Italy the Italian Republic, is a country in Southern Europe. Located in the middle of the Mediterranean Sea, Italy shares open land borders with France, Austria and the enclaved microstates San Marino and Vatican City. Italy covers an area of 301,340 km2 and has a temperate seasonal and Mediterranean climate. With around 61 million inhabitants, it is the fourth-most populous EU member state and the most populous country in Southern Europe. Due to its central geographic location in Southern Europe and the Mediterranean, Italy has been home to a myriad of peoples and cultures. In addition to the various ancient peoples dispersed throughout modern-day Italy, the most famous of which being the Indo-European Italics who gave the peninsula its name, beginning from the classical era and Carthaginians founded colonies in insular Italy and Genoa, Greeks established settlements in the so-called Magna Graecia, while Etruscans and Celts inhabited central and northern Italy respectively; the Italic tribe known as the Latins formed the Roman Kingdom in the 8th century BC, which became a republic with a government of the Senate and the People.
The Roman Republic conquered and assimilated its neighbours on the peninsula, in some cases through the establishment of federations, the Republic expanded and conquered parts of Europe, North Africa and the Middle East. By the first century BC, the Roman Empire emerged as the dominant power in the Mediterranean Basin and became the leading cultural and religious centre of Western civilisation, inaugurating the Pax Romana, a period of more than 200 years during which Italy's technology, economy and literature flourished. Italy remained the metropole of the Roman Empire; the legacy of the Roman Empire endured its fall and can be observed in the global distribution of culture, governments and the Latin script. During the Early Middle Ages, Italy endured sociopolitical collapse and barbarian invasions, but by the 11th century, numerous rival city-states and maritime republics in the northern and central regions of Italy, rose to great prosperity through shipping and banking, laying the groundwork for modern capitalism.
These independent statelets served as Europe's main trading hubs with Asia and the Near East enjoying a greater degree of democracy than the larger feudal monarchies that were consolidating throughout Europe. The Renaissance began in Italy and spread to the rest of Europe, bringing a renewed interest in humanism, science and art. Italian culture flourished, producing famous scholars and polymaths such as Michelangelo, Leonardo da Vinci, Raphael and Machiavelli. During the Middle Ages, Italian explorers such as Marco Polo, Christopher Columbus, Amerigo Vespucci, John Cabot and Giovanni da Verrazzano discovered new routes to the Far East and the New World, helping to usher in the European Age of Discovery. Italy's commercial and political power waned with the opening of trade routes that bypassed the Mediterranean. Centuries of infighting between the Italian city-states, such as the Italian Wars of the 15th and 16th centuries, left the region fragmented, it was subsequently conquered and further divided by European powers such as France and Austria.
By the mid-19th century, rising Italian nationalism and calls for independence from foreign control led to a period of revolutionary political upheaval. After centuries of foreign domination and political division, Italy was entirely unified in 1871, establishing the Kingdom of Italy as a great power. From the late 19th century to the early 20th century, Italy industrialised, namely in the north, acquired a colonial empire, while the south remained impoverished and excluded from industrialisation, fuelling a large and influential diaspora. Despite being one of the main victors in World War I, Italy entered a period of economic crisis and social turmoil, leading to the rise of a fascist dictatorship in 1922. Participation in World War II on the Axis side ended in military defeat, economic destruction and the Italian Civil War. Following the liberation of Italy and the rise of the resistance, the country abolished the monarchy, reinstated democracy, enjoyed a prolonged economic boom and, despite periods of sociopolitical turmoil became a developed country.
Today, Italy is considered to be one of the world's most culturally and economically advanced countries, with the sixth-largest worldwide national wealth. Its advanced economy ranks eighth-largest in the world and third in the Eurozone by nominal GDP. Italy owns the third-largest central bank gold reserve, it has a high level of human development, it stands among the top countries for life expectancy. The country plays a prominent role in regional and global economic, military and diplomatic affairs. Italy is a founding and leading member of the European Union and a member of numerous international institutions, including the UN, NATO, the OECD, the OSCE, the WTO, the G7, the G20, the Union for the Mediterranean, the Council of Europe, Uniting for Consensus, the Schengen Area and many more; as a reflection
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are found where tectonic plates are diverging or converging, most are found underwater. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can form where there is stretching and thinning of the crust's plates, e.g. in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "plate hypothesis" volcanism. Volcanism away from plate boundaries has been explained as mantle plumes; these so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth.
Volcanoes are not created where two tectonic plates slide past one another. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere. Volcanic winters have caused catastrophic famines; the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is sometimes spelled vulcanology. At the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock; because the crust is thin at these ridges due to the pull of the tectonic plates, the release of pressure leads to adiabatic expansion and the partial melting of the mantle, causing volcanism and creating new oceanic crust.
