1.
Summit
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A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. Mathematically, a summit is a maximum in elevation. The topographic terms acme, apex, peak, and zenith are synonymous, the UIAA definition is that a summit is independent if it has a prominence of 30 metres or more, it is a mountain if it has a prominence of at least 300 metres. This can be summarised as follows, A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top, Summit may also refer to the highest point along a line, trail, or route. In many parts of the western United States, the term refers to the highest point along a road, highway. For example, the highest point along Interstate 80 in California is referred to as Donner Summit while the highest point on Interstate 5 is Siskiyou Mountain Summit, geoid Hill List of highest mountains Maxima and minima Nadir Summit accordance Peak finder
2.
Geographic coordinate system
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A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
3.
Volcano
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A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earths volcanoes occur because its crust is broken into 17 major, therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. This type of volcanism falls under the umbrella of plate hypothesis volcanism, Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called hotspots, for example Hawaii, are postulated to arise from upwelling diapirs with magma from the boundary,3,000 km deep in the Earth. Volcanoes are usually not created where two plates slide past one another. Erupting volcanoes can pose hazards, not only in the immediate vicinity of the eruption. Historically, so-called 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 called volcanology, 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. Most divergent plate boundaries are at the bottom of the oceans, therefore, most volcanic activity is submarine, black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed, for example, subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the 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 temperature of the overlying mantle wedge. This magma tends to be very viscous due to its high content, so it often does not reach the surface. When it does reach the surface, a volcano is formed, typical examples of this kind of volcano are Mount Etna and the volcanoes in the Pacific Ring of Fire. Because tectonic plates move across them, each volcano becomes dormant and is eventually re-formed as the plate advances over the postulated plume and this theory is currently under criticism, however. The most common perception of a volcano is of a mountain, spewing lava and poisonous gases from a crater at its summit, however. The features of volcanoes are more complicated and their structure. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have features such as massive plateaus
4.
Moquegua Region
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Moquegua is a department in southern Peru that extends from the coast to the highlands. The regions volcanoes and its geomorphology make its geography remarkable and these are veritable oasis enclaved in the rocks, arid hillsides and some terraces where horticulture is possible. High quality alfalfa as well as fruits, especially grapes, are produced here, due to a good climate, the second sector is the valley of Omate, one of the most populated and fertile soils of the department. The Ubinas Volcano, Perus most active volcano, is located nearby, in the hillsides, the land is fertile in contrast with the desolation and sterility of its highlands. In the southern part of the Tambo River is located the town of Carumas, the Moquegua River is a short run one and is formed by its tributaries, the Torata, Huaracane and Tumilaca rivers. After passing through the capital, it digs deep into a canyon called the Osmare. The Moquegua Region is bordered by the Arequipa Region in the north, the Puno Region in the east, the Tacna Region in the south, the region is divided into 3 provinces, which are composed of 20 districts. As of 2002, the Instituto Nacional de Estadística e Informática estimates the population to be 156,750. According to the last census in Peru in 2007, the languages learnt first by the residents were Spanish, Aymara, Quechua, other indigenous languages were learnt first by 0. 19% and foreign languages by 0. 04%. The Quechua variety spoken in Moquegua is Cusco–Collao Quechua, the largest immigrant groups come from the Puno Region and the Arequipa Region. The population is out with 43. 3% under the age of 20,9. 9% from 20 to 24,28. 6% from 25 to 44,13. 4% from 45 to 64. Secondary education has been attended by 33. 3% of the population and 5. 5% also have graduated from non-university higher education,37. 9% only have attended primary education and 7. 1% have not had any education. The illiteracy rate in the region is 10%, according to chronicler Garcilaso de la Vega, it was Inca Mayta Cápac who organized the military expedition to expand the domains of the Cusco monarchs along this part of the coast. Since these were fertile lands, capable of supporting a larger population, in doing so, they were also protecting the Inca domain over the conquered lands. C. There is no data on the Spanish conquest or the founding of the city of Moquegua by its army. Presumably, it was founded on 25 November 1541 by Pedro Cansino and his wife, during the War of the Pacific, Moquegua suffered the invasion of Chilean troops. This army looted all buildings —including churches—, tortured women, Contisuyo Museum is also located in the city of Moquegua. The museum exhibits a variety of remains of the Uros
5.
Peru
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Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the west by the Pacific Ocean. Peruvian territory was home to ancient cultures spanning from the Norte Chico civilization in Caral, one of the oldest in the world, to the Inca Empire, the largest state in Pre-Columbian America. The Spanish Empire conquered the region in the 16th century and established a Viceroyalty with its capital in Lima, ideas of political autonomy later spread throughout Spanish America and Peru gained its independence, which was formally proclaimed in 1821. After the battle of Ayacucho, three years after proclamation, Peru ensured its independence, subsequently, the country has undergone changes in government from oligarchic to democratic systems. Peru has gone through periods of political unrest and internal conflict as well as periods of stability, Peru is a representative democratic republic divided into 25 regions. It is a country with a high Human Development Index score. Its main economic activities include mining, manufacturing, agriculture and fishing, the Peruvian population, estimated at 31.2 million in 2015, is multiethnic, including Amerindians, Europeans, Africans and Asians. The main spoken language is Spanish, although a significant number of Peruvians speak Quechua or other native languages and this mixture of cultural traditions has resulted in a wide diversity of expressions in fields such as art, cuisine, literature, and music. The name of the country may be derived from Birú, the name of a ruler who lived near the Bay of San Miguel, Panama. When his possessions were visited by Spanish explorers in 1522, they were the southernmost part of the New World yet known to Europeans, thus, when Francisco Pizarro explored the regions farther south, they came to be designated Birú or Perú. An alternative history is provided by the contemporary writer Inca Garcilasco de la Vega, son of an Inca princess, the Spanish Crown gave the name legal status with the 1529 Capitulación de Toledo, which designated the newly encountered Inca Empire as the province of Peru. Under Spanish rule, the country adopted the denomination Viceroyalty of Peru, the earliest evidences of human presence in Peruvian territory have been dated to approximately 9,000 BC. Andean societies were based on agriculture, using such as irrigation and terracing, camelid husbandry. Organization relied on reciprocity and redistribution because these societies had no notion of market or money, the oldest known complex society in Peru, the Norte Chico civilization, flourished along the coast of the Pacific Ocean between 3,000 and 1,800 BC. These early developments were followed by archaeological cultures that developed mostly around the coastal, the Cupisnique culture which flourished from around 1000 to 200 BC along what is now Perus Pacific Coast was an example of early pre-Incan culture. The Chavín culture that developed from 1500 to 300 BC was probably more of a religious than a political phenomenon, on the coast, these included the civilizations of the Paracas, Nazca, Wari, and the more outstanding Chimu and Mochica. Their capital was at Chan Chan outside of modern-day Trujillo, in the 15th century, the Incas emerged as a powerful state which, in the span of a century, formed the largest empire in pre-Columbian America with their capital in Cusco
6.
Huaynaputina
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Huaynaputina is a stratovolcano in a volcanic upland in southern Peru. The volcano does not have a mountain profile, but instead is a large volcanic crater. It has produced andesite and dacite. On 19 February 1600, it exploded catastrophically, in the largest volcanic explosion in South America in historic times, the eruption continued with a series of events into March. Huaynaputina lies in Southern Perus Moquegua Region,80 kilometres southeast of Arequipa, the volcano is part of the Central Volcanic Zone, the segment of the Andes running through Peru and Chile. It is north of at least one more complex with a resurgent dome. Despite the volcanos listed elevation of 4,800 metres, Huaynaputina has very little prominence, the mountain resides within a horseshoe-shaped crater 2.5 kilometres in width, and includes three 100-metre deep cones which formed from ash fallout of the 1600 eruption. Another external vent formed a maar just outside the caldera, before the Spanish colonization of the Americas, not much is known of the regions history. It is likely natives made human sacrifices ritualistically to the volcano, also sacrificing animals, father Alonso Ruiz of Arequipa predicted a hit from heaven in 1599, at which time activity may have begun at the volcano. This subduction process has resulted in the formation of the Peru–Chile Trench and it also produced the Andean Volcanic Belt and the rest of the Andes. Ticsani, Ubinas and Huaynaputina sit on a volcanic lineament slightly oblique to the volcanic front. Because the crust of the Central Volcanic Zone is unusually thick, Huaynaputina is rich in andesitic and dacitic rocks, which form a calc-alkalic suite high in potassium.8 mya, respectively. The history of the Huaynaputina region is marked by silicic volcanism, records of silicic eruptions begin with remnants from the Barroso formation, from the Miocene. A few days before the eruption, someone reported booming noise from the volcano, navarro tells of local wizards scrambling to appease the volcano, preparing girls, pets, and flowers for sacrifice, and of the volcano ejecting ash during the sacrifice ceremony. By February 15, the activity had increased, as earthquakes began to occur. By February 18, seismic activity occurred as frequently as three or four times every fifteen minutes, some tremors powerful enough to wake those sleeping, at 5 P. M. on February 19, Huaynaputina erupted violently, sending volcanic ash into the atmosphere. Observers described the event as a big explosion with cannonball-like explosions that had the appearance of an enormous fire, river-like pyroclastic flows flowed down the mountain, the flows on the southern side mixed with water from the Rio Tambo to create lahars. One hour after the eruption, ash began to fall from the sky, intermittent eruptions occurred for a little less than a month, concluding on March 5
7.
