A cinder cone is a steep conical hill of loose pyroclastic fragments, such as either volcanic clinkers, volcanic ash, or cinder, built around a volcanic vent. They consist of loose pyroclastic debris formed by explosive eruptions or lava fountains from a single cylindrical, vent; as the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as either cinders, clinkers, or scoria around the vent to form a cone, symmetrical. Most cinder cones have a bowl-shaped crater at the summit; the rock fragments called cinders or scoria, are glassy and contain numerous gas bubbles "frozen" into place as magma exploded into the air and cooled quickly. Cinder cones range in size from tens to hundreds of meters tall. Cinder cones are made of pyroclastic material. Many cinder cones have a bowl-shaped crater at the summit. During the waning stage of a cinder-cone eruption, the magma has lost most of its gas content; this gas-depleted magma does not fountain but oozes into the crater or beneath the base of the cone as lava.
Lava issues from the top because the loose, uncemented cinders are too weak to support the pressure exerted by molten rock as it rises toward the surface through the central vent. Because it contains so few gas bubbles, the molten lava is denser than the bubble-rich cinders. Thus, it burrows out along the bottom of the cinder cone, lifting the less dense cinders like a cork on water, advances outward, creating a lava flow around the cone's base; when the eruption ends, a symmetrical cone of cinders sits at the center of a surrounding pad of lava. If the crater is breached, the remaining walls form an amphitheatre or horseshoe shape around the vent. Cinder cones are found on the flanks of shield volcanoes and calderas. For example, geologists have identified nearly 100 cinder cones on the flanks of Mauna Kea, a shield volcano located on the island of Hawaii; these cones are referred to as'scoria cones' and'cinder and spatter cones.'The most famous cinder cone, grew out of a corn field in Mexico in 1943 from a new vent.
Eruptions continued for nine years, built the cone to a height of 424 meters, produced lava flows that covered 25 km². The Earth's most active cinder cone is Cerro Negro in Nicaragua, it is part of a group of four young cinder cones NW of Las Pilas volcano. Since its initial eruption in 1850, it has erupted more than 20 times, most in 1995 and 1999. Based on satellite images it was suggested that cinder cones might occur on other terrestrial bodies in the solar system too, they were reported on the flanks of Pavonis Mons in Tharsis, in the region of Hydraotes Chaos on the bottom of the Coprates Chasma, or in the volcanic field Ulysses Colles. It is suggested that domical structures in Marius Hills might represent lunar cinder cones; the size and shape of cinder cones depend on environmental properties as different gravity and/or atmospheric pressure might change the dispersion of ejected scoria particles. For example, cinder cones on Mars seem to be more than two times wider than terrestrial analogues as lower atmospheric pressure and gravity enable wider dispersion of ejected particles over a larger area.
Therefore, it seems that erupted amount of material is not sufficient on Mars for the flank slopes to attain the angle of repose and Martian cinder cones seem to be ruled by ballistic distribution and not by material redistribution on flanks as typical on Earth. Some cinder cones are monogenetic -- the result of a never-to-be-repeated eruption. Parícutin in Mexico, Diamond Head, Koko Head, Punchbowl Crater and some cinder cones on Mauna Kea are monogenetic cinder cones. Monogenetic eruptions can last for more than 10 years. Parícutin erupted from 1943 to 1952. List of cinder cones Volcanic cone – Landform of ejecta from a volcanic vent piled up in a conical shape Capulin Volcano National Monument
In volcanology, a lava dome or volcanic dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common in convergent plate boundary settings. Around 6% of eruptions on earth are lava dome forming; the geochemistry of lava domes can vary from basalt to rhyolite although the majority are of intermediate composition The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite. Existence of lava domes has been suggested for some domed structures on the Moon and Mars, e.g. the Martian surface in the western part of Arcadia Planitia and within Terra Sirenum. Lava domes evolve unpredictably, due to non-linear dynamics caused by crystallization and outgassing of the viscous lava in the dome's conduit.
Domes undergo various processes such as growth, collapse and erosion. Lava domes grow by exogenic dome growth; the former implies the enlargement of a lava dome due to the influx of magma into the dome interior, the latter refers to discrete lobes of lava emplaced upon the surface of the dome. It is the high viscosity of the lava that prevents it from flowing far from the vent from which it extrudes, creating a dome-like shape of sticky lava that cools in-situ. Spines and lava flows are common extrusive products of lava domes. Domes may reach heights of several hundred meters, can grow and for months, years, or centuries; the sides of these structures are composed of unstable rock debris. Due to the intermittent buildup of gas pressure, erupting domes can experience episodes of explosive eruption over time. If part of a lava dome collapses and exposes pressurized magma, pyroclastic flows can be produced. Other hazards associated with lava domes are the destruction of property from lava flows, forest fires, lahars triggered from re-mobilization of loose ash and debris.
