Vikings were sweeping up the Thames on the tide and creating havoc as in their destruction of Chertsey Abbey.


title: River Thames

text: Once King William had won total control of the strategically important Thames Valley, he went on to invade the rest of England. He had many castles built, including those at Wallingford, Rochester, Windsor and most importantly the Tower of London. Many details of Thames activity are recorded in the Domesday Book. The following centuries saw the conflict between king and barons coming to a head in AD 1215 when King John was forced to sign the Magna Carta on an island in the Thames at Runnymede. Among a host of other things, this granted the barons the right of Navigation under Clause 23.


title: River Thames

text: Another major consequence of John's reign was the completion of the multi-piered London Bridge, which acted as a barricade and barrage on the river, affecting the tidal flow upstream and increasing the likelihood of the river freezing over. In Tudor and Stuart times, various kings and queens built magnificent riverside palaces at Hampton Court, Kew, Richmond on Thames, Whitehall and Greenwich.


title: River Thames

text: As early as the 1300s, the Thames was used to dispose of waste matter produced in the city of London, thus turning the river into an open sewer. In 1357, Edward III described the state of the river in a proclamation: "... dung and other filth had accumulated in divers places upon the banks of the river with ... fumes and other abominable stenches arising therefrom."


title: River Thames

text: The growth of the population of London greatly increased the amount of waste that entered the river, including human excrement, animal waste from slaughter houses, and waste from manufacturing processes. According to historian Peter Ackroyd, "a public lavatory on London Bridge showered its contents directly onto the river below, and latrines were built over all the tributaries that issued into the Thames."


title: River Thames

text: During a series of cold winters the Thames froze over above London Bridge: in the first Frost Fair in 1607, a tent city was set up on the river, along with a number of amusements, including ice bowling.


title: River Thames

text: In good conditions, barges travelled daily from Oxford to London carrying timber, wool, foodstuffs and livestock. The stone from the Cotswolds used to rebuild St Paul's Cathedral after the Great Fire in 1666 was brought all the way down from Radcot. The Thames provided the major route between the City of London and Westminster in the 16th and 17th centuries; the clannish guild of watermen ferried Londoners from landing to landing and tolerated no outside interference. In 1715, Thomas Doggett was so grateful to a local waterman for his efforts in ferrying him home, pulling against the tide, that he set up a rowing race for professional watermen known as "Doggett's Coat and Badge".


title: River Thames

text: By the 18th century, the Thames was one of the world's busiest waterways, as London became the centre of the vast, mercantile British Empire, and progressively over the next century the docks expanded in the Isle of Dogs and beyond. Efforts were made to resolve the navigation conflicts upstream by building locks along the Thames. After temperatures began to rise again, starting in 1814, the river stopped freezing over. The building of a new London Bridge in 1825, with fewer piers (pillars) than the old, allowed the river to flow more freely and prevented it from freezing over in cold winters.


title: River Thames

text: Throughout early modern history the population of London and its industries discarded their rubbish in the river. This included the waste from slaughterhouses, fish markets, and tanneries. The buildup in household cesspools could sometimes overflow, especially when it rained, and was washed into London's streets and sewers which eventually led to the Thames. In the late 18th and 19th centuries people known as mudlarks scavenged in the river mud for a meagre living.


title: River Thames

text: In the 19th century the quality of water in Thames deteriorated further. The discharge of raw sewage into the Thames was formerly only common in the City of London, making its tideway a harbour for many harmful bacteria. Gasworks were built alongside the river, and their by-products leaked into the water, including spent lime, ammonia, cyanide, and carbolic acid. The river had an unnaturally warm temperature caused by chemical reactions in the water, which also removed the water's oxygen. Four serious cholera outbreaks killed tens of thousands of people between 1832 and 1865. Historians have attributed Prince Albert's death in 1861 to typhoid that had spread in the river's dirty waters beside Windsor Castle. Wells with water tables that mixed with tributaries (or the non-tidal Thames) faced such pollution with the widespread installation of the flush toilet in the 1850s. In the 'Great Stink' of 1858, pollution in the river reached such an extreme that sittings of the House of Commons at Westminster had to be abandoned. Chlorine-soaked drapes were hung in the windows of Parliament in an attempt to stave off the smell of the river, but to no avail.


title: River Thames

text: A concerted effort to contain the city's sewage by constructing massive sewer systems on the north and south river embankments followed, under the supervision of engineer Joseph Bazalgette. Meanwhile, similar huge undertakings took place to ensure the water supply, with the building of reservoirs and pumping stations on the river to the west of London, slowly helping the quality of water to improve.


title: River Thames

text: The Victorian era was one of imaginative engineering. The coming of the railways added railway bridges to the earlier road bridges and also reduced commercial activity on the river. However, sporting and leisure use increased with the establishment of regattas such as Henley and the Boat Race. On 3 September 1878, one of the worst river disasters in England took place, when the crowded pleasure boat collided with the "Bywell Castle", killing over 640 people.


title: River Thames

text: The growth of road transport, and the decline of the Empire in the years following 1914, reduced the economic prominence of the river. During the Second World War, the protection of certain Thames-side facilities, particularly docks and water treatment plants, was crucial to the munitions and water supply of the country. The river's defences included the Maunsell forts in the estuary, and the use of barrage balloons to counter German bombers using the reflectivity and shapes of the river to navigate during the Blitz.


title: River Thames

text: In the post-war era, although the Port of London remains one of the UK's three main ports, most trade has moved downstream from central London. In the late 1950s, the discharge of methane gas in the depths of the river caused the water to bubble, and the toxins wore away at boats' propellers.


title: River Thames

text: The decline of heavy industry and tanneries, reduced use of oil-pollutants and improved sewage treatment have led to much better water quality compared to the late 19th and early- to mid-20th centuries and aquatic life has returned to its formerly 'dead' stretches.


title: River Thames

text: In the early 1980s a pioneering flood control device, the Thames Barrier, was opened. It is closed to tides several times a year to prevent water damage to London's low-lying areas upstream (the 1928 Thames flood demonstrated the severity of this type of event).


title: River Thames

text: In the late 1990s, the long Jubilee River was built as a wide "naturalistic" flood relief channel from Taplow to Eton to help reduce the flood risk in Maidenhead, Windsor and Eton, although it appears to have increased flooding in the villages immediately downstream.


