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Galeras Castle
Galeras (Urcunina among the 16th-century indigenous people) is an Andean stratovolcano in the Colombian department of Nariño, near the departmental capital Pasto. Its summit rises above sea level. It has erupted frequently since the Spanish conquest, with its first historical eruption being recorded on December 7, 1580. A 1993 eruption killed nine people, including six scientists who had descended into the volcano's crater to sample gases and take gravity measurements in an attempt to be able to predict future eruptions. It is currently the most active volcano in Colombia. Geological history Galeras has been an active volcano for at least a million years, with andesite as the dominant product. Two major caldera-forming eruptions have occurred, the first about 560,000 years ago in an eruption which expelled about of material. The second some time between 40,000 and 150,000 years ago, in a smaller but still sizable eruption of of material. Subsequently, part of the caldera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decade Volcano
The Decade Volcanoes are 16 volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study in light of their history of large, destructive eruptions and proximity to densely populated areas. The Decade Volcanoes project encourages studies and public-awareness activities at these volcanoes, with the aim of achieving a better understanding of the volcanoes and the dangers they present, and thus being able to reduce the severity of natural disasters. They are named Decade Volcanoes because the project was initiated in the 1990s as part of the United Nations–sponsored International Decade for Natural Disaster Reduction. A volcano may be designated a Decade Volcano if it exhibits more than one volcanic hazard (people living near the Decade Volcanoes may experience tephra fall, pyroclastic flows, lava flows, lahars, volcanic edifice instability and lava dome collapse); shows recent geolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Correlation
In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics it usually refers to the degree to which a pair of variables are '' linearly'' related. Familiar examples of dependent phenomena include the correlation between the height of parents and their offspring, and the correlation between the price of a good and the quantity the consumers are willing to purchase, as it is depicted in the so-called demand curve. Correlations are useful because they can indicate a predictive relationship that can be exploited in practice. For example, an electrical utility may produce less power on a mild day based on the correlation between electricity demand and weather. In this example, there is a causal relationship, because extreme weather causes people to use more electricity for heating or cooling. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tornillo Event
A tornillo event is a low-frequency seismic event associated with volcanoes. The term, which means "screw" in Spanish, was coined in the mid-1990s at the Observatorio Vulcanológico y Sismológico de Pasto (OVSP) in Pasto, Colombia to describe seismic events seen at the Galeras volcano. A tornillo has the following characteristics that distinguish it from other seismic events: * very limited distribution of frequencies (monochromatic) * a long coda Coda or CODA may refer to: Arts, entertainment, and media Films * Movie coda, a post-credits scene * ''Coda'' (1987 film), an Australian horror film about a serial killer, made for television *''Coda'', a 2017 American experimental film from Na ... that decays slowly * small amplitude Like volcanic tremor, tornillos are thought to be caused by magma moving at depth. ReferencesTornillo-type seismic signals at Galeras volcano, Colombia, 1992−1993 External linksObservatorio Vulcanológico y Sismológico de Pasto - INGEOMINAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as '' tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galeras Volcano
Galeras (Urcunina among the 16th-century indigenous people) is an Andean stratovolcano in the Colombian department of Nariño, near the departmental capital Pasto. Its summit rises above sea level. It has erupted frequently since the Spanish conquest, with its first historical eruption being recorded on December 7, 1580. A 1993 eruption killed nine people, including six scientists who had descended into the volcano's crater to sample gases and take gravity measurements in an attempt to be able to predict future eruptions. It is currently the most active volcano in Colombia. Geological history Galeras has been an active volcano for at least a million years, with andesite as the dominant product. Two major caldera-forming eruptions have occurred, the first about 560,000 years ago in an eruption which expelled about of material. The second some time between 40,000 and 150,000 years ago, in a smaller but still sizable eruption of of material. Subsequently, part of the ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasto
Pasto, officially San Juan de Pasto (; "Saint John of Pasto"), is the capital of the department of Nariño, in southern Colombia. Pasto was founded in 1537 and named after indigenous people of the area. In the 2018 census, the city had approximately 480.000 inhabitants. Pasto is located in the Atriz Valley on the Andes cordillera, at the foot of the Galeras volcano. History The etymology of the word ''Pasto'' can be traced to the indigenous people who inhabited the region at the arrival of the Spanish conquerors, the Pastos. However, the Atriz Valley itself was inhabited by the Quillacingas. In the 2018 Colombian census, 163,873 people self-identified as Pasto, and in the 2010 Ecuadorian census, 1,409 people self-identified as Pasto. Pasto was founded in 1537 by the Spanish conquistador Sebastián de Belalcázar. In 1539 Lorenzo de Aldana, also a Spanish conquistador, moved the city to its current location, and established it under the name "San Juan de Pasto". A majo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lahar
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent 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, they have been known to be up to deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the latter of which killed thousands of people in the town of Armero. Etymology The word ''lahar'' is of Javanese origin. Berend George Escher introduced it as a geological term in 1922. Description The word ''lahar'' is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of but is capable of reaching speeds up to . The gases and tephra can reach temperatures of about . Pyroclastic flows are the most deadly of all volcanic hazards and are produced as a result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Origin of term The word ''pyroclast'' is derived from the Greek (''pýr''), meaning "fire", and (''klastós''), meaning "broken in pieces". A name for pyroclastic flows which glow red in the dark is (French, "burning cloud"); this was notably used to describe the disastrous 1902 eruption of Mount Pelée on Martinique, a Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anno Domini
The terms (AD) and before Christ (BC) are used to label or number years in the Julian and Gregorian calendars. The term is Medieval Latin and means 'in the year of the Lord', but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "''anno Domini nostri Jesu Christi''", which translates to 'in the year of our Lord Jesus Christ'. The form "BC" is specific to English and equivalent abbreviations are used in other languages: the Latin form is but is rarely seen. This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus, ''AD'' counting years from the start of this epoch and ''BC'' denoting years before the start of the era. There is no year zero in this scheme; thus ''the year AD 1 immediately follows the year 1 BC''. This dating system was devised in 525 by Dionysius Exiguus, but was not widely used until the 9th century. Traditionally, English follows Latin usage by placing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