Lava domes are one of the principal structural features of many stratovolcanoes worldwide. Lava domes are prone to unusually dangerous explosions since they can contain rhyolitic silica-rich lava. Characteristics of lava dome eruptions include shallow, long-period and hybrid seismicity, attributed to excess fluid pressures in the contributing vent chamber. Other characteristics of lava domes include their hemispherical dome shape, cycles of dome growth over long periods, sudden onsets of violent explosive activity; the average rate of dome growth may be used as a rough indicator of magma supply, but it shows no systematic relationship to the timing or characteristics of lava dome explosions. Gravitational collapse of a lava dome can produce a ash flow. A cryptodome is a dome-shaped structure created by accumulation of viscous magma at a shallow depth. One example of a cryptodome was in the May 1980 eruption of Mount St. Helens, where the explosive eruption began after a landslide caused the side of the volcano to fall, leading to explosive decompression of the subterranean cryptodome.
Coulées are lava domes that have experienced some flow away from their original position, thus resembling both lava domes and lava flows. The world's largest known dacite flow is the Chao dacite dome complex, a huge coulée flow-dome between two volcanoes in northern Chile; this flow is over 14 kilometres long, has obvious flow features like pressure ridges, a flow front 400 metres tall. There is another prominent coulée flow on the flank of Llullaillaco volcano, in Argentina, other examples in the Andes. Global Volcanism Program: Lava Domes USGS Photo glossary of volcano terms: Lava dome
A visitor center or centre, visitor information center, tourist information center, is a physical location that provides tourist information to visitors. A visitor center may be: A visitor center at a specific attraction or place of interest, such as a landmark, national park, national forest, or state park, providing information and in-depth educational exhibits and artifact displays. A film or other media display is used. If the site has permit requirements or guided tours, the visitor center is the place where these are coordinated. A tourist information center, providing visitors to a location with information on the area's attractions, lodgings and other items relevant to tourism; these centers are operated at the airport or other port of entry, by the local government or chamber of commerce. A visitor center is called an information center. A corporate visitor center, provides visitors with an accessible window into the corporation. Visitor centers used to provide basic information about the place, corporation or event they are celebrating, acting more as the entry way to a place.
The role of the visitor center has been evolving over the past 10 years to become more of an experience and to tell the story of the place or brand it represents. Many have become experiences in their own right. In the United Kingdom, there is a nationwide network of Tourist Information Centres run by the British Tourist Authority, represented online by the VisitBritain website and public relations organisation. Other TICs are run by local authorities or through private organisations such as local shops in association with BTA. In England, VisitEngland promotes domestic tourism. In Wales, the Welsh Government supports TICs through Visit Wales. In Scotland, the Scottish Government supports VisitScotland, the official tourist organisation of Scotland, which operates Tourist Information Centres across Scotland. In Poland there are special tables giving free information about tourist attractions. Offices are situated in interesting places in popular tourists' destinations and tables stay near monuments and important culture In North America, a welcome center is a rest area with a visitor center, located after the entrance from one state or province to another state or province or in some cases another country along an Interstate Highway or other freeway.
These information centers are operated by the state. The first example opened on 4 May 1935, next to US 12 in New Buffalo, near the Indiana state line. Many United States cities, such as Houston and Boca Raton, Florida, as well as counties and other areas smaller than states operate welcome centers, though with less facilities than state centers have. In Ontario, there are 11 Ontario Travel Information Centres located along 400-series highways. Peru features Iperú, Tourist Information and Assistance, a free service that provides tourist information for domestic and foreign travelers, the information covers destinations, recommended routes and licensed tourism companies in Peru, it provides assistance on various procedures or where tourists have problems of various kinds. Iperú receives suggestions for destinations and tourism companies operating in Peru. Iperú, Tourist Information and Assistance has a nationwide network represented online by the Peru.travel website, the 24/7 line 5748000, 31 local offices in 13 regions in all over Peru: Lima-Callao, Piura, Lambayeque, La Libertad, Arequipa, Puno, Cusco and Iquitos.
