1.
Mayon
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Mayon, also known as Mount Mayon or Mayon Volcano, is an active stratovolcano in the province of Albay in Bicol Region, on the island of Luzon in the Philippines. Renowned as the perfect cone because of its conical shape, the volcano and its surrounding landscape was declared a national park on July 20,1938. It was reclassified a Natural Park and renamed Mayon Volcano Natural Park in the year 2000, local folklore refers to the volcano being named after the legendary princess-heroine Daragang Magayon. Mayon is the landmark and highest point of the province of Albay. Mayon is a stratovolcano with a small central summit crater. The cone is considered the worlds most perfectly formed volcano for its symmetry, the upper slopes of the basaltic-andesitic stratovolcano are steep, averaging 35–40 degrees. Like other volcanoes around the Pacific Ocean, Mayon is a part of the Pacific Ring of Fire and it is on the southeast side of Luzon, close to the Philippine Trench, which is the convergent boundary where the Philippine Sea Plate is driven under the Philippine Mobile Belt. When a continental plate meets an oceanic plate, the lighter and thicker continental material overrides the thinner and heavier oceanic plate, forcing it down into the Earths mantle and melting it. Superheated magma and gases may be forced through weaknesses in the continental crust caused by the subduction of the oceanic plate, Mayon is the most active volcano in the Philippines, erupting over 49 times in the past 400 years. The first record of an eruption was witnessed in February 1616 by Dutch explorer Joris van Spilbergen who recorded it on his log in his circumnavigation trip around the world. The first eruption for which an extended account exists was the event of July 20,1766. The most destructive eruption of Mayon occurred on February 1,1814, lava flowed but less than the 1766 eruption. The volcano belched dark ash and eventually bombarded the town of Cagsawa with tephra that buried it, trees burned, rivers were certainly damaged. Proximate areas were devastated by the eruption, with ash accumulating to 9 m in depth. In Albay,2,200 locals perished in what is considered to be the most lethal eruption in Mayons history, though estimates by PHIVOLCS list the casualties at about 1,200. The eruption is believed to have contributed to the accumulation of atmospheric ash capped by the catastrophic 1815 eruption of Mount Tambora, from July 6,1881 until approximately August 1882, Mayon underwent a strong eruption. The viscid mass bubbled quietly but grandly, and overran the border of the crater, descending several hundred feet in a glowing wave, more than half of the mountain height was thus illuminated. Mayons longest uninterrupted eruption occurred on June 23,1897, which lasted for seven days of raining fire, lava once again flowed down to civilization
2.
Philippines
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The Philippines, officially the Republic of the Philippines, is a sovereign island country in Southeast Asia situated in the western Pacific Ocean. It consists of about 7,641 islands that are categorized broadly under three main geographical divisions from north to south, Luzon, Visayas, and Mindanao, the capital city of the Philippines is Manila and the most populous city is Quezon City, both part of Metro Manila. The Philippines has an area of 300,000 square kilometers, and it is the eighth-most populated country in Asia and the 12th most populated country in the world. As of 2013, approximately 10 million additional Filipinos lived overseas, multiple ethnicities and cultures are found throughout the islands. In prehistoric times, Negritos were some of the archipelagos earliest inhabitants and they were followed by successive waves of Austronesian peoples. Exchanges with Chinese, Malay, Indian, and Islamic nations occurred, then, various competing maritime states were established under the rule of Datus, Rajahs, Sultans or Lakans. The arrival of Ferdinand Magellan in Homonhon, Eastern Samar in 1521 marked the beginning of Hispanic colonization, in 1543, Spanish explorer Ruy López de Villalobos named the archipelago Las Islas Filipinas in honor of Philip II of Spain. With the arrival of Miguel López de Legazpi from Mexico City, in 1565, the Philippines became part of the Spanish Empire for more than 300 years. This resulted in Roman Catholicism becoming the dominant religion, during this time, Manila became the western hub of the trans-Pacific trade connecting Asia with Acapulco in the Americas using Manila galleons. Aside from the period of Japanese occupation, the United States retained sovereignty over the islands until after World War II, since then, the Philippines has often had a tumultuous experience with democracy, which included the overthrow of a dictatorship by a non-violent revolution. It is a member of the United Nations, World Trade Organization, Association of Southeast Asian Nations, the Asia-Pacific Economic Cooperation forum. It also hosts the headquarters of the Asian Development Bank, the Philippines was named in honor of King Philip II of Spain. Spanish explorer Ruy López de Villalobos, during his expedition in 1542, named the islands of Leyte, eventually the name Las Islas Filipinas would be used to cover all the islands of the archipelago. Before that became commonplace, other such as Islas del Poniente. The official name of the Philippines has changed several times in the course of its history, during the Philippine Revolution, the Malolos Congress proclaimed the establishment of the República Filipina or the Philippine Republic. From the 1898 Treaty of Paris, the name Philippines began to appear, since the end of World War II, the official name of the country has been the Republic of the Philippines. The metatarsal of the Callao Man, reliably dated by uranium-series dating to 67,000 years ago is the oldest human remnant found in the archipelago to date and this distinction previously belonged to the Tabon Man of Palawan, carbon-dated to around 26,500 years ago. Negritos were also among the archipelagos earliest inhabitants, but their first settlement in the Philippines has not been reliably dated, there are several opposing theories regarding the origins of ancient Filipinos
3.
Volcanic gas
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Volcanic gases include a variety of substances given off by active volcanoes. The sources of gases on Earth include, primordial and recycled constituents from the Earths mantle, assimilated constituents from the Earths crust, groundwater. Substances that may become gaseous or give off gases when heated are termed volatile substances. The principal components of volcanic gases are water vapor, carbon dioxide, sulfur either as sulfur dioxide or hydrogen sulfide, nitrogen, argon, helium, neon, methane, carbon monoxide and hydrogen. Other compounds detected in volcanic gases are oxygen, hydrogen chloride, hydrogen fluoride, hydrogen bromide, nitrogen oxide, sulfur hexafluoride, carbonyl sulfide, exotic trace compounds include mercury, halocarbons, and halogen oxide radicals. The abundance of gases varies considerably from volcano to volcano, water vapor is consistently the most common volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions, volcanoes located at convergent plate boundaries emit more water vapor and chlorine than volcanoes at hot spots or divergent plate boundaries. This is caused by the addition of seawater into magmas formed at subduction zones, convergent plate boundary volcanoes also have higher H2O/H2, H2O/CO2, CO2/He and N2/He ratios than hot spot or divergent plate boundary volcanoes. Magma contains dissolved volatile components, as described above, the solubilities of the different volatile constituents are dependent on pressure, temperature and the composition of the magma. As magma ascends towards the surface, the ambient pressure decreases, once the solubility decreases below the volatile concentration, the volatiles will tend to come out of solution within the magma and form a separate gas phase. The gas will initially be distributed throughout the magma as small bubbles, as the magma ascends the bubbles grow through a combination of expansion through decompression and growth as the solubility of volatiles in the magma decreases further causing more gas to exsolve. In the former case, the bubbles may rise through the magma and accumulate at a vertical surface, in volcanoes with an open path to the surface, e. g. Stromboli in Italy, the bubbles may reach the surface and as they pop small explosions occur. In the latter case, the gas can flow rapidly through the continuous permeable network towards the surface and this mechanism has been used to explain activity at Santiaguito, Santa Maria volcano, Guatemala and Soufrière Hills Volcano, Montserrat. If the gas cannot escape fast enough from the magma, it will fragment the magma into small particles of ash, the fluidised ash has a much lower resistance to motion than the viscous magma, so accelerates, causing further expansion of the gases and acceleration of the mixture. This sequence of events drives explosive volcanism, whether gas can escape gently or not is determined by the total volatile contents of the initial magma and the viscosity of the magma, which is controlled by its composition. The term closed system degassing refers to the case where gas and its parent magma ascend together, the composition of the emitted gas is in equilibrium with the composition of the magma at the pressure, temperature where the gas leaves the system. In open system degassing, the gas leaves its parent magma, the gas released at the surface has a composition that is a mass-flow average of the magma exsolved at various depths and is not representative of the magma conditions at any one depth. Molten rock near the atmosphere releases high-temperature volcanic gas, in explosive volcanic eruptions, sudden release of gases from magma may cause rapid movements of the molten rock
4.
Tephra
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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts, once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff. Tephra mixed in with precipitation can also be acidic and cause acid rain, the use of tephra layers, which bear their own unique chemistry and character, as temporal marker horizons in archaeological and geological sites is known as tephrochronology. The word tephra and pyroclast both derive from Greek, τέφρα tephra means ash, while the word pyroclast is derived from the Greek πῦρ, meaning fire, media related to Tephra at Wikimedia Commons How Volcanoes Work Volcanic Materials Identification
5.
Explosive eruption
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An explosive eruption is a volcanic term to describe a violent, explosive type of eruption. Mount St. Helens in 1980 was an example, such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such that expelled lava violently froths into volcanic ash when pressure is suddenly lowered at the vent. Sometimes a lava plug will block the conduit to the summit, Explosive eruptions can send rocks, dust, gas and pyroclastic material up to 20 km into the atmosphere at rate of up to 100,000 tonnes per second, traveling at several hundred meters per second. This cloud will collapse, creating a pyroclastic flow of hot volcanic matter. An explosive eruption always begins with some form of blockage in the crater of a volcano that prevents the release of trapped in highly viscous andesitic or rhyolitic magma. The high viscosity of these forms of magma prevents the release of trapped gases, when this type of magma flows towards the surface pressure builds, eventually causing the blockage to be blasted out in an explosive eruption. The pressure from the magma and gases are released through the weakest point in the cone, however, in the case of the eruption of Mount St. Helens, pressure was released through the side of the volcano, rather than the crater. The size and duration of the column depends on the volume of magma being released, the eruption column of ash is supported by pressure from the gases being released, and as the gases are depleted, pressure falls and the eruption column begins to collapse. When the column collapses in on itself, ash and rock fall back down to the ground and these flows can travel at up to 80 km per hour, and reach temperatures of 200° to 700° Celsius. The high temperatures can cause combustion of any flammable materials in its path, including wood, vegetation, when snow and ice melt as a part of an eruption, large amounts of water mixed in with the flow can create lahars. The risk of lahars is particularly high on volcanoes such as Mount Rainier near Seattle and Tacoma, the eruption of supervolcanoes is the rarest of volcanic eruptions but also the most destructive. The timescale between these eruptions is generally marked by hundreds or thousands of years and this type of eruption generally causes destruction on a continental scale, and can also result in the lowering of temperatures worldwide. Effusive eruption Volcanic explosivity index Recent Developments in Explosive Volcanism
6.