title: River Thames

text: In 2010, the Thames won the largest environmental award in the world – the $350,000 International Riverprize. In August 2022, the source of the river moved five miles and is located beyond Somerford Keynes due to the heatwave in July 2022.


title: River Thames

text: One of the major resources provided by the Thames is the water distributed as drinking water by Thames Water, whose area of responsibility covers the length of the River Thames. The Thames Water Ring Main is the main distribution mechanism for water in London, with one major loop linking the Hampton, Walton, Ashford and Kempton Park Water Treatment Works with central London.


title: River Thames

text: In the past, commercial activities on the Thames included fishing (particularly eel trapping), coppicing willows and osiers which provided wood, and the operation of watermills for flour and paper production and metal beating. These activities have largely disappeared.


title: River Thames

text: The Thames is popular for a wide variety of riverside housing, including high-rise flats in central London and chalets on the banks and islands upstream. Some people live in houseboats, typically around Brentford and Tagg's Island.


title: River Thames

text: In London there are many sightseeing tours in tourist boats, past the more famous riverside attractions such as the Houses of Parliament and the Tower of London as well as regular riverboat services co-ordinated by London River Services. London city Airport is situated on the Thames, in East London. Previously it was a dock.


title: River Thames

text: In summer, passenger services operate along the entire non-tidal river from Oxford to Teddington. The two largest operators are Salters Steamers and French Brothers. Salters operate services between Folly Bridge, Oxford and Staines. The whole journey takes four days and requires several changes of boat. French Brothers operate passenger services between Maidenhead and Hampton Court.


title: River Thames

text: Along the course of the river a number of smaller private companies also offer river trips at Oxford, Wallingford, Reading and Hampton Court. Many companies also provide boat hire on the river.


title: River Thames

text: The leisure navigation and sporting activities on the river have given rise to a number of businesses including boatbuilding, marinas, ships chandlers and salvage services.


title: River Thames

text: The London Cable Car over the Thames from the Greenwich Peninsula to the Royal Docks has been in operation since the 2012 Summer Olympics.


title: River Thames

text: The river is policed by five police forces. The Thames Division is the River Police arm of London's Metropolitan Police, while Surrey Police, Thames Valley Police, Essex Police and Kent Police have responsibilities on their parts of the river outside the metropolitan area. There is also a London Fire Brigade fire boat on the river. The river claims a number of lives each year.


title: River Thames

text: As a result of the Marchioness disaster in 1989 when 51 people died, the Government asked the Maritime and Coastguard Agency, the Port of London Authority and the Royal National Lifeboat Institution (RNLI) to work together to set up a dedicated Search and Rescue service for the tidal River Thames. As a result, there are four lifeboat stations on the River Thames: at Teddington, Chiswick, Tower (based at Victoria Embankment/Waterloo Bridge) and Gravesend.


title: River Thames

text: The Thames is maintained for navigation by powered craft from the estuary as far as Lechlade in Gloucestershire and for very small craft to Cricklade. The original towpath extends upstream from Putney Bridge as far as the connection with the now disused Thames and Severn Canal at Inglesham, one and a half miles upstream of the last boat lock near Lechlade. From Teddington Lock to the head of navigation, the navigation authority is the Environment Agency. Between the sea and Teddington Lock, the river forms part of the Port of London and navigation is administered by the Port of London Authority. Both the tidal river through London and the non-tidal river upstream are intensively used for leisure navigation.


title: River Thames

text: The non-tidal River Thames is divided into reaches by the 45 locks. The locks are staffed for the greater part of the day, but can be operated by experienced users out of hours. This part of the Thames links to existing navigations at the River Wey Navigation, the River Kennet and the Oxford Canal. All craft using it must be licensed. The Environment Agency has patrol boats (named after tributaries of the Thames) and can enforce the limit strictly since river traffic usually has to pass through a lock at some stage. A speed limit of applies. There are pairs of transit markers at various points along the non-tidal river that can be used to check speed – a boat travelling legally taking a minute or more to pass between the two markers.


title: River Thames

text: The tidal river is navigable to large ocean-going ships as far upstream as the Pool of London and London Bridge. Although London's upstream enclosed docks have closed and central London sees only the occasional visiting cruise ship or warship, the tidal river remains one of Britain's main ports. Around 60 active terminals cater for shipping of all types including ro-ro ferries, cruise liners and vessels carrying containers, vehicles, timber, grain, paper, crude oil, petroleum products, liquified petroleum gas etc. There is a regular traffic of aggregate or refuse vessels, operating from wharves in the west of London. The tidal Thames links to the canal network at the River Lea Navigation, the Regent's Canal at Limehouse Basin and the Grand Union Canal at Brentford.


title: River Thames

text: Upstream of Wandsworth Bridge a speed limit of is in force for powered craft to protect the riverbank environment and to provide safe conditions for rowers and other river users. There is no absolute speed limit on most of the Tideway downstream of Wandsworth Bridge, although boats are not allowed to create undue wash. Powered boats are limited to 12 knots between Lambeth Bridge and downstream of Tower Bridge, with some exceptions. Boats can be approved by the harbour master to travel at speeds of up to 30 knots from below Tower Bridge to past the Thames Barrier.


title: River Thames

text: In the Middle Ages the Crown exercised general jurisdiction over the Thames, one of the four royal rivers, and appointed water bailiffs to oversee the river upstream of Staines. The City of London exercised jurisdiction over the tidal Thames. However, navigation was increasingly impeded by weirs and mills, and in the 14th century the river probably ceased to be navigable for heavy traffic between Henley and Oxford. In the late 16th century the river seems to have been reopened for navigation from Henley to Burcot.


title: River Thames

text: The first commission concerned with the management of the river was the Oxford-Burcot Commission, formed in 1605 to make the river navigable between Burcot and Oxford.


title: River Thames

text: In 1751 the Thames Navigation Commission was formed to manage the whole non-tidal river above Staines. The City of London long claimed responsibility for the tidal river. A long running dispute between the City and the Crown over ownership of the river was not settled until 1857, when the Thames Conservancy was formed to manage the river from Staines downstream. In 1866 the functions of the Thames Navigation Commission were transferred to the Thames Conservancy, which thus had responsibility for the whole river.


title: River Thames

text: In 1909 the powers of the Thames Conservancy over the tidal river, below Teddington, were transferred to the Port of London Authority.


