1.
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
2.
Guatemala
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With an estimated population of around 15.8 million, it is the most populated state in Central America. Guatemala is a democracy, its capital and largest city is Nueva Guatemala de la Asunción. The territory of modern Guatemala once formed the core of the Maya civilization, most of the country was conquered by the Spanish in the 16th century, becoming part of the viceroyalty of New Spain. Guatemala attained independence in 1821 as part of the Federal Republic of Central America, from the mid to late 19th century, Guatemala experienced chronic instability and civil strife. Beginning in the early 20th century, it was ruled by a series of dictators backed by the United Fruit Company, in 1944, authoritarian leader Jorge Ubico was overthrown by a pro-democratic military coup, initiating a decade-long revolution that led to sweeping social and economic reforms. A U. S. -backed military coup in 1954 ended the revolution, from 1960 to 1996, Guatemala endured a bloody civil war fought between the US-backed government and leftist rebels, including genocidal massacres of the Maya population perpetrated by the military. As of 2014, Guatemala ranks 31st of 33 Latin American and Caribbean countries in terms of the Human Development Index, Guatemalas abundance of biologically significant and unique ecosystems includes a large number of endemic species and contributes to Mesoamericas designation as a biodiversity hotspot. The country is known for its rich and distinct culture. The name Guatemala comes from the Nahuatl word Cuauhtēmallān, or place of many trees and this was the name the Tlaxcaltecan soldiers who accompanied Pedro de Alvarado during the Spanish Conquest gave to this territory. The first evidence of habitation in Guatemala dates back to 12,000 BC. Evidence, such as obsidian arrowheads found in parts of the country. There is archaeological proof that early Guatemalan settlers were hunters and gatherers, pollen samples from Petén and the Pacific coast indicate that maize cultivation had been developed by 3500 BC. Sites dating back to 6500 BC have been found in the Quiché region in the Highlands, archaeologists divide the pre-Columbian history of Mesoamerica into the Preclassic period, the Classic period, and the Postclassic period. Until recently, the Preclassic was regarded as a period, with small villages of farmers who lived in huts. This period is characterized by urbanisation, the emergence of independent city-states and this lasted until approximately 900 AD, when the Classic Maya civilization collapsed. The Maya abandoned many of the cities of the lowlands or were killed off by a drought-induced famine. The cause of the collapse is debated, but the Drought Theory is gaining currency, supported by such as lakebeds, ancient pollen. A series of prolonged droughts, among other such as overpopulation, in what is otherwise a seasonal desert is thought to have decimated the Maya
3.
Honduras
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Honduras, officially the Republic of Honduras, is a republic in Central America. It has at times referred to as Spanish Honduras to differentiate it from British Honduras. Honduras was home to several important Mesoamerican cultures, most notably the Maya, the Spanish introduced Roman Catholicism and the now predominant Spanish language, along with numerous customs that have blended with the indigenous culture. Honduras has the worlds highest murder rate, Honduras spans about 112,492 km2 and has a population exceeding 8 million. Its northern portions are part of the Western Caribbean Zone, as reflected in the areas demographics and culture. Honduras is known for its natural resources, including minerals, coffee, tropical fruit, and sugar cane, as well as for its growing textiles industry. Honduras literally means depths in Spanish, the name could either refer to the bay of Trujillo as an anchorage, fondura in the Leonese dialect of Spanish, or to Columbuss alleged quote that Gracias a Dios que hemos salido de esas Honduras. It was not until the end of the 16th century that Honduras was used for the whole province, prior to 1580, Honduras only referred to the eastern part of the province, and Higueras referred to the western part. Another early name is Guaymuras, revived as the name for the dialogue in 2009 that took place in Honduras as opposed to Costa Rica. In pre-Columbian times, modern Honduras was part of the Mesoamerican cultural area, in the west, the Maya civilization flourished for hundreds of years. The dominant state within Hondurass borders was in Copán, Copán fell with the other Lowland centres during the conflagrations of the Terminal Classic in the 9th century. The Maya of this civilization survive in western Honduras as the Chorti, remains of other Pre-Columbian cultures are found throughout the country. On 30 July 1502 Columbus sent his brother Bartholomew to explore the islands and Bartholomew encountered a Mayan trading vessel from Yucatán, carrying well-dressed Maya and a rich cargo. Bartholomews men stole whatever cargo they wanted and kidnapped the elderly captain to serve as an interpreter in what was the first recorded encounter between the Spanish and the Maya. In March 1524, Gil González Dávila became the first Spaniard to enter Honduras as a conquistador, followed by Hernán Cortés, bringing forces down from Mexico. Much of the conquest was done in the two decades, first by groups loyal to Cristóbal de Olid, and then by those loyal of Francisco Montejo. In addition to Spanish resources, the conquerors relied heavily on armed forces from Mexico—Tlaxcalans, resistance to conquest was led in particular by Lempira, and many regions in the north never fell to the Spanish, notably the Miskito Kingdom. After the Spanish conquest, Honduras became part of Spains vast empire in the New World within the Kingdom of Guatemala, Trujillo and Gracias were the first city-capitals
4.
Gulf of Fonseca
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The Gulf of Fonseca, part of the Pacific Ocean, is a gulf on Central America, bordering El Salvador, Honduras, and Nicaragua. Fonseca Bay was discovered for Europeans in 1522 by Gil González de Ávila, and named by him after his patron, Archbishop Juan Fonseca, the implacable enemy of Columbus. In 1849, E. G. Squier negotiated a treaty for the United States to build a canal across Honduras from the Caribbean Sea to the Gulf. Shortly thereafter however, Squier demanded the British leave, since he had anticipated the occupation, all three countries—Honduras, El Salvador, and Nicaragua—with coastline along the Gulf have been involved in a lengthy dispute over the rights to the Gulf and the islands located within. In 1992, a chamber of the International Court of Justice decided the Land, Island and Maritime Frontier Dispute, the ICJ determined that El Salvador, Honduras, and Nicaragua were to share control of the Gulf of Fonseca. El Salvador was awarded the islands of Meanguera and Meanguerita, while Honduras was awarded El Tigre Island. The Gulf of Fonseca covers an area of about 3,200 km2, with a coastline that extends for 261 km, of which 185 km are in Honduras,40 km in Nicaragua, and 29 km in El Salvador. The climate in the Gulf is typical of tropical and subtropical regions, the Gulf receives nearly 80% of its total yearly rainfall of 1, 400–1,600 mm during the rainy season from May to November. The dry season occurs between December and May and contributes to an annual rate of 2,800 mm. As a result of water flowing into the Gulf, the currents tend to flow inward from the Pacific Ocean, and levels of salinity in the estuaries increase. Temperatures in the Gulf average between 25 and 30 °C, March and April are the warmest months and November and December the coolest, relative humidity varies between 65 and 86% depending on location. In contrast, the interior of the country is semitropical and cooler with a temperature of 26 °C. The vegetation of the ecosystem is dominated by species of mangroves. Of the six species of mangrove identified in the Gulf, red mangrove is the most common, black mangrove is the second-most pervasive species and is generally found around the rivers where sediments are deposited along the shoreline. White mangrove is the third-most dominant, followed by botoncillo, both are found further inland and are inundated by the tide less frequently. The dominance of different species over others correlates with the frequency of floods, water quality, the cycle of tides is 2.3 m on average per day in the Gulf. During low tides, the soils are inhabited by crabs, conch, during the high tide, the mangrove forests serve as a feeding ground and habitat for fish, shrimp, and other species, as the root structure of mangroves provides a refuge from larger predators. A number of volcanoes lie within and around the gulf
5.
Nicaragua
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Nicaragua, officially the Republic of Nicaragua, is the largest country in the Central American isthmus. Nicaraguas capital, Managua, is the countrys largest city and the third-largest city in Central America, the multi-ethnic population of six million includes indigenous peoples, Europeans, Africans, and Asians. Native tribes on the eastern coast speak their own languages, the Spanish Empire conquered the region in the 16th century. Nicaragua gained independence from Spain in 1821, since its independence, Nicaragua has undergone periods of political unrest, dictatorship, and fiscal crisis—the most notable causes that led to the Nicaraguan Revolution of the 1960s and 1970s. Nicaragua is a democratic republic. The biological diversity, warm climate and active volcanoes make Nicaragua an increasingly popular tourist destination. The name Nicaragua was coined by Spanish colonists based on the name Nicarao, when Spaniard Gil González Dávila came to Nicaragua in 1521 he found in the areas between Rivas and San Jorge the first pre-Columbian natives of Nicaragua. At the time the city was called Quauhcapolca and the cacique leaders name was Macuilmiquiztli. The Pipil migrated to Nicaragua from central Mexico after 500 BC, meanwhile, the Caribbean coast of Nicaragua was inhabited by other peoples, mostly Chibcha language groups. They had coalesced in Central America and migrated also to present-day northern Colombia and they lived a life based primarily on hunting and gathering. In 1502, Christopher Columbus became the first European known to have reached what is now Nicaragua as he sailed southeast toward the Isthmus of Panama, on his fourth voyage, Columbus explored the Miskito Coast on the Atlantic side of Nicaragua. The Spanish attempted to convert all three tribes to Christianity, Nicaragua and Nicarao and their people converted, but Dirangen, however, did not, the first attempt to conquer what is now known as Nicaragua was by Gil González Dávila, who arrived in Panama in January 1520. The first Spanish permanent settlements were founded in 1524, conquistador Francisco Hernández de Córdoba founded two of Nicaraguas principal towns in 1524, Granada on Lake Nicaragua was the first settlement, followed by León at a location west of Lake Managua. Córdoba soon built defenses for the cities and fought against incursions by other conquistadors, Córdoba was later publicly beheaded following a power struggle with Pedro Arias Dávila. His tomb and remains were discovered in 2000 in the ruins of León Viejo, the clashes among Spanish forces did not impede their destruction of the indigenous people and their culture. The series of battles came to be known as the War of the Captains, Pedro Arias Dávila was a winner, although he had lost control of Panama, he moved to Nicaragua and successfully established his base in León. Through adroit diplomatic machinations, he became the first governor of the colony, many indigenous people died as a result of new infectious diseases, compounded by neglect by the Spaniards, who controlled their subsistence. In 1610, the Momotombo volcano erupted, destroying the capital and it was rebuilt northwest of what is now known as the ruins of Old León
6.
