The Vogelsberg is a large volcanic mountain range in the German Central Uplands in the state of Hesse, separated from the Rhön Mountains by the Fulda river valley. Emerging 19 million years ago, the Vogelsberg is Central Europe's largest basalt formation, consisting of a multitude of layers that descend from their peak in ring-shaped terraces to the base; the main peaks of the Vogelsberg are the Taufstein, 773.0 metres, Hoherodskopf, 763 metres, both now within the High Vogelsberg Nature Park. The Vogelsberg lies in the county of Vogelsbergkreis, around 60 kilometres northeast of Frankfurt between the towns of Alsfeld, Fulda, Büdingen and Nidda. To the northeast is the Knüll, to the east the Rhön, to the southeast the Spessart and to the southwest the low-lying Wetterau, which transitions to the South Hessian lowlands of the Rhine-Main region. In the opposite direction, to the northwest, the Vogelsberg transitions into parts of the West Hesse Highlands, whilst retaining the name and the basalt rocks that bear its name continue well beyond the actual Vogelsberg.
The Vogelsberg is the largest contiguous volcanic region in Central Europe with an area of 2,500 square kilometres. It comprises many individual volcanoes, which are superimposed, thus it consists of a multitude of overlapping basalt terraces, which descend from the Oberwald, the high central plateau, 600 to 773 metres high, in series of stepped rings to the edges of the mountain region. Its present appearance, reminiscent of a large flat, shield-shaped volcano with a central dome, is the result of an interplay of uplift processes and ablation acting on all sides; the volcanic activity in the Vogelsberg, as well as that of the North Hessian Volcanic Region to the north which extends as far as Adelebsen in Lower Saxony, is connected with fault block activity that, during the Tertiary, led to the formation of the Lower Hessian Basin. It began in North Hesse about 20 million years ago during the lower Miocene, reached a peak about 13-12 million years ago and came to an end about 7 million years ago, during the upper Miocene.
The volcanism of the Vogelsberg was active during the Middle Miocene, according to potassium-argon dating 18.5-10 million years ago, reaching its peak 17-15 million years ago. As a result of volcanic activity basaltic lava and pyroclastic deposits were formed. During the course of this volcanicity and phonolite were produced in the early stages alkali-olivine basalts were deposited, which alternated with tholeiites; these volcanic products overlaid a basement of bunter sandstone and tertiary sands, in small areas in the east rocks of the muschelkalk and keuper. Erosion following the Miocene wore away the contiguous basalt nappes, which reached as far as the area of the Lower Main, back to isolated deposits in the central complex. Under tropical to subtropical conditions, the volcanic rocks were turned into red clays by lateritic weathering. In many places, red clays collected and bauxite was formed; these deposits were mined over a long period of time in order to produce raw materials for industry, the basalt was and still is a popular raw material for gravel and natural stone production.
The division of the Vogelsberg into individual natural regions is based, on the one hand, on the relief of the mountain range from its highest point towards the outside and, on the other hand, on its river catchments which radiate outwards: the catchments of the Eder, Lower Fulda and Lahn. The following natural regions form the Vogelsberg: 350 Lower Vogelsberg 350.1 Northern Lower Vogelsberg 350.2 Northwestern Lower Vogelsberg 350.3 Eastern Lower Vogelsberg 350.4 Western Lower Vogelsberg 350.5 Southern Lower Vogelsberg 350.6 Giesel Forest 351 High Vogelsberg 351.0 Western High Vogelsberg 351.1 Eastern High Vogelsberg 351.2 OberwaldSoils and rocks are, in all parts of the Vogelsberg – with the exception of the Giesel Forest – similar, but average annual temperatures drop noticeably towards the centre of the range and the annual precipitation rises towards the Oberwald to an average of 1,200 mm. The basalt areas of the Vogelsberg continue towards the east and north into its neighbouring natural regions, whilst the Giesel Forest in the east is on bunter sandstone, like the rest of the natural regions towards the east.