Bishop Tuff
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The Bishop Tuff is a welded tuff that formed 767,100 ±900 years ago as a rhyolitic pyroclastic flow during the eruption that created the Long Valley Caldera. Large outcrops of the tuff are located in Inyo and Mono Counties, California, the Bishop Tuff caps a volcanic plateau in the northern Owens Valley. The tableland formation is located east of U. S. Route 395 and west of the Nevada stateline, sitting northwest of Bishop and southeast of Crowley Lake, another part of the flow is south of Mono Lake, and surrounding the Mono-Inyo Craters. Deposits of Bishop Tuff in this area cover nearly 2, 200-square-kilometer, the Owens River cut through the volcanic plateau, creating the Owens River Gorge. One of the monsters from the 1990 film Tremors exits from the Bishop Tuff close to Bishop Glass Mountain Long Valley Observatory - Bishop Tuff BLM Bishop Field Office web page
7.
Pumice
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Pumice, called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker walls and being dark colored. Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano, the unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubility of gases that are dissolved in the lava, the simultaneous cooling and depressurization freezes the bubbles in a matrix. Eruptions under water are cooled and the large volume of pumice created can be a shipping hazard for cargo ships. Pumice is composed of highly microvesicular glass pyroclastic with very thin and it is commonly, but not exclusively of silicic or felsic to intermediate in composition, but basaltic and other compositions are known. Pumice is commonly pale in color, ranging from white, cream, blue or grey and it forms when volcanic gases exsolving from viscous magma form bubbles that remain within the viscous magma as it cools to glass. Pumice is a product of explosive eruptions and commonly forms zones in upper parts of silicic lavas. Pumice has a porosity of 90%, and initially floats on water. Scoria differs from pumice in being denser, with larger vesicles and thicker vesicle walls, it sinks rapidly. The difference is the result of the viscosity of the magma that forms scoria. When larger amounts of gas are present, the result is a variety of pumice known as pumicite. Pumice is considered a glass because it has no crystal structure, pumice varies in density according to the thickness of the solid material between the bubbles, many samples float in water. After the explosion of Krakatoa, rafts of pumice drifted through the Pacific Ocean for up to 20 years, in fact, pumice rafts disperse and support several marine species. In 1979,1984 and 2006, underwater volcanic eruptions near Tonga created large pumice rafts, there are two main forms of vesicles. Most pumice contains tubular microvesicles that can impart a silky or fibrous fabric, the elongation of the microvesicles occurs due to ductile elongation in the volcanic conduit or, in the case of pumiceous lavas, during flow. The other form of vesicles are subspherical to spherical and result from high pressure during eruption. Pumice is widely used to make concrete or insulative low-density cinder blocks
8.
Fiamme
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Fiamme are lens-shapes, usually millimetres to centimetres in size, seen on surfaces of some volcaniclastic rocks. They can occur in welded pyroclastic fall deposits and in ignimbrites, the name fiamme comes from the Italian word for flames, describing their shape. The term is descriptive and non-genetic, fiamme are most typical of welded lapilli-tuffs and are commonly found in association with eutaxitic textures, best seen under the microscope. Some fiamme represent fragments of volcanic ejecta, often pumice lapilli that have been flattened by compaction and/or shear, some fiamme are formed from flattened hot, relatively low viscosity, high porosity fragments of volcanic glass or pumice. Fiamme can also result from patchy alteration and recrystalisation of volcanic rocks, or by patchy revesiculation of welded tuff matrix
9.
Greek language
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Greek is an independent branch of the Indo-European family of languages, native to Greece and other parts of the Eastern Mediterranean. It has the longest documented history of any living language, spanning 34 centuries of written records and its writing system has been the Greek alphabet for the major part of its history, other systems, such as Linear B and the Cypriot syllabary, were used previously. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic and many other writing systems. Together with the Latin texts and traditions of the Roman world, during antiquity, Greek was a widely spoken lingua franca in the Mediterranean world and many places beyond. It would eventually become the official parlance of the Byzantine Empire, the language is spoken by at least 13.2 million people today in Greece, Cyprus, Italy, Albania, Turkey, and the Greek diaspora. Greek roots are used to coin new words for other languages, Greek. Greek has been spoken in the Balkan peninsula since around the 3rd millennium BC, the earliest written evidence is a Linear B clay tablet found in Messenia that dates to between 1450 and 1350 BC, making Greek the worlds oldest recorded living language. Among the Indo-European languages, its date of earliest written attestation is matched only by the now extinct Anatolian languages, the Greek language is conventionally divided into the following periods, Proto-Greek, the unrecorded but assumed last ancestor of all known varieties of Greek. The unity of Proto-Greek would have ended as Hellenic migrants entered the Greek peninsula sometime in the Neolithic era or the Bronze Age, Mycenaean Greek, the language of the Mycenaean civilisation. It is recorded in the Linear B script on tablets dating from the 15th century BC onwards, Ancient Greek, in its various dialects, the language of the Archaic and Classical periods of the ancient Greek civilisation. It was widely known throughout the Roman Empire, after the Roman conquest of Greece, an unofficial bilingualism of Greek and Latin was established in the city of Rome and Koine Greek became a first or second language in the Roman Empire. The origin of Christianity can also be traced through Koine Greek, Medieval Greek, also known as Byzantine Greek, the continuation of Koine Greek in Byzantine Greece, up to the demise of the Byzantine Empire in the 15th century. Much of the written Greek that was used as the language of the Byzantine Empire was an eclectic middle-ground variety based on the tradition of written Koine. Modern Greek, Stemming from Medieval Greek, Modern Greek usages can be traced in the Byzantine period and it is the language used by the modern Greeks, and, apart from Standard Modern Greek, there are several dialects of it. In the modern era, the Greek language entered a state of diglossia, the historical unity and continuing identity between the various stages of the Greek language is often emphasised. Greek speakers today still tend to regard literary works of ancient Greek as part of their own rather than a foreign language and it is also often stated that the historical changes have been relatively slight compared with some other languages. According to one estimation, Homeric Greek is probably closer to demotic than 12-century Middle English is to modern spoken English, Greek is spoken by about 13 million people, mainly in Greece, Albania and Cyprus, but also worldwide by the large Greek diaspora. Greek is the language of Greece, where it is spoken by almost the entire population
10.
Martinique
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Like Guadeloupe, it is an overseas region of France, consisting of a single overseas department. One of the Windward Islands, it is north of Saint Lucia, southeast of Puerto Rico, northwest of Barbados. As with the overseas departments, Martinique is one of the eighteen regions of France. As part of France, Martinique is part of the European Union, the official language is French, and virtually the entire population also speak Antillean Creole. Martinique owes its name to Christopher Columbus, who sighted the island in 1493, the island was then called Jouanacaëra-Matinino, which came from a mythical island described by the Tainos of Hispaniola. According to historian Sydney Daney, the island was called Jouanacaëra by the Caribs, when Columbus returned to the island in 1502, he rechristened the island as Martinica. The name then evolved into Madinina, Madiana, and Matinite, finally, through the influence of the neighboring island of Dominica, it came to be known as Martinique. The island was occupied first by Arawaks, then by Caribs, the Carib people had migrated from the mainland to the islands about 1201 CE, according to carbon dating of artifacts. They were largely displaced, exterminated and assimilated by the Taino, Martinique was charted by Columbus in 1493, but Spain had little interest in the territory. On 15 September 1635, Pierre Belain dEsnambuc, French governor of the island of St. Kitts, dEsnambuc claimed Martinique for the French King Louis XIII and the French Compagnie des Îles de lAmérique, and established the first European settlement at Fort Saint-Pierre. DEsnambuc died in 1636, leaving the company and Martinique in the hands of his nephew, in 1637, his nephew Jacques Dyel du Parquet became governor of the island. In 1636, the indigenous Caribs rose against the settlers to drive them off the island in the first of many skirmishes. The French successfully repelled the natives and forced them to retreat to the part of the island. When the Carib revolted against French rule in 1658, the Governor Charles Houël du Petit Pré retaliated with war against them, many were killed, those who survived were taken captive and expelled from the island. Some Carib had fled to Dominica or St. Vincent, where the French agreed to them at peace. They were quite industrious and became quite prosperous, from September 1686 to early 1688, the French crown used Martinique as a threat and a dumping ground for mainland Huguenots who refused to reconvert to Catholicism. Over 1,000 Huguenots were transported to Martinique during this period, usually under miserable and those that survived the trip were distributed to the island planters as Engagés under the system of serf peonage that prevailed in the French Antilles at the time. Many of them were encouraged by their Catholic brethren who looked forward to the departure of the heretics, by 1688, nearly all of Martiniques French Protestant population had escaped to the British American colonies or Protestant countries back home
11.
Saint-Pierre, Martinique
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Saint-Pierre is a town and commune of Frances Caribbean overseas department of Martinique, founded in 1635 by Pierre Belain dEsnambuc. Before the total destruction of Saint-Pierre in 1902 by an eruption, it was the most important city of Martinique culturally and economically. While Fort-de-France was the administrative capital, Saint-Pierre was the cultural capital of Martinique. After the disaster, Fort-de-France grew in economic importance, Saint-Pierre was founded in 1635 by Pierre Belain dEsnambuc, a French trader and adventurer, as the first permanent French colony on the island of Martinique. The Great Hurricane of 1780 produced a storm-surge of 8 metres which inundated the city, destroying all houses, the town was destroyed again in 1902. Legend has it that the towns doom was forecast by loud groaning noises from within the volcano and this story appears to have originated with one of the islands newspapers, published by a political opponent of the governor. The city of Saint-Pierre was never restored to its former entirety, today, the town is the district capital of the Caribbean North district of Martinique. It has been designated as a City of Art and History, there are many historic remains, and a Volcanological Museum
12.