title: River Thames

text: In 1974 the Thames Conservancy became part of the new Thames Water Authority. When Thames Water was privatised in 1990, its river management functions were transferred to the National Rivers Authority, in 1996 subsumed into the Environment Agency.


title: River Thames

text: In 2010, the Thames won the world's largest environmental award at the time, the $350,000 International Riverprize, presented at the International Riversymposium in Perth, WA in recognition of the substantial and sustained restoration of the river by many hundreds of organisations and individuals since the 1950s.


title: River Thames

text: Until enough crossings were established, the river presented a formidable barrier, with Belgic tribes and Anglo-Saxon kingdoms being defined by which side of the river they were on. When English counties were established their boundaries were partly determined by the Thames. On the northern bank were the ancient counties of Gloucestershire, Oxfordshire, Buckinghamshire, Middlesex and Essex. On the southern bank were the counties of Wiltshire, Berkshire, Surrey and Kent.


title: River Thames

text: Counting bridges to the far bank or to an island connected to such, the Thames has 223. From source to mouth a channel can be found with 138 bridges, plus the temporary footbridge often added during Reading Festival. The river is heavily splayed in Ashton Keynes and Oxford. Where the river is wide 17 tunnels that have been built, many of which for rail or notable electricity cables. The crossings have changed the dynamics and made cross-river development and shared responsibilities more practicable. In 1965, upon the creation of Greater London, the London Borough of Richmond upon Thames incorporated the former 'Middlesex and Surrey' banks, Spelthorne moved from Middlesex to Surrey; and further changes in 1974 moved some of the boundaries away from the river. For example, some areas were transferred from Berkshire to Oxfordshire, and from Buckinghamshire to Berkshire. In many river sports and traditions – for example in rowing – the banks are referred to by their traditional county names.


title: River Thames

text: Many of the present-day road bridges are on the site of earlier fords, ferries and wooden bridges. Swinford Bridge, known as the five pence toll bridge, replaced a ferry that in turn replaced a ford. The earliest known major crossings of the Thames by the Romans were at London Bridge and Staines Bridge. At Folly Bridge in Oxford the remains of an original Saxon structure can be seen, and medieval stone bridges such as Newbridge, Wallingford Bridge and Abingdon Bridge are still in use.


title: River Thames

text: Kingston's growth is believed to stem from its having the only crossing between London Bridge and Staines until the beginning of the 18th century. During the 18th century, many stone and brick road bridges were built from new or to replace existing bridges both in London and along the length of the river. These included Putney Bridge, Westminster Bridge, Datchet Bridge, Windsor Bridge and Sonning Bridge.


title: River Thames

text: Several central London road bridges were built in the 19th century, most conspicuously Tower Bridge, the only Bascule bridge on the river, designed to allow ocean-going ships to pass beneath it. The most recent road bridges are the bypasses at Isis Bridge and Marlow By-pass Bridge and the motorway bridges, most notably the two on the M25 route: Queen Elizabeth II Bridge and M25 Runnymede Bridge.


title: River Thames

text: Railway development in the 19th century resulted in a spate of bridge building including Blackfriars Railway Bridge and Charing Cross (Hungerford) Railway Bridge in central London, and the railway bridges by Isambard Kingdom Brunel at Maidenhead Railway Bridge, Gatehampton Railway Bridge and Moulsford Railway Bridge.


title: River Thames

text: The world's first underwater tunnel was Marc Brunel's Thames Tunnel built in 1843 and now used to carry the East London Line. The Tower Subway was the first railway under the Thames, which was followed by all the deep-level tube lines. Road tunnels were built in East London at the end of the 19th century, being the Blackwall Tunnel and the Rotherhithe Tunnel. The latest tunnels are the Dartford Crossings.


title: River Thames

text: Many foot crossings were established across the weirs that were built on the non-tidal river, and some of these remained when the locks were built – for example at Benson Lock. Others were replaced by a footbridge when the weir was removed as at Hart's Weir Footbridge. Around 2000, several footbridges were added along the Thames, either as part of the Thames Path or in commemoration of the millennium. These include Temple Footbridge, Bloomers Hole Footbridge, the Hungerford Footbridges and the Millennium Bridge, all of which have distinctive design characteristics.


title: River Thames

text: Before bridges were built, the main means of crossing the river was by ferry. A significant number of ferries were provided specifically for navigation purposes. When the towpath changed sides, it was necessary to take the towing horse and its driver across the river. This was no longer necessary when barges were powered by steam. Some ferries still operate on the river. The Woolwich Ferry carries cars and passengers across the river in the Thames Gateway and links the North Circular and South Circular roads. Upstream are smaller pedestrian ferries, for example Hampton Ferry and Shepperton to Weybridge Ferry, the last being the only non-permanent crossing that remains on the Thames Path.


title: River Thames

text: Whilst the use of the river to drive water-mills has largely died out, there has been a recent trend to use the head of water provided by the river's existing weirs to drive small hydro-electric power plants, using Archimedes screw turbines. Operational schemes include:


title: River Thames

text: Treated waste water from all the towns and villages in the Thames catchment flow into the Thames via sewage treatment plants. This includes all that from Swindon, Oxford, Berkshire and almost all of Surrey.


title: River Thames

text: However, untreated sewage still often enters the Thames during wet weather. When London's sewerage system was built, sewers were designed to overflow through discharge points along the river during heavy storms. Originally, this would happen once or twice a year, however overflows now happen once a week on average. In 2013, over 55 tonnes of dilute raw sewage overflowed into the tidal Thames. These discharge events kill fish, leave raw sewage on the riverbanks, and decrease the water quality of the river.


title: River Thames

text: To reduce the release of this into the river, the Thames Tideway Scheme is currently under construction at a cost of £4.2 billion. This project will collect sewage from the Greater London area before it overflows, before channelling it down a 25 km (15 mi) tunnel underneath the tidal Thames, so that it can be treated at Beckton Sewage Treatment Works. The project is planned to reduce sewage discharges into the Thames in the Greater London area by 90%, dramatically increasing water quality.


title: River Thames

text: Mercury (Hg) is an environmentally persistent heavy metal which can be toxic to marine life and humans. Sixty sediment cores of 1 m in depth, spanning the entire tidal River Thames between Brentford and the Isle of Grain, have been analysed for total Hg. The sediment records show a clear rise and fall of Hg pollution through history. Mercury concentrations in the River Thames decrease downstream from London to the outer Estuary, with the total Hg levels ranging from 0.01 to 12.07 mg/kg, giving a mean of 2.10 mg/kg which is higher than many other UK and European river estuaries.