Arequipa
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Arequipa is the capital and largest city of the Arequipa Region and the seat of the Constitutional Court of Peru. Its industrial activity includes manufactured goods and camelid wool products for export, the city has close trade ties with Chile, Bolivia and Brazil. The city was founded on August 15,1540, by Garcí Manuel de Carbajal as Villa Hermosa de Nuestra Señora de la Asunción, during the Colonial period, Arequipa became highly important for its economic prosperity and for its loyalty to the Spanish Crown. After Peru gained its independence from Spain in 1821, Arequipa acquired greater political significance, the historic center of Arequipa spans an area of 332 hectares and is a UNESCO World Heritage Site. Its historic heritage, natural scenery and cultural sites make the city a major tourist destination and its religious, colonial, and republican architectural styles blend European and native characteristics into a unique style called Escuela Arequipeña. A local tradition states that Inca Mayta Capac received a petition from his subjects to reach the valley of the River Chili and they asked him for permission to stay in the region as they were impressed by the beauty of the landscape and the mild climate. However, another tale states that when the first Europeans arrived to the valley, they pointed at the ground. The local chief, not understanding the question, assumed they were asking for a permission to sit down and gave a positive answer, which sounded like Arequipa. Another possible origin of the name comes from the Aymara language phrase qhipaya ari or Ari qipa. The early inhabitants of the Arequipa City area were people who relied on activities such as hunting, fishing and gathering for survival. Later, pre-Inca cultures domesticated llamas and became sedentary with the development of agriculture, during this time, major irrigation channels were built within the valley of the Chili river, which allowed the development of agriculture by means of terraces built on both sides of the valley. The Yarabaya and Chimbe tribes settled in the current location. Lands were then distributed among three families who founded the towns of Yanahuara, Cayma, Tiabaya, Socabaya, Characato and others. At the time of its foundation, Arequipa had already a city council, because the foundation of the town occurred in part as a relocation of Villa Hermosa de Camana, the name was partially conserved as Villa Hermosa de Arequipa. Charles V of Germany and I of Spain gave the town a status of city by Royal Decree on 22 September 1541, the relocation efforts were led by Garci Manuel de Carbajal, who was selected as the political authority for the foundation of the new town. Among the first public works carried out in the city are the Main Church, the City Hall, the bridge on the Chili River and the monastery of Nuestra Señora de Gracia. Since its Spanish founding and over three centuries, the population of the city was mostly of Spanish origin, which represented a strong following of Spain. One aspect that distinguished Arequipa from the rest of the country was the explicit and public commitment of the city to the Spanish Crown
8.
Andean Volcanic Belt
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The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador and Peru. It formed as a result of subduction of the Nazca Plate, the belt is subdivided into four main volcanic zones that are separated from each other by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, while some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Romeral in Colombia is the northernmost member of the Andean Volcanic Belt, South of latitude 49° S within the Austral Volcanic Zone volcanic activity decreases with the southernmost volcano Fueguino in Tierra del Fuego archipelago. The Andean Volcanic Belt is segmented into four areas of active volcanism. The Northern Volcanic Zone extends from Colombia to Ecuador and includes all volcanoes on the mainland of these countries. Of the zones volcanoes,55 are located in Ecuador while 19 are in Colombia, in Ecuador the volcanoes are located in the Cordillera Occidental and Cordillera Real while in Colombia they are located in Cordillera Central. The volcanic arc has formed due to subduction of the Nazca Plate under western South America, some volcanoes of the Northern Volcanic Zone, such as Galeras and Nevado del Ruiz that lie in densely populated highland areas, are major sources of hazards. It has been estimated that crustal thickness beneath this region varies from around 40 to perhaps more than 55 km, sangay is the southernmost volcano of the Northern Volcanic Zone. The Central Volcanic Zone is an arc in western South America. It is one of the four zones of the Andes. The Central Volcanic Zone extends from Peru to Chile and forms the boundary of the Altiplano plateau. The volcanic arc has formed due to subduction of the Nazca Plate under western South America along the Peru–Chile Trench, the CVZ is characterized by a continental crust that reaches a thickness of approximately 70 km. Within this zone there are 44 major and 18 minor volcanic centers that are considered to be active, other silicic systems are Los Frailes ignimbrite plateau in Bolivia, and the caldera complexes of Incapillo and Cerro Galán in Argentina. The South Volcanic Zone extends roughly from Central Chiles Andes at the latitude of Santiago, 33°S, to Cerro Arenales in Aysén Region at ca. 46°S, a distance of well over 870 mi, the arc has formed due to subduction of the Nazca Plate under the South American Plate along the Peru–Chile Trench. The southern end of the SVZ is marked by the Chile Triple Junction where the Chile Rise subducts under South America at the Taitao Peninsula giving origin to the Patagonian Volcanic Gap, further south lies the Austral Volcanic Zone. During the Pliocene the SVZ south of 38°S consisted of a volcanic arc
9.
Caldera
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A caldera is a large cauldron-like depression that forms following the evacuation of a magma chamber/reservoir. When large volumes of magma are erupted over a time period. The ground surface then collapses downward into the emptied magma chamber. Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence, only seven known caldera-forming collapses have occurred since the start of the 20th century, most recently at Bárðarbunga volcano in Iceland. The word comes from Spanish caldera, and this from Latin caldaria, in some texts the English term cauldron is also used. If enough magma is ejected, the chamber is unable to support the weight of the volcanic edifice above it. A roughly circular fracture, the fault, develops around the edge of the chamber. Ring fractures serve as feeders for fault intrusions which are known as ring dykes. Secondary volcanic vents may form above the ring fracture, as the magma chamber empties, the center of the volcano within the ring fracture begins to collapse. The collapse may occur as the result of a cataclysmic eruption. The total area that collapses may be hundreds or thousands of square kilometers, some calderas are known to host rich ore deposits. One of the worlds best-preserved mineralized calderas is the Sturgeon Lake Caldera in northwestern Ontario, Canada, if the magma is rich in silica, the caldera is often filled in with ignimbrite, tuff, rhyolite, and other igneous rocks. Silica-rich magma has a high viscosity, and therefore does not flow easily like basalt, as a result, gases tend to become trapped at high pressure within the magma. Further lava flows may be erupted, if volcanic activity continues, the center of the caldera may be uplifted in the form of a resurgent dome such as is seen at Cerro Galán, Lake Toba, Yellowstone, etc. by subsequent intrusion of magma. A silicic or rhyolitic caldera may erupt hundreds or even thousands of kilometers of material in a single event. Even small caldera-forming eruptions, such as Krakatoa in 1883 or Mount Pinatubo in 1991, may result in significant local destruction, large calderas may have even greater effects. When Yellowstone Caldera last erupted some 650,000 years ago, it released about 1,000 km3 of material, by comparison, when Mount St. Helens erupted in 1980, it released ~1.2 km3 of ejecta. The ecological effects of the eruption of a large caldera can be seen in the record of the Lake Toba eruption in Indonesia, more recently several geneticists, including Lynn Jorde and Henry Harpending have proposed that the human species was reduced to approximately five to ten thousand people
10.
Volcanic crater
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A volcanic crater is a roughly circular depression in the ground caused by volcanic activity. It is typically a bowl-shaped feature within which occurs a vent or vents, a volcanic crater can be of large dimensions, and sometimes of great depth. During certain types of eruptions, a volcanos magma chamber may empty enough for an area above it to subside. In most volcanoes, the crater is situated at the top of a formed from the erupted volcanic deposits such as lava flows. Volcanoes that terminate in such a summit crater are usually of a conical form, other volcanic craters may be found on the flanks of volcanoes, and these are commonly referred to as flank craters. Some volcanic craters may fill either fully or partially with rain and/or melted snow, a crater may be breached during an eruption, either by explosions or by lava, or through later erosion. Breached craters have a lower rim on one side. Some volcanoes, such as maars, consist of a crater alone and these volcanic explosion craters are formed when magma rises through water-saturated rocks and causes a phreatic eruption. Volcanic craters from phreatic eruptions often occur on plains away from other obvious volcanoes
11.
Explosive eruption
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An explosive eruption is a volcanic term to describe a violent, explosive type of eruption. Mount St. Helens in 1980 was an example, such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such that expelled lava violently froths into volcanic ash when pressure is suddenly lowered at the vent. Sometimes a lava plug will block the conduit to the summit, Explosive eruptions can send rocks, dust, gas and pyroclastic material up to 20 km into the atmosphere at rate of up to 100,000 tonnes per second, traveling at several hundred meters per second. This cloud will collapse, creating a pyroclastic flow of hot volcanic matter. An explosive eruption always begins with some form of blockage in the crater of a volcano that prevents the release of trapped in highly viscous andesitic or rhyolitic magma. The high viscosity of these forms of magma prevents the release of trapped gases, when this type of magma flows towards the surface pressure builds, eventually causing the blockage to be blasted out in an explosive eruption. The pressure from the magma and gases are released through the weakest point in the cone, however, in the case of the eruption of Mount St. Helens, pressure was released through the side of the volcano, rather than the crater. The size and duration of the column depends on the volume of magma being released, the eruption column of ash is supported by pressure from the gases being released, and as the gases are depleted, pressure falls and the eruption column begins to collapse. When the column collapses in on itself, ash and rock fall back down to the ground and these flows can travel at up to 80 km per hour, and reach temperatures of 200° to 700° Celsius. The high temperatures can cause combustion of any flammable materials in its path, including wood, vegetation, when snow and ice melt as a part of an eruption, large amounts of water mixed in with the flow can create lahars. The risk of lahars is particularly high on volcanoes such as Mount Rainier near Seattle and Tacoma, the eruption of supervolcanoes is the rarest of volcanic eruptions but also the most destructive. The timescale between these eruptions is generally marked by hundreds or thousands of years and this type of eruption generally causes destruction on a continental scale, and can also result in the lowering of temperatures worldwide. Effusive eruption Volcanic explosivity index Recent Developments in Explosive Volcanism
12.
