Fire services in the United Kingdom
The fire services in the United Kingdom operate under separate legislative and administrative arrangements in England and Wales, Northern Ireland, Scotland. Emergency cover is provided by over fifty agencies; these are known as a fire and rescue service, the term used in modern legislation and by government departments. The older terms of fire brigade and fire service survive in informal usage and in the names of a few organisations. England and Wales have local fire services which are each overseen by a fire authority, made up of representatives of local governments. Fire authorities have the power to raise a Council Tax levy for funding, with the remainder coming from the government. Scotland and Northern Ireland have centralised fire services, so their authorities are committees of the devolved parliaments; the total budget for fire services in 2014-15 was £2.9 billion. Central government maintains national standards and a body of independent advisers through the Chief Fire and Rescue Adviser, created in 2007, while Her Majesty's Inspectorate of Constabulary and Fire & Rescue Services provides direct oversight.
The devolved government in Scotland has HMFSI Scotland. Firefighters in the United Kingdom are allowed to join unions, the main one being the Fire Brigades Union, while chief fire officers are members of the National Fire Chiefs Council, which has some role in national co-ordination; the fire services have undergone significant changes since the beginning of the 21st century, a process, propelled by a devolution of central government powers, new legislation and a change to operational procedures in the light of terrorism attacks and threats. See separate article History of fire safety legislation in the United Kingdom Comprehensive list of recent UK fire and rescue service legislation: Fire services are established and granted their powers under new legislation which has replaced a number of Acts of Parliament dating back more than 60 years, but is still undergoing change. 1938: Fire Brigades Act 1938. This Act provided for centralised co-ordination of fire brigades in Great Britain and made it mandatory for local authorities to arrange an effective fire service.
1947: Fire Services Act 1947 This Act transferred the functions of the National Fire Service to local authorities. Now repealed in England and Wales by Schedule 2 of the Fire and Rescue Services Act 2004. 1959: Fire Services Act 1959 This Act amended the 1947 Act. It was repealed in Wales along with the 1947 Act. 1999: Greater London Authority Act 1999 This act was necessary to allow for the formation of the Greater London Authority and in turn the London Fire and Emergency Planning Authority. In 2002, there was a series of national fire strikes, with much of the discontent caused by the aforementioned report into the fire service conducted by Prof Sir George Bain. In December 2002, the Independent Review of the Fire Service was published with the industrial action still ongoing. Bain's report led to a change in the laws relating to firefighting. 2002: Independent Review of the Fire Service published 2004: Fire and Rescue Services Act 2004 only applying to England and Wales. 2006: The Regulatory Reform Order 2005 This piece of secondary legislation or statutory instrument replaces several other acts that dealt with fire precautions and fire safety in premises, including the now defunct process of issuing fire certificates.
It came into force on 1 October 2006. The DfCLG has published a set of guides for non-domestic premises: 2006: The Government of Wales Act 2006 gave the National Assembly for Wales powers to pass laws on "Fire and rescue services. Promotion of fire safety otherwise than by prohibition or regulation." But does not prevent future legislation being passed by the UK government which applies to two or more constituent countries. There are further plans to modernise the fire service according to the Local Government Association, its website outlines future changes, specific projects: "The aim of the Fire Modernisation Programme is to adopt modern work practices within the Fire & Rescue Service to become more efficient and effective, while strengthening the contingency and resilience of the Service to react to incidents. " The fire service in England and Wales is scrutinised by a House of Commons select committee. In June 2006, the fire and rescue service select committee, under the auspices of the Communities and Local Government Committee, published its latest report.
Committee report The committee's brief is described on its website: The Communities and Local Government Committee is appointed by the House of Commons to examine the expenditure and policy of the Department for Communities and Local Government and its associated bodies. Government response This document, the subsequent government response in September 2006, are important as they outlined progress on the FiReControl, efforts to address diversity and the planned closure of HMFSI in 2007 among many issues. Both documents are interesting as they refer back to Professor Bain's report and the many recommendations it made and continue to put forward the notion that there is an ongoing need to modernise FRSs. For example, where FRSs were inspected by HMFSI, much of this work is now carried out by the National Audit Office. Fire Control On 8 February 2010 the House of Commons Communities and Local Governm
England is a country, part of the United Kingdom. It shares land borders with Wales to Scotland to the north-northwest; the Irish Sea lies west of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south; the country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Palaeolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century, since the Age of Discovery, which began during the 15th century, has had a significant cultural and legal impact on the wider world; the English language, the Anglican Church, English law – the basis for the common law legal systems of many other countries around the world – developed in England, the country's parliamentary system of government has been adopted by other nations.