Eruption column
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An eruption column is a cloud of hot volcanic ash suspended in volcanic gas emitted during an explosive volcanic eruption. The ash forms a column that may rise many kilometres into the air above the vent of the volcano, in the most explosive eruptions, the eruption column may rise over 40 km, penetrating the stratosphere. Stratospheric injection of aerosols by volcanoes is a cause of short-term climate change. A common occurrence in explosive eruptions is for column collapse to occur, in this case, the eruption column is too dense to be lifted high into the air by air convection, and instead falls down the flanks of the volcano to form a pyroclastic flow or surge. On some occasions, if ash isnt dense enough to fall, eruption columns form in explosive volcanic activity, when the high concentration of volatile materials in the rising magma causes it to be disrupted into fine volcanic ash and coarser tephra. The ash and tephra are ejected at speeds of several hundred metres per second, eruption columns may be transient, if formed by a discrete explosion, or sustained, if produced by a continuous eruption or closely spaced discrete explosions. The gas expands because the pressure of rock above it rapidly reduces as it approaches the surface and this region is called the gas thrust region and typically reaches to only one or two kilometres above the vent. The convective thrust region covers most of the height of the column, the gas thrust region is very turbulent and surrounding air becomes mixed into it and heated. The air expands, reducing its density and rising, the rising air carries the solid and liquid material from the eruption entrained in it upwards. As the column rises into less dense surrounding air, it will reach an altitude where the hot. In this neutral buoyancy region, the material will then no longer rise through convection. This is called the region, and is usually marked by the column spreading out sideways. The eruptive material and the cool air has the same density at the base of the umbrella region. Because the speeds are low or negligible in this region it is often distorted by stratospheric winds. The column will stop rising once it attains an altitude where it is no longer less dense than the surrounding air, several factors control the height that an eruption column can reach. Intrinsic factors include the diameter of the vent, the gas content of the magma. Extrinsic factors can be important, with winds sometimes limiting the height of the column, the atmospheric temperature in the troposphere normally decreases by about 6-7 K/km, but small changes in this gradient can have a large effect on the final column height. Theoretically, the maximum column height is thought to be about 55 km
13.
Plinian eruption
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Plinian eruptions, also known as Vesuvian eruptions, are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in 79 AD. The eruption was described in a written by Pliny the Younger, it killed his uncle. Plinian eruptions are marked by columns of gas and volcanic ash extending high into the stratosphere, the key characteristics are ejection of large amount of pumice and very powerful continuous gas blast eruptions. According to the Volcanic Explosivity Index, Plinian eruptions have a VEI of 4,5 or 6, short eruptions can end in less than a day, but longer events can take several days to months. The longer eruptions begin with production of clouds of volcanic ash, the amount of magma erupted can be so large that it depletes the magma chamber below, causing the top of the volcano to collapse, resulting in a caldera. Fine ash can deposit over large areas, Plinian eruptions are often accompanied by loud noises, such as those generated by Krakatoa. The lava is usually rhyolitic and rich in silicates, basaltic lavas are unusual for Plinian eruptions, the most recent basaltic example is the 1886 eruption of Mount Tarawera on New Zealands North Island. Pliny the Younger provided an account of his death, and suggested that he collapsed and died through inhaling poisonous gases emitted from the volcano. His body was interred under the ashes of the Vesuvius with no apparent injuries on 26 August, after the plume had dispersed. The June 2009 eruption of Sarychev Peak in Russia, the 1991 Mount Pinatubo eruption in Zambales of Central Luzon, Philippines. The 1980 eruption of Mount St. Helens in Washington, United States, the 1912 eruption of Novarupta in Alaska, United States. The 1886 eruption of Mount Tarawera in New Zealand, the 1883 eruption of Krakatoa in Sunda Strait, Indonesia. The 1815 eruption of Mount Tambora in the island of Sumbawa, the 1783 eruptions of Lakagígar in Iceland. The 1667 and 1739 eruptions of Mount Tarumae in Hokkaido, Japan, the A. D.180 Lake Taupo eruption in New Zealand. The A. D.79 eruption of Mount Vesuvius in Campania and it was the prototypical Plinian eruption. The 400s BC eruption of the Bridge River Vent in British Columbia, the 1645 BC eruption of Santorini in the south Aegean Sea, Greece. The 4860 BC eruption forming Crater Lake in Oregon, United States, the Long Valley Caldera eruption in Eastern California of United States, which happened over 760,000 years ago. According to the Volcanic Explosivity Index, a VEI of 6 to 8 is classified as Ultra Plinian, Eruptions of this type are defined by ash plumes over 25 km high and a volume of erupted material 10 km3 to 1,000 km3 in size
14.
Eruption of Mount Vesuvius in 79
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The 79 AD eruption of Mount Vesuvius was one of the most catastrophic volcanic eruptions in European history. Historians have learned about the eruption from the account of Pliny the Younger. It is the namesake for Vesuvian eruptions, several Roman settlements were obliterated and buried underneath massive pyroclastic surges and ashfall deposits, the most well known being Pompeii and Herculaneum. The remains of about 1,500 people have found at Pompeii and Herculaneum. The 79 AD eruption was preceded by a powerful earthquake seventeen years before on February 5,62 AD, which caused widespread destruction around the Bay of Naples, some of the damage had still not been repaired when the volcano erupted. Suetonius recorded that the emperor continued singing through the earthquake until he had finished his song, the Romans grew accustomed to minor earth tremors in the region, the writer Pliny the Younger wrote that they were not particularly alarming because they are frequent in Campania. Small earthquakes started taking place on 20 August 79, becoming more frequent over the four days. Reconstructions of the eruption and its effects vary considerably in the details but have the same overall features, the eruption lasted for two days. Mount Vesuvius violently erupted, spewing up a column from which ash and pumice began to fall. Rescues and escapes occurred during this time, at some time in the night or early the next day, August 25, pyroclastic flows in the close vicinity of the volcano began. Lights seen on the mountain were interpreted as fires, people as far away as Misenum fled for their lives. These were accompanied by additional light tremors and a tsunami in the Bay of Naples. By evening of the day, the eruption was over. Pliny the Younger wrote an account of the eruption, Broad sheets of flame were lighting up many parts of Vesuvius, their light, two pyroclastic surges engulfed Pompeii, burning and asphyxiating the stragglers who had remained behind. Oplontis and Herculaneum received the brunt of the surges and were buried in ash, pumice, lava fragments. In an article published in 2002, Sigurdsson and Casey elaborate on the evidence based on excavations. Subsequently, the cloud collapsed as the gases densified and lost their capability to support their solid contents, releasing it as a pyroclastic surge, the eruption alternated between Vesuvian and Peléan six times. Surges 4 and 5 are believed by the authors to have destroyed and buried Pompeii, surges are identified in the deposits by dune and cross-bedding formations, which are not produced by fallout
15.
Convection
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Convection is the movement of groups of molecules within fluids such as liquids or gases, and within rheids. Convection takes place through advection, diffusion or both, convection cannot take place in solids because neither bulk current flows nor significant diffusion can take place in solids. Diffusion of heat can take place in solids, but that is called heat conduction, convective heat transfer is one of the major types of heat transfer, and convection is also a major mode of mass transfer in fluids. In the context of heat and mass transfer, the convection is used to refer to the sum of advective and diffusive transfer. In common use the term convection may refer loosely to heat transfer by convection, as opposed to mass transfer by convection, sometimes convection is even used to refer specifically to free heat convection as opposed to forced heat convection. However, in mechanics the correct use of the word is the general sense, convection can be qualified in terms of being natural, forced, gravitational, granular, or thermomagnetic. It may also be said to be due to combustion, capillary action, or Marangoni, heat transfer by natural convection plays a role in the structure of Earths atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be seen as clouds, natural convection also plays a role in stellar physics. The word convection may have different but related usages in different scientific or engineering contexts or applications. The broader sense is in fluid mechanics, where convection refers to the motion of fluid regardless of cause, however, in thermodynamics convection often refers specifically to heat transfer by convection. Additionally, convection includes fluid movement both by bulk motion and by the motion of individual particles, however, in some cases, convection is taken to mean only advective phenomena. Convection occurs on a scale in atmospheres, oceans, planetary mantles. Fluid movement during convection may be slow, or it may be obvious and rapid. On astronomical scales, convection of gas and dust is thought to occur in the disks of black holes. Convective heat transfer is a mechanism of heat transfer occurring because of bulk motion of fluids, heat is the entity of interest being advected, and diffused. Heat is transferred by convection in numerous examples of naturally occurring fluid flow, such as, wind, oceanic currents, convection is also used in engineering practices of homes, industrial processes, cooling of equipment, etc. The rate of heat transfer may be improved by the use of a heat sink. For instance, a typical computer CPU will have a fan to ensure its operating temperature is kept within tolerable limits
16.