title: River Thames

text: The most sedimentary-hosted Hg pollution in the Thames estuary occurs in the central London area between Vauxhall Bridge and Woolwich. The majority of sediment cores show a clear decrease in Hg concentrations close to the surface, which is attributed to an overall reduction in polluting activities as well as improved effectiveness of recent environmental legalisation and river management (e.g. Oslo-Paris convention).


title: River Thames

text: There are several watersports prevalent on the Thames, with many clubs encouraging participation and organising racing and inter-club competitions.


title: River Thames

text: The Thames is the historic heartland of rowing in the United Kingdom. There are over 200 clubs on the river, and over 8,000 members of British Rowing (over 40% of its membership). Most towns and districts of any size on the river have at least one club. Internationally attended centres are Oxford, Henley-on-Thames and events and clubs on the stretch of river from Chiswick to Putney.


title: River Thames

text: The University Boat Race (between Oxford and Cambridge) takes place in late March or early April, on the Championship Course from Putney to Mortlake in the west of London.


title: River Thames

text: Henley Royal Regatta takes place over five days at the start of July in the upstream town of Henley-on-Thames. Besides its sporting significance the regatta is an important date on the English social calendar alongside events like Royal Ascot and Wimbledon.


title: River Thames

text: Other regattas, head races and university bumping races are held along the Thames which are described under Rowing on the River Thames.


title: River Thames

text: Sailing is practised on both the tidal and non-tidal reaches of the river. The highest club upstream is at Oxford. The most popular sailing craft used on the Thames are lasers, GP14s and Wayfarers. One sailing boat unique to the Thames is the Thames Rater, which is sailed around Raven's Ait.


title: River Thames

text: Skiffing has dwindled in favour of private motor boat ownership but is competed on the river in the summer months. Six clubs and a similar number of skiff regattas exist from the Skiff Club, Teddington upstream.


title: River Thames

text: Unlike the "pleasure punting" common on the Cherwell in Oxford and the Cam in Cambridge, punting on the Thames is competitive as well as recreational and uses narrower craft, typically based at the few skiff clubs.


title: River Thames

text: Kayaking and canoeing are common, with sea kayakers using the tidal stretch for touring. Kayakers and canoeists use the tidal and non-tidal sections for training, racing and trips. Whitewater playboaters and slalom paddlers are catered for at weirs like those at Hurley Lock, Sunbury Lock and Boulter's Lock. At Teddington just before the tidal section of the river starts is Royal Canoe Club, said to be the oldest in the world and founded in 1866. Since 1950, almost every year at Easter, long distance canoeists have been competing in what is now known as the Devizes to Westminster International Canoe Race, which follows the course of the Kennet and Avon Canal, joins the River Thames at Reading and runs right up to a grand finish at Westminster Bridge.


title: River Thames

text: In 2006, British swimmer and environmental campaigner Lewis Pugh became the first person to swim the full length of the Thames from outside Kemble to Southend-on-Sea to draw attention to the severe drought in England which saw record temperatures indicative of a degree of global warming. The swim took him 21 days to complete. The official headwater of the river had stopped flowing due to the drought, forcing Pugh to run the first .


title: River Thames

text: Since June 2012, the Port of London Authority has made a by-law, which it enforces, that bans swimming between Putney Bridge and Crossness, Thamesmead (thus including all of central London), without obtaining prior permission, on the grounds that swimmers in that area of the river endanger not only themselves, due to the strong current of the river, but also other river users.


title: River Thames

text: Organised swimming events take place at various points generally upstream of Hampton Court, including Windsor, Marlow and Henley. In 2011, comedian David Walliams swam the from Lechlade to Westminster Bridge and raised over £1 million for charity.


title: River Thames

text: In non-tidal stretches swimming was, and still is, a leisure and fitness activity among experienced swimmers where safe, deeper outer channels are used in times of low stream.


title: River Thames

text: A Thames meander is a long-distance journey over all or part of the Thames by running, swimming or using any of the above means. It is often carried out as an athletic challenge in a competition or for a record attempt.


title: River Thames

text: The River Thames has been a subject for artists, great and minor, over the centuries. Four major artists with works based on the Thames are Canaletto, J. M. W. Turner, Claude Monet and James Abbott McNeill Whistler. The 20th-century British artist Stanley Spencer produced many works at Cookham.


title: River Thames

text: The river and bridges are portrayed as being destroyed – together with much of London – in the film "Independence Day 2".


title: River Thames

text: The Thames is mentioned in many works of literature including novels, diaries and poetry. It is the central theme in three in particular:


title: River Thames

text: "Three Men in a Boat" by Jerome K. Jerome, first published in 1889, is a humorous account of a boating holiday on the Thames between Kingston and Oxford. The book was intended initially to be a serious travel guide, with accounts of local history of places along the route, but the humorous elements eventually took over. The landscape and features of the Thames as described by Jerome are virtually unchanged, and the book's enduring popularity has meant that it has never been out of print since it was first published.


title: River Thames

text: Charles Dickens' "Our Mutual Friend" (written in the years 1864–65) describes the river in a grimmer light. It begins with a scavenger and his daughter pulling a dead man from the river near London Bridge, to salvage what the body might have in its pockets, and leads to its conclusion with the deaths of the villains drowned in Plashwater Lock upstream. The workings of the river and the influence of the tides are described with great accuracy. Dickens opens the novel with this sketch of the river, and the people who work on it:


title: River Thames

text: "In these times of ours, though concerning the exact year there is no need to be precise, a boat of dirty and disreputable appearance, with two figures in it, floated on the Thames, between Southwark Bridge which is of iron, and London Bridge which is of stone, as an autumn evening was closing in."


title: River Thames

text: "The figures in this boat were those of a strong man with ragged grizzled hair and a sun-browned face, and a girl of nineteen or twenty. The girl rowed, pulling a pair of sculls very easily; the man with the rudder-lines slack in his hands, and his hands loose in his waisteband, kept an eager look-out."