The Vogelsberg massif has stone runs of basalt and tuff, raised bogs and areas of ancient woodland. Numerous hiking trails cross, not only the Oberwald, but the rest of the area; the Oberwald is the heart of the Vogelsberg and is wooded. In outer areas of the Vogelsberg, by contrast, there is a tapestry of green pasture, arable fields and woodlands. Large parts of the Oberwald are protected. For example, the beech wood in the Taufstein Nature Reserve has been left to manage itself since 1906. On the northern slopes of the Taufstein are large stone runs of basalt; the valleys of the Western and Eastern High Vogelsberg lie at heights of over 500 m in the north. In the west, some descend to under 400 m. In the main, the boundaries follow the watersheds of the source region of the most important rivers and that of the Rhine-Weser watershed, which runs from southeast to northwest, the Lahn-Main watershed wh
Hungary is a country in Central Europe. Spanning 93,030 square kilometres in the Carpathian Basin, it borders Slovakia to the north, Ukraine to the northeast, Austria to the northwest, Romania to the east, Serbia to the south, Croatia to the southwest, Slovenia to the west. With about 10 million inhabitants, Hungary is a medium-sized member state of the European Union; the official language is Hungarian, the most spoken Uralic language in the world, among the few non-Indo-European languages to be spoken in Europe. Hungary's capital and largest city is Budapest; the territory of modern Hungary was for centuries inhabited by a succession of peoples, including Celts, Germanic tribes, West Slavs and the Avars. The foundations of the Hungarian state were established in the late ninth century CE by the Hungarian grand prince Árpád following the conquest of the Carpathian Basin, his great-grandson Stephen I ascended the throne in 1000, converting his realm to a Christian kingdom. By the 12th century, Hungary became a regional power, reaching its cultural and political height in the 15th century.
Following the Battle of Mohács in 1526, Hungary was occupied by the Ottoman Empire. It came under Habsburg rule at the turn of the 18th century, joined Austria to form the Austro–Hungarian Empire, a major European power; the Austro-Hungarian Empire collapsed after World War I, the subsequent Treaty of Trianon established Hungary's current borders, resulting in the loss of 71% of its territory, 58% of its population, 32% of ethnic Hungarians. Following the tumultuous interwar period, Hungary joined the Axis Powers in World War II, suffering significant damage and casualties. Hungary became a satellite state of the Soviet Union, which contributed to the establishment of a socialist republic spanning four decades; the country gained widespread international attention as a result of its 1956 revolution and the seminal opening of its previously-restricted border with Austria in 1989, which accelerated the collapse of the Eastern Bloc. On 23 October 1989, Hungary became a democratic parliamentary republic.
Hungary is an OECD high-income economy and has the world's 58th largest economy by PPP. It ranks 45th on the Human Development Index, owing in large part to its social security system, universal health care, tuition-free secondary education. Hungary's rich cultural history includes significant contributions to the arts, literature, sports and technology, it is the 13th most popular tourist destination in Europe, attracting 15.8 million international tourists in 2017, owing to attractions such as the largest thermal water cave system in the world, second largest thermal lake, the largest lake in Central Europe and the largest natural grasslands in Europe. Hungary's cultural and academic prominence classify it as a middle power in global affairs. Hungary joined the European Union in 2004 and has been part of the Schengen Area since 2007, it is a member of numerous international organizations, including the United Nations, NATO, WTO, World Bank, the AIIB, the Council of Europe, the Visegrád Group.
The "H" in the name of Hungary is most due to early founded historical associations with the Huns, who had settled Hungary prior to the Avars. The rest of the word comes from the Latinized form of Byzantine Greek Oungroi. According to an explanation,the Greek name was borrowed from Old Bulgarian ągrinŭ, in turn borrowed from Oghur-Turkic Onogur. Onogur was the collective name for the tribes who joined the Bulgar tribal confederacy that ruled the eastern parts of Hungary after the Avars; the Hungarian endonym is Magyarország, composed of ország. The word magyar is taken from the name of one of the seven major semi-nomadic Hungarian tribes, magyeri; the first element magy is from Proto-Ugric *mäńć-'man, person' found in the name of the Mansi people. The second element eri,'man, lineage', survives in Hungarian férj'husband', is cognate with Mari erge'son', Finnish archaic yrkä'young man'; the Roman Empire conquered the territory west of the Danube between 35 and 9 BC. From 9 BC to the end of the 4th century, Pannonia was part of the Roman Empire, located within part of Hungary's territory.