El Salvador
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El Salvador, officially the Republic of El Salvador, is the smallest and the most densely populated country in Central America. El Salvadors capital and largest city is San Salvador, as of 2015, the country had a population of approximately 6.38 million, consisting largely of Mestizos of European and Indigenous American descent. El Salvador was for centuries inhabited by several Mesoamerican nations, especially the Cuzcatlecs, as well as the Lenca, in the early 16th century, the Spanish Empire conquered the territory, incorporating it into the Viceroyalty of New Spain ruled from Mexico City. In 1821, the country achieved independence from Spain as part of the First Mexican Empire, from the late 19th to the mid-20th century, El Salvador endured chronic political and economic instability characterized by coups, revolts, and a succession of authoritarian rulers. The conflict ended with a settlement that established a multiparty constitutional republic. El Salvador has since reduced its dependence on coffee and embarked on diversifying the economy by opening up trade and financial links, the colón, the official currency of El Salvador since 1892, was replaced by the U. S. dollar in 2001. As of 2010, El Salvador ranks 12th among Latin American countries in terms of the Human Development Index, however, the country continues to struggle with high rates of poverty, inequality, and crime. Conquistador Pedro de Alvarado named the new province for Jesus Christ – El Salvador, the full name was Provincia De Nuestro Señor Jesus Cristo, El Salvador Del Mundo, which was subsequently abbreviated to El Salvador. Tomayate is a site located on the banks of the river of the same name in the municipality of Apopa. The site has produced abundant Salvadoran megafauna fossils belonging to the Pleistocene epoch, at the same time, it is considered the richest vertebrate paleontological site in Central America and one of the largest accumulations of proboscideans in the Americas. Sophisticated civilization in El Salvador dates to its settlement by the indigenous Lenca people, theirs was the first, the Lenca were succeeded by the Olmecs, who eventually also disappeared, leaving their monumental architecture in the form of the pyramids still extant in western El Salvador. The Maya arrived and settled in place of the Olmecs, the Pipil were the last indigenous people to arrive in El Salvador. They called their territory Kuskatan, a Pipil word meaning The Place of Precious Jewels, backformed into Classical Nahuatl Cōzcatlān, the people of El Salvador today are referred to as Salvadoran, while the term Cuzcatleco is commonly used to identify someone of Salvadoran heritage. In pre-Columbian times, the country was inhabited by various other indigenous peoples, including the Lenca. Cuzcatlan was the domain until the Spanish conquest. Since El Salvador resided on the edge of the Maya Civilization. However, it is agreed that Mayas likely occupied the areas around Lago de Guija. Other ruins such as Tazumal, Joya de Cerén and San Andrés may have built by the Pipil or the Maya or possibly both
7.
Coast
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A coastline or a seashore is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox, the term coastal zone is a region where interaction of the sea and land processes occurs. Both the terms coast and coastal are often used to describe a location or region, for example, New Zealands West Coast. Edinburgh for example is a city on the coast of Scotland, a pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the hand, can refer to parts of the land which adjoin any large body of water, including oceans. Similarly, the related term refers to the land alongside or sloping down to a river or to a body of water smaller than a lake. Bank is also used in parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. According to the UN atlas, 44% of people live within 150 kilometres of the sea, tides often determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, the tidal range is influenced by the size and shape of the coastline. Tides do not typically cause erosion by themselves, however, tidal bores can erode as the waves surge up river estuaries from the ocean. Waves erode coastline as they break on shore releasing their energy, the larger the wave the more energy it releases and the more sediment it moves. Coastlines with longer shores have more room for the waves to disperse their energy, while coasts with cliffs and short shore faces give little room for the wave energy to be dispersed. In these areas the wave energy breaking against the cliffs is higher, sediment deposited by waves comes from eroded cliff faces and is moved along the coastline by the waves. This forms an abrasion or cliffed coast, sediment deposited by rivers is the dominant influence on the amount of sediment located on a coastline. Today riverine deposition at the coast is often blocked by dams and other human regulatory devices, like the ocean which shapes them, coasts are a dynamic environment with constant change. The coast and its adjacent areas on and off shore are an important part of a local ecosystem, Salt marshes and beaches also support a diversity of plants, animals and insects crucial to the food chain. The high level of biodiversity creates a level of biological activity. More and more of the people live in coastal regions
8.
Caribbean Sea
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The Caribbean Sea is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. The entire area of the Caribbean Sea, the islands of the West Indies. The Caribbean Sea is one of the largest seas and has an area of about 2,754,000 km2, the seas deepest point is the Cayman Trough, between the Cayman Islands and Jamaica, at 7,686 m below sea level. The Caribbean coastline has many gulfs and bays, the Gulf of Gonâve, Gulf of Venezuela, Gulf of Darién, Golfo de los Mosquitos, Gulf of Paria, the Caribbean Sea has the worlds second biggest barrier reef, the Mesoamerican Barrier Reef. It runs 1,000 km along the coasts of Mexico, Belize, Guatemala, the name Caribbean derives from the Caribs, one of the regions dominant Native American groups at the time of European contact during the late 15th century. During the first century of development, Spanish dominance in the region remained undisputed, from the 16th century, Europeans visiting the Caribbean region identified the South Sea as opposed to the North Sea. The Caribbean Sea had been unknown to the populations of Eurasia until 1492, at that time the Western Hemisphere in general was unknown to Europeans. Following the discovery of the islands by Columbus, the area was colonised by several Western cultures. As of 2015 the area is home to 22 island territories, the International Hydrographic Organization defines the limits of the Caribbean Sea as follows, On the North. In the Windward Channel – a line joining Caleta Point and Pearl Point in Haïti, in the Mona Passage – a line joining Cape Engano and the extreme of Agujereada in Puerto Rico. From Galera Point through Trinidad to Galeota Point and thence to Baja Point in Venezuela, note that, although Barbados is an island on the same continental shelf, it is considered to be in the Atlantic Ocean rather than the Caribbean Sea. The Caribbean Sea is an oceanic sea largely situated on the Caribbean Plate, the Caribbean Sea is separated from the ocean by several island arcs of various ages. The youngest stretches from the Lesser Antilles to the Virgin Islands to the north east of Trinidad, the larger islands in the northern part of the sea Cuba, Hispaniola, Jamaica and Puerto Rico lie on an older island arc. The geological age of the Caribbean Sea is estimated to be between 160 and 180 million years and was formed by a fracture that split the supercontinent called Pangea in the Mesozoic Era. It is assumed the proto-caribbean basin existed in the Devonian period, in the early Carboniferous movement of Gondwana to the north and its convergence with the Euramerica basin decreased in size. The next stage of the Caribbean Seas formation began in the Triassic, powerful rifting led to the formation of narrow troughs, stretching from modern Newfoundland to the west coast of the Gulf of Mexico which formed siliciclastic sedimentary rocks. In the early Jurassic due to powerful marine transgression, water broke into the present area of the Gulf of Mexico creating a vast shallow pool, the emergence of deep basins in the Caribbean occurred during the Middle Jurassic rifting. The emergence of these marked the beginning of the Atlantic Ocean
9.
Earthquake
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An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earths lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to people around. The seismicity or seismic activity of an area refers to the frequency, type, Earthquakes are measured using measurements from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe and these two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly imperceptible or weak and magnitude 7 and over potentially cause damage over larger areas. The largest earthquakes in historic times have been of magnitude slightly over 9, intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the damage to structures it causes. At the Earths surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground, when the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity, in its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of faults, but also by other events such as volcanic activity, landslides, mine blasts. An earthquakes point of rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter, tectonic earthquakes occur anywhere in the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the surface that increase the frictional resistance. Most fault surfaces do have such asperities and this leads to a form of stick-slip behavior, once the fault has locked, continued relative motion between the plates leads to increasing stress and therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the portion of the fault. This energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface and this process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory. It is estimated that only 10 percent or less of a total energy is radiated as seismic energy. Most of the energy is used to power the earthquake fracture growth or is converted into heat generated by friction
10.
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
11.
Caribbean Basin
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Indigenous peoples were the first inhabitants of the West Indies. In 1492, Christopher Columbus became the first European to arrive at the islands, after the first of the voyages of Christopher Columbus to the Americas, Europeans began to use the term West Indies to distinguish the region from the East Indies of South Asia and Southeast Asia. In the late century, French, English and Dutch merchants and privateers began their operations in the Caribbean Sea, attacking Spanish and Portuguese shipping. These African slaves wrought a demographic revolution, replacing or joining with either the indigenous Caribs or the European settlers who were there as indentured servants. The Dutch, allied with the Caribs of the Orinoco would eventually carry the struggles deep into South America, first along the Orinoco and these interconnected commercial and diplomatic relations made up the Western Caribbean Zone which was in place in the early eighteenth century. In 1916, Denmark sold the Danish West Indies to the United States for US$25 million in gold, the Danish West Indies became an insular area of the US, called the United States Virgin Islands. Between 1958 and 1962, the United Kingdom re-organised all their West Indies island territories into the West Indies Federation and they hoped that the Federation would coalesce into a single, independent nation. West Indian is the term used by the U. S. government to refer to people of the West Indies. Tulane University professor Rosanne Adderly says he phrase West Indies distinguished the territories encountered by Columbus, … The term West Indies was eventually used by all European nations to describe their own acquired territories in the Americas. Despite the collapse of the Federation … the West Indies continues to field a joint cricket team for international competition, the West Indies cricket team includes participants from Guyana, which is geographically located in South America. More than Slaves and Sugar, Recent Historiography of the Trans-imperial Caribbean, a Concise History of the Caribbean. Martin, Tony, Caribbean History, From Pre-colonial Origins to the Present
12.