Volcanic ash
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Volcanic ash consists of fragments of pulverized rock, minerals and volcanic glass, created during volcanic eruptions and measuring less than 2 mm in diameter. The term volcanic ash is often loosely used to refer to all explosive eruption products. Volcanic ash is formed during volcanic eruptions when dissolved gases in magma expand. The force of the escaping gas shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, once in the air, ash is transported by wind up to thousands of kilometers away. Volcanic ash is formed during volcanic eruptions, phreatomagmatic eruptions. Explosive eruptions occur when magma decompresses as it rises, allowing dissolved volatiles to exsolve into gas bubbles, as more bubbles nucleate a foam is produced, which decreases the density of the magma, accelerating it up the conduit. Fragmentation occurs when bubbles occupy ~70-80 vol% of the erupting mixture, when fragmentation occurs, violently expanding bubbles tear the magma apart into fragments which are ejected into the atmosphere where they solidify into ash particles. Fragmentation is an efficient process of ash formation and is capable of generating very fine ash even without the addition of water. Volcanic ash is produced during phreatomagmatic eruptions. During these eruptions fragmentation occurs when magma comes into contact with bodies of water groundwater, as the magma, which is significantly hotter than the boiling point of water, comes into contact with water an insulating vapor film forms. Eventually this vapor film will collapse leading to direct coupling of the cold water and this increases the heat transfer which leads to the rapid expansion of water and fragmentation of the magma into small particles which are subsequently ejected from the volcanic vent. Fragmentation causes an increase in area between magma and water creating a feedback mechanism, leading to further fragmentation and production of fine ash particles. Pyroclastic density currents can also produce ash particles and these are typically produced by lava dome collapse or collapse of the eruption column. Within pyroclastic density currents particle abrasion occurs as particles interact with each resulting in a reduction in grain size. In addition, ash can be produced during secondary fragmentation of pumice fragments and these processes produce large quantities of very fine grained ash which is removed from pyroclastic density currents in co-ignimbrite ash plumes. Physical and chemical characteristics of volcanic ash are primarily controlled by the style of volcanic eruption, another parameter controlling the amount of ash produced is the duration of the eruption, the longer the eruption is sustained, the more ash will be produced. The types of minerals present in volcanic ash are dependent on the chemistry of the magma from which it erupted, low energy eruptions of basalt produce a characteristically dark coloured ash containing ~45 - 55% silica that is generally rich in iron and magnesium
13.
Pleistocene
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The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the worlds most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period, the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, all of these stages were defined in southern Europe. In addition to this subdivision, various regional subdivisions are often used. Charles Lyell introduced the term pleistocene in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today and this distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. The Pleistocene has been dated from 2.588 million to 11,700 years before present and it covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell. The end of the Younger Dryas has been dated to about 9640 BC, the IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75°06 N 42°18 W, the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils, Discoaster pentaradiatus, the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. The revised definition of the Quaternary, by pushing back the date of the Pleistocene to 2.58 Ma. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places and it is estimated that, at maximum glacial extent, 30% of the Earths surface was covered by ice. In addition, a zone of permafrost stretched southward from the edge of the sheet, a few hundred kilometres in North America. The mean annual temperature at the edge of the ice was −6 °C, during interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions. The effects of glaciation were global, antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap, there were glaciers in New Zealand and Tasmania. The current decaying glaciers of Mount Kenya, Mount Kilimanjaro, glaciers existed in the mountains of Ethiopia and to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one, the Cordilleran ice sheet covered the North American northwest, the east was covered by the Laurentide
14.
Eruption column
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An eruption column is a cloud of hot volcanic ash suspended in volcanic gas emitted during an explosive volcanic eruption. The ash forms a column that may rise many kilometres into the air above the vent of the volcano, in the most explosive eruptions, the eruption column may rise over 40 km, penetrating the stratosphere. Stratospheric injection of aerosols by volcanoes is a cause of short-term climate change. A common occurrence in explosive eruptions is for column collapse to occur, in this case, the eruption column is too dense to be lifted high into the air by air convection, and instead falls down the flanks of the volcano to form a pyroclastic flow or surge. On some occasions, if ash isnt dense enough to fall, eruption columns form in explosive volcanic activity, when the high concentration of volatile materials in the rising magma causes it to be disrupted into fine volcanic ash and coarser tephra. The ash and tephra are ejected at speeds of several hundred metres per second, eruption columns may be transient, if formed by a discrete explosion, or sustained, if produced by a continuous eruption or closely spaced discrete explosions. The gas expands because the pressure of rock above it rapidly reduces as it approaches the surface and this region is called the gas thrust region and typically reaches to only one or two kilometres above the vent. The convective thrust region covers most of the height of the column, the gas thrust region is very turbulent and surrounding air becomes mixed into it and heated. The air expands, reducing its density and rising, the rising air carries the solid and liquid material from the eruption entrained in it upwards. As the column rises into less dense surrounding air, it will reach an altitude where the hot. In this neutral buoyancy region, the material will then no longer rise through convection. This is called the region, and is usually marked by the column spreading out sideways. The eruptive material and the cool air has the same density at the base of the umbrella region. Because the speeds are low or negligible in this region it is often distorted by stratospheric winds. The column will stop rising once it attains an altitude where it is no longer less dense than the surrounding air, several factors control the height that an eruption column can reach. Intrinsic factors include the diameter of the vent, the gas content of the magma. Extrinsic factors can be important, with winds sometimes limiting the height of the column, the atmospheric temperature in the troposphere normally decreases by about 6-7 K/km, but small changes in this gradient can have a large effect on the final column height. Theoretically, the maximum column height is thought to be about 55 km
15.
Lava
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Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is called lava. The molten rock is formed in the interior of planets, including Earth. The source of the heat melts the rock within the earth is geothermal energy. When first erupted from a vent, lava is a liquid usually at temperatures from 700 to 1,200 °C. A lava flow is an outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock, the term lava flow is commonly shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic, explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word lava comes from Italian, and is derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma was apparently in an account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4,1737. Serao described a flow of lava as an analogy to the flow of water. The composition of almost all lava of the Earths crust is dominated by silicate minerals, mostly feldspars, olivine, pyroxenes, amphiboles, micas, igneous rocks, which form lava flows when erupted, can be classified into three chemical types, felsic, intermediate, and mafic. These classes are primarily chemical, however, the chemistry of lava also tends to correlate with the temperature, its viscosity. Felsic or silicic lavas such as rhyolite and dacite typically form lava spines, most silicic lava flows are extremely viscous, and typically fragment as they extrude, producing blocky autobreccias. Felsic magmas can erupt at temperatures as low as 650 to 750 °C, unusually hot rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States. Intermediate or andesitic lavas are lower in aluminium and silica, and usually somewhat richer in magnesium, intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes. Poorer in aluminium and silica than felsic lavas, and also commonly hotter, greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, mafic or basaltic lavas are typified by their high ferromagnesian content, and generally erupt at temperatures in excess of 950 °C
16.
Quechuan languages
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Quechua /ˈkɛtʃwə/, also known as runa simi, is an indigenous language family, with variations spoken by the Quechua peoples, primarily living in the Andes and highlands of South America. Derived from an ancestral language, it is the most widely spoken language family of indigenous peoples of the Americas. Approximately 13% of Peruvians speak Quechua and it is perhaps most widely known for being the main language of the Inca Empire, and was disseminated by the colonizers throughout their reign. Quechua had already expanded across wide ranges of the central Andes long before the expansion of the Inca Empire, the Inca were one among many peoples in present-day Peru who already spoke forms of Quechua. In the Cusco region, Quechua was influenced by languages such as Aymara. The Cuzco variety of Quechua developed as quite distinct, in similar ways, diverse dialects developed in different areas, related to existing local languages, when the Inca Empire ruled and imposed Quechua as the official language. After the Spanish conquest of the Inca Empire in the 16th century and it was officially recognized by the Spanish administration and many Spanish learned it in order to communicate with the local peoples. Clergy of the Catholic Church adopted Quechua to use as the language of evangelization, given its use by the Catholic missionaries, the range of Quechua continued to expand in some areas. In the late 18th century, colonial officials ended administrative and religious use of Quechua, the Crown banned even loyal pro-Catholic texts in Quechua, such as Garcilaso de la Vegas Comentarios Reales. Despite a brief revival of the immediately after the Latin American nations achieved independence in the 19th century. Gradually its use declined so that it was mostly by indigenous people in the more isolated. Nevertheless in the 21st century, those speaking Quechua language speakers number 8 to 10 million people across South America, the oldest written records of the language are by missionary Domingo de Santo Tomás, who arrived in Peru in 1538 and learned the language from 1540. He published his Grammatica o arte de la lengua de los indios de los reynos del Perú in 1560. In 1975 Peru became the first country to recognize Quechua as one of its official languages, the major obstacle to the usage and teaching of Quechua is the lack of written materials in that language, such as books, newspapers, software, and magazines. The Bible has been translated into Quechua and is distributed by certain missionary groups, Quechua, along with Aymara and the minor indigenous languages, remains essentially a spoken language. In recent years, Quechua has been introduced in intercultural education in Bolivia, Ecuador. Even in these areas, the governments are reaching only a part of the Quechua-speaking populations, some indigenous people in each of the countries are having their children study in Spanish for the purposes of social advancement. Radio Nacional del Perú broadcasts news and agrarian programs in Quechua for periods in the mornings, Quechua and Spanish are now heavily intermixed in much of the Andean region, with many hundreds of Spanish loanwords in Quechua
17.
Demon
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A demon is a supernatural, mythological and often malevolent being prevalent in religion, occultism, literature, fiction, mythology and folklore. The original Greek word daimon does not carry the negative connotation initially understood by implementation of the Koine δαιμόνιον, the Ancient Greek word δαίμων daimōn denotes a spirit or divine power, much like the Latin genius or numen. Daimōn most likely came from the Greek verb daiesthai, the Greek conception of a daimōn notably appears in the works of Plato, where it describes the divine inspiration of Socrates. To distinguish the classical Greek concept from its later Christian interpretation, the Greek terms do not have any connotations of evil or malevolence. In fact, εὐδαιμονία eudaimonia, means happiness, far into the Byzantine period Christians eyed their cities old pagan statuary as a seat of the demons presence. It was no longer beautiful, it was infested, the term had first acquired its negative connotations in the Septuagint translation of the Hebrew Bible into Greek, which drew on the mythology of ancient Semitic religions. This was then inherited by the Koine text of the New Testament, the Western medieval and neo-medieval conception of a demon derives seamlessly from the ambient popular culture of Late Antiquity. The Hellenistic daemon eventually came to include many Semitic and Near Eastern gods as evaluated by Christianity, the supposed existence of demons remains an important concept in many modern religions and occultist traditions. Demons are still feared largely due to their power to possess living creatures. In the contemporary Western occultist tradition, a demon is a metaphor for certain inner psychological processes. According to the Jewish Encyclopedia, In Chaldean mythology the seven evil deities were known as shedu, storm-demons and they were represented as winged bulls, derived from the colossal bulls used as protective jinn of royal palaces. From Chaldea, the term shedu traveled to the Israelites, the writers of the Tanach applied the word as a dialogism to Canaanite deities. There are indications that demons in popular Hebrew mythology were believed to come from the nether world, various diseases and ailments were ascribed to them, particularly those affecting the brain and those of internal nature. Examples include catalepsy, headache, epilepsy and nightmares, there also existed a demon of blindness, Shabriri who rested on uncovered water at night and blinded those who drank from it. Demons supposedly entered the body and caused the disease while overwhelming or seizing the victim, to cure such diseases, it was necessary to draw out the evil demons by certain incantations and talismanic performances, at which the Essenes excelled. In mythology, there were few defences against Babylonian demons, the mythical mace Sharur had the power to slay demons such as Asag, a legendary gallu or edimmu of hideous strength. As referring to the existence or non-existence of shedim there are converse opinions in Judaism, there are practically nil roles assigned to demons in the Jewish Bible. In conclusion, Jews are not obligated to believe in the existence of shedim, the word shedim appears only in two places in the Tanakh
18.