Around AD 41–54, a 500-strong cavalry unit created the settlement of Aquincum and a Roman legion of 6,000 men was stationed here by AD 89. A civil city grew in the neighbourhood of the military settlement and in AD 106 Aquincum became the focal point of the commercial life of this area and the capital city of the province of Pannonia Inferior; this area now corresponds to the Óbuda district of Budapest, with the Roman ruins now forming part of the modern Aquincum museum. Came the Huns, a Central Asian tribe who built a powerful empire. After Hunnish rule, the Germanic Ostrogoths and Gepids, the Avar Khaganate, had a presence in the Carpathian Basin. In the 9th century, East Francia, the First Bulgarian Empire and Great Moravia ruled the territory of the Carpathian Basin; the freshly unified Hungarians led by Árpád, settled in the Carpathian Basin starting in 895. According to linguistic evidence, they originated from an ancient Uralic-speaking population that inhabited the forested area between the Volga River and the Ural Mountains.
As a federation of united tribes, Hungary was established in 895, some 50 years after the division of the Carolingian Empire at the Treaty of Verdun in 843, before the unification of the Anglo-Saxon king
In geography, a plain is a flat, sweeping landmass that does not change much in elevation. Plains occur as lowlands along the bottoms of valleys or on the doorsteps of mountains, as coastal plains, as plateaus or uplands. In a valley, a plain is enclosed on two sides, but in other cases a plain may be delineated by a complete or partial ring of hills, by mountains, or by cliffs. Where a geological region contains more than one plain, they may be connected by a pass. Coastal plains would rise from sea level until they run into elevated features such as mountains or plateaus. Plains are one of the major landforms on earth, where they are present on all continents, would cover more than one-third of the world’s land area. Plains may have been formed from flowing lava, deposited by water, wind, or formed by erosion by these agents from hills and mountains. Plains would be under the grassland, savannah or tundra biomes. In a few instances and rainforests can be plains. Plains in many areas are important for agriculture because where the soils were deposited as sediments they may be deep and fertile, the flatness facilitates mechanization of crop production.
Depositional plains formed by the deposition of materials brought by various agents of transportation such as glaciers, rivers and wind. Their fertility and economic relevance depend on the types of sediments that are laid down; the types of depositional plains include: Abyssal plains, flat or gently sloping areas of the deep ocean basin. Planitia, the Latin word for plain, is used in the naming of plains on extraterrestrial objects, such as Hellas Planitia on Mars or Sedna Planitia on Venus. Alluvial plains, which are formed by rivers and which may be one of these overlapping types: Alluvial plains, formed over a long period of time by a river depositing sediment on their flood plains or beds, which become alluvial soil; the difference between a flood plain and an alluvial plain is: a flood plain represents areas experiencing flooding regularly in the present or whereas an alluvial plain includes areas where a flood plain is now and used to be, or areas which only experience flooding a few times a century.
Flood plain, adjacent to a lake, stream, or wetland that experiences occasional or periodic flooding. Scroll plain, a plain through which a river meanders with a low gradient. Glacial plains, formed by the movement of glaciers under the force of gravity: Outwash plain, a glacial out-wash plain formed of sediments deposited by melt-water at the terminus of a glacier. Sandar consist of stratified gravel and sand. Till plains, plain of glacial till that form when a sheet of ice becomes detached from the main body of a glacier and melts in place depositing the sediments it carries. Till plains are composed of unsorted material of all sizes. Lacustrine plains, plains that formed in a lacustrine environment, that is, as the bed of a lake. Lava plains, formed by sheets of flowing lava. Erosional plains have been leveled by various agents of denudation such as running water, rivers and glacier which wear out the rugged surface and smoothens them. Plain resulting from the action of these agents of denudation are called peneplains while plains formed from wind action are called pediplains.