Caribbean Plate
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The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America. Roughly 3.2 million square kilometers in area, the Caribbean Plate borders the North American Plate, the South American Plate, the Nazca Plate and these borders are regions of intense seismic activity, including frequent earthquakes, occasional tsunamis, and volcanic eruptions. Part of the Puerto Rico Trench, the deepest part of the Atlantic Ocean, the Puerto Rico trench is at a complex transition from the subduction boundary to the south and the transform boundary to the west. The eastern boundary is a zone, the Lesser Antilles subduction zone. Subduction forms the islands of the Lesser Antilles Volcanic Arc from the Virgin Islands in the north to the islands off the coast of Venezuela in the south. Large historical earthquakes in 1839 and 1843 in this region are possibly megathrust earthquakes and this boundary is in part the result of transform faulting along with thrust faulting and some subduction. The rich Venezuelan petroleum fields possibly result from this complex plate interaction, the Caribbean plate is moving eastward about 22 millimeters per year in relation to the South American plate. In Venezuela much of the movement between the Caribbean Plate and the South American plate occurs along the faults of Boconó, El Pilar, the western portion of the plate is occupied by Central America. The Cocos Plate in the Pacific Ocean is subducted beneath the Caribbean Plate and this subduction forms the volcanoes of Guatemala, El Salvador, Nicaragua, and Costa Rica, also known as the Central America Volcanic Arc. The usual theory as to the origin of the Caribbean Plate was confronted by a theory in 2002. The mainstream theory holds that it is the Caribbean large igneous province formed in the Pacific Ocean tens of millions of years ago. As the Atlantic Ocean widened, North America and South America were pushed westward, the Pacific Ocean floor subducted under this oceanic crust between the continents. With the formation of the Isthmus of Panama 3 million years ago, the more recent theory asserts that the Caribbean Plate came into being from an Atlantic hotspot which no longer exists. The Caribbean Plate began its eastward migration 80 million years ago during the Late Cretaceous and this migration eventually resulted in a volcanic arc stretching from north-western South America to the Yucatán Peninsula, today represented by the Aves Islands and the Lesser and Greater Antilles
13.
Cocos Plate
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The Cocos Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created by sea floor spreading along the East Pacific Rise, from the rise the plate is pushed eastward and pushed or dragged under the less dense overriding Caribbean Plate, in the process called subduction. The subducted leading edge heats up and adds its water to the mantle above it, in the mantle layer called the asthenosphere, mantle rock melts to make magma, trapping superheated water under great pressure. The northern boundary of the Cocos Plate is the Middle America Trench, the eastern boundary is a transform fault, the Panama Fracture Zone. The southern boundary is a ridge, the Galapagos Rise. The western boundary is another ridge, the East Pacific Rise. The Cocos and Nazca Plates are the remnants of the former Farallon Plate, a hotspot under the Galapagos Islands lies along the Galapagos Rise. The Rivera Plate north of the Cocos Plate is thought to have separated from the Cocos Plate 5-10 million years ago, the boundary between the two plates appears to lack a definite transform fault, yet they are regarded as distinct. The devastating 1985 Mexico City earthquake was a result of the subduction of the Cocos Plate beneath the North American Plate, the also devastating 2001 El Salvador earthquakes were generated in the subduction of this plate on the Caribbean Plate. The volcanic arc Martin Meschede and Udo Barckhausen, Plate tectonic evolution of the Cocos-Nazca plate, reconstructing its geological evolution
14.
Basalt
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Basalt is a common extrusive igneous rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of basalt flows. By definition, basalt is an igneous rock with generally 45-55% silica and less than 10% feldspathoid by volume. Basalt commonly features a very fine-grained or glassy matrix interspersed with visible mineral grains, the average density is 3.0 gm/cm3. Basalt is defined by its content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic minerals into hematite, although usually characterized as dark, basaltic rocks exhibit a wide range of shading due to regional geochemical processes. Due to weathering or high concentrations of plagioclase, some basalts can be quite light-coloured and these phenocrysts usually are of olivine or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt. Basalt with a texture is called vesicular basalt, when the bulk of the rock is mostly solid. Gabbro is often marketed commercially as black granite and these ultramafic volcanic rocks, with silica contents below 45% are usually classified as komatiites. Agricola applied basalt to the black rock of the Schloßberg at Stolpen. Tholeiitic basalt is relatively rich in silica and poor in sodium, included in this category are most basalts of the ocean floor, most large oceanic islands, and continental flood basalts such as the Columbia River Plateau. Basalt rocks are in some cases classified after their content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and it has greater than 17% alumina and is intermediate in composition between tholeiite and alkali basalt, the relatively alumina-rich composition is based on rocks without phenocrysts of plagioclase. Alkali basalt is relatively poor in silica and rich in sodium and it is silica-undersaturated and may contain feldspathoids, alkali feldspar and phlogopite. Boninite is a form of basalt that is erupted generally in back-arc basins. Ocean island basalt Lunar basalt On Earth, most basalt magmas have formed by melting of the mantle. Basalt commonly erupts on Io, the third largest moon of Jupiter, and has formed on the Moon, Mars, Venus. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below, the mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene
15.
Granite
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Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be white, pink, or gray in color. The word granite comes from the Latin granum, a grain, in reference to the structure of such a holocrystalline rock. By definition, granite is a rock with at least 20% quartz. The term granitic means granite-like and is applied to granite and a group of igneous rocks with similar textures and slight variations in composition. Occasionally some individual crystals are larger than the groundmass, in case the texture is known as porphyritic. A granitic rock with a texture is known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks, petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite, Granite is nearly always massive, hard and tough, and therefore it has gained widespread use throughout human history, and more recently as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6 •1019 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C, it is reduced in the presence of water. Granite has poor primary permeability, but strong secondary permeability, true granite according to modern petrologic convention contains both plagioclase and alkali feldspars. When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite, when a granitoid contains less than 10% orthoclase, it is called tonalite, pyroxene and amphibole are common in tonalite. A granite containing both muscovite and biotite micas is called a binary or two-mica granite, two-mica granites are typically high in potassium and low in plagioclase, and are usually S-type granites or A-type granites. A worldwide average of the composition of granite, by weight percent, based on 2485 analyses. Much of it was intruded during the Precambrian age, it is the most abundant basement rock that underlies the relatively thin veneer of the continents. Outcrops of granite tend to form tors and rounded massifs, granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite often occurs as small, less than 100 km² stock masses
16.
Middle America Trench
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The Middle America Trench is a major subduction zone, an oceanic trench in the eastern Pacific Ocean off the southwestern coast of Middle America, stretching from central Mexico to Costa Rica. The trench is 1,700 miles long and is 21,880 feet at its deepest point, the trench is the boundary between the Rivera, Cocos, and Nazca plates, and the North American and Caribbean plates. It is currently the 18th deepest trench in the world, many large earthquakes have occurred in the area of the Middle America Trench. The Middle America Trench can be divided into a northern and a southern section, however, the division is not the same in its seaward side and its landward side. On the landward side, the division is demarcated along the Polochic-Motagua fault system, the dividing point in the landward side is about 400 km east of that in the seaward side
17.
Geyser
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A geyser is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist in only a few places on Earth, generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Generally, surface water works its way down to a depth of around 2,000 metres where it contacts hot rocks. The resultant boiling of the water results in the geyser effect of hot water. Over one thousand known geysers exist worldwide, at least 1,283 geysers have erupted in Yellowstone National Park, Wyoming, United States, and an average of 465 geysers are active there in a given year. Like many other phenomena, geysers are not unique to planet Earth. Jet-like eruptions, often referred to as cryogeysers, have been observed on several of the moons of the solar system. Due to the low ambient pressures, these eruptions consist of vapor without liquid, they are more easily visible by particles of dust. Water vapor jets have been observed near the pole of Saturns moon Enceladus. There are also signs of carbon dioxide eruptions from the polar ice cap of Mars. In the latter two cases, instead of being driven by energy, the eruptions seem to rely on solar heating via a solid-state greenhouse effect. The word geyser comes from Geysir, the name of a spring at Haukadalur, Iceland, that name, in turn, comes from the Icelandic verb geysa, to gush. Geysers are generally associated with volcanic areas, as the water boils, the resulting pressure forces a superheated column of steam and water to the surface through the geysers internal plumbing. The formation of geysers specifically requires the combination of three conditions that are usually found in volcanic terrain. The heat needed for geyser formation comes from magma that needs to be near the surface of the earth, the fact that geysers need heat much higher than normally found near the earths surface is the reason they are associated with volcanoes or volcanic areas. The pressures encountered at the areas where the water is heated make the point of the water much higher than at normal atmospheric pressures. The water ejected from a geyser travels underground through deep, pressurized fissures in the Earths crust, in order for the heated water to form a geyser, a plumbing system made of fractures, fissures, porous spaces, and sometimes cavities is required. This includes a reservoir to hold the water while it is being heated, Geysers are generally aligned along faults
18.