The official tourist organization or national tourist board of Peru is PromPerú, a national organization that promotes both tourism and international commerce of this country worldwide. In Australia, most visitor centres are local or state government-run, or in some cases as an association of tourism operators on behalf of the government managed by a board or executive; those that comply with a national accreditation programme use the italic "i" as pictured above. These visitor information centres provide information on the local area, perform services such as accommodation and tour bookings, flight/bus/train/hire car options, act as the first point of contact a visitor has with the town or region. Heritage center Heritage interpretation Interpretation center Nature center United States Capitol Visitor Center Communicating with visitors – 16 tips for visitor centers
Types of volcanic eruptions
Several types of volcanic eruptions—during which lava and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are named after famous volcanoes where that type of behavior has been observed; some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different types of eruptions; the most well-observed are magmatic eruptions, which involve the decompression of gas within magma that propels it forward. Phreatomagmatic eruptions are another type of volcanic eruption, driven by the compression of gas within magma, the direct opposite of the process powering magmatic activity; the third eruptive type is the phreatic eruption, driven by the superheating of steam via contact with magma. Within these wide-defining eruptive types are several subtypes; the weakest are Hawaiian and submarine Strombolian, followed by Vulcanian and Surtseyan.
The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions. Subglacial and phreatic eruptions are defined by their eruptive mechanism, vary in strength. An important measure of eruptive strength is Volcanic Explosivity Index, an order of magnitude scale ranging from 0 to 8 that correlates to eruptive types. Volcanic eruptions arise through three main mechanisms: Gas release under decompression causing magmatic eruptions Thermal contraction from chilling on contact with water causing phreatomagmatic eruptions Ejection of entrained particles during steam eruptions causing phreatic eruptionsThere are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels tephra. Effusive eruptions, are characterized by the outpouring of lava without significant explosive eruption. Volcanic eruptions vary in strength. On the one extreme there are effusive Hawaiian eruptions, which are characterized by lava fountains and fluid lava flows, which are not dangerous.
On the other extreme, Plinian eruptions are large and dangerous explosive events. Volcanoes are not bound to one eruptive style, display many different types, both passive and explosive in the span of a single eruptive cycle. Volcanoes do not always erupt vertically from a single crater near their peak, either; some volcanoes exhibit lateral and fissure eruptions. Notably, many Hawaiian eruptions start from rift zones, some of the strongest Surtseyan eruptions develop along fracture zones. Scientists believed that pulses of magma mixed together in the chamber before climbing upward—a process estimated to take several thousands of years, but Columbia University volcanologists found that the eruption of Costa Rica’s Irazú Volcano in 1963 was triggered by magma that took a nonstop route from the mantle over just a few months. The Volcanic Explosivity Index is a scale, for measuring the strength of eruptions, it is used by the Smithsonian Institution's Global Volcanism Program in assessing the impact of historic and prehistoric lava flows.
It operates in a way similar to the Richter scale for earthquakes, in that each interval in value represents a tenfold increasing in magnitude. The vast majority of volcanic eruptions are of VEIs between 0 and 2. Volcanic eruptions by VEI index Magmatic eruptions produce juvenile clasts during explosive decompression from gas release, they range in intensity from the small lava fountains on Hawaii to catastrophic Ultra-Plinian eruption columns more than 30 km high, bigger than the eruption of Mount Vesuvius in 79 that buried Pompeii. Hawaiian eruptions are a type of volcanic eruption, named after the Hawaiian volcanoes with which this eruptive type is hallmark. Hawaiian eruptions are the calmest types of volcanic events, characterized by the effusive eruption of fluid basalt-type lavas with low gaseous content; the volume of ejected material from Hawaiian eruptions is less than half of that found in other eruptive types. Steady production of small amounts of lava builds up the broad form of a shield volcano.