Structural plains are undisturbed horizontal surfaces of the Earth. They are structurally depressed areas of the world that make up some of the most extensive natural lowlands on the Earth's surface. Altiplano Altiplano Cundiboyacense Caroni Plain Chilean Central Valley Gran Chaco Los Llanos Venezuelan Llanos Argentine Pampas Atlantic coastal plain Carrizo Plain Great Plains Gulf Coastal Plain Interior Plains Lake Superior Lowland Laramie Plains Mississippi Alluvial Plain Oxnard Plain Snake River Plain Chianan Plain Depsang Plains Kantō Plain Kedu Plain Kewu Plain Mallig Plains Nōbi Plain North China Plain Osaka Plain Pingtung Plain Sarobetsu plain West Siberian Plain Yilan Plain Bhuikhel Depsang Plains Dooars Eastern coastal plains Indo-Gangetic Plains More plains North Bengal plains Punjab Plains Terai Utkal Plains Western coastal plains Al-Ghab Plain Aleppo plateau Ararat plain Israeli coastal plain Khuzestan Plain Mugan plain Nineveh Plains Shiraki Plain Limagne North German Plain Ochsenfeld Pannonian Basin Parndorf Plain Westphalian Lowland Bărăgan Plain Danubian Plain Dnieper Lowland East European Plain European Plain Great Hungarian Plain Kosovo field Little Hungarian Plain Pannonian Steppe Polesian Lowland Upper Thracian Plain Wallachian Plain Cheshire Plain Hardangervidda Kaffiøyra Muddus plains North
Poland the Republic of Poland, is a country located in Central Europe. It is divided into 16 administrative subdivisions, covering an area of 312,696 square kilometres, has a temperate seasonal climate. With a population of 38.5 million people, Poland is the sixth most populous member state of the European Union. Poland's capital and largest metropolis is Warsaw. Other major cities include Kraków, Łódź, Wrocław, Poznań, Gdańsk, Szczecin. Poland is bordered by the Baltic Sea, Russia's Kaliningrad Oblast and Lithuania to the north and Ukraine to the east and Czech Republic, to the south, Germany to the west; the establishment of the Polish state can be traced back to AD 966, when Mieszko I, ruler of the realm coextensive with the territory of present-day Poland, converted to Christianity. The Kingdom of Poland was founded in 1025, in 1569 it cemented its longstanding political association with the Grand Duchy of Lithuania by signing the Union of Lublin; this union formed the Polish–Lithuanian Commonwealth, one of the largest and most populous countries of 16th and 17th century Europe, with a uniquely liberal political system which adopted Europe's first written national constitution, the Constitution of 3 May 1791.
More than a century after the Partitions of Poland at the end of the 18th century, Poland regained its independence in 1918 with the Treaty of Versailles. In September 1939, World War II started with the invasion of Poland by Germany, followed by the Soviet Union invading Poland in accordance with the Molotov–Ribbentrop Pact. More than six million Polish citizens, including 90% of the country's Jews, perished in the war. In 1947, the Polish People's Republic was established as a satellite state under Soviet influence. In the aftermath of the Revolutions of 1989, most notably through the emergence of the Solidarity movement, Poland reestablished itself as a presidential democratic republic. Poland is regional power, it has the fifth largest economy by GDP in the European Union and one of the most dynamic economies in the world achieving a high rank on the Human Development Index. Additionally, the Polish Stock Exchange in Warsaw is the largest and most important in Central Europe. Poland is a developed country, which maintains a high-income economy along with high standards of living, life quality, safety and economic freedom.