North American Plate
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The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, the Bahamas, extreme northeastern Russia, and parts of Iceland and the Azores. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia, the plate includes both continental and oceanic crust. The interior of the continental landmass includes an extensive granitic core called a craton. Along most of the edges of this craton are fragments of material called terranes. It is thought that much of North America west of the Rocky Mountains is composed of such terranes, the parallel Septentrional and Enriquillo-Plantain Garden faults, which run through the island of Hispaniola and bound the Gonâve Microplate, are also a part of the boundary. On the northerly boundary is a continuation of the Mid-Atlantic ridge called the Gakkel Ridge, the rest of the boundary in the far northwestern part of the plate extends into Siberia. On its western edge, the Farallon Plate has been subducting under the North American Plate since the Jurassic Period, the Juan de Fuca, Explorer, Gorda, Rivera, Cocos and Nazca plates are remnants of the Farallon Plate. The boundary along the Gulf of California is complex and it is generally accepted that a piece of the North American Plate was broken off and transported north as the East Pacific Rise propagated northward, creating the Gulf of California. A few hotspots are thought to exist below the North American Plate, the most notable hotspots are the Yellowstone, Raton, and Anahim hotspots. The Yellowstone and Anahim hotspots are thought to have first arrived during the Miocene period and are still geologically active, for the most part, the North American Plate moves in roughly a southwest direction away from the Mid-Atlantic Ridge. One recent study suggests that a convective current is propelling the plate. Geologic timeline of Western North America New Madrid Seismic Zone - an ancient intraplate fault zone within the North American Plate, notable as early as 1699 Notes
19.
San Andreas Fault
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The San Andreas Fault is a continental transform fault that extends roughly 800 miles through California. It forms the boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip. The fault was first identified in 1895 by Professor Andrew Lawson of UC Berkeley and it is often described as having been named after San Andreas Lake, a small body of water that was formed in a valley between the two plates. However, according to some of his reports from 1895 and 1908, following the 1906 San Francisco earthquake, Lawson concluded that the fault extended all the way into southern California. In 1953, geologist Thomas Dibblee astounded the scientific establishment with his conclusion that hundreds of miles of lateral movement could occur along the fault. A project called the San Andreas Fault Observatory at Depth near Parkfield, Monterey County, is drilling into the fault to improve prediction and this is the approximate location of the epicenter of the 1906 San Francisco earthquake. The fault returns onshore at Bolinas Lagoon just north of Stinson Beach in Marin County, from Fort Ross the northern segment continues overland, forming in part a linear valley through which the Gualala River flows. It goes back offshore at Point Arena, after that, it runs underwater along the coast until it nears Cape Mendocino, where it begins to bend to the west, terminating at the Mendocino Triple Junction. The central segment of the San Andreas fault runs in a direction from Parkfield to Hollister. The southern segment begins near Bombay Beach, California, box Canyon, near the Salton Sea, contains upturned strata associated with that section of the fault. The fault then runs along the base of the San Bernardino Mountains, crosses through the Cajon Pass. These mountains are a result of movement along the San Andreas Fault and are called the Transverse Range. In Palmdale, a portion of the fault is easily examined at a roadcut for the Antelope Valley Freeway, the fault continues northwest alongside the Elizabeth Lake Road to the town of Elizabeth Lake. As it passes the towns of Gorman, Tejon Pass and Frazier Park and this restraining bend is thought to be where the fault locks up in Southern California, with an earthquake-recurrence interval of roughly 140–160 years. Northwest of Frazier Park, the runs through the Carrizo Plain. The Elkhorn Scarp defines the fault trace along much of its length within the plain, the southern segment, which stretches from Parkfield in Monterey County all the way to the Salton Sea, is capable of an 8. 1-magnitude earthquake. At its closest, this fault passes about 35 miles to the northeast of Los Angeles. Such a large earthquake on this segment would kill thousands of people in Los Angeles, San Bernardino, Riverside, and surrounding areas
20.
San Salvador
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San Salvador is the capital and largest city of El Salvador and its eponymous department. It is the political, cultural, educational and financial center. As a gamma global city, San Salvador is also an important financial hub of Central America, San Salvador is located in the Salvadoran highlands, surrounded by volcanoes and prone to earthquakes. The city is home to the Catholic Archdiocese, as well as many Protestant branches of Christianity, including Evangelicals, Latter-day Saints, Baptists. San Salvador has the second largest Jewish community in Central America, San Salvador has been the host city for various regional and international sporting, political, and social events. It hosted the Central American and Caribbean Games in 1935 and 2002, San Salvador was also the host city of the 18th Ibero-American Summit, held October 29–31,2008, the most important sociopolitical event in the Spanish and Portuguese sphere. The Central American Integration System has its headquarters in San Salvador, the Central American Bank for Economic Integration also has its headquarters in San Salvador. Before the Spanish conquest, the Pipil people established their capital, Cuzcatlan, not much is known about Cuzcatlan, as it was abandoned by its inhabitants in an effort to avoid Spanish rule. Under the orders of conquistador Pedro de Alvarado, his associates Gonzalo de Alvarado and Diego de Holguín occupied the empty settlement, Diego de Holguín became the first mayor of San Salvador after the town was founded on April 1,1525. The town changed location twice, in 1528 and 1545, the new site was chosen because it had more space and more fertile land, thanks to the Acelhuate River. The population of the city remained relatively small until the early 20th century, in January 1885, during the presidency of Dr. Rafael Zaldivar, a group of businessmen and the presidents family contributed funds for building the Sara Zaldivar Asylum for Indigents and the Elderly. In 1902, the Hospital Rosales was built, named after its benefactor, Dr. Jose Rosales, the hospitals construction was begun by president Carlos Ezeta and finished during the presidency of Tomás Regalado. In 1905 president Pedro José Escalón initiated construction of the National Palace, the Monumento a los Próceres de 1811, located in the Plaza Libertad, and the Teatro Nacional were built in 1911 during Dr. Manuel Enrique Araujos presidency. In 1917, an earthquake during an eruption of the nearby San Salvador volcano damaged the city, on December 2,1931, president Arturo Araujo was ousted by a military coup détat and replaced by a military directorate. The directorate named vice-president Maximiliano Hernández Martínez as president and Araujo went into exile, the Martínez regime lasted from December 4,1931 to May 6,1944. In 1964, the Christian Democratic Party candidate, José Napoleon Duarte, during his term he ordered construction of the Pancho Lara park in the Vista Hermosa neighborhood, renewed the electrical grid, and set up a system of schools for adult education. The 1960s to the 1980s were the age of San Salvador in all aspects of security, quality of life. Today the tallest building in the country has 28 floors and is 110 meters high, with the commencement of the Salvadoran Civil War in the 1980s, many modernization projects were halted
21.
Izalco (volcano)
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Izalco is a stratovolcano on the side of the Santa Ana Volcano, which is located in western El Salvador. It is situated on the flank of the Santa Ana volcano. Izalco erupted almost continuously from 1770 to 1958 earning it the nickname of Lighthouse of the Pacific, during an eruption in 1926, the village of Matazano was buried and 56 people were killed. Izalcos formation was preceded by fumorolic activity in 1658, before Izalco was born in 1770, today, Izalco experiences only fumarolic activity in the form of rainwater seeping into the volcano and contacting hot rocks, rather than steam emissions from underground gases. The fumarole deposits of the volcano are noted as sources for several rare minerals and it is the type locality for the copper vanadium minerals, bannermanite, blossite, fingerite, howardevansite, lyonsite, mcbirneyite, stoiberite and ziesite. The volcano is visited and climbed regularly by tourists to El Salvador via the Cerro Verde National Park and is an icon of the country. The volcano is currently quiescent but may erupt again, a hotel was built on the nearby Cerro Verde to provide accommodation with a view of the erupting volcano, but the volcano ceased to erupt shortly before the hotel was completed. In the French novella The Little Prince by Antoine de Saint-Exupéry, Izalco and Santa Ana Volcano are the two active, and Cerro Verde is the dormant volcano. The book was inspired by Antoines life with his Salvadoran wife Consuelo de Saint Exupéry, covers genuinely used with these stamps are rare. So far, only 37 have been recorded, List of volcanoes in El Salvador List of stratovolcanoes
22.
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
23.
Sierra Madre de Chiapas
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The Sierra Madre de Chiapas is a major mountain range in Central America. The range runs northwest–southeast from the state of Chiapas in Mexico, across western Guatemala, into El Salvador, most of the volcanoes of Guatemala, part of the Central America Volcanic Arc, are within the range. A narrow coastal plain lies south the range, between the Sierra Madre and the Pacific Ocean, the range forms the main drainage divide between the Pacific and Atlantic river systems. On the Pacific side the distance to the sea is short, a few of the streams of the Pacific slopes rise in the Guatemalan Highlands, and force a way through the Sierra Madre at the bottom of deep ravines. On the eastern side a number of the rivers of the Atlantic slopes attain a considerable volume and it is known near Guatemala city as the Sierra de las Nubes, and enters Mexico as the Sierra de Istatan. Its summit is not a well-defined crest, but is rounded or flattened into a table-land. The base of many of the volcanic igneous peaks rests among the foothills in the southern region of the range. Viewed from the coast, the volcanic cones seem to directly from the central heights of the Sierra Madre, above which they tower. East of the Guatemalan border, the forms the boundary between El Salvador and Honduras. In El Salvador, the form a line well south of the range. Between the Sierra Madre and the Volcanic line lies a central plateau, geography of Mesoamerica Sierra Madre de Chiapas topics This article incorporates text from a publication now in the public domain, Chisholm, Hugh, ed. article name needed
24.