title: River Thames

text: Kenneth Grahame's "The Wind in the Willows", written in 1908, is set in the middle to upper reaches of the river. It starts as a tale of anthropomorphic characters "simply messing about in boats" but develops into a more complex story combining elements of mysticism with adventure and reflection on Edwardian society. It is generally considered one of the most beloved works of children's literature and the illustrations by E.H.Shepard and Arthur Rackham feature the Thames and its surroundings.


title: River Thames

text: The river almost inevitably features in many books set in London. Most of Dickens' other novels include some aspect of the Thames. "Oliver Twist" finishes in the slums and rookeries along its south bank. The Sherlock Holmes stories by Arthur Conan Doyle often visit riverside parts as in "The Sign of Four". In "Heart of Darkness" by Joseph Conrad, the serenity of the contemporary Thames is contrasted with the savagery of the Congo River, and with the wilderness of the Thames as it would have appeared to a Roman soldier posted to Britannia two thousand years before. Conrad also gives a description of the approach to London from the Thames Estuary in his essays "" (1906). Upriver, Henry James' "Portrait of a Lady" uses a large riverside mansion on the Thames as one of its key settings.


title: River Thames

text: Literary non-fiction works include Samuel Pepys' diary, in which he recorded many events relating to the Thames including the Fire of London. He was disturbed while writing it in June 1667 by the sound of gunfire as Dutch warships broke through the Royal Navy on the Thames.


title: River Thames

text: T. S. Eliot makes several references to the Thames in "The Fire Sermon, Section III" of "The Waste Land".


title: River Thames

text: The "Sweet Thames" line is taken from Edmund Spenser's "Prothalamion" which presents a more idyllic image:


title: River Thames

text: Dylan Thomas mentions the Thames in his poem "A Refusal to Mourn the Death, by Fire, of a Child in London". "London's Daughter", the subject of the poem, lays "Deep with the first dead...secret by the unmourning water of the riding Thames".


title: River Thames

text: Science-fiction novels make liberal use of a futuristic Thames. The utopian "News from Nowhere" by William Morris is mainly the account of a journey through the Thames valley in a socialist future. The Thames features in H. G. Wells' "The War of the Worlds". The Thames also features prominently in Philip Pullman's "His Dark Materials" trilogy, as a communications artery for the waterborne Gyptian people of Oxford and the Fens, and as a prominent setting for his novel La Belle Sauvage.


title: River Thames

text: In "The Deptford Mice" trilogy by Robin Jarvis, the Thames appears several times. In one book, rat characters swim through it to Deptford. Winner of the Nestlé Children's Book Prize Gold Award "I, Coriander", by Sally Gardner is a fantasy novel in which the heroine lives on the banks of the Thames. Mark Wallington describes a journey up the Thames in a camping skiff, in his 1989 book "Boogie up the River".


title: River Thames

text: Many of the principal characters of the Rivers of London urban fantasy series by Ben Aaronovitch are genii locorum (local gods) associated with River Thames and its tributaries. This includes Father Thames, the original god of the Thames but now (in the books) confined to non-tidal reaches above Teddington Lock and Mama Thames the goddess of the tidal Thames below Teddington.


title: River Thames

text: The Water Music composed by George Frideric Handel premiered on 17 July 1717, when King George I requested a concert on the River Thames. The concert was performed for King George I on his barge and he is said to have enjoyed it so much that he ordered the 50 exhausted musicians to play the suites three times on the trip.


title: River Thames

text: The song 'Old Father Thames' was recorded by Peter Dawson at Abbey Road Studios in 1933 and by Gracie Fields five years later. Jessie Matthews sings "My river" in the 1938 film "Sailing Along", and the tune is the centrepiece of a major dance number near the end of the film.


title: River Thames

text: The Sex Pistols played a concert on the "Queen Elizabeth Riverboat" on 7 June 1977, Queen Elizabeth II's Silver Jubilee year, while sailing down the river. The choral line "(I) "(liaised)" live by the river" in the song "London Calling" by the Clash refers to the River Thames.


title: River Thames

text: Two songs by the Kinks feature the Thames as the setting of the first song's title and, for the second song, arguably in its mention of 'the river': "Waterloo Sunset" is about a couple's meetings on Waterloo Bridge, London and starts: "Dirty old river, must you keep rolling, flowing into the night?" and continues "Terry meets Julie, Waterloo station" and "...but Terry and Julie cross over the river where they feel safe and sound...". "See My Friends" continually refers to the singer's friends "playing 'cross the river" instead of the girl who "just left". Furthermore, Ray Davies as a solo artist refers to the river Thames in his "London Song".


title: River Thames

text: Ewan MacColl's "Sweet Thames, Flow Softly", written in the early 1960s, is a tragic love ballad set on trip up the river (see Edmund Spenser's love poem's refrain above). Culture Club are travelling the River Thames in a riverboat in the video for "Karma Chameleon". English musician Imogen Heap wrote a song from the point of view of the River Thames entitled "You Know Where To Find Me". The song was released in 2012 on 18 October as the sixth single from her fourth album Sparks.


title: River Thames

text: The 1928 Thames flood was a disastrous flood of the River Thames that affected much of riverside London on 7 January 1928, as well as places further downriver. Fourteen people were drowned in London and thousands were made homeless when flood waters poured over the top of the Thames Embankment and part of the Chelsea Embankment collapsed. It was the last major flood to affect central London, and, particularly following the disastrous North Sea flood of 1953, helped lead to the implementation of new flood-control measures that culminated in the construction of the Thames Barrier in the 1970s.


title: River Thames

text: The 1947 Thames flood was overall the worst 20th-century flood of the River Thames, affecting much of the Thames Valley as well as elsewhere in England during the middle of March 1947 after a very severe winter.


title: River Thames

text: The floods were caused by of rainfall (including snow); the peak flow was of water per day and the damage cost a total of £12 million to repair.


title: River Thames

text: Other significant Thames floods since 1947 have occurred in 1968, 1993, 1998, 2000, 2003, 2006 and 2014.


title: River Thames

text: On the night of 31 January, the North Sea flood of 1953 devastated the island, taking the lives of 58 islanders, and led to the temporary evacuation of the 13,000 residents. Canvey is consequently protected by modern sea defences comprising of concrete seawall. Many of the victims were in the holiday bungalows of the eastern Newlands estate and perished as the water reached ceiling level. The small village area of the island is approximately above sea level and consequently escaped the effects of the flood.