The Industrial Revolution began in 18th-century England, transforming its society into the world's first industrialised nation. England's terrain is chiefly low hills and plains in central and southern England. However, there is upland and mountainous terrain in the west; the capital is London, which has the largest metropolitan area in both the United Kingdom and the European Union. England's population of over 55 million comprises 84% of the population of the United Kingdom concentrated around London, the South East, conurbations in the Midlands, the North West, the North East, Yorkshire, which each developed as major industrial regions during the 19th century; the Kingdom of England – which after 1535 included Wales – ceased being a separate sovereign state on 1 May 1707, when the Acts of Union put into effect the terms agreed in the Treaty of Union the previous year, resulting in a political union with the Kingdom of Scotland to create the Kingdom of Great Britain. In 1801, Great Britain was united with the Kingdom of Ireland to become the United Kingdom of Great Britain and Ireland.
In 1922 the Irish Free State seceded from the United Kingdom, leading to the latter being renamed the United Kingdom of Great Britain and Northern Ireland. The name "England" is derived from the Old English name Englaland, which means "land of the Angles"; the Angles were one of the Germanic tribes that settled in Great Britain during the Early Middle Ages. The Angles came from the Anglia peninsula in the Bay of Kiel area of the Baltic Sea; the earliest recorded use of the term, as "Engla londe", is in the late-ninth-century translation into Old English of Bede's Ecclesiastical History of the English People. The term was used in a different sense to the modern one, meaning "the land inhabited by the English", it included English people in what is now south-east Scotland but was part of the English kingdom of Northumbria; the Anglo-Saxon Chronicle recorded that the Domesday Book of 1086 covered the whole of England, meaning the English kingdom, but a few years the Chronicle stated that King Malcolm III went "out of Scotlande into Lothian in Englaland", thus using it in the more ancient sense.
According to the Oxford English Dictionary, its modern spelling was first used in 1538. The earliest attested reference to the Angles occurs in the 1st-century work by Tacitus, Germania, in which the Latin word Anglii is used; the etymology of the tribal name itself is disputed by scholars. How and why a term derived from the name of a tribe, less significant than others, such as the Saxons, came to be used for the entire country and its people is not known, but it seems this is related to the custom of calling the Germanic people in Britain Angli Saxones or English Saxons to distinguish them from continental Saxons of Old Saxony between the Weser and Eider rivers in Northern Germany. In Scottish Gaelic, another language which developed on the island of Great Britain, the Saxon tribe gave their name to the word for England. An alternative name for England is Albion; the name Albion referred to the entire island of Great Britain. The nominally earliest record of the name appears in the Aristotelian Corpus the 4th-century BC De Mundo: "Beyond the Pillars of Hercules is the ocean that flows round the earth.
In it are two large islands called Britannia. But modern scholarly consensus ascribes De Mundo not to Aristotle but to Pseudo-Aristotle, i.e. it was written in the Graeco-Roman period or afterwards. The word Albion or insula Albionum has two possible origins, it either derives from a cognate of the Latin albus meaning white, a reference to the white cliffs of Dover or from the phrase the "island of the Albiones" in the now lost Massaliote Periplus, attested through Avienus' Ora Maritima to which the former served as a source. Albion is now applied to England in a more poetic capacity. Another romantic name for England is Loegria, related to the Welsh word for England and made popular by its use in Arthurian legend; the earliest known evidence of human presence in the area now known as England was that of Homo antecessor, dating to approximate
Emergency medical services in the United Kingdom
Emergency medical services in the United Kingdom provide emergency care to people with acute illness or injury and are predominantly provided free at the point of use by the four National Health Services of England, Scotland and Northern Ireland. Emergency care including ambulance and emergency department treatment is free to everyone, regardless of immigration or visitor status; the NHS commissions most emergency medical services through the 14 NHS organisations with ambulance responsibility across the UK. As with other emergency services, the public access emergency medical services through one of the valid emergency telephone numbers. In addition to ambulance services provided by NHS organisations, there are some private and volunteer emergency medical services arrangements in place in the UK, the use of private or volunteer ambulances at public events or large private sites, as part of community provision of services such as community first responders. Air ambulance services in the UK are not part of the NHS and are funded through charitable donations.