Overexploitation
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Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource, the term applies to natural resources such as, wild medicinal plants, grazing pastures, game animals, fish stocks, forests, and water aquifers. In ecology, overexploitation describes one of the five main activities threatening global biodiversity, ecologists use the term to describe populations that are harvested at a rate that is unsustainable, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the level and even extinction of whole species. The term is used and defined somewhat differently in fisheries, hydrology. Overexploitation can lead to destruction, including extinctions. However it is possible for overexploitation to be sustainable, as discussed below in the section on fisheries. Overexploitation is not an activity limited to humans, introduced predators and herbivores, for example, can overexploit native flora and fauna. Concern about overexploitation is relatively recent, though overexploitation itself is not a new phenomenon and it has been observed for millennia. For example, ceremonial cloaks worn by the Hawaiian kings were made from the mamo bird, the dodo, a flightless bird from Mauritius, is another well-known example of overexploitation. As with many species, it was naive about certain predators, allowing humans to approach. From the earliest of times, hunting has been an important human activity as a means of survival, there is a whole history of overexploitation in the form of overhunting. The overkill hypothesis explains why the megafaunal extinctions occurred within a short period of time. This can be traced with human migration, the most convincing evidence of this theory is that 80% of the North American large mammal species disappeared within 1000 years of the arrival of humans on the western hemisphere continents. A second wave of extinctions occurred later with European settlement, overexploitation doesnt necessarily lead to the destruction of the resource, nor is it necessarily unsustainable. However, depleting the numbers or amount of the resource can change its quality, for example, footstool palm is a wild palm tree found in Southeast Asia. Its leaves are used for thatching and food wrapping, and overharvesting has resulted in its leaf size becoming smaller, the tragedy of the commons refers to a dilemma described in an article by that name written by Garrett Hardin and first published in the journal Science in 1968. Central to Hardins essay is an example which is a parable for understanding how overexploitation can occur
25.
Alluvium
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Alluvium is loose, unconsolidated soil or sediments, which has been eroded, reshaped by water in some form, and redeposited in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand, when this loose alluvial material is deposited or cemented into a lithological unit, or lithified, it is called an alluvial deposit. The term alluvium is not typically used in situations where the formation of the sediment can clearly be attributed to another process that is well described. This includes, lake sediments, river sediments, or glacially-derived sediments, sediments that are formed or deposited in a perennial stream or river are typically not referred to as alluvial. Most alluvium is very young, and is often referred to as cover because these sediments obscure the underlying bedrock. Most sedimentary material that fills a basin that is not lithified is typically lumped together as alluvial, alluvium of Pliocene age occurs, for example, in parts of Idaho. Alluvium of late Miocene age occurs, for example, in the valley of the San Joaquin River, alluvium can contain valuable ores such as gold and platinum and a wide variety of gemstones. Such a concentration of ores is termed a placer deposit
26.
Coffee
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Coffee is a brewed drink prepared from roasted coffee beans, which are the seeds of berries from the Coffea plant. The genus Coffea is native to tropical Africa, and Madagascar, the two most commonly grown are the highly regarded arabica, and the less sophisticated but stronger and more hardy robusta. Once ripe, coffee berries are picked, processed, and dried, dried coffee seeds are roasted to varying degrees, depending on the desired flavor. Roasted beans are ground and brewed with boiling water to produce coffee as a beverage. Coffee is slightly acidic and can have an effect on humans because of its caffeine content. Coffee is one of the most popular drinks in the world and it can be prepared and presented in a variety of ways. It is usually served hot, although iced coffee is also served, the earliest credible evidence of coffee-drinking appears in the middle of the 15th century in the Sufi shrines of Yemen. It was here in Arabia that coffee seeds were first roasted and brewed in a way to how it is now prepared. Coffee seeds were first exported from East Africa to Yemen, as the coffea arabica plant is thought to have been indigenous to the former, yemeni traders took coffee back to their homeland and began to cultivate the seed. By the 16th century, it had reached Persia, Turkey, from there, it spread to Europe and the rest of the world. Coffee is an export commodity, it is the top agricultural export for numerous countries and is among the worlds largest legal agricultural exports. It is one of the most valuable commodities exported by developing countries, green coffee is one of the most traded agricultural commodities in the world. Consequently, the markets for fair trade coffee and organic coffee are expanding. The first reference to coffee in the English language is in the form chaona, dated to 1598 and understood to be a misprint of chaoua, equivalent, in the orthography of the time, to chaova. This term and coffee both derive from the Ottoman Turkish kahve, by way of the Italian caffè and it has also been proposed that the source may be the Proto-Central Semitic root q-h-h meaning dark. Alternatively, the word Khat, a plant widely used as stimulant in Yemen and Ethiopia before being supplanted by coffee has been suggested as a possible origin, the expression coffee break was first attested in 1952. The term coffee pot dates from 1705, other accounts attribute the discovery of coffee to Sheikh Omar. According to the ancient chronicle, Omar, who was known for his ability to cure the sick through prayer, was exiled from Mocha in Yemen to a desert cave near Ousab
27.
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
28.
La Libertad, La Libertad
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La Libertad is a municipality in the La Libertad Department of El Salvador. It had a population of 35,997 inhabitants in 2007 according to the census of that year. It is one of the main tourist attractions in the country, in 1770 this area was referred to by Pedro Cortes, the Archbishop of Guatemala, as the hacienda Tepeahua, one of the largest estates in the parish of San Jacinto. The national assembly chartered commercial trade on the Pacific coast in 1831, La Libertad was incorporated as a village by an Executive decree of July 19,1858, which was approved by the Congress on February 11,1859. This was done to relieve the communitys dependence on the town of Huizúcar, located at a considerable distance. The town became part of the department of La Libertad on January 28,1865, on May 4,1867, the Salvadoran government awarded the contract for construction of an iron pier, which opened on October 7,1869. Prior to this, barges were unloaded by securing them with mooring lines, the Salvadoran government enfranchised La Libertad as a villa on March 10,1874, and as a ciudad on 23 August 1957. The telegraph line between San Salvador and the port was inaugurated on April 27,1870, the municipality covers an area of 162 km² and its highest elevation is 10m above sea level. The local economy is based on agriculture and the service sector, the fiestas patronales are celebrated in December in honor of the Immaculate Conception. El Puerto de La Libertad is one of the most representative tourist destinations in El Salvador, the resort includes a boardwalk, restaurants and an amphitheater, while small seafood markets and craft shops are located at the wharf. Construction of the first phase of the work was inaugurated on January 6,2006, other beaches located in the municipality include Las Flores, San Diego, El Obispo, La Paz and El Majahual. The Deiningers were the first German immigrants to settle in the La Libertad department and they established dairies, cattle ranches and coffee plantations. La Libertad has one of the best right hand point breaks in Central America, Punta Roca hosts regional and international surfing championships. It is known for its fast and hollow waves, many of which break for 100–200 yards, as recently as the 1970s only a few local surfers ventured there, until it was discovered by a few internationally recognized surfers, including Gerry Lopez, who traveled there frequently. He encouraged a new cadre of locals to adopt the sport, El Salvador went through a civil war in the 1980s, and getting to Punta Roca became dangerous. The well-known local surfer, Yepi, was one of the first in his generation to take a role in popularizing the sport among Salvadorans. Other local surfers have helped spread surfings popularity throughout the country by offering custom surf tours to tourists, the main break extends from La Punta to the township, a distance of about 800m, although single rides do not normally connect the sections through the whole distance. There are three sections, the top of the point is a hollow and fast wave called La Punta
29.
Lake Ilopango
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Lake Ilopango is a crater lake which fills a scenic 8 by 11 km volcanic caldera in central El Salvador, on the borders of the San Salvador, La Paz, and Cuscatlán departments. The caldera, which contains the second largest lake in the country and is immediately east of the capital city, any surplus drains via the Jiboa River to the Pacific Ocean. The lake is known for being a source for the extreme weather events of 535–536. The military airbase, Ilopango International Airport, has annual airshows where international pilots from all over the fly over San Salvador City. Four major dacitic - rhyolitic eruptions occurred during the late Pleistocene and Holocene, producing pyroclastic flows, the caldera collapsed most recently sometime between 410 and 535 AD, which produced widespread pyroclastic flows and devastated Mayan cities. The eruption produced about 25 km3 of tephra, thus rating a 6 on the Volcanic Explosivity Index, the ash-cloud fallout blanketed an area of at least 10,000 square kilometres waist-deep in pumice and ash, which would have stopped all agricultural endeavor in the area for decades. There is an opinion that this caused the extreme weather events of 535–536 in Europe. Later eruptions formed several lava domes within the lake and near its shore, the only historical eruption, which occurred from December 31,1879, up to March 26,1880, produced a lava dome and had a VEI of 3. The lava dome reached the surface of the lake, forming the islets known as Islas Quemadas, list of volcanoes in El Salvador Global Volcanism Program, Ilopango Lake Ilopango at NASA Earth Observatory website
30.
Coatepeque Caldera
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Caldera De Coatepeque is a volcanic caldera in El Salvador in Central America. The caldera was formed during a series of major rhyolitic explosive eruptions between about 72,000 and 57,000 years ago, since then, basaltic cinder cones and lava flows formed near the west edge of the caldera, and six rhyodacitic lava domes have formed. The youngest dome, Cerro Pacho, formed after 8000 BC, lake Coatepeque is a large crater lake in the east part of the Coatepeque Caldera. It is in Coatepeque municipality, Santa Ana, El Salvador, there are hot springs near the lake margins. At 26 square kilometres, it is one of the largest lakes in El Salvador, in the lake is the island of Teopan, which was a Mayan site of some importance. List of volcanoes in El Salvador Coatepeque Caldera
31.