Having a developed school educational system, the country provides free university education, state-funded social security, a universal health care system for all citizens. Poland has 15 UNESCO World Heritage Sites. Poland is a member state of the European Union, the Schengen Area, the United Nations, NATO, the OECD, the Three Seas Initiative, the Visegrád Group; the origin of the name "Poland" derives from the West Slavic tribe of Polans that inhabited the Warta river basin of the historic Greater Poland region starting in the 6th century. The origin of the name "Polanie" itself derives from the early Slavic word "pole". In some languages, such as Hungarian, Lithuanian and Turkish, the exonym for Poland is Lechites, which derives from the name of a semi-legendary ruler of Polans, Lech I. Early Bronze Age in Poland begun around 2400 BC, while the Iron Age commenced in 750 BC. During this time, the Lusatian culture, spanning both the Bronze and Iron Ages, became prominent; the most famous archaeological find from the prehistory and protohistory of Poland is the Biskupin fortified settlement, dating from the Lusatian culture of the early Iron Age, around 700 BC.
Throughout the Antiquity period, many distinct ancient ethnic groups populated the regions of what is now Poland in an era that dates from about 400 BC to 500 AD. These groups are identified as Celtic, Slavic and Germanic tribes. Recent archeological findings in the Kujawy region, confirmed the presence of the Roman Legions on the territory of Poland; these were most expeditionary missions sent out to protect the amber trade. The exact time and routes of the original migration and settlement of Slavic peoples lacks written records and can only be defined as fragmented; the Slavic tribes who would form Poland migrated to these areas in the second half of the 5th century AD. Up until the creation of Mieszko's state and his subsequent conversion to Christianity in 966 AD, the main religion of Slavic tribes that inhabited the geographical area of present-day Poland was Slavic paganism. With the Baptism of Poland the Polish rulers accepted Christianity and the religious authority of the Roman Church.
However, the transition from paganism was not a smooth and instantaneous process for the rest of the population as evident from the pagan reaction of the 1030s. Poland began to form into a recognizable unitary and territorial entity around the middle of the 10th century under the Piast dynasty. Poland's first documented ruler, Mieszko I, accepted Christianity with the Baptism of Poland in 966, as the new official religion of his subjects; the bulk of the population converted in the course of the next few centuries. In 1000, Boleslaw the Brave, continuing the policy of his father Mieszko, held a Congress of Gniezno and created the metropolis of Gniezno and the dioceses of Kraków, Kołobrzeg, Wrocław. However, the pagan unrest led to the transfer of the capital to Kraków in 1038 by Casimir I the Restorer. In 1109, Prince Bolesław III Wrymouth defeated the King of Germany Henry V at the Battle of Hundsfeld, stopping the Ge
In geology, the places known as hotspots or hot spots are volcanic regions thought to be fed by underlying mantle, anomalously hot compared with the surrounding mantle. Their position on the Earth's surface is independent of tectonic plate boundaries. There are two hypotheses. One suggests that hotspots are due to mantle plumes that rise as thermal diapirs from the core–mantle boundary; the other hypothesis is that lithospheric extension permits the passive rising of melt from shallow depths. This hypothesis considers the term "hotspot" to be a misnomer, asserting that the mantle source beneath them is, in fact, not anomalously hot at all. Well-known examples include the Hawaii and Yellowstone hotspots; the origins of the concept of hotspots lie in the work of J. Tuzo Wilson, who postulated in 1963 that the formation of the Hawaiian Islands resulted from the slow movement of a tectonic plate across a hot region beneath the surface, it was postulated that hotspots are fed by narrow streams of hot mantle rising from the Earth's core–mantle boundary in a structure called a mantle plume.