Vulcanian eruption
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The term vulcanian was first used by Giuseppe Mercalli, witnessing the 1888-1890 eruptions on the island of Vulcano. His description of the style is now used all over the world for eruptions characterised by a dense cloud of ash-laden gas exploding from the crater. Mercalli described vulcanian eruptions as. Explosions like cannon fire at irregular intervals and their explosive nature is due to increased silica content of the magma. Almost all types of magma can be involved, but magma with about 55% or more silica is most common, increasing silica levels increase the viscosity of the magma which means increased explosiveness. They usually commence with phreatomagmatic eruptions which can be noisy due the rising magma heating water in the ground. This is usually followed by the clearing of the vent. As the vent clears, further ash clouds become grey-white and creamy in colour, vulcanian eruptions display several common characteristics. The mass of rock ejected during the eruption is usually between 102 -106 tonnes and contains a proportion of non-juvinial material. During active periods of activity, intervals between explosions vary from less than 1 minute to about a day. Pyroclastic flows are common features of this type of eruption. The gas streaming phase of vulcanian eruptions are characterised by discrete cannon-like explosions and these expulsions of gas can reach supersonic velocities resulting in shock waves. The tephra is dispersed over an area than that from Strombolian eruptions. The pyroclastic rock and the surge deposits form an ash volcanic cone. The eruption ends with a flow of viscous lava, vulcanian eruptions may throw large metre-size blocks several hundred metres, occasionally up to several kilometres. Vulcanian eruptions are dangerous to persons within several hundred metres of the vent, volcanic bombs are common products of this type of eruption. These are initially molten blobs of lava, which cool into blocks often 2 to 3 m across. At Galeras, an eruption ejected bombs which struck several volcanologists who were in the crater. The 11 September 1930 eruption of Stromboli was a vulcanian eruption and it started at 08,10 hours, when ash was vented for about 10 minutes
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Ignimbrite
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Ignimbrites are made of a very poorly sorted mixture of volcanic ash and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified rock called lapilli-tuff, near the volcanic source, ignimbrites commonly contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown or black depending on their composition, many pale ignimbrites are dacitic or rhyolitic. Darker coloured ignimbrites may be densely welded volcanic glass or, less commonly, there are two main models that have been proposed to explain the deposition of ignimbrites from a pyroclastic density current, the en masse deposition and the progressive aggradation models. The en masse model was proposed by volcanologist Robert Stephen John Sparks in 1976, Sparks attributed the poor sorting in ignimbrites to laminar flows of very high particle concentration. Pyroclastic flows were envisioned as being similar to flows, with a body undergoing laminar flow. The flow would travel as a flow, with an essentially non-deforming mass travelling on a thin shear zone. This would produce a unit with an inversely graded base. There are several problems with the en masse model, since ignimbrite is a deposit, its characteristics cannot completely represent the flow, and the deposit may only record the depositional process. It has been posited that the changes are recording progressive aggradation at the base of the flow from an eruption whose composition changes with time. For this to be so, the base of the flow cannot be turbulent, the instantaneous deposition of an entire body of material is not possible because displacement of the fluid is not possible instantaneously. Any displacement of the fluid would mobilize the upper part of the flow, rheomorphic structures are only observed in high grade ignimbrites. There are two types of flow, post-depositional re-mobilization, and late stage viscous flow. While there is debate in the field of the relative importance of either mechanism. A change from particulate flow to a fluid could cause the rapid en masse cooling in the last few meters. It is also theorized that transformation occurs at a layer at the base of the flow. Another model proposed is that the density current became stationary before the structures form
18.
Novarupta
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Novarupta is a volcano that was created in 1912, located on the Alaska Peninsula in Katmai National Park and Preserve, about 290 miles southwest of Anchorage. Formed during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of magma of the 1980 eruption of Mount St. Helens. The eruption of Novarupta within the Aleutian Range began on June 6,1912, rated a 6 on the Volcanic Explosivity Index, the 60-hour-long eruption expelled 13 to 15 cubic kilometers of ash,30 times as much as the 1980 eruption of Mount St. Helens. The erupted magma of rhyolitic, dacitic, and andesitic composition resulted in more than 17 cubic kilometers of air fall tuff and approximately 11 cubic kilometers of pyroclastic ash-flow tuff. During the 20th century, only the 1991 eruption of Mt. Pinatubo in the Philippines was of a similar magnitude, at least two larger eruptions occurred in the 19th century, the 1815 eruption of Tambora and the 1883 eruption of Indonesias Krakatoa. The Novarupta eruption occurred about 2.5 miles from the peak of Mount Katmai Volcano and 4,000 feet below the post-eruption Mount Katmai summit, the eruption ended with the extrusion of a lava dome of rhyolite that plugged the vent. The 295-foot high and 1, 180-foot wide dome and the caldera it created form what is now referred to as Novarupta, despite the magnitude of the eruption, no deaths directly resulted. The eruption is said to have had an effect on the level of the Nile River, pyroclastic ash flow from the eruption formed the Valley of Ten Thousand Smokes, named by botanist Robert F. Griggs, who explored the volcanos aftermath for the National Geographic Society in 1916. The eruption forming the Valley of Ten Thousand Smokes is one of the few in recorded history to have produced welded tuff, producing numerous fumaroles that persisted for 15 years. Established as a National Park & Preserve in 1980, Katmai is located on the Alaska Peninsula, across from Kodiak Island, with headquarters in nearby King Salmon, about 290 mi southwest of Anchorage. List of volcanoes in the United States Timeline of volcanism on Earth Parícutin, a cinder cone volcano in Mexico whose emergence could be fully observed
19.
Lava dome
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In volcanology, a lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. The geochemistry of lava domes can vary from basalt to rhyolite although most preserved domes tend to have high silica content, the characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways, by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the domes have high silica content. Existence of lava domes has been suggested for some domed structures on the Martian surface in the part of Arcadia Planitia. Lava domes evolve unpredictably, due to non-linear dynamics caused by crystallization, domes undergo various processes such as growth, collapse, solidification and erosion. Lava domes grow by endogenic dome growth or exogenic dome growth, the former implies dome interior expansion to accommodate new lava and the latter refers to superficial piling up of lava. It is the viscosity of the lava that prevents it from flowing far from the vent from which it extrudes. Domes may reach heights of several hundred meters, and can grow slowly and steadily for months, years, the sides of these structures are composed of unstable rock debris. Due to the intermittent buildup of gas pressure, erupting domes can often experience episodes of explosive eruption over time, if part of a lava dome collapses while it is still molten, it can produce pyroclastic flows, one of the most lethal forms of volcanic event. Other hazards associated with domes are the destruction of property, forest fires. Lava domes are one of the structural features of many stratovolcanoes worldwide. Lava domes are prone to unusually dangerous explosions since they contain rhyolitic silica-rich lava, characteristics of lava dome eruptions include shallow, long-period and hybrid seismicity, which is attributed to excess fluid pressures in the contributing vent chamber. Other characteristics of lava domes include their hemispherical shape, cycles of dome growth over long periods. The average rate of growth may be used as a rough indicator of magma supply. A cryptodome is a structure created by accumulation of viscous magma at a shallow depth. Coulées are lava domes that have experienced some flow away from their original position, the worlds largest known dacite flow is the Chao dacite dome complex, a huge coulée flow-dome between two volcanoes in northern Chile. This flow is over 14 kilometres long, has obvious flow features like pressure ridges, there is another prominent coulée flow on the flank of Llullaillaco volcano, in Argentina, and other examples in the Andes
20.
1980 eruption of Mount St. Helens
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On May 18,1980, a major volcanic eruption occurred at Mount St. Helens, a volcano located in Skamania County, in the state of Washington, United States. The eruption was the significant volcanic eruption to occur in the contiguous 48 U. S. states since the 1915 eruption of Lassen Peak in California. However, it has often declared as the most disastrous volcanic eruption in United States history. An earthquake at 8,32,17 a. m. PDT on Sunday, May 18,1980, caused the entire weakened north face to slide away, creating the largest landslide ever recorded. An eruption column rose 80,000 feet into the atmosphere, at the same time, snow, ice and several entire glaciers on the volcano melted, forming a series of large lahars that reached as far as the Columbia River, nearly 50 miles to the southwest. Less severe outbursts continued into the day, only to be followed by other large. Approximately fifty-seven people were killed directly, including innkeeper Harry R. Truman, photographer Reid Blackburn and geologist David A. Johnston. Hundreds of square miles were reduced to wasteland, causing over a billion U. S. dollars in damage, thousands of animals were killed. At the time of the eruption, the summit of the volcano was owned by the Burlington Northern Railroad, the area was later preserved, as it was, in the Mount St. Helens National Volcanic Monument. Mount St. Helens remained dormant from its last period of activity in the 1840s and 1850s until March 1980, several small earthquakes, apparently beginning on March 15, indicated that magma may have begun moving below the volcano. Then on March 20, at 3,45 p. m. Pacific Standard Time, a total of 174 shocks of magnitude 2.6 or greater were recorded during those two days. Initially there was no sign of eruption, but small earthquake-induced avalanches of snow. At 12,36 p. m. on March 27, phreatic eruptions ejected and smashed rock from within the old crater, excavating a new crater 250 feet wide. By this date a 16, 000-foot long eastward-trending fracture system had developed across the summit area. This was followed by more earthquake swarms and a series of explosions that sent ash 10,000 to 11,000 feet above their vent. Most of this ash fell between 3 and 12 miles from its vent, but some was carried 150 miles south to Bend, Oregon, or 285 miles east to Spokane, a second, new crater and a blue flame were observed on March 29. The flame was visibly emitted from both craters and was created by burning gases. Static electricity generated from ash clouds rolling down the volcano sent out lightning bolts that were up to 2 miles long
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Mount St. Helens
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Mount St. Helens or Louwala-Clough is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 96 miles south of Seattle, Washington, and 50 miles northeast of Portland, Mount St. Helens takes its English name from the British diplomat Lord St Helens, a friend of explorer George Vancouver who made a survey of the area in the late 18th century. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc and this volcano is well known for its ash explosions and pyroclastic flows. Mount St. Helens is most notorious for its major 1980 eruption, fifty-seven people were killed,250 homes,47 bridges,15 miles of railways, and 185 miles of highway were destroyed. The debris avalanche was up to 0.7 cubic miles in volume, the Mount St. Helens National Volcanic Monument was created to preserve the volcano and allow for its aftermath to be scientifically studied. As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, the mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted. The largest of the domes formed the previous summit. Both were destroyed in the 1980 eruption, Mount St. Helens is 34 miles west of Mount Adams, in the western part of the Cascade Range. These sister and brother volcanic mountains are approximately 50 miles from Mount Rainier, Mount Hood, the nearest major volcanic peak in Oregon, is 60 miles southeast of Mount St. Helens. Mount St. Helens is geologically young compared with the other major Cascade volcanoes and it formed only within the past 40,000 years, and the pre-1980 summit cone began rising about 2,200 years ago. The volcano is considered the most active in the Cascades within the Holocene epoch, prior to the 1980 eruption, Mount St. Helens was the fifth-highest peak in Washington. It stood out prominently from surrounding hills because of the symmetry and extensive snow and ice cover of the summit cone. The peak rose more than 5,000 feet above its base, the mountain is 6 miles across at its base, which is at an elevation of 4,400 feet on the northeastern side and 4,000 feet elsewhere. At the pre-eruption tree line, the width of the cone was 4 miles. Streams that originate on the volcano enter three main systems, the Toutle River on the north and northwest, the Kalama River on the west. The streams are fed by abundant rain and snow, the average annual rainfall is 140 inches, and the snow pack on the mountains upper slopes can reach 16 feet. The Lewis River is impounded by three dams for power generation. The southern and eastern sides of the drain into an upstream impoundment, the Swift Reservoir
22.