Weathered
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Weathered is the third studio album by American rock band Creed, released on November 20,2001. Some versions are enhanced CDs and include videos and it has been certified 6× platinum by the RIAA. The album contains Creeds shortest and longest song, the album has sold more than 6 million copies in the U. S alone. Weathered was the last Creed album released until Full Circle came out in 2009 and it is the only Creed album not to include bassist Brian Marshall, who departed from the band in 2000. Guitarist Mark Tremonti played bass on the album in his absence, the album received mixed reviews from critics. All songs written by Scott Stapp and Mark Tremonti
19.
Cirque
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A cirque is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie and cwm, a cirque may also be a similarly shaped landform arising from fluvial erosion. The concave shape of a glacial cirque is open on the downhill side, cliff-like slopes down which ice and glaciated debris combine and converge from the three or more higher sides. The fluvial cirque or makhtesh, found in karst landscapes, is formed by intermittent river flow cutting through layers of limestone, a common feature for all fluvial-erosion cirques is a terrain which includes erosion resistant upper structures overlying materials which are more easily eroded. Glacial cirques are found amongst mountain ranges throughout the world, classic cirques are typically about one kilometer long, situated high on a mountainside near the firn line, they are typically partially surrounded on three sides by steep cliffs. The highest cliff often is called a headwall, the fourth side forms the lip, threshold or sill, the side at which the glacier flowed away from the cirque. Many glacial cirques contain tarns dammed by either till or a bedrock threshold, when enough snow accumulates it can flow out the opening of the bowl and form valley glaciers which may be several kilometers long. These areas are sheltered from heat, encouraging the accumulation of snow, if the accumulation of snow increases, the process of nivation follows, whereby a hollow in a slope may be enlarged by ice segregation weathering and glacial erosion. Ice segregation erodes the rock vertical rock face and causes it to disintegrate, eventually, this hollow may become large enough that glacial erosion intensifies. The enlarging of this open ended concavity creates a larger leeward deposition zone, debris in the ice also may abrade the bed surface, should ice move down a slope it would have a ‘sandpaper effect’ on the bedrock beneath, on which it scrapes. Eventually, the hollow may become a bowl shape in the side of the mountain, with the headwall being weathered by ice segregation. The basin will become deeper as it continues to be eroded by ice segregation and abrasion, should ice segregation, plucking and abrasion continue, the dimensions of the cirque will increase, but the proportion of the landform would remain roughly the same. A bergschrund forms when the movement of the glacier separates the moving ice from the ice forming a crevasse. The method of erosion of the headwall lying between the surface of the glacier and the floor has been attributed to freeze-thaw mechanisms. The temperature within the bergschrund changes very little, however, studies have shown that ice segregation may happen with only changes in temperature. Water that flows into the bergschrund can be cooled to freezing temperatures by the ice allowing freeze-thaw mechanisms to occur. If two adjacent cirques erode toward one another, an arête, or steep sided ridge, forms, when three or more cirques erode toward one another, a pyramidal peak is created. In some cases, this peak will be accessible by one or more arêtes
20.
Moraine
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A moraine is any glacially formed accumulation of unconsolidated glacial debris that occurs in both currently and formerly glaciated regions on Earth, through geomorphological processes. Moraines are formed from debris previously carried along by a glacier, lateral moraines are formed at the side of the ice flow and terminal moraines at the foot, marking the maximum advance of the glacier. Other types of moraine include ground moraines, till-covered areas with irregular topography, moraines may be composed of debris ranging in size from silt-sized glacial flour to large boulders. The debris is typically sub-angular to rounded in shape, moraines may be on the glacier’s surface or deposited as piles or sheets of debris where the glacier has melted. Moraines may form through a number of processes, depending on the characteristics of sediment, the dynamics on the ice, moraine forming processes may be loosely divided into passive and active. Passive processes involve the placing of chaotic supraglacial sediments onto the landscape with limited reworking and these moraines are composed of supraglacial sediments from the ice surface. Active processes form or rework moraine sediment directly by the movement of ice and these form push moraines and thrust-block moraines, which are often composed of till and reworked proglacial sediment. Moraine may also form by the accumulation of sand and gravel deposits from glacial streams emanating from the ice margin and these fan deposits may coalesce to form a long moraine bank marking the ice margin. Several processes may combine to form and rework a single moraine, moraines can be classified either by origin, location with respect to a glacier or former glacier, or by shape. Some moraine types are only from ancient glaciers, while medial moraines of valley glaciers are poorly preserved. Lateral moraines are parallel ridges of debris deposited along the sides of a glacier, the unconsolidated debris can be deposited on top of the glacier by frost shattering of the valley walls and/or from tributary streams flowing into the valley. The till is carried along the glacial margin until the glacier melts, lateral moraines stand high because they protect the ice under them from the elements, causing it to melt or sublime less than the uncovered parts of the glacier. Multiple lateral moraines may develop as the glacier advances and retreats, ground moraines are till-covered areas with irregular topography and no ridges, often forming gently rolling hills or plains. They are accumulated at the base of the ice as lodgment till, in alpine glaciers, ground moraines are often found between the two lateral moraines. Ground moraines may be modified into drumlins by the overriding ice, Rogen moraines or ribbed moraines are a type of basal moraines that form a series of ribs perpendicular to the ice flow in an ice sheet. The depressions between the ribs are sometimes filled with water, making the Rogen moraines look like tigerstripes on aerial photographs, Rogen moraines are named after Lake Rogen in Härjedalen, Sweden, the landform’s type locality. End moraines, or terminal moraines, are ridges of unconsolidated debris deposited at the snout or end of the glacier and they usually reflect the shape of the glaciers terminus. Glaciers act much like a belt, carrying debris from the top of the glacier to the bottom where it deposits it in end moraines
21.
Glacier
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A glacier is a persistent body of dense ice that is constantly moving under its own weight, it forms where the accumulation of snow exceeds its ablation over many years, often centuries. Glaciers slowly deform and flow due to stresses induced by their weight, creating crevasses, seracs and they also abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice, between 35°N and 35°S, glaciers occur only in the Himalayas, Andes, Rocky Mountains, a few high mountains in East Africa, Mexico, New Guinea and on Zard Kuh in Iran. Glaciers cover about 10 percent of Earths land surface, continental glaciers cover nearly 13,000,000 km2 or about 98 percent of Antarcticas 13,200,000 km2, with an average thickness of 2,100 m. Greenland and Patagonia also have huge expanses of continental glaciers, Glacial ice is the largest reservoir of fresh water on Earth. Within high altitude and Antarctic environments, the temperature difference is often not sufficient to release meltwater. A large piece of compressed ice, or a glacier, appears blue as large quantities of water appear blue and this is because water molecules absorb other colors more efficiently than blue. The other reason for the color of glaciers is the lack of air bubbles. Air bubbles, which give a color to ice, are squeezed out by pressure increasing the density of the created ice. The word Glaceon is a loanword from French and goes back, via Franco-Provençal, to the Vulgar Latin glaciārium, derived from the Late Latin glacia, the processes and features caused by or related to glaciers are referred to as glacial. The process of establishment, growth and flow is called glaciation. The corresponding area of study is called glaciology, Glaciers are important components of the global cryosphere. Glaciers are categorized by their morphology, thermal characteristics, and behavior, cirque glaciers form on the crests and slopes of mountains. A glacier that fills a valley is called a valley glacier, a large body of glacial ice astride a mountain, mountain range, or volcano is termed an ice cap or ice field. Ice caps have a less than 50,000 km2 by definition. Glacial bodies larger than 50,000 km2 are called ice sheets or continental glaciers, several kilometers deep, they obscure the underlying topography. Only nunataks protrude from their surfaces, the only extant ice sheets are the two that cover most of Antarctica and Greenland. They contain vast quantities of water, enough that if both melted, global sea levels would rise by over 70 m
22.
Last Glacial Maximum
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The Last Glacial Maximum was the last period in the Earths climate history during the last glacial period when ice sheets were at their greatest extension. Growth of the ice sheets reached their positions in about 24,500 BCE. Vast ice sheets covered much of North America, northern Europe, the ice sheets profoundly affected Earths climate by causing drought, desertification, and a dramatic drop in sea levels. It was followed by the Late Glacial, the formation of an ice sheet or ice cap requires both prolonged cold and precipitation. Hence, despite having temperatures similar to those of glaciated areas in North America and Europe and this difference was because the ice sheets in Europe produced extensive anticyclones above them. These anticyclones generated air masses that were so dry on reaching Siberia and Manchuria that precipitation sufficient for the formation of glaciers could never occur, all over the world, climates at the Last Glacial Maximum were cooler and almost everywhere drier. Even in less affected regions, rainforest cover was greatly diminished, only in Central America and the Chocó region of Colombia did tropical rainforests remain substantially intact – probably due to the extraordinarily heavy rainfall of these regions. Most of the worlds deserts expanded and this also occurred in Afghanistan and Iran, where a major lake formed in the Dasht-e Kavir. In Australia, shifting sand dunes covered half the continent, whilst the Chaco, in northern China – unglaciated despite its cold climate – a mixture of grassland and tundra prevailed, and even here, the northern limit of tree growth was at least 20° farther south than today. During the Last Glacial Maximum, much of the world was cold, dry, and inhospitable, with frequent storms, the dustiness of the atmosphere is a prominent feature in ice cores, dust levels were as much as 20 to 25 times greater than now. This was probably due to a number of factors, reduced vegetation, stronger global winds, the massive sheets of ice locked away water, lowering the sea level, exposing continental shelves, joining land masses together, and creating extensive coastal plains. During the last glacial maximum,21,000 years ago, Northern Europe was largely covered by ice, the southern boundary of the ice sheets passing through Germany and Poland. This ice extended northward to cover Svalbard and Franz Josef Land and northeastward to occupy the Barents Sea, permafrost covered Europe south of the ice sheet down to present-day Szeged in Southern Hungary. Ice covered the whole of Iceland and almost all of the British Isles, britain was no more than a peninsula of Europe, its north capped in ice, and its south a polar desert. There were ice sheets in modern Tibet as well as in Baltistan, in Southeast Asia, many smaller mountain glaciers formed, and permafrost covered Asia as far south as Beijing. Palawan was also part of Sundaland, while the rest of the Philippine Islands formed one large island separated from the continent only by the Sibutu Passage and the Mindoro Strait. In Africa and the Middle East, many mountain glaciers formed. The Persian Gulf averages about 35 metres in depth and the seabed between Abu Dhabi and Qatar is even shallower, being less than 15 metres deep
23.