Most divergent plate boundaries are at the bottom of the oceans. Black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed. Subduction zones are places where two plates an oceanic plate and a continental plate, collide. In this case, the oceanic plate subducts, or submerges, under the continental plate, forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the melting temperature of the overlying mantle wedge, thus creating magma; this magma tends to be viscous because of its high silica content, so it does not attain the surface but cools and solidifies at depth. When it does reach the surface, however, a volcano is formed. Typical examples are the volcanoes in the Pacific Ring of Fire. Hotspots are volcanic areas believed to be formed by mantle plumes, which are hypothesized to be columns of hot material rising from the core-mantle boundary in a fixed space that causes large-volume melting.
Because tectonic plates move across them, each volcano becomes dormant and is re-formed as the plate advances over the postulated plume. The Hawaiian Islands are said to have been formed in such a manner; this theory, has been doubted. The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit; the features of volcanoes are much more complicated and their structure and behavior depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have landscape features such as massive plateaus. Vents that issue volcanic material and gases can develop anywhere on the landform and may give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Hawaii's Kīlauea. Other types of volcano include cryovolcanoes on some moons of Jupiter and Neptune. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes except when the mud volcano is a vent of an igneous volcano.
Volcanic fissure vents are linear fractures through which lava emerges. Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent, they do not explode catastrophically. Since low-viscosity magma is low in silica, shield volcanoes are more common in oceanic than continental settings; the Hawaiian volcanic chain is a series of shield cones, they are common in Iceland, as well. Lava domes are built by slow eruptions of viscous lava, they are sometimes formed within the crater of a previous volcanic eruption, as in the case of Mount Saint Helen
Limestone is a carbonate sedimentary rock, composed of the skeletal fragments of marine organisms such as coral and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. A related rock is dolostone, which contains a high percentage of the mineral dolomite, CaMg2. In fact, in old USGS publications, dolostone was referred to as magnesian limestone, a term now reserved for magnesium-deficient dolostones or magnesium-rich limestones. About 10% of sedimentary rocks are limestones; the solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. Limestone has numerous uses: as a building material, an essential component of concrete, as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, as a chemical feedstock for the production of lime, as a soil conditioner, or as a popular decorative addition to rock gardens.
Like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of marine organisms such as foraminifera; these organisms secrete shells made of aragonite or calcite, leave these shells behind when they die. Other carbonate grains composing limestones are ooids, peloids and extraclasts. Limestone contains variable amounts of silica in the form of chert or siliceous skeletal fragment, varying amounts of clay and sand carried in by rivers; some limestones do not consist of grains, are formed by the chemical precipitation of calcite or aragonite, i.e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters; this produces speleothems, such as stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance; the primary source of the calcite in limestone is most marine organisms. Some of these organisms can construct mounds of rock building upon past generations. Below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone does not form in deeper waters.
Limestones may form in lacustrine and evaporite depositional environments. Calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors with weathered surfaces. Limestone may be crystalline, granular, or massive, depending on the method of formation. Crystals of calcite, dolomite or barite may line small cavities in the rock; when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams where there are waterfalls and around hot or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution supersaturated with the chemical constituents of calcite.
Tufa, a porous or cellular variety of travertine, is found near waterfalls. Coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the mountain building process, limestone recrystallizes into marble. Limestone is a parent material of Mollisol soil group. Two major classification schemes, the Folk and the Dunham, are used for identifying the types of carbonate rocks collectively known as limestone. Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks. Based on composition, there are three main components: allochems and cement; the Folk system uses two-part names. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample; the Dunham scheme focuses on depositional textures. Each name is based upon the texture of the grains. Robert J. Dunham published his system for limestone in 1962.
Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles. Dunham names are for rock families, his efforts deal with the question of whether or not the grains were in mutual contact, therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of the rock; the Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample. A revised classification was proposed by Wright, it adds some diagenetic patterns and can be summarized as follows: See: Carbonate platform About 10% of all sedimentary rocks are limestones. Limestone is soluble in acid, therefore forms many erosional landforms; these include limestone pavements, pot holes, cenotes and gorges. Such erosion landscapes are known
In earth science, erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust, transports it to another location. This natural process is caused by the dynamic activity of erosive agents, that is, ice, air, plants and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind erosion, zoogenic erosion, anthropogenic erosion; the particulate breakdown of rock or soil into clastic sediment is referred to as physical or mechanical erosion. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Natural rates of erosion are controlled by the action of geological weathering geomorphic drivers, such as rainfall; the rates at which such processes act control. Physical erosion proceeds fastest on steeply sloping surfaces, rates may be sensitive to some climatically-controlled properties including amounts of water supplied, wind speed, wave fetch, or atmospheric temperature.
Feedbacks are possible between rates of erosion and the amount of eroded material, carried by, for example, a river or glacier. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, which control the arrival and emplacement of material at a new location. While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the natural rate of erosion in the region. Excessive erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses.