Paramedics are seconded from a local NHS ambulance service, with the exception of Great North Air Ambulance Service who employ their own paramedics. Doctors are provided by their home hospital and spend no more than 40% of their time with an air ambulance service. Public ambulance services across the UK are required by law to respond to four types of requests for care, which are: Emergency calls Doctor's urgent admission requests High dependency and urgent inter-hospital transfers Major incidentsAmbulance trusts and services may undertake non-urgent patient transport services on a commercial arrangement with their local hospital trusts or health boards, or in some cases on directly funded government contracts, although these contracts are fulfilled by private and voluntary providers; the National Health Service Act 1946 gave county and borough councils a statutory responsibility to provide an emergency ambulance service, although they could contract a voluntary ambulance service to provide this, with many contracting the British Red Cross, St John Ambulance or another local provider.
The last St John Division, to be so contracted is reputed to have been at Whittlesey in Cambridgeshire, where the two-bay ambulance garage can still be seen at the branch headquarters. The Regional Ambulance Officers’ Committee reported in 1979 that “There was considerable local variation in the quality of the service provided in relation to vehicles and equipment. Most Services were administered by Local Authorities through their Medical Officer of Health and his Ambulance Officer, a few were under the aegis of the Fire Service, whilst others relied upon agency methods for the provision of part or all of their services.” The 142 existing ambulance services were transferred by the National Health Service Reorganisation Act 1973 from local authority to central government control in 1974, consolidated into 53 services under regional or area health authorities. This led to the formation of predominantly county based ambulance services, which merged up and changed responsibilities until 2006, when there were 31 NHS ambulance trusts in England.
The June 2005 report "Taking healthcare to the Patient", authored by Peter Bradley, Chief Executive of the London Ambulance Service, for the Department of Health led to the merging of the 31 trusts into 13 organisations in England, plus one organisation each in Wales and Northern Ireland. Following further changes as part of the NHS foundation trust pathway, this has further reduced to 10 ambulance service trusts in England, plus the Isle of Wight which has its own provision. Following the passage of the Health and Social Care Act 2012, commissioning of the ambulance services in each area passed from central government control into the hands of regional clinical commissioning groups; the commissioners in each region are responsible for contracting with a suitable organisation to provide ambulance services within their geographical territory. The primary provider for each area is held by a public NHS body, of which there are 11 in England, 1 each in the other three countries. In England there are now ten NHS ambulance trusts, as well as an ambulance service on the Isle of Wight, run directly by Isle of Wight NHS Trust, with boundaries following those of the former regional government offices.
The ten trusts are: East Midlands Ambulance Service NHS Trust East of England Ambulance Service NHS Trust London Ambulance Service NHS Trust North East Ambulance Service NHS Foundation Trust North West Ambulance Service NHS Trust South Central Ambulance Service NHS Foundation Trust South East Coast Ambulance Service NHS Foundation Trust South Western Ambulance Service NHS Foundation Trust West Midlands Ambulance Service University NHS Foundation Trust Yorkshire Ambulance Service NHS TrustThe English ambulance trusts are represented by the Association of Ambulance Chief Executives, with the Scottish and Northern Irish providers all associate members. On the 14 November 2018 West Midlands Ambulance Service became the UK's first university-ambulance trust; the service was operated before reorganisation in 1974 by the St Andrews’ Ambulance Association under contract to the Secretary of State for Scotland. The Scottish Ambulance Service is a Special Health Board that provides ambulance services throughout whole of Scotland, on behalf of the Health and Social Care Directorates of the Scottish Government.