Plateau
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Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, and erosion by water and glaciers. Magma rises from the mantle, causing the ground to swell upward, in way, large, flat areas of rock are uplifted. Plateaus can also be built up by lava spreading outward from cracks, plateaus can also be formed by the erosional processes of glaciers on mountain ranges, leaving them sitting between the mountain ranges. Water can also erode mountains and other landforms down into plateaus, volcanic plateaus are produced by volcanic activity. The Columbia Plateau in the northwestern United States is an example, dissected plateaus are highly eroded plateaus cut by rivers and broken by deep narrow valleys. Plateaus are classified according to their surrounding environment, intermontane plateaus are the highest in the world, bordered by mountains. The Tibetan Plateau is one such plateau, Piedmont plateaus are bordered on one side by mountains and on the other by a plain or a sea. The Piedmont Plateau of the Eastern United States between the Appalachian Mountains and the Atlantic Coastal Plain is an example, continental plateaus are bordered on all sides by plains or oceans, forming away from the mountains. The Tibetan plateau covers approximately 2,500,000 km2, the plateau is sufficiently high enough to reverse the Hadley cell convection cycles and to drive the monsoons of India towards the south. The second-highest plateau is the Deosai Plateau of the Deosai National Park at an elevation of 4,114 m. It is located in the Astore and Skardu districts of Gilgit-Baltistan, Deosai means the land of giants. The park protects an area of 3,000 km2 and it is known for its rich flora and fauna of the Karakoram-West Tibetan Plateau alpine steppe ecoregion. In spring it is covered by sweeps of wildflowers and a variety of butterflies. The highest point in Deosai is Deosai Lake, or Sheosar Lake from the Shina language meaning Blind lake near the Chilim Valley. The lake lies at an elevation of 4,142 m, one of the highest lakes in the world, and is 2.3 km long,1.8 km wide, and 40 m deep on average. Some other major plateaus in Asia are, Armenian Highlands, Iranian plateau, Anatolian Plateau, Mongolian Plateau, and the Deccan Plateau. This polar ice cap is so massive that the echolocation sound measurements of ice thickness have shown that parts of the Antarctic dry land surface have been pressed below sea level. Thus, if that same ice cap were removed, the large areas of the frozen white continent would be flooded by the surrounding Antarctic Ocean or Southern Ocean
24.
Lava dome
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In volcanology, a lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. The geochemistry of lava domes can vary from basalt to rhyolite although most preserved domes tend to have high silica content, the characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very 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 easily break apart by further input of fluid lava, most of the domes have high silica content. Existence of lava domes has been suggested for some domed structures on the Martian surface in the part of Arcadia Planitia. Lava domes evolve unpredictably, due to non-linear dynamics caused by crystallization, domes undergo various processes such as growth, collapse, solidification and erosion. Lava domes grow by endogenic dome growth or exogenic dome growth, the former implies dome interior expansion to accommodate new lava and the latter refers to superficial piling up of lava. It is the viscosity of the lava that prevents it from flowing far from the vent from which it extrudes. Domes may reach heights of several hundred meters, and can grow slowly and steadily for months, years, the sides of these structures are composed of unstable rock debris. Due to the intermittent buildup of gas pressure, erupting domes can often experience episodes of explosive eruption over time, if part of a lava dome collapses while it is still molten, it can produce pyroclastic flows, one of the most lethal forms of volcanic event. Other hazards associated with domes are the destruction of property, forest fires. Lava domes are one of the structural features of many stratovolcanoes worldwide. Lava domes are prone to unusually dangerous explosions since they contain rhyolitic silica-rich lava, characteristics of lava dome eruptions include shallow, long-period and hybrid seismicity, which is attributed to excess fluid pressures in the contributing vent chamber. Other characteristics of lava domes include their hemispherical shape, cycles of dome growth over long periods. The average rate of growth may be used as a rough indicator of magma supply. A cryptodome is a structure created by accumulation of viscous magma at a shallow depth. Coulées are lava domes that have experienced some flow away from their original position, the worlds 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, there is another prominent coulée flow on the flank of Llullaillaco volcano, in Argentina, and other examples in the Andes
25.
Hydrothermal
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Hydrothermal circulation in its most general sense is the circulation of hot water. Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earths crust, in general, this occurs near volcanic activity, but can occur in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism. Hydrothermal circulation in the oceans is the passage of the water through mid-oceanic ridge systems, the former circulation type is sometimes termed active, and the latter passive. The heat source for the active vents is the newly formed basalt, and, for the highest temperature vents, the heat source for the passive vents is the still-cooling older basalts. Heat flow studies of the seafloor suggest that basalts within the oceanic crust take millions of years to cool as they continue to support passive hydrothermal circulation systems. Hydrothermal vents are locations on the seafloor where hydrothermal fluids mix into the overlying ocean, perhaps the best-known vent forms are the naturally occurring chimneys referred to as black smokers. Hydrothermal circulation is not limited to ocean ridge environments, the source water for hydrothermal explosions, geysers, and hot springs is heated groundwater convecting below and lateral to the hot water vent. Hydrothermal circulating convection cells exist any place an anomalous source of heat, such as an intruding magma or volcanic vent, hydrothermal also refers to the transport and circulation of water within the deep crust, in general from areas of hot rocks to areas of cooler rocks. During the early 1900s, various geologists worked to classify hydrothermal ore deposits that they assumed formed from upward-flowing aqueous solutions, waldemar Lindgren developed a classification based on interpreted decreasing temperature and pressure conditions of the depositing fluid. His terms, hypothermal, mesothermal, epithermal and teleothermal, expressed decreasing temperature, recent studies retain only the epithermal label
26.
Geophysics
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Although geophysics was only recognized as a separate discipline in the 19th century, its origins date back to ancient times. The first magnetic compasses were made from lodestones, while more modern magnetic compasses played an important role in the history of navigation, the first seismic instrument was built in 132 BC. Geophysics is applied to societal needs, such as resources, mitigation of natural hazards. Geophysics is a highly interdisciplinary subject, and geophysicists contribute to area of the Earth sciences. To provide an idea of what constitutes geophysics, this section describes phenomena that are studied in physics and how they relate to the Earth. The gravitational pull of the Moon and Sun give rise to two high tides and two low tides every lunar day, or every 24 hours and 50 minutes, therefore, there is a gap of 12 hours and 25 minutes between every high tide and between every low tide. Gravitational forces make rocks press down on rocks, increasing their density as the depth increases. Measurements of gravitational acceleration and gravitational potential at the Earths surface, the surface gravitational field provides information on the dynamics of tectonic plates. The geopotential surface called the geoid is one definition of the shape of the Earth, the geoid would be the global mean sea level if the oceans were in equilibrium and could be extended through the continents. The Earth is cooling, and the heat flow generates the Earths magnetic field through the geodynamo. The main sources of heat are the heat and radioactivity. Some heat is carried up from the bottom of the mantle by mantle plumes, the heat flow at the Earths surface is about 4.2 ×1013 W, and it is a potential source of geothermal energy. Seismic waves are vibrations that travel through the Earths interior or along its surface, the entire Earth can also oscillate in forms that are called normal modes or free oscillations of the Earth. Ground motions from waves or normal modes are measured using seismographs, if the waves come from a localized source such as an earthquake or explosion, measurements at more than one location can be used to locate the source. The locations of earthquakes provide information on plate tectonics and mantle convection, measurements of seismic waves are a source of information on the region that the waves travel through. If the density or composition of the rock changes suddenly, some waves are reflected, reflections can provide information on near-surface structure. Changes in the direction, called refraction, can be used to infer the deep structure of the Earth. Earthquakes pose a risk to humans, understanding their mechanisms, which depend on the type of earthquake, can lead to better estimates of earthquake risk and improvements in earthquake engineering
27.
Crater lake
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Sometimes lakes which form inside calderas are called caldera lakes, but often this distinction is not made. Crater lakes covering active volcanic vents are known as volcanic lakes, and the water within them is often acidic, saturated with volcanic gases. For example, the lake of Kawah Ijen in Indonesia has a pH of under 0.5. Lakes located in dormant or extinct volcanoes tend to have water. Crater lakes form as the depression, within the crater rim, is filled by water. The water may come from precipitation, groundwater circulation or melted ice and its level rises until an equilibrium is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation, subsurface seepage, if the volcanic dam portion erodes rapidly or fails catastrophically, the occurrence produces a breakout or outburst flood. With changes in environmental conditions over time, the occurrence of floods is common to all natural dam types. A well-known crater lake, which bears the name as the geological feature, is Crater Lake in Oregon. It is located in the caldera of Mount Mazama and it is the deepest lake in the United States with a depth of 594 m. Crater Lake is fed solely by falling rain and snow, with no inflow or outflow at the surface, and hence is one of the clearest lakes in the world. The highest volcano in the world,6, 893-m Ojos del Salado in Chile, has a permanent crater lake about 100 m in diameter at an elevation of 6,390 m on its eastern side. This is most likely the highest lake of any kind in the world, due to their unstable environments, some crater lakes exist only intermittently. Hence, making Lake Toba the largest crater lake in the world, while many crater lakes are picturesque, they can also be deadly. Gas discharges from Lake Nyos suffocated 1,800 people in 1986, example of such impact crater lakes include Manicouagan in Canada, Lake Bosumtwi in Ghana and Siljan in Sweden. More rarely they can also fill craters caused by artificial explosions, lava lake Volcanic crater Caldera Types of volcanic eruptions Maar Atoll Impact crater Delmelle, Pierre, Bernard, Alain. Journal of Volcanology and Geothermal Research, kusakabe, Minoru, ed. Geochemistry of Crater Lakes. California Davis Crater Lake National Park documentation in Building Oregon, Architecture of Oregon & the Pacific Northwest archive World Volcanic Lakes Map
28.