title: Calcium carbonate

text: Calcium carbonate is a chemical compound with the formula . It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which is a type of sedimentary rock consisting mainly of calcite) and is the main component of eggshells, gastropod shells, shellfish skeletons and pearls. Things containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues.


title: Calcium carbonate

text: Calcium carbonate reacts with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate.


title: Calcium carbonate

text: This reaction is important in the erosion of carbonate rock, forming caverns, and leads to hard water in many regions.


title: Calcium carbonate

text: The vast majority of calcium carbonate used in industry is extracted by mining or quarrying. Pure calcium carbonate (such as for food or pharmaceutical use), can be produced from a pure quarried source (usually marble).


title: Calcium carbonate

text: Alternatively, calcium carbonate is prepared from calcium oxide. Water is added to give calcium hydroxide then carbon dioxide is passed through this solution to precipitate the desired calcium carbonate, referred to in the industry as precipitated calcium carbonate (PCC) This process is called carbonatation:


title: Calcium carbonate

text: In laboratory, Calcium Carbonate can easily be crystallized from calcium chloride (CaCl), by placing an aqueous solution of CaCl in a desiccator alongside ammonium carbonate (NH4)CO. In the desiccator, ammonium carbonate is exposed to air and decomposes into ammonia, carbon dioxide, and water. The carbon dioxide then diffuses into the aqueous solution of calcium chloride, reacts with the calcium ions and the water, and forms calcium carbonate.


title: Calcium carbonate

text: The thermodynamically stable form of under normal conditions is hexagonal β- (the mineral calcite). Other forms can be prepared, the denser (2.83 g/cm) orthorhombic λ- (the mineral aragonite) and hexagonal μ-, occurring as the mineral vaterite. The aragonite form can be prepared by precipitation at temperatures above 85 °C; the vaterite form can be prepared by precipitation at 60 °C. Calcite contains calcium atoms coordinated by six oxygen atoms; in aragonite they are coordinated by nine oxygen atoms. The vaterite structure is not fully understood. Magnesium carbonate () has the calcite structure, whereas strontium carbonate () and barium carbonate () adopt the aragonite structure, reflecting their larger ionic radii.


title: Calcium carbonate

text: Calcium carbonate crystalizes as three anhydrous polymorphs, of which calcite is the thermodynamically most stable at room temperature, aragonite is only slightly less so, and vaterite is the least stable.


title: Calcium carbonate

text: Calcite crystal structure is trigonal, with space group R-3c (No.167 in the International Table for Crystallography), and Pearson symbol hR10. Aragonite is orthorhombic, with space group Pmcn (No 62), and Pearson Symbol oP20. Vaterite is composed of at least two different coexisting crystallographic structures. The major structure exhibits hexagonal symmetry of space group P6/mmc, the minor structure is still unknown.


title: Calcium carbonate

text: All three polymorphs crystallize simultaneoulsy from aqueous solutions under ambient conditions. In additive-free aqueous solutions, calcite forms easily as the major product, while aragonite appears only as a minor product.


title: Calcium carbonate

text: At high saturation, vaterite is typically the first phase precipitated, and is followed by a transformation of the vaterite to calcite. This behavior seems to follow Ostwald's step rule, in which the least stable polymorph crystallizes first, followed by the crytallization of different polymorphs via a sequence of increasingly stable phases. However, Aragonite, which stability lies between those of vaterite and calcite, seems to be the exception to this rule, as aragonite does not form as a precursor to calcite under ambient conditions.


title: Calcium carbonate

text: Aragonite occurs in majority when the reaction conditions inhibit the formation of calcite and/or promote the nucleation of aragonite. For example, the formation of aragonite is promoted by the presence of magnesium ions, or by using proteins and peptides derived from biological calcium carbonate. Some polyamines such as Cadaverine and Poly(ethylene imine) have been shown to facilitate the formation of aragonite over calcite.


title: Calcium carbonate

text: Organisms, such as molluscs and arthropods, have shown the ability to grow all three crystal polymorphs of calcium carbonate, mainly as protection (shells) and muscle attachments. Moreover, they exhibit a remarkable capability of phase selection over calcite and aragonite, and some organisms can switch between the two polymorphs. The ability of phase selection is usually attributed to the use of specific macromolecules or combinations of macromolecules by such organisms.


title: Calcium carbonate

text: Calcite, aragonite and vaterite are pure calcium carbonate minerals. Industrially important source rocks which are predominantly calcium carbonate include limestone, chalk, marble and travertine.


title: Calcium carbonate

text: Eggshells, snail shells and most seashells are predominantly calcium carbonate and can be used as industrial sources of that chemical. Oyster shells have enjoyed recent recognition as a source of dietary calcium, but are also a practical industrial source. Dark green vegetables such as broccoli and kale contain dietarily significant amounts of calcium carbonate, but they are not practical as an industrial source.


title: Calcium carbonate

text: Beyond Earth, strong evidence suggests the presence of calcium carbonate on Mars. Signs of calcium carbonate have been detected at more than one location (notably at Gusev and Huygens craters). This provides some evidence for the past presence of liquid water.


title: Calcium carbonate

text: Carbonate is found frequently in geologic settings and constitutes an enormous carbon reservoir. Calcium carbonate occurs as aragonite, calcite and dolomite as significant constituents of the calcium cycle. The carbonate minerals form the rock types: limestone, chalk, marble, travertine, tufa, and others.


title: Calcium carbonate

text: In warm, clear tropical waters corals are more abundant than towards the poles where the waters are cold. Calcium carbonate contributors, including plankton (such as coccoliths and planktic foraminifera), coralline algae, sponges, brachiopods, echinoderms, bryozoa and mollusks, are typically found in shallow water environments where sunlight and filterable food are more abundant. Cold-water carbonates do exist at higher latitudes but have a very slow growth rate. The calcification processes are changed by ocean acidification.


title: Calcium carbonate

text: Where the oceanic crust is subducted under a continental plate sediments will be carried down to warmer zones in the asthenosphere and lithosphere. Under these conditions calcium carbonate decomposes to produce carbon dioxide which, along with other gases, give rise to explosive volcanic eruptions.


title: Calcium carbonate

text: The carbonate compensation depth (CCD) is the point in the ocean where the rate of precipitation of calcium carbonate is balanced by the rate of dissolution due to the conditions present. Deep in the ocean, the temperature drops and pressure increases. Calcium carbonate is unusual in that its solubility increases with decreasing temperature. Increasing pressure also increases the solubility of calcium carbonate. The carbonate compensation depth can range from 4,000 to 6,000 meters below sea level.