Whether or not such mantle plumes exist is the subject of a major controversy in Earth science. Estimates for the number of hotspots postulated to be fed by mantle plumes have ranged from about 20 to several thousands, over the years, with most geologists considering a few tens to exist. Hawaii, Réunion, Galápagos, Iceland are some of the most active volcanic regions to which the hypothesis is applied. Most hotspot volcanoes are basaltic; as a result, they are less explosive than subduction zone volcanoes, in which water is trapped under the overriding plate. Where hotspots occur in continental regions, basaltic magma rises through the continental crust, which melts to form rhyolites; these rhyolites can form violent eruptions. For example, the Yellowstone Caldera was formed by some of the most powerful volcanic explosions in geologic history. However, when the rhyolite is erupted, it may be followed by eruptions of basaltic magma rising through the same lithospheric fissures. An example of this activity is the Ilgachuz Range in British Columbia, created by an early complex series of trachyte and rhyolite eruptions, late extrusion of a sequence of basaltic lava flows.
The hotspot hypothesis is now linked to the mantle plume hypothesis. Hotspot volcanoes are considered to have a fundamentally different origin from island arc volcanoes; the latter form over subduction zones, at converging plate boundaries. When one oceanic plate meets another, the denser plate is forced downward into a deep ocean trench; this plate, as it is subducted, releases water into the base of the over-riding plate, this water mixes with the rock, thus changing its composition causing some rock to melt and rise. It is this; the joint mantle plume/hotspot hypothesis envisages the feeder structures to be fixed relative to one another, with the continents and seafloor drifting overhead. The hypothesis thus predicts. Examples are Yellowstone, which lies at the end of a chain of extinct calderas, which become progressively older to the west. Another example is the Hawaiian archipelago, where islands become progressively older and more eroded to the northwest. Geologists have tried to use hotspot volcanic chains to track the movement of the Earth's tectonic plates.
This effort has been vexed by the lack of long chains, by the fact that many are not time-progressive and by the fact that hotspots do not appear to be fixed relative to one another Hawaiian–Emperor seamount chain Louisville Ridge Walvis Ridge Kodiak–Bowie Seamount chain Cobb–Eickelberg Seamount chain New England Seamounts Anahim Volcanic Belt Mackenzie dike swarm Great Meteor hotspot track St. Helena Seamount Chain – Cameroon Volcanic Line Southern Mascarene Plateau–Chagos-Maldives-Laccadive Ridge Ninety East Ridge Tuamotu–Line Island chain Austral–Gilbert–Marshall chain Juan Fernández Ridge Tasmantid Seamount Chain Eifel hotspot 50°12′N 6°42′E, w= 1 az= 082° ±8° rate= 12 ±2 mm/yr Iceland hotspot 64°24′N 17°18′W Eurasian Plate, w=.8 az= 075° ±10° rate= 5 ±3 mm/yr North American Plate, w=.8 az= 287° ±10° rate= 15 ±5 mm/yr Possibly related to the North Atlantic continental rifting, Greenland. Azores hotspot 37°54′N 26°00′W Eurasian Plate, w=.5 az= 110° ±12° North American Plate, w=.3 az= 280° ±15° Jan Mayen hotspot 71°N 9°W Hainan hotspot 20°N 110°E, az= 000° ±15° Mount Etna 37°45.304′N 14°59.715′E Hoggar hotspot 23°18′N 5°36′E, w=.3 az= 046° ±12° Tibesti hotspot 20°48′N 17°30′E, w=.2 az= 030° ±15° Jebel Marra/Darfur hotspot 13°00′N 24°12′E, w=.5 az= 045° ±8° Afar hotspot 7°00′N 39°30′E, w=.2 az= 030° ±15° rate= 16 ±8 mm/yr Possibly related to the Afar Triple Junction, 30 Ma.