Due to the remote nature of many areas of Scotland compared to the other Home Nations, the Scottish Ambulance Service has Britain's only publi
The Benedictines the Order of Saint Benedict, are a monastic Catholic religious order of monks and nuns that follow the Rule of Saint Benedict. They are sometimes called the Black Monks, in reference to the colour of the members' religious habits. Despite being called an order, the Benedictines do not operate under a single hierarchy but are instead organised as a collection of independent monastic communities, with each community within the order maintaining its own autonomy. Unlike other religious orders, the Benedictines do not have a superior general or motherhouse with universal jurisdiction. Instead, the order is represented internationally by the Benedictine Confederation, an organisation, set up in 1893 to represent the order's shared interests; the monastery at Subiaco in Italy, established by Saint Benedict of Nursia c. 529, was the first of the dozen monasteries he founded. He founded the Abbey of Monte Cassino. There is no evidence, that he intended to found an order and the Rule of Saint Benedict presupposes the autonomy of each community.
When Monte Cassino was sacked by the Lombards about the year 580, the monks fled to Rome, it seems probable that this constituted an important factor in the diffusion of a knowledge of Benedictine monasticism. It was from the monastery of St. Andrew in Rome that Augustine, the prior, his forty companions set forth in 595 on their mission for the evangelization of England. At various stopping places during the journey, the monks left behind them traditions concerning their rule and form of life, also some copies of the Rule. Lérins Abbey, for instance, founded by Honoratus in 375 received its first knowledge of the Benedictine Rule from the visit of St. Augustine and his companions in 596. Gregory of Tours says that at Ainay Abbey, in the sixth century, the monks "followed the rules of Basil, Cassian and other fathers and using whatever seemed proper to the conditions of time and place", doubtless the same liberty was taken with the Benedictine Rule when it reached them. In Gaul and Switzerland, it supplemented the much stricter Irish or Celtic Rule introduced by Columbanus and others.
In many monasteries it entirely displaced the earlier codes. By the ninth century, the Benedictine had become the standard form of monastic life throughout the whole of Western Europe, excepting Scotland and Ireland, where the Celtic observance still prevailed for another century or two. Through the work of Benedict of Aniane, it became the rule of choice for monasteries throughout the Carolingian empire. Monastic scriptoria flourished from the ninth through the twelfth centuries. Sacred Scripture was always at the heart of every monastic scriptorium; as a general rule those of the monks who possessed skill as writers made this their chief, if not their sole active work. An anonymous writer of the ninth or tenth century speaks of six hours a day as the usual task of a scribe, which would absorb all the time available for active work in the day of a medieval monk. In the Middle Ages monasteries were founded by the nobility. Cluny Abbey was founded by William I, Duke of Aquitaine in 910; the abbey was noted for its strict adherence to the Rule of St. Benedict.
The abbot of Cluny was the superior of all the daughter houses, through appointed priors. One of the earliest reforms of Benedictine practice was that initiated in 980 by Romuald, who founded the Camaldolese community; the dominance of the Benedictine monastic way of life began to decline towards the end of the twelfth century, which saw the rise of the Franciscans and Dominicans. Benedictines took a fourth vow of "stability". Not being bound by location, the mendicants were better able to respond to an "urban" environment; this decline was further exacerbated by the practice of appointing a commendatory abbot, a lay person, appointed by a noble to oversee and to protect the goods of the monastery. Oftentimes, this resulted in the appropriation of the assets of monasteries at the expense of the community which they were intended to support; the English Benedictine Congregation is the oldest of the nineteen Benedictine congregations. Augustine of Canterbury and his monks established the first English Benedictine monastery at Canterbury soon after their arrival in 597.