Kinetic energy
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In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes, the same amount of work is done by the body in decelerating from its current speed to a state of rest. In classical mechanics, the energy of a non-rotating object of mass m traveling at a speed v is 12 m v 2. In relativistic mechanics, this is an approximation only when v is much less than the speed of light. The standard unit of energy is the joule. The adjective kinetic has its roots in the Greek word κίνησις kinesis, the dichotomy between kinetic energy and potential energy can be traced back to Aristotles concepts of actuality and potentiality. The principle in classical mechanics that E ∝ mv2 was first developed by Gottfried Leibniz and Johann Bernoulli, Willem s Gravesande of the Netherlands provided experimental evidence of this relationship. By dropping weights from different heights into a block of clay, Émilie du Châtelet recognized the implications of the experiment and published an explanation. The terms kinetic energy and work in their present scientific meanings date back to the mid-19th century, early understandings of these ideas can be attributed to Gaspard-Gustave Coriolis, who in 1829 published the paper titled Du Calcul de lEffet des Machines outlining the mathematics of kinetic energy. William Thomson, later Lord Kelvin, is given the credit for coining the term kinetic energy c, energy occurs in many forms, including chemical energy, thermal energy, electromagnetic radiation, gravitational energy, electric energy, elastic energy, nuclear energy, and rest energy. These can be categorized in two classes, potential energy and kinetic energy. Kinetic energy is the movement energy of an object, Kinetic energy can be transferred between objects and transformed into other kinds of energy. Kinetic energy may be best understood by examples that demonstrate how it is transformed to, for example, a cyclist uses chemical energy provided by food to accelerate a bicycle to a chosen speed. On a level surface, this speed can be maintained without further work, except to overcome air resistance, the chemical energy has been converted into kinetic energy, the energy of motion, but the process is not completely efficient and produces heat within the cyclist. The kinetic energy in the moving cyclist and the bicycle can be converted to other forms, for example, the cyclist could encounter a hill just high enough to coast up, so that the bicycle comes to a complete halt at the top. The kinetic energy has now largely converted to gravitational potential energy that can be released by freewheeling down the other side of the hill. Since the bicycle lost some of its energy to friction, it never regains all of its speed without additional pedaling, the energy is not destroyed, it has only been converted to another form by friction
23.
Pompeii
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Pompeii was an ancient Roman town-city near modern Naples, in the Campania region of Italy, in the territory of the comune of Pompei. Pompeii, along with Herculaneum and many villas in the area, was mostly destroyed and buried under 4 to 6 m of volcanic ash. Researchers believe that the town was founded in the seventh or sixth century BC by the Osci or Oscans. It came under the domination of Rome in the 4th century BC, by the time of its destruction,160 years later, its population was estimated at 11,000 people, and the city had a complex water system, an amphitheatre, gymnasium, and a port. The eruption destroyed the city, killing its inhabitants and burying it under tons of ash, the site was lost for about 1,500 years until its initial rediscovery in 1599 and broader rediscovery almost 150 years later by Spanish engineer Rocque Joaquin de Alcubierre in 1748. The objects that lay beneath the city have been preserved for centuries because of the lack of air and these artefacts provide an extraordinarily detailed insight into the life of a city during the Pax Romana. During the excavation, plaster was used to fill in the voids in the ash layers that once held human bodies and this allowed archaeologists to see the exact position the person was in when he or she died. Pompeii has been a tourist destination for over 250 years, today it has UNESCO World Heritage Site status and is one of the most popular tourist attractions in Italy, with approximately 2.5 million visitors every year. Pompeii in Latin is a second declension plural, the ruins of Pompeii are located near the modern suburban town of Pompei. It stands on a formed by a lava flow to the north of the mouth of the Sarno River. Today it is some distance inland, but in ancient times was nearer to the coast, Pompeii is about 8 km away from Mount Vesuvius. It covered a total of 64 to 67 hectares and was home to approximately 11,000 to 11,500 people on the basis of household counts and it was a major city in the region of Campania. Three sheets of sediment have been found on top of the lava that lies below the city and, mixed in with the sediment, archaeologists have found bits of bone, pottery shards. Carbon dating has placed the oldest of these layers from the 8th–6th centuries BC, the other two strata are separated either by well-developed soil layers or Roman pavement, and were laid in the 4th century BC and 2nd century BC. It is theorized that the layers of the sediment were created by large landslides. The town was founded around the 7th-6th century BC by the Osci or Oscans and it had already been used as a safe port by Greek and Phoenician sailors. According to Strabo, Pompeii was also captured by the Etruscans, and in recent excavations have shown the presence of Etruscan inscriptions. Pompeii was captured for the first time by the Greek colony of Cumae, allied with Syracuse, in the 5th century BC, the Samnites conquered it, the new rulers imposed their architecture and enlarged the town
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Herculaneum
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Located in the shadow of Mount Vesuvius, Herculaneum was an ancient Roman town destroyed by volcanic pyroclastic flows in 79 AD. Its ruins are located in the commune of Ercolano, Campania and it had been thought until then that the town had been evacuated by the inhabitants. Herculaneum was a town than Pompeii, possessing an extraordinary density of fine houses with, for example. Ancient tradition connected Herculaneum with the name of the Greek hero Herakles, in fact, it seems that some forefathers of the Samnite tribes of the Italian mainland founded the first civilization on the site of Herculaneum at the end of the 6th century BC. Soon after, the town came under Greek control and was used as a trading post because of its proximity to the Gulf of Naples, the Greeks named the city Ἡράκλειον, Heraklion. In the 4th century BC, Herculaneum again came under the domination of the Samnites. The city remained under Samnite control until it became a Roman municipium in 89 BC, when, having participated in the Social War, it was defeated by Titus Didius, a legate of Sulla. After the eruption of Mount Vesuvius in 79 AD, the town of Herculaneum was buried under approximately 20 metres of ash, excavations continued sporadically up to the present and today many streets and buildings are visible, although over 75% of the town remains buried. Today, the Italian towns of Ercolano and Portici lie on the site of Herculaneum. Until 1969 the town of Ercolano was called Resina and it changed its name to Ercolano, the Italian modernization of the ancient name in honour of the old city. The inhabitants worshipped above all Hercules, who was believed to be the founder of both the town and Mount Vesuvius, Other important deities worshipped include Venus and Apollo. The catastrophic eruption of Mt. Vesuvius occurred on the afternoon of 24 August 79 AD, because Vesuvius had been dormant for approximately 800 years, it was no longer even recognized as a volcano. Based on archaeological excavations and on two letters of Pliny the Younger to the Roman historian Tacitus, the course of the eruption can be reconstructed, at around 1pm on 24 August, Vesuvius began spewing volcanic ash and stone thousands of meters into the sky. When it reached the tropopause, the top of the cloud flattened, the prevailing winds at the time blew toward the southeast, causing the volcanic material to fall primarily on the city of Pompeii and the surrounding area. Since Herculaneum lay to the west of Vesuvius, it was only affected by the first phase of the eruption. While roofs in Pompeii collapsed under the weight of falling debris, only a few centimetres of ash fell on Herculaneum, causing little damage, during the following night, the eruptive column which had risen into the stratosphere collapsed onto Vesuvius and its flanks. The first pyroclastic surge, formed by a mixture of ash and hot gases, a succession of six flows and surges buried the citys buildings, causing little damage in some areas and preserving structures, objects and victims almost intact. In 1709 the digging of a deep well revealed some exceptional statues at the lowest levels which was found to be the site of the theatre
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Volcanology
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Volcanology is the study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena. The term volcanology is derived from the Latin word vulcan, vulcan was the ancient Roman god of fire. A volcanologist is a geologist who studies the activity and formation of volcanoes. Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra, rock and lava samples. One major focus of enquiry is the prediction of eruptions, there is no accurate way to do this. In 1841, the first volcanological observatory, the Vesuvius Observatory, was founded in the Kingdom of the Two Sicilies, surface deformation monitoring includes the use of geodetic techniques such as leveling, tilt, strain, angle and distance measurements through tiltmeters, total stations and EDMs. This also includes GNSS observations and InSAR, surface deformation indicates magma upwelling, increased magma supply produces bulges in the volcanic centers surface. Gas emissions may be monitored with equipment including portable ultra-violet spectrometers, increased gas emissions, and more particularly changes in gas compositions, may signal an impending volcanic eruption. Temperature changes are monitored using thermometers and observing changes in properties of volcanic lakes and vents. Satellites are widely used to monitor volcanoes, as they allow an area to be monitored easily. They can measure the spread of an ash plume, such as the one from Eyjafjallajokulls 2010 eruption, InSAR and thermal imaging can monitor large, scarcely populated areas where it would be too expensive to maintain instruments on the ground. Stratigraphic analyses includes analyzing tephra and lava deposits and dating these to give volcano eruption patterns, with estimated cycles of intense activity and size of eruptions. The earliest known recording of an eruption may be on a wall painting dated to about 7,000 BCE found at the Neolithic site at Çatal Höyük in Anatolia. This painting has been interpreted as a depiction of a volcano, with a cluster of houses below shows a twin peaked volcano in eruption. The volcano may be either Hasan Dağ, or its smaller neighbour, the classical world of Greece and the early Roman Empire explained volcanoes as sites of various gods. Greeks considered that Hephaestus, the god of fire, sat below the volcano Etna, the Greek word used to describe volcanoes was etna, or hiera, after Heracles, the son of Zeus. Enceladus brother Mimas was buried beneath Vesuvius by Hephaestus, and the blood of other defeated giants welled up in the Phlegrean Fields surrounding Vesuvius, the Greek philosopher Empedocles saw the world divided into four elemental forces, of Earth, Air, Fire and Water. Volcanoes, Empedocles maintained, were the manifestation of Elemental Fire, plato contended that channels of hot and cold waters flow in inexhaustible quantities through subterranean rivers
26.