Cameroon hotspot 2°00′N 5°06′E, w=.3 az= 032° ±3° rate= 15 ±5 mm/yr Madeira hotspot 32°36′N 17°18′W, w=.3 az= 055° ±15° rate= 8 ±3 mm/yr Canary hotspot 28°12′N 18°00′W, w= 1 az= 094° ±8° rate= 20 ±4 mm/yr New England/Great Meteor hotspot 29°24′N 29°12′W, w=.8 az= 040° ±10° Cape Verde hotspot 16°00′N 24°00′W, w=.2 az= 060° ±30° St. Helena hotspot 16°30′S 9°30′W, w= 1 az= 078° ±5° rate= 20 ±3 mm/yr Gough
The British Isles are a group of islands in the North Atlantic off the north-western coast of continental Europe that consist of the islands of Great Britain, the Isle of Man, the Hebrides and over six thousand smaller isles. They have a total area of about 315,159 km2 and a combined population of 72 million, include two sovereign states, the Republic of Ireland, the United Kingdom of Great Britain and Northern Ireland; the islands of Alderney, Jersey and Sark, their neighbouring smaller islands, are sometimes taken to be part of the British Isles though, as islands off the coast of France, they do not form part of the archipelago. The oldest rocks in the group are in the north west of Scotland and North Wales and are 2.7 billion years old. During the Silurian period, the north-western regions collided with the south-east, part of a separate continental landmass; the topography of the islands is modest in scale by global standards. Ben Nevis rises to an elevation of only 1,345 metres, Lough Neagh, notably larger than other lakes in the island group, covers 390 square kilometres.
The climate is temperate marine, with warm summers. The North Atlantic drift brings significant moisture and raises temperatures 11 °C above the global average for the latitude; this led to a landscape, long dominated by temperate rainforest, although human activity has since cleared the vast majority of forest cover. The region was re-inhabited after the last glacial period of Quaternary glaciation, by 12,000 BC, when Great Britain was still part of a peninsula of the European continent. Ireland, which became an island by 12,000 BC, was not inhabited until after 8000 BC. Great Britain became an island by 5600 BC. Hiberni and Britons tribes, all speaking Insular Celtic, inhabited the islands at the beginning of the 1st millennium AD. Much of Brittonic-occupied Britain was conquered by the Roman Empire from AD 43; the first Anglo-Saxons arrived as Roman power waned in the 5th century, dominated the bulk of what is now England. Viking invasions began in the 9th century, followed by more permanent settlements and political change in England.
The Norman conquest of England in 1066 and the Angevin partial conquest of Ireland from 1169 led to the imposition of a new Norman ruling elite across much of Britain and parts of Ireland. By the Late Middle Ages, Great Britain was separated into the Kingdoms of England and Kingdom of Scotland, while control in Ireland fluxed between Gaelic kingdoms, Hiberno-Norman lords and the English-dominated Lordship of Ireland, soon restricted only to The Pale; the 1603 Union of the Crowns, Acts of Union 1707 and Acts of Union 1800 attempted to consolidate Britain and Ireland into a single political unit, the United Kingdom of Great Britain and Ireland, with the Isle of Man and the Channel Islands remaining as Crown Dependencies. The expansion of the British Empire and migrations following the Irish Famine and Highland Clearances resulted in the dispersal of some of the islands' population and culture throughout the world, a rapid depopulation of Ireland in the second half of the 19th century. Most of Ireland seceded from the United Kingdom after the Irish War of Independence and the subsequent Anglo-Irish Treaty, with six counties remaining in the UK as Northern Ireland.
The term "British Isles" is controversial in Ireland, where there are nationalist objections to its usage. The Government of Ireland does not recognise the term, its embassy in London discourages its use. Britain and Ireland is used as an alternative description, Atlantic Archipelago has seen limited use in academia; the earliest known references to the islands as a group appeared in the writings of sea-farers from the ancient Greek colony of Massalia. The original records have been lost. In the 1st century BC, Diodorus Siculus has Prettanikē nēsos, "the British Island", Prettanoi, "the Britons". Strabo used Βρεττανική, Marcian of Heraclea, in his Periplus maris exteri, used αἱ Πρεττανικαί νῆσοι to refer to the islands. Historians today, though not in absolute agreement agree that these Greek and Latin names were drawn from native Celtic-language names for the archipelago. Along these lines, the inhabitants of the islands were called the Πρεττανοί; the shift from the "P" of Pretannia to the "B" of Britannia by the Romans occurred during the time of Julius Caesar.