Other foundations followed. Through the influence of Wilfrid, Benedict Biscop, Dunstan, the Benedictine Rule spread with extraordinary rapidity, in the North it was adopted in most of the monasteries, founded by the Celtic missionaries from Iona. Many of the episcopal sees of England were founded and governed by the Benedictines, no fewer than nine of the old cathedrals were served by the black monks of the priories attached to them. Monasteries served as places of refuge for the weak and homeless; the monks studied the healing properties of plants and minerals to alleviate the sufferings of the sick. Germany was evangelized by English Benedictines. Willibrord and Boniface preached there in the seventh and eighth centuries and founded several abbeys. In the English Reformation, all monasteries were dissolved and their lands confiscated by the Crown, forcing their Catholic members to flee into exile on the Continent. During the 19th century they were able to return to England, including to Selby Abbey in Yorkshire, one of the few great monastic churches to survive the Dissolution.
St. Mildred's Priory, on the Isle of Thanet, was built in 1027 on the site of an abbey founded in 670 by the daughter of the first Christian King of Kent; the priory is home to a community of Benedictine nuns. Five of
A storey or story is any level part of a building with a floor that could be used by people. The plurals are "stories", respectively; the terms "floor", "level", or "deck" are used in a similar way, except that it is usual to talk of a "14-storey building", but "the 14th floor". The floor at ground or street level is called the "ground floor" in many places; the words "storey" and "floor" exclude levels of the building that are not covered by a roof, such as the terrace on the top roof of many buildings. Houses have only one or two floors. Buildings are classified as low-rise, mid-rise and high-rise according to how many levels they contain, but these categories are not well-defined. A single-storey house is referred to in the United Kingdom, as a bungalow; the tallest skyscraper in the world, Burj Khalifa, has 163 floors. The height of each storey is based on the ceiling height of the rooms plus the thickness of the floors between each pane; this is around 14 feet total. Storeys within a building need not be all the same height—often the lobby is taller, for example.
Additionally, higher levels may have less floor area than the ones beneath them. In English, the principal floor or main floor of a house is the floor that contains the chief apartments. In Italy the main floor of a home is above the ground level, may be called the piano nobile; the attic or loft is a storey just below the building's roof. A penthouse is a luxury apartment on the topmost storey of a building. A basement is a storey below the main or ground floor. Split-level homes have floors. A mezzanine, in particular, is a floor halfway between the ground floor and the next higher floor. Homes with a split-level entry have the entire main floor raised half a storey height above the street entrance level, a basement, half a storey below this level. In Macy's Herald Square, there is a "one-and-a-half" floor between the second. There are multi-storey car parks known as parking garages. Floor numbering is the numbering scheme used for a building's floors. There are two major schemes in use across the world.
In one system, used in the majority of European countries, the ground floor is the floor at ground level having no number, identified sometimes as "G" or "0". The next floor up is assigned the number 1 and is the first floor, so on; the other system, used in the United States and Canada, counts the bottom floor as the first floor, the next floor up as the second floor, so on. In both systems, the numbering of higher floors continues sequentially as one goes up, as shown in the following table: Each scheme has further variations depending on how one refers to the ground floor and the subterranean levels; the existence of two incompatible conventions is a common source of confusion in international communication. In all English-speaking countries the storeys in a building are counted in the same way: a "seven-storey building" is unambiguous, although the top floor would be called "6th floor" in Britain and "7th floor" in America. Mezzanines may not be counted as storeys. In most of Europe, the "first floor" is the second level.
This scheme is used in many former British colonies, many Latin American countries, in Hawaii and in many of the Commonwealth nations. This convention can be traced back to Medieval European usage. In countries that use this system, the floor at ground level is referred to by a special name translating as "ground floor" or equivalent. For example, Erdgeschoss in Germany, piano terra in Italy, begane grond in the Netherlands, planta baja or planta baixa in Spain, beheko solairua in Basque, andar térreo in Brazil, rés-do-chão in Portugal, földszint in Hungary, parter in Romania and Poland, prízemie in Slovakia and pritličje in Slovenia. In some countries that use this scheme, the higher floors may be explicitly qualified as being above the ground level, such as in Slovenian "prvo nadstropje". In Spain, the level above ground level is sometimes called "entresuelo", elevators may skip it; the next level is sometimes called "principal". The "first floor" can therefore be three levels above ground level.