Tropics
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The tropics are a region of the Earth surrounding the equator. The tropics are also referred to as the zone and the torrid zone. The tropics include all the areas on the Earth where the Sun is at a point directly overhead at least once during the solar year. The tropics are distinguished from the climatic and biomatic regions of Earth, which are the middle latitudes. Tropical is sometimes used in a sense for a tropical climate to mean warm to hot and moist year-round. Many tropical areas have a dry and wet season, the wet season, rainy season or green season, is the time of year, ranging from one or more months, when most of the average annual rainfall in a region falls. Areas with wet seasons are disseminated across portions of the tropics and subtropics, under the Köppen climate classification, for tropical climates, a wet season month is defined as a month where average precipitation is 60 millimetres or more. Tropical rainforests technically do not have dry or wet seasons, since their rainfall is distributed through the year. When the wet season occurs during the season, or summer, precipitation falls mainly during the late afternoon. The wet season is a time when air quality improves, freshwater quality improves and vegetation grows significantly, floods cause rivers to overflow their banks, and some animals to retreat to higher ground. Soil nutrients diminish and erosion increases, the incidence of malaria increases in areas where the rainy season coincides with high temperatures. Animals have adaptation and survival strategies for the wetter regime, unfortunately, the previous dry season leads to food shortages into the wet season, as the crops have yet to mature. Regions within the tropics may well not have a tropical climate, there are alpine tundra and snow-capped peaks, including Mauna Kea, Mount Kilimanjaro, and the Andes as far south as the northernmost parts of Chile and Argentina. Under the Köppen climate classification, much of the area within the tropics is classed not as tropical but as dry including the Sahara Desert. Tropical plants and animals are those native to the tropics. Tropical ecosystems may consist of rainforests, dry forests, spiny forests, desert. There are often significant areas of biodiversity, and species present, particularly in rainforests. In biogeography, the tropics are divided into Paleotropics and Neotropics, together, they are sometimes referred to as the Pantropic
32.
Tropical cyclone
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Depending on its location and strength, a tropical cyclone is referred to by names such as hurricane, typhoon /taɪˈfuːn/, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean, a typhoon occurs in the northwestern Pacific Ocean, Tropical cyclones typically form over large bodies of relatively warm water. They derive their energy through the evaporation of water from the ocean surface and this energy source differs from that of mid-latitude cyclonic storms, such as noreasters and European windstorms, which are fueled primarily by horizontal temperature contrasts. The strong rotating winds of a tropical cyclone are a result of the conservation of momentum imparted by the Earths rotation as air flows inwards toward the axis of rotation. As a result, they form within 5° of the equator. Tropical cyclones are typically between 100 and 2,000 km in diameter, Tropical refers to the geographical origin of these systems, which form almost exclusively over tropical seas. Cyclone refers to their nature, with wind blowing counterclockwise in the Northern Hemisphere. The opposite direction of circulation is due to the Coriolis effect, in addition to strong winds and rain, tropical cyclones are capable of generating high waves, damaging storm surge, and tornadoes. They typically weaken rapidly over land where they are cut off from their energy source. For this reason, coastal regions are vulnerable to damage from a tropical cyclone as compared to inland regions. Heavy rains, however, can cause significant flooding inland, though their effects on human populations are often devastating, tropical cyclones can relieve drought conditions. They also carry heat away from the tropics and transport it toward temperate latitudes. Tropical cyclones are areas of low pressure in the troposphere. On Earth, the pressures recorded at the centers of tropical cyclones are among the lowest ever observed at sea level, the environment near the center of tropical cyclones is warmer than the surroundings at all altitudes, thus they are characterized as warm core systems. The near-surface wind field of a cyclone is characterized by air rotating rapidly around a center of circulation while also flowing radially inwards. At the outer edge of the storm, air may be nearly calm, however, due to the Earths rotation, as air flows radially inward, it begins to rotate cyclonically in order to conserve angular momentum. At an inner radius, air begins to ascend to the top of the troposphere and this radius is typically coincident with the inner radius of the eyewall, and has the strongest near-surface winds of the storm, consequently, it is known as the radius of maximum winds. Once aloft, air flows away from the center, producing a shield of cirrus clouds
33.
Hurricane Mitch
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Hurricane Mitch was the most powerful and destructive hurricane of the 1998 Atlantic hurricane season, with maximum sustained winds of 180 mph. The storm was the tropical storm, ninth hurricane. Along with Hurricane Georges, Mitch was the most notable hurricane in the season, at the time, Hurricane Mitch was the strongest Atlantic hurricane observed in the month of October, though it has since been surpassed by Hurricane Wilma of the 2005 season. The hurricane matched the fourth most intense Atlantic hurricane on record, after drifting southwestward and weakening, the hurricane hit Honduras as a minimal hurricane. It drifted through Central America, reformed in the Bay of Campeche, due to its slow motion from October 29 to November 3, Hurricane Mitch dropped historic amounts of rainfall in Honduras, Guatemala, and Nicaragua, with unofficial reports of up to 75 inches. Additionally, roughly 2.7 million were homeless as a result of the hurricane. The flooding caused damage, estimated at over $6 billion. Tropical Depression Thirteen formed on October 22 over the southwestern Caribbean Sea and it executed a small loop, and while doing so intensified into Tropical Storm Mitch. A weakness in a ridge allowed the storm to track slowly to the north, after becoming disorganized due to wind shear from an upper-level low, Mitch quickly intensified in response to favorable conditions, including warm waters and good outflow. It became a hurricane on October 24 and developed an eye, after turning to the west, Mitch rapidly intensified, first into a major hurricane on October 25 and then into a Category 5 on the Saffir-Simpson Hurricane Scale the next day. At peak intensity, Mitch maintained maximum sustained winds of 180 mph while off the northern coast of Honduras. Hurricane Hunters reported a barometric pressure of 905 mbar, which at the time was the lowest in the month of October. Initially, the National Hurricane Center and various tropical cyclone forecast models anticipated a turn to the north, instead, Mitch turned to the south due to a ridge that was not observed while the storm was active. Land interaction imparted weakening, and the hurricane made landfall on Honduras on October 29 with winds of 80 mph, Mitch slowly weakened while turning to the west over land, maintaining deep convection over waters. After moving across mountainous terrain in Central America, the circulation of Mitch dissipated on November 1. The next day, the reached the Gulf of Mexico. Mitch accelerated to the northeast ahead of a front, moving across the Yucatán peninsula before striking southwestern Florida on November 5. Shortly thereafter, the became an extratropical cyclone, which was tracked by the NHC until November 9
34.
1973 Pacific hurricane season
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The 1973 Pacific hurricane season was an event in tropical cyclone meteorology. The most important system this year was Hurricane Ava, which was the most intense Pacific hurricane known at the time, several other much weaker tropical cyclones came close to, or made landfall on, the Pacific coast of Mexico. The most serious of these was Hurricane Irah, which downed power and communication lines in parts of the Baja California Peninsula, no tropical cyclone this season caused any deaths. This season had a start but a slow end. Overall activity was below average, with twelve named systems in total, of these, five were tropical storms, seven were hurricanes, of which three were major. Just one storm formed in August, one of the least active Augusts ever in the east Pacific, the season officially started May 15,1973, in the eastern Pacific, and June 1,1973, in the central Pacific, and lasted until November 30,1973. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean, all tropical cyclones this season formed in the eastern north Pacific Ocean, often off the coast of Mexico. As is usual in the hemisphere, most traveled generally westward or northwestward. The season began with the formation of the tropical depression on June 2. The season lasted a total of 129 days, no named storms formed in May, three in June, four in July, one in August, three in September, one in October, and none in November. Another six tropical depressions formed during the year, but data on them is unavailable, all of these tropical cyclones formed in the eastern north Pacific tropical cyclone basin, which encompasses the Pacific Ocean north of the equator east of 140°W. None formed in the central north Pacific, which is the remainder of the Pacific Ocean east of the international dateline, of the tropical cyclones that formed this year, were twelve tropical storms and seven were hurricanes. Of those hurricanes, three of them were major hurricanes because they reached Category 3 or higher on the Saffir-Simpson Scale and these totals are all below the long-term averages of thirteen tropical storms, nine hurricanes, and four major hurricanes. At the time, this total of twelve named tropical cyclones was exactly average. The EPHC covered the area between the coast of North America and 140°W, and the CPHC the remainder of the area, a tropical depression formed on June 2. It steadily strengthened and headed in a westerly direction. It moved slowly and became Hurricane Ava on June 4, two days later, it became a major hurricane and it sped up. On June 7, it became a Category 5 hurricane and it then started weakening and slowed down until it dissipated on June 12
35.
Trade winds
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Trade winds also transport African dust westward across the Atlantic Ocean into the Caribbean Sea, as well as portions of southeastern North America. Shallow cumulus clouds are seen within trade wind regimes, and are capped from becoming taller by a trade wind inversion, the weaker the trade winds become, the more rainfall can be expected in the neighboring landmasses. The term trade winds originally derives from the fourteenth century late Middle English word trade. The Portuguese recognized the importance of the winds in navigation in both the north and south Atlantic ocean as early as the 15th century. From West Africa, the Portuguese had to sail away from continental Portugal and they could then turn northeast, to the area around the Azores islands, and finally east to mainland Europe. They also learned that to reach South Africa, they needed to go far out in the ocean, head for Brazil, following the African coast southbound means upwind in the Southern hemisphere. In the Pacific ocean, the wind circulation, which included both the trade wind easterlies and higher-latitude Westerlies, was unknown to Europeans until Andres de Urdanetas voyage in 1565. The captain of a sailing ship seeks a course along which the winds can be expected to blow in the direction of travel, for example, Manila galleons could not sail into the wind at all. Between 1847 and 1849, Matthew Fontaine Maury collected enough information to create wind, as part of the Hadley cell circulation, surface air flows toward the equator while the flow aloft is towards the poles. A low-pressure area of calm, light winds near the equator is known as the doldrums, near-equatorial trough, intertropical front. When located within a region, this zone of low pressure. Around 30° in both hemispheres, air begins to descend toward the surface in subtropical high-pressure belts known as subtropical ridges. The subsident air is dry because as it descends, the temperature increases, but the absolute humidity remains constant. This warm, dry air is known as an air mass. An increase of temperature with height is known as a temperature inversion, when it occurs within a trade wind regime, it is known as a trade wind inversion. The surface air flows from these subtropical high-pressure belts toward the Equator is deflected toward the west in both hemispheres by the Coriolis effect. These winds blow predominantly from the northeast in the Northern Hemisphere, the trade winds of both hemispheres meet at the doldrums. As they blow across tropical regions, air masses heat up over lower latitudes due to direct sunlight
36.