The Greco-Egyptian scientist Claudius Ptolemy referred to the larger island as great Britain and to Ireland as little Britain in his work Almagest. In his work, Geography, he gave these islands the names Alwion and Mona, suggesting these may have been names of the individual islands not known to him at the time of writing Almagest; the name Albion appears to have fallen out of use sometime after the Roman conquest of Great Britain, after which Britain became the more commonplace name for the island called Great Britain. The earliest known use of the phrase Brytish Iles in the English language is dated 1577 in a work by John Dee. Today, this name is seen by some as carrying imperialist overtones although it is still used. Other names used to describe the islands include the Anglo-Celtic Isles, Atlantic archipelago, British-Irish Isles and Ireland, UK
A mountain is a large landform that rises above the surrounding land in a limited area in the form of a peak. A mountain is steeper than a hill. Mountains are formed through tectonic forces or volcanism; these forces can locally raise the surface of the earth. Mountains erode through the action of rivers, weather conditions, glaciers. A few mountains are isolated summits. High elevations on mountains produce colder climates than at sea level; these colder climates affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction and recreation, such as mountain climbing; the highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m. There is no universally accepted definition of a mountain.
Elevation, relief, steepness and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which to the adjacent elevation, is impressive or notable."Whether a landform is called a mountain may depend on local usage. Mount Scott outside Lawton, Oklahoma, USA, is only 251 m from its base to its highest point. Whittow's Dictionary of Physical Geography states "Some authorities regard eminences above 600 metres as mountains, those below being referred to as hills." In the United Kingdom and the Republic of Ireland, a mountain is defined as any summit at least 2,000 feet high, whilst the official UK government's definition of a mountain, for the purposes of access, is a summit of 600 metres or higher. In addition, some definitions include a topographical prominence requirement 100 or 500 feet. At one time the U.
S. Board on Geographic Names defined a mountain as being 1,000 feet or taller, but has abandoned the definition since the 1970s. Any similar landform lower. However, the United States Geological Survey concludes that these terms do not have technical definitions in the US; the UN Environmental Programme's definition of "mountainous environment" includes any of the following: Elevation of at least 2,500 m. Using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, 14% of Africa; as a whole, 24% of the Earth's land mass is mountainous. There are three main types of mountains: volcanic and block. All three types are formed from plate tectonics: when portions of the Earth's crust move and dive. Compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features; the height of the feature makes it either a hill or, if steeper, a mountain. Major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity.
Volcanoes are formed when a plate is pushed at a mid-ocean ridge or hotspot. At a depth of around 100 km, melting occurs in rock above the slab, forms magma that reaches the surface; when the magma reaches the surface, it builds a volcanic mountain, such as a shield volcano or a stratovolcano. Examples of volcanoes include Mount Pinatubo in the Philippines; the magma does not have to reach the surface in order to create a mountain: magma that solidifies below ground can still form dome mountains, such as Navajo Mountain in the US. Fold mountains occur when two plates collide: shortening occurs along thrust faults and the crust is overthickened. Since the less dense continental crust "floats" on the denser mantle rocks beneath, the weight of any crustal material forced upward to form hills, plateaus or mountains must be balanced by the buoyancy force of a much greater volume forced downward into the mantle, thus the continental crust is much thicker under mountains, compared to lower lying areas.
Rock can fold either asymmetrically. The upfolds are anticlines and the downfolds are synclines: in asymmetric folding there may be recumbent and overturned folds; the Balkan Mountains and the Jura Mountains are examples of fold mountains. Block mountains are caused by faults in the crust: a plane; when rocks on one side of a fault rise relative to the other, it can form a mountain. The uplifted blocks are block horsts; the intervening dropped blocks are termed graben: these can be small or form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges, the Basin and Range Province of Western North America and the Rhine valley; these areas occur when the regional stress is extensional and the crust is thinned. During and following uplift, mountains are subjected to the agents of erosion which wear the uplifted area down. Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arêtes, bowl-shaped cirques that can contai