Eruptions are not centralized at the main summit as with other volcanic types, occur at vents around the summit and from fissure vents radiating out of the center. Hawaiian eruptions begin as a line of vent eruptions along a fissure vent, a so-called "curtain of fire." These die down. Central-vent eruptions, meanwhile take the form of large lava fountains, which can reach heights of hundreds of meters or more; the particles from lava fountains cool in the air before hitting the ground, resulting in the accumulation of cindery scoria fragments. If eruptive rates are high enough, they may form splatter-fed lava flows. Hawaiian eruptions are extremely long lived. Another Hawaiian volcanic feature is the formation of active lava lakes, self-maintaining pools of raw lava with a thin crust of semi-cooled rock. Flows from Hawaiian eruptions are basal
Departments of France
In the administrative divisions of France, the department is one of the three levels of government below the national level, between the administrative regions and the commune. Ninety-six departments are in metropolitan France, five are overseas departments, which are classified as regions. Departments are further subdivided into 334 arrondissements, themselves divided into cantons; each department is administered by an elected body called a departmental council. From 1800 to April 2015, these were called general councils; each council has a president. Their main areas of responsibility include the management of a number of social and welfare allowances, of junior high school buildings and technical staff, local roads and school and rural buses, a contribution to municipal infrastructures. Local services of the state administration are traditionally organised at departmental level, where the prefect represents the government; the departments were created in 1790 as a rational replacement of Ancien Régime provinces with a view to strengthen national unity.
All of them were named after physical geographical features, rather than after historical or cultural territories which could have their own loyalties. The division of France into departments was a project identified with the French revolutionary leader the Abbé Sieyès, although it had been discussed and written about by many politicians and thinkers; the earliest known suggestion of it is from 1764 in the writings of d'Argenson. They have inspired similar divisions in some of them former French colonies. Most French departments are assigned a two-digit number, the "Official Geographical Code", allocated by the Institut national de la statistique et des études économiques. Overseas departments have a three-digit number; the number is used, for example, in the postal code, was until used for all vehicle registration plates. While residents use the numbers to refer to their own department or a neighbouring one, more distant departments are referred to by their names, as few people know the numbers of all the departments.
For example, inhabitants of Loiret might refer to their department as "the 45". In 2014, President François Hollande proposed to abolish departmental councils by 2020, which would have maintained the departments as administrative divisions, to transfer their powers to other levels of governance; this reform project has since been abandoned. The first French territorial departments were proposed in 1665 by Marc-René d'Argenson to serve as administrative areas purely for the Ponts et Chaussées infrastructure administration. Before the French Revolution, France gained territory through the annexation of a mosaic of independent entities. By the close of the Ancien Régime, it was organised into provinces. During the period of the Revolution, these were dissolved in order to weaken old loyalties; the modern departments, as all-purpose units of the government, were created on 4 March 1790 by the National Constituent Assembly to replace the provinces with what the Assembly deemed a more rational structure.
Their boundaries served two purposes: Boundaries were chosen to break up France's historical regions in an attempt to erase cultural differences and build a more homogeneous nation. Boundaries were set so that every settlement in the country was within a day's ride of the capital of a department; this was a security measure, intended to keep the entire national territory under close control. This measure was directly inspired by the Great Terror, during which the government had lost control of many rural areas far from any centre of government; the old nomenclature was avoided in naming the new departments. Most were named after other physical features. Paris was in the department of Seine. Savoy became the department of Mont-Blanc; the number of departments 83, had been increased to 130 by 1809 with the territorial gains of the Republic and of the First French Empire. Following Napoleon's defeats in 1814–1815, the Congress of Vienna returned France to its pre-war size and the number of departments was reduced to 86.
In 1860, France acquired the County of Nice and Savoy, which led to the creation of three new departments. Two were added from the new Savoyard territory, while the department of Alpes-Maritimes was created from Nice and a portion of the Var department; the 89 departments were given numbers based on the alphabetical order of their names. The department of Bas-Rhin and parts of Meurthe, Moselle and Haut-Rhin were ceded to the German Empire in 1871, following France's defeat in the Franco-Prussian War. A small part of Haut-Rhin became known as the Territoire de Belfort; when France regained the ceded departments after World War I, the Territoire de Belfort was not re-integrated into Haut-Rhin. In 1922, it became France's 90th department; the Lorraine departments were not changed back to their original boundaries, a new Moselle department was created in the regaine
Raymond Poulidor, nicknamed "Pou-Pou", is a French former professional bicycle racer, who rode for Mercier his entire career. His career was distinguished, despite coinciding with two great riders - Jacques Anquetil and Eddy Merckx; this underdog position may have been the reason. He was known as "The Eternal Second", because he never won the Tour de France despite finishing in second place three times, in third place five times. Despite his consistency, he never once wore the yellow jersey as leader of the general classification in 14 Tours, of which he completed 12, he did win one Grand Tour, the 1964 Vuelta a España. Raymond Poulidor was the son of Martial and Maria Poulidor, small farmers outside the hamlet of Masbaraud-Mérignat, where the Creuse region east of Limoges meets the département of Haute-Vienne, he was born in the same year that his eventual directeur sportif, Antonin Magne, became world road race champion. Poulidor began working on the farm where, he remembered, "we had to work hard.