title: Calcium carbonate

text: Calcium carbonate can preserve fossils through permineralization. Most of the vertebrate fossils of the Two Medicine Formation—a geologic formation known for its duck-billed dinosaur eggs—are preserved by permineralization. This type of preservation conserves high levels of detail, even down to the microscopic level. However, it also leaves specimens vulnerable to weathering when exposed to the surface.


title: Calcium carbonate

text: Trilobite populations were once thought to have composed the majority of aquatic life during the Cambrian, due to the fact that their calcium carbonate-rich shells were more easily preserved than those of other species, which had purely chitinous shells.


title: Calcium carbonate

text: The main use of calcium carbonate is in the construction industry, either as a building material, or limestone aggregate for road building, as an ingredient of cement, or as the starting material for the preparation of builders' lime by burning in a kiln. However, because of weathering mainly caused by acid rain, calcium carbonate (in limestone form) is no longer used for building purposes on its own, but only as a raw primary substance for building materials.


title: Calcium carbonate

text: Calcium carbonate is also used in the purification of iron from iron ore in a blast furnace. The carbonate is calcined "in situ" to give calcium oxide, which forms a slag with various impurities present, and separates from the purified iron.


title: Calcium carbonate

text: In the oil industry, calcium carbonate is added to drilling fluids as a formation-bridging and filtercake-sealing agent; it is also a weighting material which increases the density of drilling fluids to control the downhole pressure. Calcium carbonate is added to swimming pools, as a pH corrector for maintaining alkalinity and offsetting the acidic properties of the disinfectant agent.


title: Calcium carbonate

text: It is also used as a raw material in the refining of sugar from sugar beet; it is calcined in a kiln with anthracite to produce calcium oxide and carbon dioxide. This burnt lime is then slaked in fresh water to produce a calcium hydroxide suspension for the precipitation of impurities in raw juice during carbonatation.


title: Calcium carbonate

text: Calcium carbonate in the form of chalk has traditionally been a major component of blackboard chalk. However, modern manufactured chalk is mostly gypsum, hydrated calcium sulfate . Calcium carbonate is a main source for growing biorock. Precipitated calcium carbonate (PCC), pre-dispersed in slurry form, is a common filler material for latex gloves with the aim of achieving maximum saving in material and production costs.


title: Calcium carbonate

text: Fine ground calcium carbonate (GCC) is an essential ingredient in the microporous film used in diapers and some building films, as the pores are nucleated around the calcium carbonate particles during the manufacture of the film by biaxial stretching. GCC and PCC are used as a filler in paper because they are cheaper than wood fiber. In terms of market volume, GCC are the most important types of fillers currently used. Printing and writing paper can contain 10–20% calcium carbonate. In North America, calcium carbonate has begun to replace kaolin in the production of glossy paper. Europe has been practicing this as alkaline papermaking or acid-free papermaking for some decades. PCC used for paper filling and paper coatings is precipitated and prepared in a variety of shapes and sizes having characteristic narrow particle size distributions and equivalent spherical diameters of 0.4 to 3 micrometers.


title: Calcium carbonate

text: Calcium carbonate is widely used as an extender in paints, in particular matte emulsion paint where typically 30% by weight of the paint is either chalk or marble. It is also a popular filler in plastics. Some typical examples include around 15 to 20% loading of chalk in unplasticized polyvinyl chloride (uPVC) drainpipes, 5% to 15% loading of stearate-coated chalk or marble in uPVC window profile. PVC cables can use calcium carbonate at loadings of up to 70 phr (parts per hundred parts of resin) to improve mechanical properties (tensile strength and elongation) and electrical properties (volume resistivity). Polypropylene compounds are often filled with calcium carbonate to increase rigidity, a requirement that becomes important at high usage temperatures. Here the percentage is often 20–40%. It also routinely used as a filler in thermosetting resins (sheet and bulk molding compounds) and has also been mixed with ABS, and other ingredients, to form some types of compression molded "clay" poker chips. Precipitated calcium carbonate, made by dropping calcium oxide into water, is used by itself or with additives as a white paint, known as whitewashing.


title: Calcium carbonate

text: Calcium carbonate is added to a wide range of trade and do it yourself adhesives, sealants, and decorating fillers. Ceramic tile adhesives typically contain 70% to 80% limestone. Decorating crack fillers contain similar levels of marble or dolomite. It is also mixed with putty in setting stained glass windows, and as a resist to prevent glass from sticking to kiln shelves when firing glazes and paints at high temperature.


title: Calcium carbonate

text: In ceramic glaze applications, calcium carbonate is known as "whiting", and is a common ingredient for many glazes in its white powdered form. When a glaze containing this material is fired in a kiln, the whiting acts as a flux material in the glaze. Ground calcium carbonate is an abrasive (both as scouring powder and as an ingredient of household scouring creams), in particular in its calcite form, which has the relatively low hardness level of 3 on the Mohs scale, and will therefore not scratch glass and most other ceramics, enamel, bronze, iron, and steel, and have a moderate effect on softer metals like aluminium and copper. A paste made from calcium carbonate and deionized water can be used to clean tarnish on silver.


title: Calcium carbonate

text: Calcium carbonate is widely used medicinally as an inexpensive dietary calcium supplement for gastric antacid (such as Tums and Eno). It may be used as a phosphate binder for the treatment of hyperphosphatemia (primarily in patients with chronic kidney failure). It is used in the pharmaceutical industry as an inert filler for tablets and other pharmaceuticals.


title: Calcium carbonate

text: Calcium carbonate is used in the production of calcium oxide as well as toothpaste and has seen a resurgence as a food preservative and color retainer, when used in or with products such as organic apples.


title: Calcium carbonate

text: Calcium carbonate is used therapeutically as phosphate binder in patients on maintenance haemodialysis. It is the most common form of phosphate binder prescribed, particularly in non-dialysis chronic kidney disease. Calcium carbonate is the most commonly used phosphate binder, but clinicians are increasingly prescribing the more expensive, non-calcium-based phosphate binders, particularly sevelamer.