In Italy, in the ancient palaces the first floor is called piano nobile, since the noble owners of the palace lived there. In France, there are two distinct names for storeys in buildings which have two "ground floors" at different levels; the lower one is called rez-de-chaussée, the upper one is rez-de-jardin (lit. "adjacent to the gar
Fishing tackle is the equipment used by anglers when fishing. Any equipment or gear used for fishing can be called fishing tackle; some examples are hooks, sinkers, rods, baits, spears, gaffs, traps and tackle boxes. Gear, attached to the end of a fishing line is called terminal tackle; this includes hooks, swivels, floats, split rings and wire, beads, blades and clevises to attach spinner blades to fishing lures. Sometimes the term fishing rig is used for a completed assembly of tackle ready for fishing. Fishing tackle can be contrasted with fishing techniques. Fishing tackle refers to the physical equipment, used when fishing, whereas fishing techniques refers to the manner in which the tackle is used when fishing; the term tackle, with the meaning "apparatus for fishing", has been in use from 1398 AD. Fishing tackle is called fishing gear; however the term fishing gear is more used in the context of commercial fishing, whereas fishing tackle is more used in the context of recreational fishing.
This article covers equipment used by recreational anglers. Hook and sinker is a classic combination of tackle empowering an angler to catch fish; the use of the hook in angling is descended from what would today be called a "gorge". The word "gorge", in this context, comes from an archaic word meaning "throat". Gorges were used by ancient peoples to capture fish. A gorge was a thin piece of bone or stone attached by its midpoint to a thin line; the gorge would be fixed with a bait. When a fish swallowed the bait, a tug on the line caused the gorge to orient itself at right angles to the line, thereby sticking in the fish's gullet. A fish hook is a device for catching fish either by impaling them in the mouth or, more by snagging the body of the fish. Fish hooks have been employed for millennia by anglers to catch fresh and saltwater fish. Early hooks were made from the upper bills of eagles and from bones, shells and thorns of plants. In 2005, the fish hook was chosen by Forbes as one of the top twenty tools in the history of man.
Fish hooks are attached to some form of line or lure device which connects the caught fish to the angler. There is an enormous variety of fish hooks. Sizes, designs and materials are all variable depending on the intended purpose of the hook, they are manufactured for a range of purposes from general fishing to limited and specialized applications. Fish hooks are designed to hold various types of artificial, dead or live baits. A fishing line is a cord made for fishing; the earliest fishing lines were made from leaves or plant stalk. Lines were constructed from horse hair or silk thread, with catgut leaders. From the 1850s, modern industrial machinery was employed to fashion fishing lines in quantity. Most of these lines were made from linen or silk, more cotton. Modern lines are made from artificial substances, including nylon, polyethylene and dyneema; the most common type is monofilament made of a single strand. Anglers use monofilament because of its buoyant characteristics and its ability to stretch under load.
Alternatives such as fluorocarbon, the least visible type, braided fishing line known as'superlines' because of their small diameter, minimal amount of stretch, great strength relative to standard nylon monofilament lines. Important parameters of a fishing line are its diameter. Factors that may determine what line an angler chooses for a given fishing environment include breaking strength, diameter,castability, stretch, knot strength, UV resistance, abrasion resistance, visibility. Fishing with a hook and line is called angling. In addition to the use of the hook and line used to catch a fish, a heavy fish may be landed by using a landing net or a hooked pole called a gaff. Trolling is a technique. Snagging is a technique. A sinker or plummet is a weight used when angling to force the lure or bait to sink more or to increase the distance that it may be cast; the ordinary plain sinker is traditionally made of lead. It can be any shape, is shaped round like a pipe-stem, with a swelling in the middle.