Katia and Maurice Krafft
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Katia Krafft and her husband, Maurice Paul Krafft, were French volcanologists who died in a pyroclastic flow on Mount Unzen, in Japan, on June 3,1991. The Kraffts were known for being pioneers in filming, photographing and recording volcanoes and their obituary appeared in the Bulletin of Volcanology. Katia Conrad and Maurice Krafft met at the University of Strasbourg, with little money, they saved up for a trip to Stromboli and photographed its near-continuous eruption. Finding that people were interested in this documentation of eruptions, they made a career out of this. The Kraftts were often the first to be at an active volcano and their footage of the effects of volcanic eruptions was a considerable factor in gaining the cooperation of local authorities faced with volcanic threats. They were killed instantly along with 41 other people, including fellow volcanologist Harry Glicken, several firemen, the work of the Kraffts was highlighted in a video issue of National Geographic, which contained a large amount of their film footage and photographs as well as interviews with both. A volcanic crater, M. and K. Krafft Crater, of the volcano Piton de la Fournaise on the island of Reunion, is named after Maurice, the crater is located at 21°13′23″S 55°43′2″E. Lava erupted from this crater in March 1998, guide des volcans d’Europe, généralités, France, Islande, Italie, Grèce, Allemagne. Neuchâtel, Delachaux et Niestlé,1974,412 pp
27.
Mount Unzen
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Mount Unzen is an active volcanic group of several overlapping stratovolcanoes, near the city of Shimabara, Nagasaki Prefecture, on the island of Kyūshū, Japans southernmost main island. In 1792, the collapse of one of its several lava domes triggered a megatsunami that killed 14,524 people in Japans worst-ever volcanic-related disaster. The volcano was most recently active from 1990 to 1995, currently its highest peaks are Fugen-dake at 1,359 metres and Heisei-shinzan at 1,486 metres. The latter emerged during the eruptions of the early, eponymous Heisei era, Mount Unzen is part of Shimabara Peninsula, which has seen extensive volcanism over millions of years. The oldest volcanic deposits in the date from over 6 million years ago. The origins of the Unzen complex are traced to the formation of a graben through crustal faulting and this caused parts of the peninsula to subside by up to 1,000 metres below sea level and may have caused eruptive activity to localize at one site inside the graben. Eruptions of dacitic lava began from a site slightly to the south of todays Mount Unzen, the volcano rapidly grew during its first 200,000 years, forming a large cone. Later eruptions over the following 150,000 years filled in much of the graben, initially, activity was dominated by blocky andesitic lava and ash flows, changing to dacitic pumice flows and airfall deposits from 500,000 to 400,000 years ago. The period from 400,000 to 300,000 years ago saw the emplacement of large areas of flow and lahar deposits. Beginning 300,000 to 150,000 years ago, thick phreatomagmatic deposits were laid down, Fugen-dake has been the site of most eruptions during the past 20,000 years and lies about 6 kilometres from the center of Shimabara. Unzens deadliest eruption occurred in 1792, with a large lava flow coming from Fugen-dake. The east flank of the Mayu-yama dome collapsed unexpectedly following a post-eruption earthquake and this caused a megatsunami that reached a height of 100 metres, and killed an estimated 15,000 people. As of 2011 it is the worst volcanic related eruption in Japan, after 1792, the volcano remained dormant until November 1989 when an earthquake swarm began about 20 kilometres underneath and 10 kilometres west of Fugendake. Over the following year, earthquakes continued, their hypocentres gradually migrating towards the summit, the first phreatic eruptions began in November 1990, and after inflation of the summit area, fresh lava began to emerge on May 20,1991. The threat of further disastrous events prompted authorities to evacuate 12,000 local residents from their homes, on June 3,1991, the volcano erupted violently, possibly as a result of depressurisation of the magma column after a landslide in the crater. Between 1991 and 1994 the volcano generated at least 10,000 small pyroclastic flows, from 1993 onward, the rate of lava effusion gradually decreased, and eruptions came to an end in 1995. Since then heavy rains have frequently remobilised pyroclastic material, generating lahars, dikes have been constructed in several river valleys to channel lahar flows away from vulnerable areas, and warning systems and evacuation plans have been developed and deployed. In 1999, a project began at Mount Unzen to drill deep inside the volcano
28.
Caribbean
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The Caribbean is a region that consists of the Caribbean Sea, its islands and the surrounding coasts. The region is southeast of the Gulf of Mexico and the North American mainland, east of Central America, situated largely on the Caribbean Plate, the region comprises more than 700 islands, islets, reefs and cays. These islands generally form island arcs that delineate the eastern and northern edges of the Caribbean Sea, in a wider sense, the mainland countries of Belize, Guyana, Suriname and French Guiana are often included due to their political and cultural ties with the region. Geopolitically, the Caribbean islands are usually regarded as a subregion of North America and are organized into 30 territories including sovereign states, overseas departments, and dependencies. From December 15,1954, to October 10,2010, there was a known as the Netherlands Antilles composed of five states. The West Indies cricket team continues to represent many of those nations, the region takes its name from that of the Caribs, an ethnic group present in the Lesser Antilles and parts of adjacent South America at the time of the Spanish conquest. The two most prevalent pronunciations of Caribbean are KARR-ə-BEE-ən, with the accent on the third syllable. The former pronunciation is the older of the two, although the variant has been established for over 75 years. It has been suggested that speakers of British English prefer KARR-ə-BEE-ən while North American speakers more typically use kə-RIB-ee-ən, usage is split within Caribbean English itself. The word Caribbean has multiple uses and its principal ones are geographical and political. The Caribbean can also be expanded to include territories with strong cultural and historical connections to slavery, European colonisation, the United Nations geoscheme for the Americas accords the Caribbean as a distinct region within the Americas. Physiographically, the Caribbean region is mainly a chain of islands surrounding the Caribbean Sea, to the north, the region is bordered by the Gulf of Mexico, the Straits of Florida and the Northern Atlantic Ocean, which lies to the east and northeast. To the south lies the coastline of the continent of South America, politically, the Caribbean may be centred on socio-economic groupings found in the region. For example, the known as the Caribbean Community contains the Co-operative Republic of Guyana. Bermuda and the Turks and Caicos Islands, which are in the Atlantic Ocean, are members of the Caribbean Community. The Commonwealth of the Bahamas is also in the Atlantic and is a member of the Caribbean Community. According to the ACS, the population of its member states is 227 million people. The geography and climate in the Caribbean region varies, Some islands in the region have relatively flat terrain of non-volcanic origin and these islands include Aruba, Barbados, Bonaire, the Cayman Islands, Saint Croix, the Bahamas, and Antigua
29.
Montserrat
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Montserrat is a Caribbean island—specifically in the Leeward Islands, which is part of the chain known as the Lesser Antilles, in the British West Indies. It is a British Overseas Territory, Montserrat measures approximately 16 km long and 11 km wide, with approximately 40 km of coastline. Montserrat is nicknamed The Emerald Isle of the Caribbean both for its resemblance to coastal Ireland and for the Irish ancestry of many of its inhabitants, on 18 July 1995, the previously dormant Soufrière Hills volcano, in the southern part of the island, became active. Eruptions destroyed Montserrats Georgian era capital city of Plymouth, between 1995 and 2000, two-thirds of the islands population was forced to flee, primarily to the United Kingdom, leaving fewer than 1,200 people on the island as of 1997. Visitors are generally not permitted entry into the zone. Relatively quiet since early 2010, the continues to be closely monitored by the Montserrat Volcano Observatory. It is the most studied volcano in the world and Montserrat has been regarded as a Modern Day Pompeii in the Caribbean, a new town and port is being developed at Little Bay, which is on the northwest coast of the island. While this construction proceeds, the centre of government and businesses is at Brades, in 1493, Christopher Columbus named the island Santa María de Montserrate, after the Virgin of Montserrat in the Monastery of Montserrat, on Montserrat mountain, near Barcelona in Catalonia, Spain. Montserrat means serrated mountain in Catalan, archaeological field work in 2012, in Montserrats Centre Hills indicated there was an Archaic occupation between 4000 and 2500 BP. Later coastal sites show the presence of the Saladoid culture, in November 1493, Christopher Columbus passed Montserrat in his second voyage, after being told that the island was unoccupied due to raids by the Caribs. A number of Irishmen settled in Montserrat in 1642, the island was captured by the French in 1666. It was captured shortly afterwards by the English and English control of the island was confirmed under the Treaty of Breda the following year, despite the interruption to English rule, the islands legal status is that of a colony acquired by settlement. A neo-feudal colony developed amongst the redlegs, the colonists began to transport Sub-Saharan African slaves for labour, as was common to most Caribbean islands. The colonists built an economy based on the production of sugar, rum, arrowroot and sea island cotton, by the late 18th century, numerous plantations had been developed on the island. Many Irish continued to be transported to the island, to work as indentured servants, on 17 March 1768, slaves rebelled but failed to achieve freedom. The people of Montserrat celebrate St Patricks Day as a public holiday due to the slave revolt, festivities held that week commemorate the culture of Montserrat in song, dance, food and traditional costumes. In 1782, during the American Revolutionary War, France briefly captured Montserrat after supporting the American rebels, the French returned the island to Great Britain under the 1783 Treaty of Paris, which ended that conflict. The Irish constituted the largest proportion of the population from the founding of the colony in 1628
30.