U.S. state
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A U. S. state is a constituent political entity of the United States of America. There are 50 states, which are together in a union with each other. Each state holds administrative jurisdiction over a geographic territory. Due to the shared sovereignty between each state and the government, Americans are citizens of both the federal republic and of the state in which they reside. State citizenship and residency are flexible, and no government approval is required to move between states, except for persons covered by certain types of court orders. States range in population from just under 600,000 to over 39 million, four states use the term commonwealth rather than state in their full official names. States are divided into counties or county-equivalents, which may be assigned some local authority but are not sovereign. County or county-equivalent structure varies widely by state, State governments are allocated power by the people through their individual constitutions. All are grounded in principles, and each provides for a government. States possess a number of powers and rights under the United States Constitution, Constitution has been amended, and the interpretation and application of its provisions have changed. The general tendency has been toward centralization and incorporation, with the government playing a much larger role than it once did. There is a debate over states rights, which concerns the extent and nature of the states powers and sovereignty in relation to the federal government. States and their residents are represented in the federal Congress, a legislature consisting of the Senate. Each state is represented in the Senate by two senators, and is guaranteed at least one Representative in the House, members of the House are elected from single-member districts. Representatives are distributed among the states in proportion to the most recent constitutionally mandated decennial census, the Constitution grants to Congress the authority to admit new states into the Union. Since the establishment of the United States in 1776, the number of states has expanded from the original 13 to 50, alaska and Hawaii are the most recent states admitted, both in 1959. The Constitution is silent on the question of states have the power to secede from the Union. Shortly after the Civil War, the U. S. Supreme Court, in Texas v. White, as a result, while the governments of the various states share many similar features, they often vary greatly with regard to form and substance
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Massachusetts
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It is bordered by the Atlantic Ocean to the east, the states of Connecticut and Rhode Island to the south, New Hampshire and Vermont to the north, and New York to the west. The state is named for the Massachusett tribe, which inhabited the area. The capital of Massachusetts and the most populous city in New England is Boston, over 80% of Massachusetts population lives in the Greater Boston metropolitan area, a region influential upon American history, academia, and industry. Originally dependent on agriculture, fishing and trade, Massachusetts was transformed into a manufacturing center during the Industrial Revolution, during the 20th century, Massachusetts economy shifted from manufacturing to services. Modern Massachusetts is a leader in biotechnology, engineering, higher education, finance. Plymouth was the site of the first colony in New England, founded in 1620 by the Pilgrims, in 1692, the town of Salem and surrounding areas experienced one of Americas most infamous cases of mass hysteria, the Salem witch trials. In 1777, General Henry Knox founded the Springfield Armory, which during the Industrial Revolution catalyzed numerous important technological advances, in 1786, Shays Rebellion, a populist revolt led by disaffected American Revolutionary War veterans, influenced the United States Constitutional Convention. In the 18th century, the Protestant First Great Awakening, which swept the Atlantic World, in the late 18th century, Boston became known as the Cradle of Liberty for the agitation there that led to the American Revolution. The entire Commonwealth of Massachusetts has played a commercial and cultural role in the history of the United States. Before the American Civil War, Massachusetts was a center for the abolitionist, temperance, in the late 19th century, the sports of basketball and volleyball were invented in the western Massachusetts cities of Springfield and Holyoke, respectively. Many prominent American political dynasties have hailed from the state, including the Adams, both Harvard University and the Massachusetts Institute of Technology, also in Cambridge, have been ranked among the most highly regarded academic institutions in the world. Massachusetts public school students place among the top nations in the world in academic performance, the official name of the state is the Commonwealth of Massachusetts. While this designation is part of the official name, it has no practical implications. Massachusetts has the position and powers within the United States as other states. Massachusetts was originally inhabited by tribes of the Algonquian language family such as the Wampanoag, Narragansett, Nipmuc, Pocomtuc, Mahican, and Massachusett. While cultivation of crops like squash and corn supplemented their diets, villages consisted of lodges called wigwams as well as longhouses, and tribes were led by male or female elders known as sachems. Between 1617 and 1619, smallpox killed approximately 90% of the Massachusetts Bay Native Americans, the first English settlers in Massachusetts, the Pilgrims, arrived via the Mayflower at Plymouth in 1620, and developed friendly relations with the native Wampanoag people. This was the second successful permanent English colony in the part of North America that later became the United States, the event known as the First Thanksgiving was celebrated by the Pilgrims after their first harvest in the New World which lasted for three days
38.
Territorial waters
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Adjustment of these boundaries is called, in international law, maritime delimitation. Normally, the baseline from which the sea is measured is the low-water line along the coast as marked on large-scale charts officially recognized by the coastal state. Straight baselines can alternatively be defined connecting fringing islands along a coast, across the mouths of rivers, or with certain restrictions across the mouths of bays. An indentation shall not, however, be regarded as a bay unless its area is as large as, or larger than, the baseline across the bay must also be no more than 24 nautical miles in length. Waters landward of the baseline are defined as waters, over which the state has complete sovereignty. Lakes and rivers are considered internal waters, however, archipelagic states may designate certain sea lanes through these waters. A states territorial sea extends up to 12 nautical miles from its baseline, if this would overlap with another states territorial sea, the border is taken as the median point between the states baselines, unless the states in question agree otherwise. A state can also choose to claim a territorial sea. Conflicts still occur whenever a coastal nation claims an entire gulf as its territorial waters while other nations recognize the more restrictive definitions of the UN convention. In the U. S. federal system, individual states exercise ownership up to 3 nautical miles from shore and this will typically be 12 nautical miles wide, but could be more, or less, if it would otherwise overlap another states contiguous zone. However, unlike the sea, there is no standard rule for resolving such conflicts. The United States invoked a contiguous zone out to 24 nmi on 24 September 1999, an exclusive economic zone extends from the outer limit of the territorial sea to a maximum of 200 nautical miles from the territorial sea baseline, thus it includes the contiguous zone. A coastal nation has control of all resources within its exclusive economic zone, including fishing, mining, oil exploration. Indeed, the economic zone is still popularly, though erroneously. Article 76 gives the definition of continental shelf of coastal countries. For the physical geography definition, see the continental shelf page, coastal states have the right of exploration and exploitation of its natural resources, however other states could lay cables and pipelines if they are authorised by the coastal state. The foot of the slope is determined as the point of maximum change in the gradient at its base. The portion of the continental shelf beyond the 200 nautical mile limit is known as the extended continental shelf
39.
Nautical mile
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A nautical mile is a unit of measurement defined as exactly 1852 meters. Historically, it was defined as one minute of latitude, which is equivalent to one sixtieth of a degree of latitude. Today it is an SI derived unit, being rounded to a number of meters. The derived unit of speed is the knot, defined as one mile per hour. The geographical mile is the length of one minute of longitude along the Equator, there is no internationally agreed symbol. M is used as the abbreviation for the mile by the International Hydrographic Organization and by the International Bureau of Weights. NM is used by the International Civil Aviation Organization, nm is used by the U. S. National Oceanic and Atmospheric Administration. Nmi is used by the Institute of Electrical and Electronics Engineers, the word mile is from the Latin word for a thousand paces, mīlia. In 1617 the Dutch scientist Snell assessed the circumference of the Earth at 24,630 Roman miles, around that time British mathematician Edmund Gunter improved navigational tools including a new quadrant to determine latitude at sea. He reasoned that the lines of latitude could be used as the basis for a unit of measurement for distance, as one degree is 1/360 of a circle, one minute of arc is 1/21600 of a circle. These sexagesimal units originated in Babylonian astronomy, Gunter used Snells circumference to define a nautical mile as 6,080 feet, the length of one minute of arc at 48 degrees latitude.3 metres. Other countries measure the minute of arc at 45 degrees latitude, in 1929, the international nautical mile was defined by the First International Extraordinary Hydrographic Conference in Monaco as 1,852 meters. Imperial units and United States customary units used a definition of the nautical mile based on the Clarke Spheroid, the United States nautical mile was defined as 6,080.20 feet based in the Mendenhall Order foot of 1893. It was abandoned in favour of the nautical mile in 1954.181 meters. It was abandoned in 1970 and, legally, references to the unit are now converted to 1,853 meters. Conversion of units Orders of magnitude
40.
Sea level
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Mean sea level is an average level of the surface of one or more of Earths oceans from which heights such as elevations may be measured. A common and relatively straightforward mean sea-level standard is the midpoint between a low and mean high tide at a particular location. Sea levels can be affected by factors and are known to have varied greatly over geological time scales. The careful measurement of variations in MSL can offer insights into ongoing climate change, the term above sea level generally refers to above mean sea level. Precise determination of a sea level is a difficult problem because of the many factors that affect sea level. Sea level varies quite a lot on several scales of time and this is because the sea is in constant motion, affected by the tides, wind, atmospheric pressure, local gravitational differences, temperature, salinity and so forth. The easiest way this may be calculated is by selecting a location and calculating the mean sea level at that point, for example, a period of 19 years of hourly level observations may be averaged and used to determine the mean sea level at some measurement point. One measures the values of MSL in respect to the land, hence a change in MSL can result from a real change in sea level, or from a change in the height of the land on which the tide gauge operates. In the UK, the Ordnance Datum is the sea level measured at Newlyn in Cornwall between 1915 and 1921. Prior to 1921, the datum was MSL at the Victoria Dock, in Hong Kong, mPD is a surveying term meaning metres above Principal Datum and refers to height of 1. 230m below the average sea level. In France, the Marégraphe in Marseilles measures continuously the sea level since 1883 and it is used for a part of continental Europe and main part of Africa as official sea level. Elsewhere in Europe vertical elevation references are made to the Amsterdam Peil elevation, satellite altimeters have been making precise measurements of sea level since the launch of TOPEX/Poseidon in 1992. A joint mission of NASA and CNES, TOPEX/Poseidon was followed by Jason-1 in 2001, height above mean sea level is the elevation or altitude of an object, relative to the average sea level datum. It is also used in aviation, where some heights are recorded and reported with respect to sea level, and in the atmospheric sciences. An alternative is to base height measurements on an ellipsoid of the entire Earth, in aviation, the ellipsoid known as World Geodetic System 84 is increasingly used to define heights, however, differences up to 100 metres exist between this ellipsoid height and mean tidal height. The alternative is to use a vertical datum such as NAVD88. When referring to geographic features such as mountains on a topographic map, the elevation of a mountain denotes the highest point or summit and is typically illustrated as a small circle on a topographic map with the AMSL height shown in metres, feet or both. In the rare case that a location is below sea level, for one such case, see Amsterdam Airport Schiphol
41.