The need for working hands on the farm meant he left school at 14 though he wanted to continue his studies. Local entertainment went little further than village fairs, with coconut shies, sack-races, competitions for bottles of home-made jam... and inter-village cycle races. Poulidor rode on a bike given to him by André Marquet, who ran a cycle shop in nearby Sauviat-sur-Vige. Marquet took Poulidor to his first races by motorcycle. Success on a local level came and Poulidor added the money he won — which he said could be considerable at the time because the crowd put up prizes all through the race — to the family's income, he acquired his first racing licence when joined La Pédale Marchoise at La Forêt-Montboucher when he was 17. He came seventh at St-Mareil, he wanted to ride the local round of a national youth competition called the Premier Pas Dunlop. It fell in the middle of harvest and Poulidor could train only at night after 15 hours in the fields, he raced for three years as an amateur. It was only when Poulidor was taken into the army for compulsory national service in 1955 that he first travelled in a train.
Pierre Chany, a French reporter who followed 49 Tours de France, drew the comparison with Poulidor's eventual rival, Jacques Anquetil: by the time Poulidor first stepped into a train, Anquetil had been to Helsinki, ridden the Olympic Games, won a medal for France, turned professional and won the Grand Prix des Nations. Yet there was less than two years between them; the army sent Poulidor to the war going on in Algeria, where he worked as a driver and put on 12 kg through lack of exercise. In 1960 he lost the weight in a month, he won his first race after army service by six minutes. When he came second in the GP de Peyrat-le-Château and won 80,000 old francs, he calculated that he had won more in one race than he would have earned in six years on the farm, his farming background went before him and whenever he won a prize, other riders would laugh: "Hey, Pouli can buy himself another cow!" Poulidor referred to his background throughout his career, once remarking: "No race, however difficult, goes on as long as a harvest."
Poulidor was discovered in 1959 by another French rider, Bernard Gauthier, who said in the Belgian publication Coups de Pédales: It was me who brought Poulidor to Mercier where, like Desbats and me, he spent all his career. In a criterium, I saw this unknown, riding all around us. I saw him again in the Bol d'Or and I spoke to him, he said that he was in talks. When I got home, I spoke straight away to Antonin Magne, who asked me: "You're sure that he rides well?" I said I was and he contacted him and took him on. Poulidor said it happened near St Léonard-de-Noblat. Gauthier had just won his fourth Bordeaux–Paris, but... "...that day, I lapped him, I took four laps out of him though it was a difficult circuit. He was impressed."Magne offered Poulidor 25,000 old francs a month. Poulidor asked for 30,000. Magne countered that, more than he paid Gauthier and Louis Privat and refused. Aware that he had a rival for Anquetil, he conceded. Gauthier's confidence was justified when in 1961 Poulidor won Milan–San Remo in his second season as a professional.
He started the race stung by Press criticism of his tactical sense. Poulidor got off to a bad start in Milan–San Remo when he punctured before halfway and lost two minutes. Magne insisted that he chase back to the race, which he did, catching up in time to ride the Capo Verde hill with 20 km to go, he recovered fast enough to counter an attack by Jean-Claude Annaert, catching him with the Dutchman Ab Geldermans, who had won the previous year's Liège–Bastogne–Liège. Poulidor attacked and dropped Annaert left Geldermans, he had a lead of 20 seconds at the summit. He stayed clear alone to win by three seconds from Rik Van Looy of Belgium. Poulidor's rivalry with Anquetil is a legend in cycling. While a good climber, Poulidor had a hard time matching Anquetil in the individual time trial having victory snatched from him by losing time in time-trial stages of the Tour de France. Poulidor's riding style was aggressive and attacking, whereas Anquetil preferred to control the race in the mountains and win time in the time-trials.
Poulidor became the darling of the French public, to the ire of Anquetil. Poulidor's mid-France upbringing and his slow Limousin speech contrasted with Anquetil's northern backg
Clermont-Ferrand is a city and commune of France, in the Auvergne-Rhône-Alpes region, with a population of 141,569. Its metropolitan area had 467,178 inhabitants at the 2011 census, it is the prefecture of the Puy-de-Dôme department. Olivier Bianchi is its current mayor. Clermont-Ferrand sits on the plain of Limagne in the Massif Central and is surrounded by a major industrial area; the city known for the chain of volcanoes, the Chaîne des Puys surrounding it, including the dormant volcano Puy de Dôme (10 kilometres, one of the highest, topped by communications towers, visible from the city. Clermont-Ferrand hosts the Clermont-Ferrand International Short Film Festival, one of the world's leading international festivals for short films, it is home to the corporate headquarters of Michelin, the global tyre company founded there more than 100 years ago. Clermont-Ferrand's most famous public square is Place de Jaude, on which stands a grand statue of Vercingetorix sitting imperiously on a horse and holding a sword.