1883 eruption of Krakatoa
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The 1883 eruption was one of the deadliest and most destructive volcanic events in recorded history. At least 36,417 deaths are attributed to the eruption, significant additional effects were also felt around the world in the days and weeks after the volcanos destruction. In the years before the 1883 eruption, seismic activity around the Krakatoa volcano was intense, beginning May 20,1883, steam venting began to occur regularly from Perboewatan, the northernmost of the islands three cones. Eruptions of ash reached an altitude of 6 km and explosions could be heard in New Batavia 160 km away. Activity died down by the end of May, and there was no recorded activity for several weeks. Eruptions at Krakatoa started again around June 16, with loud explosions, on June 24, a prevailing east wind cleared the cloud, and two ash columns could be seen issuing from Krakatoa. The seat of the eruption is believed to have been a new vent or vents that formed between Perboewatan and Danan, the violence of the ongoing eruptions caused tides in the vicinity to be unusually high, and ships at anchor had to be moored with chains. Earthquakes were felt at Anyer, Banten, and ships began to report large pumice masses to the west in the Indian Ocean, on August 11, a Dutch topographical engineer, Captain H. J. G. Ferzenaar, investigated the Krakatoa islands. He noted three major ash columns, which obscured the western part of the island, and steam plumes from at least eleven other vents, mostly between Danan and Rakata. When he landed, he noted an ash layer about 0.5 m thick, and he advised against any further landings. The next day, a passing to the north reported a new vent only a few meters above sea level. By August 25, the Krakatoa eruptions intensified, at about 13,00 on August 26, the volcano went into its paroxysmal phase. By 14,00, a cloud of ash could be seen 27 km high. At this point, the eruption was virtually continuous and explosions could be heard every ten minutes or so, ships within 20 km of the volcano reported heavy ash fall, with pieces of hot pumice up to 10 cm in diameter landing on their decks. Between 18,00 and 19,00 hours, a tsunami hit the shores of Java and Sumatra. On August 27, four enormous explosions occurred, at 5,30 am, the first explosion was at Perboewatan, triggering a tsunami heading straight to Telok Betong, now known as Bandar Lampung. At 6,44 am, Krakatoa exploded again at Danan, the third explosion has been reported as the loudest sound heard in historic times. The loudness of the blast heard 160 km from the volcano has been calculated to have been 180 dB, each explosion was accompanied by tsunamis estimated to have been over 30 meters high in places
31.
Sumatra
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Sumatra is a large island in western Indonesia that is part of the Sunda Islands. It is the largest island that is entirely in Indonesia and the sixth-largest island in the world at 473,481 km2, Sumatra is an elongated landmass spanning a diagonal northwest-southeast axis. The Indian Ocean borders the west, northwest, and southwest sides of Sumatra with the chain of Simeulue, Nias. On the northeast side the narrow Strait of Malacca separates the island from the Malay Peninsula, on the southeast the narrow Sunda Strait separates Sumatra from Java. The northern tip of Sumatra borders the Andaman Islands, while on the eastern side are the islands of Bangka and Belitung, Karimata Strait. The Bukit Barisan mountains, which several active volcanoes, form the backbone of the island, while the northeast sides are outlying lowlands with swamps, mangrove. The equator crosses the island at its center on West Sumatra, the climate of the island is tropical, hot and humid with lush tropical rain forest once dominating the landscape. Sumatra was known in ancient times by the Sanskrit names of Swarnadwīpa and Swarnabhūmi, the first word mentioning the name of Sumatra was the name of Srivijayan Haji Sumatrabhumi, who sent an envoy to China in 1017. Arab geographers referred to the island as Lamri in the tenth through thirteenth centuries, late in the 14th century the name Sumatra became popular in reference to the kingdom of Samudra Pasai, which was a rising power until it was replaced by Sultanate of Aceh. Sultan Alauddin Shah of Aceh, on letters written in 1602 addressed to Queen Elizabeth I of England, referred to himself as king of Aceh, the word itself is from Sanskrit Samudra, meaning gathering together of waters, sea or ocean. European writers in the 19th century found that the inhabitants did not have a name for the island. The Melayu Kingdom was absorbed by Srivijaya, Srivijaya was a Buddhist monarchy centred in what is now Palembang. Dominating the region trade and conquest throughout the 7th to 9th centuries. The empire was a thalassocracy or maritime power that extended its influence from island to island, Palembang was a center for scholarly learning, and it was there the Chinese Buddhist pilgrim I Ching studied Sanskrit in 671 CE before departing for India. On his journey to China, he spent four years in Palembang translating Buddhist texts, Srivijayan influence waned in the 11th century after it was defeated by the Chola Empire of southern India. At the same time, Islam made its way to Sumatra through Arabs, by the late 13th century, the monarch of the Samudra kingdom had converted to Islam. Marco Polo visited the island in 1292, and Ibn Battuta visited twice during 1345–1346, Samudra was succeeded by the powerful Aceh Sultanate, which survived to the 20th century. With the coming of the Dutch, the many Sumatran princely states fell under their control
32.
University of Kiel
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The University of Kiel is a university in the city of Kiel, Germany. It was founded in 1665 as the Academia Holsatorum Chiloniensis by Christian Albert, the University of Kiel is the largest, oldest, and most prestigious in the state of Schleswig-Holstein. Until 1864/66 it was not only the northernmost university in Germany, faculty, alumni, and researchers of the University of Kiel have won 12 Nobel Prizes. The University of Kiel is a member of the German Universities Excellence Initiative since 2006, the Cluster of Excellence The Future Ocean, which was established in cooperation with the GEOMAR Helmholtz Centre for Ocean Research Kiel in 2006, is internationally recognized. The second Cluster of Excellence Inflammation at Interfaces deals with chronic inflammatory diseases, the world-renowned Kiel Institute for the World Economy is also affiliated with the University of Kiel. The University of Kiel was founded under the name Christiana Albertina on 5 October 1665 by Christian Albert, but those in the city who envisioned economic advantages of a university in the city won, and Kiel thus became the northernmost university in the German Holy Roman Empire. After 1773, when Kiel had come under Danish rule, the university began to thrive, and when Kiel became part of Prussia in the year 1867, the university grew rapidly in size. The university opened one of the first botanical gardens in Germany, during World War II, the University of Kiel suffered heavy damage, therefore it was later rebuilt at a different location with only a few of the older buildings housing the medical school. Dr. Doris König, current judge of the Federal Constitutional Court of Germany, Germanys highest court Dr
33.
Lahar
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A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley, lahars are extremely destructive, they can flow tens of metres per second, be 140 metres deep, and destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the word lahar is the Javanese term for flowing lava. A lahar is a volcanic mudflow or debris flow, lahars have the consistency, viscosity and approximate density of wet concrete, fluid when moving, solid at rest. Lahars can be huge.3 cubic kilometres, a lahar of sufficient size and intensity can erase virtually any structure in its path, and is capable of carving its own pathway, making the prediction of its course difficult. Conversely, a lahar quickly loses force when it leaves the channel of its flow, even frail huts may remain standing, a lahars viscosity decreases with time, and can be further thinned by rain, but it nevertheless solidifies quickly when coming to a stop. Lahars vary in size and speed, small lahars less than a few metres wide and several centimetres deep may flow a few metres per second. Large lahars hundreds of metres wide and tens of metres deep can flow tens of metres per second. With the potential to flow at speeds up to 100 kilometres per hour, and flow distances of more than 300 kilometres, a lahar can cause catastrophic destruction in its path. Lahars from the 1985 Nevado del Ruiz eruption in Colombia caused the Armero tragedy, which killed an estimated 23,000 people, a lahar caused New Zealands Tangiwai disaster, where 151 people died after a Christmas Eve express train fell into the Whangaehu River in 1953. Lahars have been responsible for 17% of volcano-related deaths between 1783 and 1997, a lahar can cause fatalities years after its precipitating eruption. For example, the Cabalantian tragedy occurred four years subsequent to the 1991 eruption of Mount Pinatubo, the word lahar is of Indonesian origin. Lahars have several causes, Snow and glaciers can be melted by lava or pyroclastic flows during an eruption. Lava flows out of vents and can mix with wet soil and mud on the slope of the volcano making a very viscous. A flood caused by a glacier, lake breakout, or heavy rainfall can release a lahar, also called glacier run or jökulhlaup Water from a crater lake, heavy rainfall on unconsolidated pyroclastic deposits. Snow and glaciers can melt during periods of mild weather Earthquakes underneath or close to the volcano can shake material loose and cause it to collapse triggering a lahar avalanche. Rainfall can cause the still-hanging slabs of solidified mud to come rushing down the slopes at a speed of more than 30 kilometres per hour, causing devastating results. Several towns in the Puyallup River valley in Washington state, including Orting, are built on top of lahar deposits that are only about 500 years old
34.
Rille
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Rille is typically used to describe any of the long, narrow depressions in the surface of the Moon that resemble channels. The Latin term is rima, plural rimae, typically a rille can be up to several kilometers wide and hundreds of kilometers in length. However, the term has also used loosely to describe similar structures on a number of planets in the Solar System, including Mars, Venus. All bear a resemblance to each other. They usually begin at a volcano, then meander and sometimes split as they are followed across the surface. Vallis Schröteri in Oceanus Procellarum is the largest sinuous rille, and Rima Hadley is the one visited by humans. Another prominent example is Rima Herigonius, arcuate rilles have a smooth curve and are found on the edges of the dark lunar maria. They are believed to form when the flows that created a mare cool, contract. These are found all over the moon, examples can be seen near the border of Mare Tranquillitatis. Rima Sulpicius Gallus is an example in southwestern Mare Serenitatis. Straight rilles follow long, linear paths and are believed to be grabens, sections of the crust that have sunk between two parallel faults and these can be readily identified when they pass through craters or mountain ranges. Rilles which show more than one structure are termed hybrid rilles, Rima Hyginus in Sinus Medii is an example, initially formed through a fault and subsequently subject to volcanic activity. Precise formation mechanisms of rilles have yet to be determined and it is likely that different types formed by different processes. Common features shared by lunar rilles and similar structures on other bodies suggest that common causative mechanisms operate widely in the solar system. Leading theories include lava channels, collapsed lava tubes, near-surface dike intrusion, nuée ardente, subsidence of lava-covered basin and crater floors, on-site examination would be necessary to clarify exact methods. According to NASA, the origin of lunar sinuous rilles remains controversial, the Hadley Rille is a 1.5 km wide and over 300 m deep sinuous rille. It is thought to be a giant conduit that carried lava from an eruptive vent far to the south, topographic information obtained from the Apollo 15 photographs supports this possibility, however, many puzzles about the rille remain. Arachnoid Chaos terrain Dark dune spot List of features on the Moon Lunar lava tube Martian spiders Planetary geology Splitting of the moon General
35.