Hydropower
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Hydropower or water power is power derived from the energy of falling water or fast running water, which may be harnessed for useful purposes. A trompe, which compressed air from falling water, is sometimes used to power other machinery at a distance. In the late 19th century, hydropower became a source for generating electricity, cragside in Northumberland was the first house powered by hydroelectricity in 1878 and the first commercial hydroelectric power plant was built at Niagara Falls in 1879. In 1881, street lamps in the city of Niagara Falls were powered by hydropower, since the early 20th century, the term has been used almost exclusively in conjunction with the modern development of hydroelectric power. In China and the rest of the Far East, hydraulically operated pot wheel pumps raised water into crop or irrigation canals, the power of a wave of water released from a tank was used for extraction of metal ores in a method known as hushing. The method was first used at the Dolaucothi Gold Mines in Wales from 75 AD onwards, hushing was also widely used in Britain in the Medieval and later periods to extract lead and tin ores. It later evolved into hydraulic mining when used during the California Gold Rush and these include an endless belt with jugs attached, a cow-powered shadoof, and a reciprocating device with hinged valves. In 1753, French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical-, the growing demand for the Industrial Revolution would drive development as well. At the beginning of the Industrial Revolution in Britain, water was the source of power for new inventions such as Richard Arkwrights water frame. In the 1830s, at the peak in US canal-building, hydropower provided the energy to transport barge traffic up. Technological advances had moved the water wheel into an enclosed turbine or water motor. Francis, while working as engineer of Lowells Locks and Canals company. He applied scientific principles and testing methods to the problem of turbine design and his mathematical and graphical calculation methods allowed confident design of high efficiency turbines to exactly match a sites specific flow conditions. The Francis reaction turbine is still in use today. Hydraulic power networks used pipes to carrying pressurized water and transmit power from the source to end users. The power source was normally a head of water, which could also be assisted by a pump and these were extensive in Victorian cities in the United Kingdom. A hydraulic power network was developed in Geneva, Switzerland. The world-famous Jet dEau was originally designed as the relief valve for the network
42.
Geothermal power
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Geothermal power is power generated by geothermal energy. Technologies in use include dry steam power stations, flash steam power stations, Geothermal electricity generation is currently used in 24 countries, while geothermal heating is in use in 70 countries. As of 2015, worldwide geothermal power capacity amounts to 12.8 gigawatts, International markets grew at an average annual rate of 5 percent over the last three years and global geothermal power capacity is expected to reach 14. 5–17.6 GW by 2020. Countries generating more than 15 percent of their electricity from geothermal sources include El Salvador, Kenya, Geothermal power is considered to be a sustainable, renewable source of energy because the heat extraction is small compared with the Earths heat content. In the 20th century, demand for electricity led to the consideration of geothermal power as a generating source, prince Piero Ginori Conti tested the first geothermal power generator on 4 July 1904 in Larderello, Italy. It successfully lit four light bulbs, later, in 1911, the worlds first commercial geothermal power station was built there. Experimental generators were built in Beppu, Japan and the Geysers, California, in the 1920s, in 1958, New Zealand became the second major industrial producer of geothermal electricity when its Wairakei station was commissioned. Wairakei was the first station to use flash steam technology, in 1960, Pacific Gas and Electric began operation of the first successful geothermal electric power station in the United States at The Geysers in California. The original turbine lasted for more than 30 years and produced 11 MW net power, the binary cycle power station was first demonstrated in 1967 in Russia and later introduced to the USA in 1981, following the 1970s energy crisis and significant changes in regulatory policies. This technology allows the use of lower temperature resources than were previously recoverable. In 2006, a binary cycle station in Chena Hot Springs, Alaska, came on-line, Geothermal electric stations have until recently been built exclusively where high temperature geothermal resources are available near the surface. The development of binary cycle power plants and improvements in drilling, demonstration projects are operational in Landau-Pfalz, Germany, and Soultz-sous-Forêts, France, while an earlier effort in Basel, Switzerland was shut down after it triggered earthquakes. Other demonstration projects are under construction in Australia, the United Kingdom, the thermal efficiency of geothermal electric stations is low, around 7–10%, because geothermal fluids are at a low temperature compared with steam from boilers. By the laws of thermodynamics this low temperature limits the efficiency of engines in extracting useful energy during the generation of electricity. Exhaust heat is wasted, unless it can be used directly and locally, for example in greenhouses, timber mills, and district heating. The efficiency of the system does not affect operational costs as it would for a coal or other fossil fuel plant, in order to produce more energy than the pumps consume, electricity generation requires high temperature geothermal fields and specialized heat cycles. Because geothermal power does not rely on sources of energy, unlike, for example, wind or solar. However the global average capacity factor was 74. 5% in 2008, the earth’s heat content is about 1031 joules
43.
Petroleum
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Petroleum is a naturally occurring, yellow-to-black liquid found in geological formations beneath the Earths surface, which is commonly refined into various types of fuels. Components of petroleum are separated using a technique called fractional distillation and it consists of hydrocarbons of various molecular weights and other organic compounds. The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock, Petroleum has mostly been recovered by oil drilling. Drilling is carried out studies of structural geology, sedimentary basin analysis. Petroleum is used in manufacturing a variety of materials. Concern over the depletion of the earths finite reserves of oil, the burning of fossil fuels plays the major role in the current episode of global warming. The word petroleum comes from Greek, πέτρα for rocks and Greek, the term was found in 10th-century Old English sources. It was used in the treatise De Natura Fossilium, published in 1546 by the German mineralogist Georg Bauer, Petroleum, in one form or another, has been used since ancient times, and is now important across society, including in economy, politics and technology. Great quantities of it were found on the banks of the river Issus, ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper levels of their society. By 347 AD, oil was produced from bamboo-drilled wells in China, early British explorers to Myanmar documented a flourishing oil extraction industry based in Yenangyaung that, in 1795, had hundreds of hand-dug wells under production. The mythological origins of the oil fields at Yenangyaung, and its hereditary monopoly control by 24 families, Pechelbronn is said to be the first European site where petroleum has been explored and used. The still active Erdpechquelle, a spring where petroleum appears mixed with water has been used since 1498, Oil sands have been mined since the 18th century. In Wietze in lower Saxony, natural asphalt/bitumen has been explored since the 18th century, both in Pechelbronn as in Wietze, the coal industry dominated the petroleum technologies. In 1848 Young set up a small business refining the crude oil, Young eventually succeeded, by distilling cannel coal at a low heat, in creating a fluid resembling petroleum, which when treated in the same way as the seep oil gave similar products. The production of oils and solid paraffin wax from coal formed the subject of his patent dated 17 October 1850. In 1850 Young & Meldrum and Edward William Binney entered into partnership under the title of E. W. Binney & Co. at Bathgate in West Lothian, the worlds first oil refinery was built in 1856 by Ignacy Łukasiewicz. The demand for petroleum as a fuel for lighting in North America, edwin Drakes 1859 well near Titusville, Pennsylvania, is popularly considered the first modern well
44.
Arable land
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Arable land is, according to one definition, land capable of being ploughed and used to grow crops. In Britain, it was contrasted with pasturable lands such as heaths which could be used for sheep-rearing. A quite different kind of definition is used by various agencies concerned with agriculture, the abandoned land resulting from shifting cultivation is not included in this category. Data for ‘Arable land’ are not meant to indicate the amount of land that is potentially cultivable, a briefer definition appearing in the Eurostat glossary similarly refers to actual, rather than potential use, land worked regularly, generally under a system of crop rotation. According to Food and Agriculture Organization of the United Nations the worlds Arable land amounted to 1,407 M ha, out of a total 4,924 M ha land used for agriculture, as for year 2013. Agricultural land that is not arable according to the FAO definition above includes, Permanent crop - land that produces crops from woody vegetation, other non-arable land includes land unsuitable for any agricultural use. Although such limitations may preclude cultivation, and some will in some cases preclude any agricultural use, for example, US NRCS statistics indicate that about 59 percent of US non-federal pasture and unforested rangeland is unsuitable for cultivation, yet such land has value for grazing of livestock. Similar examples can be found in many rangeland areas elsewhere, land incapable of being cultivated for production of crops can sometimes be converted to arable land. New arable land makes more food, and can reduce starvation and this outcome also makes a country more self-sufficient and politically independent, because food importation is reduced. This process is extremely expensive. An alternative is the Seawater Greenhouse which desalinates water through evaporation and condensation using solar energy as the energy input. This technology is optimized to grow crops on land close to the sea. The people covered the islands with a layer of seaweed. Israel, The construction of desalination plants along Israels coast allowed agriculture in areas that were formerly desert. The desalination plants, which remove the salt from water, have created a new source of water for farming, drinking. Slash and burn agriculture uses nutrients in wood ash, but these expire within a few years, terra preta, fertile tropical soils created by adding charcoal. Some examples of fertile land being turned into infertile land are. Rainforest deforestation, The fertile tropical forests are converted into infertile desert land, for example, Madagascars central highland plateau has become virtually totally barren, as a result of slash-and-burn deforestation, an element of shifting cultivation practiced by many natives
This article incorporates public domain material from the Library of Congress Country Studies website http://lcweb2.loc.gov/frd/cs/.
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