Acid
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An acid is a molecule or ion capable of donating a hydron, or, alternatively, capable of forming a covalent bond with an electron pair. The first category of acids is the donors or Brønsted acids. In the special case of solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents, acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals to form salts. The word acid is derived from the Latin acidus/acēre meaning sour, an aqueous solution of an acid has a pH less than 7 and is colloquially also referred to as acid, while the strict definition refers only to the solute. A lower pH means a higher acidity, and thus a higher concentration of hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic, common aqueous acids include hydrochloric acid, acetic acid, sulfuric acid, and citric acid. As these examples show, acids can be solutions or pure substances, strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes and boric acid. The second category of acids are Lewis acids, which form a covalent bond with an electron pair, however, hydrogen chloride, acetic acid, and most other Brønsted-Lowry acids cannot form a covalent bond with an electron pair and are therefore not Lewis acids. Conversely, many Lewis acids are not Arrhenius or Brønsted-Lowry acids, in modern terminology, an acid is implicitly a Brønsted acid and not a Lewis acid, since chemists almost always refer to a Lewis acid explicitly as a Lewis acid. Modern definitions are concerned with the chemical reactions common to all acids. Most acids encountered in life are aqueous solutions, or can be dissolved in water, so the Arrhenius. The Brønsted-Lowry definition is the most widely used definition, unless otherwise specified, hydronium ions are acids according to all three definitions. Interestingly, although alcohols and amines can be Brønsted-Lowry acids, they can function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms. The Swedish chemist Svante Arrhenius attributed the properties of acidity to hydrogen ions or protons in 1884, an Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in the water. Thus, an Arrhenius acid can also be described as a substance that increases the concentration of ions when added to water. Examples include molecular substances such as HCl and acetic acid, an Arrhenius base, on the other hand, is a substance which increases the concentration of hydroxide ions when dissolved in water. Thus, an Arrhenius acid could also be said to be one that decreases hydroxide concentration, in an acidic solution, the concentration of hydronium ions is greater than 10−7 moles per liter
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Spring (hydrology)
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A spring is any natural situation where water flows from an aquifer to the Earths surface. It is a component of the hydrosphere, a spring may be the result of karst topography where surface water has infiltrated the Earths surface, becoming part of the area groundwater. The groundwater then travels through a network of cracks and fissure—openings ranging from intergranular spaces to large caves, the water eventually emerges from below the surface, in the form of a karst spring. The forcing of the spring to the surface can be the result of an aquifer in which the recharge area of the spring water table rests at a higher elevation than that of the outlet. Spring water forced to the surface by elevated sources are artesian wells and this is possible even if the outlet is in the form of a 300-foot-deep cave. In this case the cave is used like a hose by the higher elevated area of groundwater to exit through the lower elevation opening. Non-artesian springs may simply flow from a higher elevation through the earth to a lower elevation, still other springs are the result of pressure from an underground source in the earth, in the form of volcanic activity. The result can be water at elevated temperature such as a hot spring, the action of the groundwater continually dissolves permeable bedrock such as limestone and dolomite, creating vast cave systems. The term seep refers to springs with small flow rates in which the water has filtered through permeable earth. Fracture springs, discharge from faults, joints, or fissures in the earth, tubular springs, in which the water flows from underground caverns. Spring discharge, or resurgence, is determined by the springs recharge basin, factors that affect the recharge include the size of the area in which groundwater is captured, the amount of precipitation, the size of capture points, and the size of the spring outlet. Water may leak into the system from many sources including permeable earth, sinkholes. In some cases entire creeks seemingly disappear as the water sinks into the ground via the stream bed, grand Gulf State Park in Missouri is an example of an entire creek vanishing into the groundwater system. The water emerges 9 miles away, forming some of the discharge of Mammoth Spring in Arkansas, human activity may also affect a springs discharge--withdrawal of groundwater reduces the water pressure in an aquifer, decreasing the volume of flow. Springs are often classified by the volume of the water they discharge, the largest springs are called first-magnitude, defined as springs that discharge water at a rate of at least 2800 liters or 100 cubic feet of water per second. The scale for spring flow is as follows, Minerals become dissolved in the water as it moves through the underground rocks and this may give the water flavor and even carbon dioxide bubbles, depending on the nature of the geology through which it passes. This is why spring water is bottled and sold as mineral water. Springs that contain significant amounts of minerals are sometimes called mineral springs, Springs that contain large amounts of dissolved sodium salts, mostly sodium carbonate, are called soda springs
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Silicon
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Silicon is a chemical element with symbol Si and atomic number 14. A hard and brittle crystalline solid with a metallic luster. It is a member of group 14 in the table, along with carbon above it and germanium, tin, lead. It is not very reactive, although more reactive than germanium, Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earths crust. It is most widely distributed in dusts, sands, planetoids, over 90% of the Earths crust is composed of silicate minerals, making silicon the second most abundant element in the Earths crust after oxygen. Most silicon is used commercially without being separated, and often with little processing of the natural minerals, such use includes industrial construction with clays, silica sand, and stone. Silicate is used in Portland cement for mortar and stucco, and mixed with sand and gravel to make concrete for walkways, foundations. Silicates are used in whiteware ceramics such as porcelain, and in traditional quartz-based soda-lime glass, Silicon compounds such as silicon carbide are used as abrasives and components of high-strength ceramics. Elemental silicon also has an impact on the modern world economy. Most free silicon is used in the refining, aluminium-casting. Silicon is the basis of the widely used synthetic polymers called silicones, Silicon is an essential element in biology, although only tiny traces are required by animals. However, various sea sponges and microorganisms, such as diatoms and radiolaria, silica is deposited in many plant tissues, such as in the bark and wood of Chrysobalanaceae and the silica cells and silicified trichomes of Cannabis sativa, horsetails and many grasses. Silicon is a solid at room temperature, with a point of 1,414 °C. Like water, it has a density in a liquid state than in a solid state and it expands when it freezes. With a relatively high conductivity of 149 W·m−1·K−1, silicon conducts heat well. In its crystalline form, pure silicon has a gray color, like germanium, silicon is rather strong, very brittle, and prone to chipping. Silicon, like carbon and germanium, crystallizes in a cubic crystal structure with a lattice spacing of 0.5430710 nm. The outer electron orbital of silicon, like that of carbon, has four valence electrons, the 1s, 2s, 2p and 3s subshells are completely filled while the 3p subshell contains two electrons out of a possible six
31.
Confluence
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In geography, a confluence is the meeting of two or more bodies of water. The term is used to describe the meeting of tidal or other non-riverine bodies of water. A one-mile portion of the Industrial Canal in New Orleans accommodates the Gulf Intracoastal Waterway, niagara-on-the-Lake, Ontario, Canada is at the confluence of the Niagara River and Lake Ontario. The junction of the Green River and Colorado River forms the heart of Canyonlands National Park in Utahs Canyon Country, the Sangam, near Allahabad, India, where the sacred rivers Ganges and Yamuna meet to create one of the holiest places in Hinduism. The Ohio River is formed by the confluence of the Monongahela and Allegheny rivers, located in Pittsburgh, the Madison, Jefferson and Gallatin Rivers in Three Forks, Montana form the confluence of the Missouri River, one of the longest rivers in the United States. Kuala Lumpur, the capital of Malaysia, is at the confluence of the Gombak River and the Klang River. Passau known also as the Dreiflüssestadt, because the Danube River is joined there by the Inn River from the South, manaus, Brazil is on the Rio Negro near its confluence with the Amazon. It is the port and a hub for the regions extensive river system. Osijek, Croatia, is on the bank of the river Drava 25 km upstream of its confluence with the Danube. Belgrade, the capital of Serbia lies at the confluence of the Sava, the Hochelaga Archipelago, including the island and city of Montreal, is located at the confluence of the St. Lawrence River and Ottawa River in Quebec, Canada. Winnipeg, Canada, is at the confluence of the Red River, the area is referred to as The Forks by locals, and has been an important trade location for over 6000 years. The confluence of the rivers Danube and Morava in Devín on the border between Slovakia and Austria, triangle of Three Emperors, former tripoint in Europe. Cairo, Illinois, in the United States, where the Ohio River flows into the Mississippi River, St. Louis, Missouri, is built just south of the confluence of the Mississippi River and the Missouri River. Lyon, France is located on the confluence of the Saône and Rhone rivers, lytton, British Columbia, Canada, is located at the confluence of the muddy Fraser River and the clearer Thompson River. The confluence between the Franklin River and Gordon River in south-western Tasmania The confluence of the Snake and Columbia River at the Tri-Cities of Washington, the confluence of the rivers Pivka and Rak is one of the largest subterranean confluences in Europe. The confluence at Lokoja, Nigeria, where the Niger and Benue rivers merge, the Sudanese capital of Khartoum, located at the confluence of the White Nile and the Blue Nile. This merging point is the beginning of the Nile, columbus, Ohio, in the United States is at the confluence of the Scioto and Olentangy rivers. Luang Prabang in Laos is at the confluence of the Mekong, River Kabul and River Swat at Attock, in Pakistan
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Pacific Ocean
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The Pacific Ocean is the largest and deepest of the Earths oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west, the Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean, the oceans current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means peaceful sea, important human migrations occurred in the Pacific in prehistoric times. Long-distance trade developed all along the coast from Mozambique to Japan, trade, and therefore knowledge, extended to the Indonesian islands but apparently not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality, from 1404 to 1433 Zheng He led expeditions into the Indian Ocean. The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and he named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. Later, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Castilian expedition of world circumnavigation starting in 1519, Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters. The ocean was often called the Sea of Magellan in his honor until the eighteenth century, sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, and Papua New Guinea. In 1542–43 the Portuguese also reached Japan, in 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands. The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history, Spanish expeditions also discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands in the South Pacific. In the 16th and 17th century Spain considered the Pacific Ocean a Mare clausum—a sea closed to other naval powers, as the only known entrance from the Atlantic the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western end of the Pacific Ocean the Dutch threatened the Spanish Philippines, Spain also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest, one of the earliest voyages of scientific exploration was organized by Spain in the Malaspina Expedition of 1789–1794. It sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia, and the South Pacific. Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, Japan, in Oceania, France got a leading position as imperial power after making Tahiti and New Caledonia protectorates in 1842 and 1853 respectively. After navy visits to Easter Island in 1875 and 1887, Chilean navy officer Policarpo Toro managed to negotiate an incorporation of the island into Chile with native Rapanui in 1888, by occupying Easter Island, Chile joined the imperial nations
33.