Moon
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The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
36.
Schroter's Valley
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Schroters Valley, frequently known by the Latinized name Vallis Schröteri, is a sinuous valley or rille on the surface of the near side of the Moon. It is located on a rise of ground, sometimes called the Aristarchus plateau, that is surrounded by the Oceanus Procellarum to the south and west. At the southern edge of this rise are the craters Aristarchus and Herodotus and this is the largest sinuous rille on the Moon. It begins at a 6 km diameter crater located 25 km to the north of Herodotus, the rille has a maximum width of about 10 km, then gradually narrows to less than a kilometer near its terminus. The origins of this rille are believed to be volcanic, the interior floor has been resurfaced and is very level. However there is a slender rille located on the floor, which can be photographed from Earth with a good telescope, the rille has been the subject of numerous transient lunar phenomena observations. The selenographic coordinates of this valley are 26. 2°N50. 8°W /26.2, -50.8 and it is named for Johannes H. Schröter. It was a landing site for the canceled Apollo 18 mission
37.
Pyroclastic fall
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A pyroclastic fall is a uniform deposit of material which has been ejected from a volcanic eruption or plume such as an ash fall or tuff. They exhibit mantle bedding—the deposits directly overlie pre-existing topography and maintain a uniform thickness over relatively short distances, sorting by size is more pronounced than pyroclastic surge or pyroclastic flows. Early settling of crystals and lithic fragments near an eruptive vent, the St Vincent eruption in 1902 ejected a large eruption column which when settled near the vent contained 73% crystals, and ash deposited in Jamaica 1,600 km away consisted entirely of glass dust. The distribution of pyroclastic ash depends largely on the direction of wind at intermediate, the general trend of pyroclastic dispersal is shown using isopachs and show the dispersal as elongated with wind direction. The Krakatoa eruption of 1883 produced a column which rose to more than 50 km. An ash flow from this explosion was recognised 2,500 km west of the volcano, the total area of recognisable pyroclastic fall was greater than 800,000 km². The pyroclastic ash encircled the globe in 13.5 days, the ash remained in the upper atmosphere and produced brilliant sunsets for many years, lowered the global temperature by 0.5 °C for at least five years. This is commonly known as an inversion of the magma chamber, the 79 AD eruption of Mount Vesuvius produced the Pompeii Pumice which is an example of lateral and vertical variations. The deposit is well sorted with density and size of pumice, the bottom layer of the pumice is white felsic rich pumice with a darker grey mafic pumice overlying it. These changes represent the increasing vigour of the eruption, the mafic upper part of the deposit reflects the increasing depth of the origin or compositionally zoned magma chamber. This unit represents an inversion of the chamber as progressively deeper materials from the chamber were tapped as the eruption progressed. Pyroclastic flow Pyroclastic rock Pyroclastic surge
38.
Pyroclastic rock
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Pyroclastic rocks or pyroclastics are clastic rocks composed solely or primarily of volcanic materials. Where the volcanic material has been transported and reworked through mechanical action, such as by wind or water, pyroclastic rocks may be a range of clast sizes, from the largest agglomerates, to very fine ashes and tuffs. Pyroclasts of different sizes are classified as bombs, lapilli. Ash is considered to be pyroclastic because it is a fine dust made up of volcanic rock, one of the most spectacular forms of pyroclastic deposit are the ignimbrites, deposits formed by the high-temperature gas-and-ash mix of a pyroclastic flow event. Three modes of transport can be distinguished, pyroclastic flow, pyroclastic surge, during Plinian eruptions, pumice and ash are formed when silicic magma is fragmented in the volcanic conduit, because of decompression and the growth of bubbles. Pyroclasts are then entrained in a buoyant eruption plume which can rise several kilometers into the air, particles falling from the eruption clouds form layers on the ground. Pyroclastic density currents, which are referred to as flows or surges depending on particle concentration, the deposits of pumice-rich pyroclastic flows can be called ignimbrites. A pyroclastic eruption entails spitting or fountaining lava, where the lava will be thrown into the air along with ash, pyroclastic materials, hawaiian eruptions such as those at Kīlauea can eject clots of magma suspended into gas, this is called a fire fountain. The magma clots, if hot enough may coalesce upon landing to form a lava flow, pyroclastic deposits consist of pyroclasts which are not cemented together. Pyroclastic rocks are pyroclastic deposits which have been lithified
39.
Tuff
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Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is compacted into a rock in a process called consolidation. Tuff is sometimes called tufa, particularly used as construction material. Rock that contains greater than 50% tuff is considered tuffaceous, Tuff is a relatively soft rock, so it has been used for construction since ancient times. Since it is common in Italy the Romans used it often for construction, the Rapa Nui people used it to make most of the moai statues in Easter Island. Tuff can be classified as either sedimentary or igneous rocks and they are usually studied in the context of igneous petrology, although they are sometimes described using sedimentological terms. The material that is expelled in a volcanic eruption can be classified into three types, Volcanic gases, a mixture mostly of water vapour, carbon dioxide. Lava, the name of magma when it emerges and flows over the surface, and tephra, chunks of solid material of all shapes and sizes ejected and thrown through the air. Tephra is made when magma inside the volcano is blown apart by the expansion of hot volcanic gases. It is common for magma to explode as the gas dissolved in it comes out of solution as the pressure decreases when it flows to the surface and these violent explosions produce solid chunks of material that can then fly from the volcano. When these chunks are smaller than 2 mm in diameter they are called volcanic ash and it is made of small, slaggy pieces of lava and rock that have been tossed into the air by outbursts of steam and other gases. Among the loose beds of ash that cover the slopes of many volcanoes, in addition to true ashes of the kind described above, there are lumps of the old lavas and tuffs forming the walls of the crater, etc. In some great volcanic explosions nothing but materials of the kind were emitted. The ashes vary in size from large blocks twenty feet or more in diameter to the minutest impalpable dust, the large masses are called volcanic bombs, they have mostly a rounded, elliptical or pear-shaped form owing to rotation in the air before they solidified. Many of them have ribbed or nodular surfaces, and sometimes they have a crust intersected by many cracks like the surface of a loaf of bread, any ash in which they are very abundant is called an agglomerate. But many volcanoes stand near the sea, and the ashes cast out by them are mingled with the sediments that are gathering at the bottom of the waters, in this way ashy muds or sands or even in some cases ashy limestones are being formed. As a matter of fact most of the found in the older formations contain admixtures of clay, sand, and sometimes fossil shells. The showers of ashes often follow one another after longer or shorter intervals, the coarsest materials or agglomerates show this least distinctly, in the fine beds it is often developed in great perfection
40.
Bulletin of Volcanology
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The Bulletin of Volcanology is a peer reviewed scientific journal that is published ten times per year by Springer Science+Business Media. It is the journal of the International Association of Volcanology. The focus of the journal is volcanoes, volcanic products, eruptive behavior, the Executive Editor is James DL White. The impact factor for Bulletin of Volcanology in 2011 is 2.205, applying geochemical, petrological, and geophysical techniques to understand volcanic systems and their evolution is part of this journals focus. Publishing formats include original papers, reviews, communications. Additionally, this journal is a continuation of Bulletin Volcanologique which was published first in 1922, in 1986 Springer-Verlag started publishing this journal with Volume 48
41.
IMDb
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In 1998 it became a subsidiary of Amazon Inc, who were then able to use it as an advertising resource for selling DVDs and videotapes. As of January 2017, IMDb has approximately 4.1 million titles and 7.7 million personalities in its database, the site enables registered users to submit new material and edits to existing entries. Although all data is checked before going live, the system has open to abuse. The site also featured message boards which stimulate regular debates and dialogue among authenticated users, IMDb shutdown the message boards permanently on February 20,2017. Anyone with a connection can read the movie and talent pages of IMDb. A registration process is however, to contribute info to the site. A registered user chooses a name for themselves, and is given a profile page. These badges range from total contributions made, to independent categories such as photos, trivia, bios, if a registered user or visitor happens to be in the entertainment industry, and has an IMDb page, that user/visitor can add photos to that page by enrolling in IMDbPRO. Actors, crew, and industry executives can post their own resume and this fee enrolls them in a membership called IMDbPro. PRO can be accessed by anyone willing to pay the fee, which is $19.99 USD per month, or if paid annually, $149.99, which comes to approximately $12.50 per month USD. Membership enables a user to access the rank order of each industry personality, as well as agent contact information for any actor, producer, director etc. that has an IMDb page. Enrolling in PRO for industry personnel, enables those members the ability to upload a head shot to open their page, as well as the ability to upload hundreds of photos to accompany their page. Anyone can register as a user, and contribute to the site as well as enjoy its content, however those users enrolled in PRO have greater access and privileges. IMDb originated with a Usenet posting by British film fan and computer programmer Col Needham entitled Those Eyes, others with similar interests soon responded with additions or different lists of their own. Needham subsequently started an Actors List, while Dave Knight began a Directors List, and Andy Krieg took over THE LIST from Hank Driskill, which would later be renamed the Actress List. Both lists had been restricted to people who were alive and working, the goal of the participants now was to make the lists as inclusive as possible. By late 1990, the lists included almost 10,000 movies and television series correlated with actors and actresses appearing therein. On October 17,1990, Needham developed and posted a collection of Unix shell scripts which could be used to search the four lists, at the time, it was known as the rec. arts. movies movie database
42.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