Water and wind erosion are the two primary causes of land degradation. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, gully erosion. Splash erosion is seen as the first and least severe stage in the soil erosion process, followed by sheet erosion rill erosion and gully erosion. In splash erosion, the impact of a falling raindrop creates a small crater in the soil, ejecting soil particles; the distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs.
If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are of the order of a few centimetres or less and along-channel slopes may be quite steep; this means that rills exhibit hydraulic physics different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and flows in narrow channels during or after heavy rains or melting snow, removing soil to a considerable depth. Valley or stream erosion occurs with continued water flow along a linear feature; the erosion is both downward, deepening the valley, headward, extending the valley into the hillside, creating head cuts and steep banks.
In the earliest stage of stream erosion, the erosive activity is dominantly vertical, the valleys have a typical V cross-section and the stream gradient is steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain; the stream gradient becomes nearly flat, lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far the most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone
Lapland referred to as Lappi Province, is the largest and northernmost region of Finland. The municipalities in the region cooperate in a Regional Council. Lapland borders the region of North Ostrobothnia in the south, it borders the Gulf of Bothnia, Norrbotten County in Sweden, Finnmark County and Troms County in Norway, Murmansk Oblast and the Republic of Karelia in Russia. Lapland's cold and wintry climate, coupled with the relative abundance of conifer trees such as pines and spruces means that it has become associated with Christmas in some countries, most notably the United Kingdom, holidays to Lapland are common towards the end of the year. Rovaniemi Airport is the third busiest airport in Finland; the region has been associated with Father Christmas since 1927, when proposed by Finnish radio host Markus Rautio. The area of Lapland region is 100,367 km², which consists of 92,667 km² of dry land, 6,316 km² fresh water and 1,383 km² of sea areas. In the south it borders Northern Ostrobothnia region, in the west Sweden, in the north and west Norway and in the east Russia.
Its borders follow three rivers: Tana and Torne. The largest lake is Lake Inari, 1,102 km². Highest point is on Halti; the areas of Enontekiö and Utsjoki in northern Lapland are known as Fell-Lapland. The bulk and remaining Lapland is known as Forest-Lapland. Lake Inari, the many fens of the region and the Salla-Saariselkä mountains are all part of Forest-Lapland. Fell-Lapland lies in the fells of the Scandinavian Mountains. Where it is not made up of barren ground like blockfields it has a vegetation of birch forests, willow thickets or heath. Common soil types in Forest-Lapland are sand with conifer forest growing on top; these forest show little variation across Lapland. Compared to southern Finland forest tree species grow slower. Understory is made of blueberry, lichens and ling; the landscape of large parts of Lapland is an inselberg plain. It has been suggested the inselberg plains formed in Late Cretaceous or Paleogene time by pediplanation or etchplanation. Relative to southern Finland Lapland stand out for its thick till cover.
The hills and mountains are made up of resistant rocks like granite, gneiss and amphibolite. The ice sheet that covered Finland intermittently during the Quaternary grew out from the Scandinavian Mountains; the central parts of the Fennoscandian ice sheet had cold-based conditions during the times of maximum extent. This mean that in areas like north-east Sweden and northern Finland pre-existing landforms and deposits escaped glacier erosion and are well preserved at present. Northwest to southeast movement of the ice has left a field of aligned drumlins in central Lapland. Ribbed moraines found in the same area reflect a west to east change in movement of the ice. During the last deglaciation ice in Lapland retreated from north-east and southeast so that the lower course of Tornio was the last part of Finland to be deglaciated 10,100 years ago. Present-day periglacial conditions in Lapland are reflected in the existence of numerous palsas, permafrost landforms developed on peat; the bedrock of Lapland belong to the Karelian Domain occupying the bulk of the region, the Kola Domain in the northeast around Lake Inari and the Scandinavian Caledonides in the tip of Lapland's northwestern arm.
With few exceptions rocks are of Proterozoic age. Granites, gneiss and metavolcanics are common rocks while greenstone belts are recurring features. More rare rock associations include mafic and ultramafic layered intrusions and one of the world's oldest ophiolites; the region hosts valuable deposits of gold, chromium and phosphate. The first snowflakes fall to the ground in late August or early September over the higher peaks; the first ground-covering snow arrives in average in late September. Permanent snow cover comes between mid-October and end of November earlier than in southern Finland; the winter is long seven months. The snow cover is thickest in early April. Soon after that the snow cover starts to melt fast; the thickest snow cover was measured in Kilpisjärvi in 19 April 1997 and it was 190 cm. The annual mean temperature varies from a couple of degrees below zero in northwest to a couple of degrees above zero in the southwest. Lapland exhibits a trend of increasing precipitation towards the south, with the dryest part being located at the two arms.