Salinas y Aguada Blanca National Reserve
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Salinas y Aguada Blanca National Reserve is a protected area located in the regions of Arequipa and Moquegua, Peru. The main purpose of this area is to protect the flora, fauna. The area was declared a reserve on 9 August 1979 by decree N° 070-79-AA. Salinas y Aguada Blanca was designated as a Ramsar site in 2003, Salinas y Aguada Blanca National Reserve is located in the provinces of Caylloma and Arequipa in the region of Arequipa, and in the province of Sanchez Cerro in the region of Moquegua. It spans an area of 366,936 hectares which covers the headwaters of important local rivers like Yura, although initially declared an area with the aim to protect local camelids, it has since become a protected water source for the city of Arequipa. Precipitation carried by the winds is captured by the local vegetation and stored in the lakes, meadows and soil. The reserve is populated to some extent, most of its territory belongs to thirteen peasant communities, the area is representative of the puna ecosystem. Assessment of Threats to Flamingos at the Salinas and Aguada Blanca National Nature Reserve, Salinas y Aguada Blanca National Reserve. Salinas y Aguada Blanca National Reserve, photos of Salinas y Aguada Blanca National Reserve
34.
Reservoir
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A reservoir is a storage space for fluids. These fluids may be water, hydrocarbons or gas, a reservoir usually means an enlarged natural or artificial lake, storage pond or impoundment created using a dam or lock to store water. Reservoirs can be created by controlling a stream that drains a body of water. They can also be constructed in river valleys using a dam, alternately, a reservoir can be built by excavating flat ground or constructing retaining walls and levees. Tank reservoirs store liquids or gases in storage tanks that may be elevated, at grade level, tank reservoirs for water are also called cisterns. Underground reservoirs are used to store liquids, principally either water or petroleum, a dam constructed in a valley relies on the natural topography to provide most of the basin of the reservoir. Dams are typically located at a part of a valley downstream of a natural basin. The valley sides act as walls, with the dam located at the narrowest practical point to provide strength. In many reservoir construction projects, people have to be moved and re-housed, construction of a reservoir in a valley will usually need the river to be diverted during part of the build, often through a temporary tunnel or by-pass channel. In hilly regions, reservoirs are constructed by enlarging existing lakes. Sometimes in such reservoirs the new top water level exceeds the height on one or more of the feeder streams such as at Llyn Clywedog in Mid Wales. In such cases additional side dams are required to contain the reservoir, where water is pumped or siphoned from a river of variable quality or quantity, bank-side reservoirs may be built to store the water. Such reservoirs are usually formed partly by excavation and partly by building a complete encircling bund or embankment, the water stored in such reservoirs may stay there for several months, during which time normal biological processes may substantially reduce many contaminants and almost eliminate any turbidity. The use of reservoirs also allows water abstraction to be stopped for some time. Service reservoirs store fully treated potable water close to the point of distribution, many service reservoirs are constructed as water towers, often as elevated structures on concrete pillars where the landscape is relatively flat. Other service reservoirs can be almost entirely underground, especially in hilly or mountainous country. In the United Kingdom, Thames Water has many underground reservoirs, sometimes called cisterns, built in the 1800s. A good example is the Honor Oak Reservoir in London, constructed between 1901 and 1909, when it was completed it was said to be the largest brick built underground reservoir in the world and it is still one of the largest in Europe
35.
Mining
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Mining is extraction of valuable minerals or other geological materials from the earth usually from an orebody, lode, vein, seam, reef or placer deposits. These deposits form a mineralized package that is of economic interest to the miner, ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain any material that cannot be grown through agricultural processes, Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Mining of stones and metal has been a human activity since pre-historic times, Mining operations usually create a negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the nations have passed regulations to decrease the impact. Work safety has long been a concern as well, and modern practices have significantly improved safety in mines, levels of metals recycling are generally low. Unless future end-of-life recycling rates are stepped up, some rare metals may become unavailable for use in a variety of consumer products, due to the low recycling rates, some landfills now contain higher concentrations of metal than mines themselves. Since the beginning of civilization, people have used stone, ceramics and, later and these were used to make early tools and weapons, for example, high quality flint found in northern France, southern England and Poland was used to create flint tools. Flint mines have been found in areas where seams of the stone were followed underground by shafts. The mines at Grimes Graves and Krzemionki are especially famous, other hard rocks mined or collected for axes included the greenstone of the Langdale axe industry based in the English Lake District. The oldest-known mine on archaeological record is the Lion Cave in Swaziland, at this site Paleolithic humans mined hematite to make the red pigment ochre. Mines of an age in Hungary are believed to be sites where Neanderthals may have mined flint for weapons. Ancient Egyptians mined malachite at Maadi, at first, Egyptians used the bright green malachite stones for ornamentations and pottery. Later, between 2613 and 2494 BC, large building projects required expeditions abroad to the area of Wadi Maghareh in order to secure minerals and other resources not available in Egypt itself. Quarries for turquoise and copper were found at Wadi Hammamat, Tura, Aswan and various other Nubian sites on the Sinai Peninsula. Mining in Egypt occurred in the earliest dynasties, the gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by the Greek author Diodorus Siculus, who mentions fire-setting as one used to break down the hard rock holding the gold. One of the complexes is shown in one of the earliest known maps, the miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust
36.
Road
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Roads consist of one or two roadways, each with one or more lanes and any associated sidewalks and road verges. Roads that are available for use by the public may be referred to as parkways, avenues, freeways, interstates, highways, or primary, secondary, and tertiary local roads. In urban areas roads may diverge through a city or village and be named as streets, serving a function as urban space easement. Modern roads are normally smoothed, paved, or otherwise prepared to allow easy travel, historically many roads were simply recognizable routes without any formal construction or maintenance. In the United Kingdom there is ambiguity between the terms highway and road. The Highway code details rules for road users and this includes footpaths, bridleways and cycle tracks, and also road and driveways on private land and many car parks. Vehicle Excise Duty, a use tax, is payable on some vehicles used on the public road. The definition of a road depends on the definition of a highway, in the United States, laws distinguish between public roads, which are open to public use, and private roads, which are privately controlled. The assertion that the first pathways were the trails made by animals has not been universally accepted, others believe that some roads originated from following animal trails. The Icknield Way is given as an example of type of road origination. By about 10,000 BC, rough roads/pathways were used by human travelers, the worlds oldest known paved road was constructed in Egypt some time between 2600 and 2200 BC. Stone-paved streets are found in the city of Ur in the Middle East dating back to 4000 BC, corduroy roads are found dating to 4000 BC in Glastonbury, England. The Sweet Track, a timber causeway in England, is one of the oldest engineered roads discovered. Built in winter 3807 BC or spring 3806 BC, tree-ring dating enabled very precise dating and it was claimed to be the oldest road in the world until the 2009 discovery of a 6, 000-year-old trackway in Plumstead, London. Brick-paved streets were used in India as early as 3000 BC, in 500 BC, Darius I the Great started an extensive road system for Persia, including the Royal Road, which was one of the finest highways of its time. The road remained in use after Roman times, a hybrid of road transport and ship transport beginning in about 1740 is the horse-drawn boat in which the horse follows a cleared path along the river bank. From about 312 BC, the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa, at its peak the Roman Empire was connected by 29 major roads moving out from Rome and covering 78,000 kilometers or 52,964 Roman miles of paved roads. In the 8th century AD, many roads were built throughout the Arab Empire, the most sophisticated roads were those in Baghdad, which were paved with tar
37.