However, the use of smaller lead based fishing sinkers has now been banned in the UK, Canada and some states in the USA, since lead can cause toxic lead poisoning if ingested. There are loops of brass wire on either end of the sinker to attach the line. Weights can range from a quarter of an ounce for trout fishing up to a couple of pounds or more for sea bass and menhaden; the swivel sinker is similar to the plain one, except that instead of loops, there are swivels on each end to attach the line. This is a decided improvement, as it prevents the line from tangling. In trolling, swivel sinkers are indispensable; the slide sinker, for bottom fishing, is a leaden tube which allows the line to slip through it, when the fish bites. This is an excellent arrangement, as the angler can feel the smallest bite, whereas in the other case the fish must first move the sinker before the angler feels him. A fishing rod is an additional tool used with the hook and sinker. A length of fishing line is attached to a long, flexible rod or pole: one end terminates wit
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun, the rotation of the Earth. Tide tables can be used for any given locale to find the predicted times and amplitude; the predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide, the amphidromic systems of the oceans, the shape of the coastline and near-shore bathymetry. They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience low tides each day. Other locations have a diurnal tide -- one low tide each day. A "mixed tide" – two uneven magnitude tides a day – is a third regular category. Tides vary on timescales ranging from hours to years due to a number of factors, which determine the lunitidal interval. To make accurate records, tide gauges at fixed stations measure water level over time. Gauges ignore; these data are compared to the reference level called mean sea level.
While tides are the largest source of short-term sea-level fluctuations, sea levels are subject to forces such as wind and barometric pressure changes, resulting in storm surges in shallow seas and near coasts. Tidal phenomena are not limited to the oceans, but can occur in other systems whenever a gravitational field that varies in time and space is present. For example, the shape of the solid part of the Earth is affected by Earth tide, though this is not as seen as the water tidal movements. Tide changes proceed via the following stages: Sea level rises over several hours, covering the intertidal zone; the water rises to its highest level. Sea level falls over several hours; the water stops reaching low tide. Oscillating currents produced by tides are known as tidal streams; the moment that the tidal current ceases is called slack tide. The tide reverses direction and is said to be turning. Slack water occurs near high water and low water, but there are locations where the moments of slack tide differ from those of high and low water.
Tides are semi-diurnal, or diurnal. The two high waters on a given day are not the same height; the two low waters each day are the higher low water and the lower low water. The daily inequality is not consistent and is small when the Moon is over the Equator. From the highest level to the lowest: Highest astronomical tide – The highest tide which can be predicted to occur. Note that meteorological conditions may add extra height to the HAT. Mean high water springs – The average of the two high tides on the days of spring tides. Mean high water neaps – The average of the two high tides on the days of neap tides. Mean sea level – This is the average sea level; the MSL is constant for any location over a long period. Mean low water neaps – The average of the two low tides on the days of neap tides. Mean low water springs – The average of the two low tides on the days of spring tides. Lowest astronomical tide and Chart Datum – The lowest tide which can be predicted to occur. Modern charts use this as the chart datum.
Note that under certain meteorological conditions the water may fall lower than this meaning that there is less water than shown on charts. Tidal constituents are the net result of multiple influences impacting tidal changes over certain periods of time. Primary constituents include the Earth's rotation, the position of the Moon and Sun relative to the Earth, the Moon's altitude above the Earth's Equator, bathymetry. Variations with periods of less than half a day are called harmonic constituents. Conversely, cycles of days, months, or years are referred to as long period constituents. Tidal forces affect the entire earth. In contrast, the atmosphere is much more fluid and compressible so its surface moves by kilometers, in the sense of the contour level of a particular low pressure in the outer atmosphere. In most locations, the largest constituent is the "principal lunar semi-diurnal" known as the M2 tidal constituent, its period is about 12 hours and 25.2 minutes half a tidal lunar day, the average time separating one lunar zenith from the next, thus is the time required for the Earth to rotate once relative to the Moon.
Simple tide clocks track this constituent. The lunar day is longer than the Earth day because the Moon orbits in the same direction the Earth spins; this is analogous to the minute hand on a watch crossing the hour hand at 12:00 and again at about 1:05½. The Moon orbits the Earth in the same direction as the Earth rotates on its axis, so it takes more than a day—about 24 hours and 50 minutes—for the Moon to return to the same location in the sky. During this time, it has passed overhead once and underfoot once, so in many places the period of strongest tidal forcing is the above-mentioned, about 12 hours and 25 minutes; the moment of highest tide is not when the Moon is nearest to zenith or nadir, but the period of the forcing still determines the time between high tides. Because the gravitational field created by the Moon weakens