The area of Lapland was split between two counties of the Swedish Realm from 1634 to 1809. The northern and western areas were part of Västerbotten County, while the southern areas were part of Ostrobothnia County; the northern and western areas were transferred in 1809 to Oulu County. Under the royalist constitution of Finland during the first half of 1918, Lapland was to become a Grand Principality and part of the inheritance of the proposed king of Finland. Lapland Province was separated from Oulu Province in 1938. During the Interim Peace and beginning of the Continuation War the government of Finland allowed the Nazi German Army to station itself in Lapland as a part of Operation Barbarossa. After Finland made a separate peace with the Soviet Union in 1944, the Soviet Union demanded that Finland expel the German army from its soil; the result was the Lapland War, during which the whole civilian population of Lapland was evacuated. The Germans used scorched earth tactics in Lapland. Forty t
Western Sahara is a disputed territory on the northwest coast and in the Maghreb region of North and West Africa controlled by the self-proclaimed Sahrawi Arab Democratic Republic and occupied by neighboring Morocco. Its surface area amounts to 266,000 square kilometres, it is one of the most sparsely populated territories in the world consisting of desert flatlands. The population is estimated at just over 500,000, of which nearly 40% live in Laayoune, the largest city in Western Sahara. Occupied by Spain until the late 20th century, Western Sahara has been on the United Nations list of non-self-governing territories since 1963 after a Moroccan demand, it is the most populous territory on that list, by far the largest in area. In 1965, the UN General Assembly adopted its first resolution on Western Sahara, asking Spain to decolonize the territory. One year a new resolution was passed by the General Assembly requesting that a referendum be held by Spain on self-determination. In 1975, Spain relinquished the administrative control of the territory to a joint administration by Morocco and Mauritania.
A war erupted between those countries and a Sahrawi nationalist movement, the Polisario Front, which proclaimed the Sahrawi Arab Democratic Republic with a government in exile in Tindouf, Algeria. Mauritania withdrew its claims in 1979, Morocco secured de facto control of most of the territory, including all the major cities and natural resources; the United Nations considers the Polisario Front to be the legitimate representative of the Sahrawi people, maintains that the Sahrawis have a right to self-determination. Since a United Nations-sponsored ceasefire agreement in 1991, two thirds of the territory has been administered by the Moroccan government, with tacit support from France and the United States, the remainder by the SADR, backed by Algeria. Internationally, countries such as Russia have taken a ambiguous and neutral position on each side's claims, have pressed both parties to agree on a peaceful resolution. Both Morocco and Polisario have sought to boost their claims by accumulating formal recognition from African and Latin American states in the developing world.
The Polisario Front has won formal recognition for SADR from 46 states, was extended membership in the African Union. Morocco has won support for its position from several African governments and from most of the Muslim world and Arab League. In both instances, recognitions have, over the past two decades, been extended and withdrawn according to changing international trends; as of 2017, no other member state of the United Nations has officially recognized Moroccan sovereignty over parts of Western Sahara. However, a number of countries have expressed their support for a future recognition of the Moroccan annexation of the territory as an autonomous part of the Kingdom. Overall, the annexation has not garnered as much attention in the international community as many other disputed annexations. Western Sahara is located on the northwest coast in West Africa and on the cusp of North Africa, bordering the North Atlantic Ocean to the northwest, Morocco proper to the north-northeast, Algeria to the east-northeast, Mauritania to the east and south.
The land is some of the most inhospitable on the planet. The land along the coast is low flat desert and rises in the north, to small mountains reaching up to 600 metres on the eastern side. While the area can experience flash flooding in the spring, there are no permanent streams. At times a cool off-shore current can produce heavy dew; the interior experiences extreme summer heat with average highs reaching as high as 43–45 °C in July and in August. The earliest known inhabitants of Western Sahara were the Gaetuli. Depending on the century, Roman-era sources describe the area as inhabited by Gaetulian Autololes or the Gaetulian Daradae tribes. Berber heritage is still evident from regional and place-name toponymy, as well as from tribal names. Other early inhabitants of Western Sahara may be the Bafour and the Serer; the Bafour were replaced or absorbed by Berber-speaking populations which merged in turn with the migrating Beni Ḥassān Arab tribes. The arrival of Islam in the 8th century played a major role in the development of the Maghreb region.
Trade developed further, the territory may have been one of the routes for caravans between Marrakesh and Tombouctou in Mali. In the 11th century, the Maqil Arabs settled in Morocco. Towards the end of the Almohad Caliphate, the Beni Hassan, a sub-tribe of the Maqil, were called by the local ruler of the Sous to quell a rebellion. During Marinid dynasty rule, the Beni Hassan rebelled but were defeated by the Sultan and escaped beyond the Saguia el-Hamra dry river; the Beni Hassan were at constant war with the Lamtuna nomadic Berbers of the Sahara. Over