title: Calcium carbonate

text: Excess calcium from supplements, fortified food, and high-calcium diets can cause milk-alkali syndrome, which has serious toxicity and can be fatal. In 1915, Bertram Sippy introduced the "Sippy regimen" of hourly ingestion of milk and cream, and the gradual addition of eggs and cooked cereal, for 10 days, combined with alkaline powders, which provided symptomatic relief for peptic ulcer disease. Over the next several decades, the Sippy regimen resulted in kidney failure, alkalosis, and hypercalcaemia, mostly in men with peptic ulcer disease. These adverse effects were reversed when the regimen stopped, but it was fatal in some patients with protracted vomiting. Milk-alkali syndrome declined in men after effective treatments for peptic ulcer disease arose. Since the 1990s it has been most frequently reported in women taking calcium supplements above the recommended range of 1.2 to 1.5 grams daily, for prevention and treatment of osteoporosis, and is exacerbated by dehydration. Calcium has been added to over-the-counter products, which contributes to inadvertent excessive intake. Excessive calcium intake can lead to hypercalcemia, complications of which include vomiting, abdominal pain and altered mental status.


title: Calcium carbonate

text: As a food additive it is designated E170, and it has an INS number of 170. Used as an acidity regulator, anticaking agent, stabilizer or color it is approved for usage in the EU, US and Australia and New Zealand. It is "added by law to all UK milled bread flour except wholemeal". It is used in some soy milk and almond milk products as a source of dietary calcium; at least one study suggests that calcium carbonate might be as bioavailable as the calcium in cow's milk. Calcium carbonate is also used as a firming agent in many canned and bottled vegetable products.


title: Calcium carbonate

text: Several calcium supplement formulations have been documented to contain the chemical element lead, posing a public health concern. Lead is commonly found in natural sources of calcium.


title: Calcium carbonate

text: Agricultural lime, powdered chalk or limestone, is used as a cheap method for neutralising acidic soil, making it suitable for planting, also used in aquaculture industry for pH regulation of pond soil before initiating culture.


title: Calcium carbonate

text: Calcium carbonate is a key ingredient in many household cleaning powders like Comet and is used as a scrubbing agent.


title: Calcium carbonate

text: In 1989, a researcher, Ken Simmons, introduced into the Whetstone Brook in Massachusetts. His hope was that the calcium carbonate would counter the acid in the stream from acid rain and save the trout that had ceased to spawn. Although his experiment was a success, it did increase the amount of aluminium ions in the area of the brook that was not treated with the limestone. This shows that can be added to neutralize the effects of acid rain in river ecosystems. Currently calcium carbonate is used to neutralize acidic conditions in both soil and water. Since the 1970s, such "liming" has been practiced on a large scale in Sweden to mitigate acidification and several thousand lakes and streams are limed repeatedly.


title: Calcium carbonate

text: Calcium carbonate is also used in flue gas desulfurisation applications eliminating harmful and emissions from coal and other fossil fuels burnt in large fossil fuel power stations.


title: Calcium carbonate

text: Calcination of limestone using charcoal fires to produce quicklime has been practiced since antiquity by cultures all over the world. The temperature at which limestone yields calcium oxide is usually given as 825 °C, but stating an absolute threshold is misleading. Calcium carbonate exists in equilibrium with calcium oxide and carbon dioxide at any temperature. At each temperature there is a partial pressure of carbon dioxide that is in equilibrium with calcium carbonate. At room temperature the equilibrium overwhelmingly favors calcium carbonate, because the equilibrium pressure is only a tiny fraction of the partial pressure in air, which is about 0.035 kPa.


title: Calcium carbonate

text: At temperatures above 550 °C the equilibrium pressure begins to exceed the pressure in air. So above 550 °C, calcium carbonate begins to outgas into air. However, in a charcoal fired kiln, the concentration of will be much higher than it is in air. Indeed, if all the oxygen in the kiln is consumed in the fire, then the partial pressure of in the kiln can be as high as 20 kPa.


title: Calcium carbonate

text: The table shows that this partial pressure is not achieved until the temperature is nearly 800 °C. For the outgassing of from calcium carbonate to happen at an economically useful rate, the equilibrium pressure must significantly exceed the ambient pressure of . And for it to happen rapidly, the equilibrium pressure must exceed total atmospheric pressure of 101 kPa, which happens at 898 °C.


title: Calcium carbonate

text: Calcium carbonate is poorly soluble in pure water (47 mg/L at normal atmospheric partial pressure as shown below).


title: Calcium carbonate

text: The equilibrium of its solution is given by the equation (with dissolved calcium carbonate on the right):


title: Calcium carbonate

text: where the solubility product for is given as anywhere from "K" = to "K" = at 25 °C, depending upon the data source. What the equation means is that the product of molar concentration of calcium ions (moles of dissolved per liter of solution) with the molar concentration of dissolved cannot exceed the value of "K". This seemingly simple solubility equation, however, must be taken along with the more complicated equilibrium of carbon dioxide with water (see carbonic acid). Some of the combines with in the solution according to


title: Calcium carbonate

text: For ambient air, "P" is around atmospheres (or equivalently 35 Pa). The last equation above fixes the concentration of dissolved as a function of "P", independent of the concentration of dissolved . At atmospheric partial pressure of , dissolved concentration is moles per liter. The equation before that fixes the concentration of as a function of concentration. For [] = , it results in = moles per liter. When is known, the remaining three equations together with


title: Calcium carbonate

text: (which is true for all aqueous solutions), and the fact that the solution must be electrically neutral, i.e., the overall charge of dissolved positive ions must be cancelled out by the overall charge of dissolved negative ions , make it possible to solve simultaneously for the remaining five unknown concentrations (note that the previously mentioned form of the neutrality is valid only if calcium carbonate has been put in contact with pure water or with a neutral pH solution; in the case where the initial water solvent pH is not neutral, the balance is not neutral).


title: Calcium carbonate

text: The adjacent table shows the result for and (in the form of pH) as a function of ambient partial pressure of ("K" = has been taken for the calculation).


title: Calcium carbonate

text: The effect of the latter is especially evident in day-to-day life of people who have hard water. Water in aquifers underground can be exposed to levels of much higher than atmospheric. As such water percolates through calcium carbonate rock, the dissolves according to the second trend. When that same water then emerges from the tap, in time it comes into equilibrium with levels in the air by outgassing its excess . The calcium carbonate becomes less soluble as a result, and the excess precipitates as lime scale. This same process is responsible for the formation of stalactites and stalagmites in limestone caves.