Tectonic plates
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The theoretical model builds on the concept of continental drift developed during the first few decades of the 20th century. The geoscientific community accepted plate-tectonic theory after seafloor spreading was validated in the late 1950s, the lithosphere, which is the rigid outermost shell of a planet, is broken up into tectonic plates. The Earths lithosphere is composed of seven or eight major plates, where the plates meet, their relative motion determines the type of boundary, convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries. The relative movement of the plates typically ranges from zero to 100 mm annually, tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle, the material lost is balanced by the formation of new crust along divergent margins by seafloor spreading. In this way, the surface of the lithosphere remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle, earlier theories, since disproven, proposed gradual shrinking or gradual expansion of the globe. Tectonic plates are able to move because the Earths lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the ridge and drag, with downward suction. Another explanation lies in the different forces generated by forces of the Sun. The relative importance of each of these factors and their relationship to other is unclear. The outer layers of the Earth are divided into the lithosphere and asthenosphere and this is based on differences in mechanical properties and in the method for the transfer of heat. Mechanically, the lithosphere is cooler and more rigid, while the asthenosphere is hotter, in terms of heat transfer, the lithosphere loses heat by conduction, whereas the asthenosphere also transfers heat by convection and has a nearly adiabatic temperature gradient. The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, Plate motions range up to a typical 10–40 mm/year, to about 160 mm/year. The driving mechanism behind this movement is described below, tectonic lithosphere plates consist of lithospheric mantle overlain by either or both of two types of crustal material, oceanic crust and continental crust. Average oceanic lithosphere is typically 100 km thick, its thickness is a function of its age, as passes, it conductively cools
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Nazca Plate
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The Nazca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Nazca Plate under the South American Plate is largely responsible for the Andean orogeny. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise respectively. The movement of the Nazca Plate over several hotspots has created some volcanic islands as well as east-west running seamount chains that subduct under South America, the oldest rocks of the plate are about 50 million years old. A triple junction, the Chile Triple Junction, occurs on the seafloor of the Pacific Ocean off Taitao, here three tectonic plates meet, the Nazca Plate, the South American Plate, and the Antarctic Plate. The eastern margin is a convergent boundary subduction zone under the South American Plate, the southern side is a divergent boundary with the Antarctic Plate, the Chile Rise, where seafloor spreading permits magma to rise. The western side is a divergent boundary with the Pacific Plate, the northern side is a divergent boundary with the Cocos Plate, the Galapagos Rise. The subduction of the Nazca plate under southern Chile has a history of producing massive earthquakes, including the largest ever recorded on earth, the moment magnitude 9.51960 Valdivia earthquake. A second triple junction occurs at the northwest corner of the plate where the Nazca, Cocos, yet another triple junction occurs at the southwest corner at the intersection of the Nazca, Pacific, and Antarctic Plates off the coast of southern Chile. At each of these triple junctions an anomalous microplate exists, the Galapagos Microplate at the northern junction, the Easter Island Microplate is a third microplate that is located just north of the Juan Fernandez Microplate and lies just west of Easter Island. The Carnegie Ridge is a 1, 350-km-long and up to 300-km-wide feature on the floor of the northern Nazca Plate that includes the Galápagos archipelago at its western end. It is being subducted under South America with the rest of the Nazca Plate, Darwin Gap is the area between the Nazca Plate and the coast of Chile, where Charles Darwin experienced the earthquake of 1835. It is expected that this area will be the epicenter of a quake in the near future. The absolute motion of the Nazca Plate has been calibrated at 3.7 cm/yr east motion, the subducting Nazca Plate, which exhibits unusual flat-slab subduction, is tearing as well as deforming as it is subducted. The subduction has formed, and continues to form, the volcanic Andes Mountain Range, deformation of the Nazca Plate even affects the geography of Bolivia, far to the east. Aside from the Juan Fernández Islands, this area has few other islands that are affected by the earthquakes that are a result of complicated movements at these junctions. The precursor of both the Nazca Plate and the Cocos Plate was the Farallon Plate, which split in late Oligocene, about 22.8 Mya, a date arrived at by interpreting magnetic anomalies. Subduction under the South American continent began about 140 Mya, although the formation of the parts of the Central Andes
39.
Subduct
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Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced or sinks due to gravity into the mantle. Regions where this occurs are known as subduction zones. Rates of subduction are typically in centimeters per year, with the rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Plates include both oceanic crust and continental crust, stable subduction zones involve the oceanic lithosphere of one plate sliding beneath the continental or oceanic lithosphere of another plate due to the higher density of the oceanic lithosphere. That is, the lithosphere is always oceanic while the overriding lithosphere may or may not be oceanic. Subduction zones are sites that have a rate of volcanism, earthquakes. Subduction zones are sites of convective downwelling of Earths lithosphere, subduction zones exist at convergent plate boundaries where one plate of oceanic lithosphere converges with another plate. The descending slab, the plate, is over-ridden by the leading edge of the other plate. The slab sinks at an angle of approximately twenty-five to forty-five degrees to Earths surface and this sinking is driven by the temperature difference between the subducting oceanic lithosphere and the surrounding mantle asthenosphere, as the colder oceanic lithosphere is, on average, denser. At a depth of approximately 80–120 kilometers, the basalt of the oceanic crust is converted to a rock called eclogite. At that point, the density of the oceanic crust increases and provides additional negative buoyancy and it is at subduction zones that Earths lithosphere, oceanic crust, sedimentary layers and some trapped water are recycled into the deep mantle. Earth is so far the only planet where subduction is known to occur, subduction is the driving force behind plate tectonics, and without it, plate tectonics could not occur. Subduction zones dive down into the mantle beneath 55,000 kilometers of convergent plate margins, subduction zones burrow deeply but are imperfectly camouflaged, and geophysics and geochemistry can be used to study them. Not surprisingly, the shallowest portions of subduction zones are known best, subduction zones are strongly asymmetric for the first several hundred kilometers of their descent. They start to go down at oceanic trenches and their descents are marked by inclined zones of earthquakes that dip away from the trench beneath the volcanoes and extend down to the 660-kilometer discontinuity. Subduction zones are defined by the array of earthquakes known as the Wadati–Benioff zone after the two scientists who first identified this distinctive aspect. Subduction zone earthquakes occur at greater depths than elsewhere on Earth, such deep earthquakes may be driven by deep phase transformations, thermal runaway, the subducting basalt and sediment are normally rich in hydrous minerals and clays. Additionally, large quantities of water are introduced into cracks and fractures created as the slab bends downward
40.
South American Plate
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The South American Plate is a tectonic plate which includes the continent of South America and also a sizeable region of the Atlantic Ocean seabed extending eastward to the Mid-Atlantic Ridge. The easterly side is a divergent boundary with the African Plate forming the part of the Mid-Atlantic Ridge. The southerly side is a boundary with the Antarctic Plate. The westerly side is a convergent boundary with the subducting Nazca Plate, the northerly side is a boundary with the Caribbean Plate and the oceanic crust of the North American Plate. At the Chile Triple Junction in Taitato-Tres Montes Peninsula, an oceanic ridge — the Chile Rise — is subducting under the South American plate, the South American Plate is in motion. Parts of the plate boundaries consisting of alternations of relatively short transform fault, moving westward away from the Mid-Atlantic Ridge. The eastward-moving and more dense Nazca Plate is subducting under the edge of the South American Plate along the Pacific coast of the continent at a rate of 77 mm per year. This collision of plates is responsible for lifting the massive Andes Mountains and causing the volcanoes which are strewn throughout them
41.
Andes
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The Andes or Andean Mountains are the longest continental mountain range in the world. They are a range of highlands along the western edge of South America. This range is about 7,000 km long, about 200 to 700 km wide, the Andes extend from north to south through seven South American countries, Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina and Chile. Along their length, the Andes are split into several ranges, the Andes are the location of several high plateaus – some of which host major cities, such as Quito, Bogotá, Arequipa, Medellín, Sucre, Mérida and La Paz. The Altiplano plateau is the worlds second-highest after the Tibetan plateau and these ranges are in turn grouped into three major divisions based on climate, the Tropical Andes, the Dry Andes, and the Wet Andes. The Andes are the worlds highest mountain range outside of Asia, the highest mountain outside Asia, Mount Aconcagua, rises to an elevation of about 6,961 m above sea level. The peak of Chimborazo in the Ecuadorean Andes is farther from the Earths center than any other location on the Earths surface, the worlds highest volcanoes are in the Andes, including Ojos del Salado on the Chile-Argentina border, which rises to 6,893 m. The etymology of the word Andes has been debated, the majority consensus is that it derives from the Quechua word anti, which means east as in Antisuyu, one of the four regions of the Inca Empire. In the northern part of the Andes, the isolated Sierra Nevada de Santa Marta range is considered to be part of the Andes. The term cordillera comes from the Spanish word cordel, meaning rope, the Andes range is about 200 km wide throughout its length, except in the Bolivian flexure where it is about 640 kilometres wide. The Andes are the result of plate tectonics processes, caused by the subduction of oceanic crust beneath the South American plate. The main cause of the rise of the Andes is the compression of the rim of the South American Plate due to the subduction of the Nazca Plate. In the south, the Andes share a boundary with the former Patagonia Terrane. To the west, the Andes end at the Pacific Ocean, from a geographical approach, the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and a less rugged topography. The Andes Mountains also contain large quantities of iron ore located in mountains within the range. The Andean orogen has a series of bends or oroclines, the Bolivian Orocline is a seaward concave bending in the coast of South America and the Andes Mountains at about 18° S. At this point the orientation of the Andes turns from Northwest in Peru to South in Chile, the Andean segment north and south of the orocline have been rotated 15° to 20° counter clockwise and clockwise respectively. The Bolivian Orocline area overlaps with the area of maximum width of the Altiplano Plateau, the specific point at 18° S where the coastline bends is known as the Arica Elbow
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Altiplano
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The Altiplano, Collao, Andean Plateau or Bolivian Plateau, in west-central South America, is the area where the Andes are the widest. It is the most extensive area of high plateau on Earth outside Tibet, the bulk of the Altiplano lies in Bolivia, but its northern parts lie in Peru, and its southern parts lie in Chile and Argentina. The plateau hosts several cities of three nations, including El Alto, La Paz, Oruro, and Puno. The northeastern Altiplano is more humid than the southwestern area, the latter area has several salares, or salt flats, due to its aridity. At the Bolivia–Peru border lies Lake Titicaca, the largest lake in South America, South of that in Bolivia was Lake Poopó, which was declared dried up and defunct as of December 2015. It is unclear if this second-largest lake in Bolivia can be revitalized, the Altiplano was the site of several pre-Columbian cultures, including the Chiripa, Tiawanaku and the Inca Empire. Spain conquered the region in the 16th century, major economic activities in the Altiplano include mining, llama and vicuña herding, and services in the cities. The Altiplano is an area of inland drainage lying in the central Andes, occupying parts of northern Chile and Argentina, western Bolivia and its height averages about 3,750 meters, slightly less than that of the Tibetan Plateau. The Atacama Desert, one of the driest areas on the planet, lies to the southwest of the Altiplano, the Altiplano is noted for hypoxic air caused by very high elevation. At various times during the Pleistocene epoch, both the southern and northern Altiplano were covered by vast pluvial lakes, remnants are Lake Titicaca, straddling the Peru–Bolivia border, and Poopó, a salt lake that extends south of Oruro, Bolivia. Salar de Uyuni, locally known as Salar de Tunupa, scientists classify the latter as commencing at an elevation of approximately 4,500 meters. Alternate names used in place of altiplano in this context include puna, the diurnal cycle of temperature is very wide, with maximum temperatures in the order of 12 to 24 °C and the minimum in the order of -20 to 10 °C. The coldest temperatures occur in the portion of the Altiplano during the months of June and July. The seasonal cycle of rainfall is marked, with the rainy season concentrated between December and March, the rest of the year tends to be very dry, cool, windy and sunny. Snowfall may happen between April and September, especially to the north, but it is not very common, such weaknesses would cause the partition of tectonic deformation and uplift into the eastern and western cordillera, leaving the necessary space for the formation of the altiplano basin. Altiplano - Where Bolivia meets the sky