The inscription reads: J'ai pris les armes pour la liberté de tous. This statue was sculpted by Frédéric Bartholdi, who created the Statue of Liberty. Clermont-Ferrand's first name was Augusta Nemetum, it was born on the central knoll where the cathedral is situated today, known as Nemossos. It overlooked the capital of Gaulish Avernie; the fortified castle of Clarus Mons gave its name to the whole town in 848, to which the small episcopal town of Montferrand was attached in 1731, together taking the name of Clermont-Ferrand. The old part of Clermont is delimited by the route of the ramparts, as they existed at the end of the Middle Ages; the town of Clermont-Ferrand came about with the joining together of two separate towns and Montferrand, decreed by Louis XIII and confirmed by Louis XV. Clermont ranks among the oldest cities of France; the first known mention was by the Greek geographer Strabo, who called it the "metropolis of the Arverni". The city was at that time called Nemessos – a Gaulish word for a sacred forest, was situated on the mound where the cathedral of Clermont-Ferrand stands today.
Somewhere in the area around Nemossos the Arverni chieftain Vercingetorix was born around 72 BC. Nemossos was situated not far from the plateau of Gergovia, where Vercingetorix repulsed the Roman assault at the Battle of Gergovia in 52 BC. After the Roman conquest, the city became known as Augustonemetum sometime in the 1st century, a name which combined its original Gallic name with that of the Emperor Augustus, its population was estimated at 15,000–30,000 in the 2nd century, making it one of the largest cities of Roman Gaul. It became Arvernis in the 3rd century, taking its name, like other Gallic cities in this era, from the people who lived within its walls; the city became the seat of a bishop in the 5th century, at the time of the bishop Namatius or Saint Namace, who built a cathedral here described by Gregory of Tours. Clermont went through a dark period after the disappearance of the Roman Empire and during the whole High Middle Ages, marked by pillaging by the peoples who invaded Gaul.
Between 471 and 475, Auvergne was the target of Visigothic expansion, the city was besieged, including once by Euric. Although defended by Sidonius Apollinaris, at the head of the diocese from 468 to 486, the patrician Ecdicius, the city was ceded to the Visigoths by emperor Julius Nepos in 475 and became part of the Visigothic kingdom until 507. A generation it became part of the Kingdom of the Franks. On 8 November 535 the first Council of Clermont opened at Arvernis, with fifteen bishops participating, including Caesarius of Arles, Nizier of Lyons, Bishop of Trier, Saint Hilarius, Bishop of Mende; the Council issued 16 decrees. The second canon reiterythe principal that the granting of episcopal dignity must be according to the merits and not as a result of intrigues. In 570, Bishop Avitus ordered the Jews of the city, who numbered over 500, to accept Christian baptism or be expelled. In 848, the city was renamed Clairmont, after the castle Clarus Mons. During this era, it was an episcopal city ruled by its bishop.
Clermont was not spared by the Vikings at the time of the weakening of the Carolingian Empire: it was ravaged by the Normans under Hastein or Hastingen in 862 and 864 and, while its bishop Sigon carried out reconstruction work, again in 898. Bishop Étienne II built a new Romanesque cathedral, consecrated in 946, it was entirely replaced by the current Gothic cathedral, though the crypt survives and the towers were only replaced in the 19th century. Clermont was the starting point of the First Crusade, in which Christendom sought to free Jerusalem from Muslim domination. Pope Urban II preached the crusade at the Second Council of Clermont. In 1120, following repeated crises between the counts of Auvergne and the bishops of Clermont and in order to counteract the clergy’s power, the counts founded the rival city of Montferrand on a mound next to the fortifications of Clermont, on the model of the new cities of the Midi that appeared in the 12th and 13th centuries; until the early modern period, the two remained separate cities: an episcopal city.
Clermont became a royal city in 1551, in 1610, the inseparable property of the French Crown. On 15 April 1630 the Edict of Troyes joined the two cities of Montferrand. T