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Search Results: 1 - 10 of 15311 matches for " MARCO CISTERNAS "
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Suelos enterrados revelan la prehistoria sísmica del centro-sur de Chile durante los últimos dos milenios
Marco Cisternas
Revista de Geografía, Norte Grande , 2005,
Abstract: Se presentan las principales lecciones obtenidas durante tres a os de investigación paleosismológica en el centro sur de Chile. Gracias a estas claves, un equipo conformado por investigadores nacionales, nor-te americanos y japoneses, en el marco del proyecto Fondecyt No1020224 "Evidencias sedimentarias de eventos catastróficos naturales para la determinación de su periodicidad y riesgo", reconstruyeron la prehistoria de grandes terremotos y tsunamis ocurridos durante los últi-mos 2.000 a os en esta parte de Chile. Sobre la base de los resultados,se propone una nueva tasa de recurrencia para dichos eventos. Parale-lamente, se plantea una explicación a la enormidad del terremoto Chi-leno de 1960.
El terremoto de 1647 de Chile central como un evento intraplaca: otra amenaza para Chile metropolitano?
Marco Cisternas
Revista de Geografía, Norte Grande , 2012,
Abstract: El terremoto del 13 de mayo de 1647, la mayor catástrofe en la historia colonial de Chile central, es considerado como el segundo evento de la secuencia de terremotos interplaca que ha ocurrido con una sorprendente regularidad en esta parte de Chile. Sin embargo, el análisis histórico realizado sugiere que este terremoto, además de generar un enérgico y extenso sacudimiento en el valle central, no habría producido un tsunami. Ambas características podrían signifi car que se trató de un evento tipo intraplaca, originado superfi cialmente en la placa continental o profundo en la de Nazca. Los efectos reportados se asemejan más a los del terremoto de Chillán de 1939, un evento intraplaca de profundidad intermedia que aunque no produjo un tsunami generó grandes intensidades en el valle central y una enorme cantidad de víctimas. Si el terremoto de 1647 fue intraplaca, se plantea un problemático escenario de riesgo para la región más poblada del país.
Impacto ambiental temprano en la Araucanía deducido de crónicas espa?olas y estudios historiográficos
TORREJON,FERNANDO; CISTERNAS,MARCO;
Bosque (Valdivia) , 2003, DOI: 10.4067/S0717-92002003000300005
Abstract: chilean historiography states araucanian territory kept its pristine conditions until the republican period beginning. however, the presence of border military enclaves would have produced an early environmental disturbance in the araucania. to validate this hypothesis, a study of the spanish chronicles, old documents and historiographical studies was done. results indicate there was significant environmental disturbance on the araucanian ecological system, as a result of the intercultural contact during the arauco war and the spanish-creole settlement. native species extinction, exotic species introduction, mapuche crops substitution, natural resources mistreatment, land use changes, mapuche culture modification, and araucanian mortality and migration rising are among the environmental effects occurred under the area influenced by the forts.
Variaciones isotópicas (210Pb, 137Cs) antropogénicas en el registro estratigráfico de un lago de la cordillera de Nahuelbuta, Chile
Cisternas,Marco; Araneda,Alberto;
Revista geológica de Chile , 2001, DOI: 10.4067/S0716-02082001000100006
Abstract: anthropogenic isotope (210pb, 137cs) variations in the sedimentary record from a lake in the nahuelbuta mountain range, chile. the activity and distribution of 210pb and 137cs through the sedimentary record of a lake, which is located in the nahuelbuta mountain range, are influenced by anthropic activity. isotope analyses, x-rays, magnetic susceptibility, pollen and grain size analyses show both erosion rates variations-produced by land use changes within the watershed-and the 137cs atmospheric inputs have affected on the behavior of those isotopes in the record. the role of some natural variables -as the low ratio of land to ocean in southern latitudes, and the nahuelbuta mountain range locations are also discussed
Variaciones isotópicas (210Pb, 137Cs) antropogénicas en el registro estratigráfico de un lago de la cordillera de Nahuelbuta, Chile
Marco Cisternas,Alberto Araneda
Revista geológica de Chile , 2001,
Abstract: La actividad y distribución de 210Pb y 137Cs en el registro sedimentario de un lago de la cordillera de Nahuelbuta están influenciadas por la actividad antrópica. Análisis isotópicos, de rayos X, susceptibilidad magnética, polen y granulometría muestran que tanto las variaciones en las tasas de erosión, generadas por cambios en el uso del suelo de la cuenca, como las inyecciones atmosféricas del 137Cs han operado sobre el comportamiento de dichos isótopos en la columna estratigráfica. Se discute, también, el papel desempe ado por algunas variables naturales, como la proporción entre continentes y océanos en el hemisferio sur y la localización de la cordillera de Nahuelbuta. Anthropogenic isotope (210Pb, 137Cs) variations in the sedimentary record from a lake in the Nahuelbuta mountain range, Chile. The activity and distribution of 210Pb and 137Cs through the sedimentary record of a lake, which is located in the Nahuelbuta mountain range, are influenced by anthropic activity. Isotope analyses, X-rays, magnetic susceptibility, pollen and grain size analyses show both erosion rates variations-produced by land use changes within the watershed-and the 137Cs atmospheric inputs have affected on the behavior of those isotopes in the record. The role of some natural variables -as the low ratio of land to ocean in southern latitudes, and the Nahuelbuta mountain range locations are also discussed
Impacto ambiental temprano en la Araucanía deducido de crónicas espa olas y estudios historiográficos Early environmental impact in the Araucania territory inferred from Spanish chronicles and historiographical studies
FERNANDO TORREJON,MARCO CISTERNAS
Bosque (Valdivia) , 2003,
Abstract: La historiografía chilena sostiene que el territorio araucano mantuvo condiciones prístinas hasta los inicios del período republicano. Sin embargo, la presencia de enclaves militares espa oles fronterizos habría generado temprana intervención ambiental en la Araucanía. Para validar esta hipótesis, se realizó un análisis de las crónicas espa olas, documentación de la época y de estudios historiográficos. Los resultados indican que existió significativa perturbación ambiental sobre el sistema ecológico araucano producto del contacto intercultural durante la guerra de Arauco y el proceso de poblamiento hispano-criollo. Entre los efectos ambientales, generados en el área influenciada por los fuertes, se reconocen extinciones de especies endémicas, introducción de especies exóticas, sustitución de cultivos mapuches, explotación predatoria de los recursos naturales, cambios en el uso del suelo, modificación de la cultura mapuche y aumento de la mortalidad y migración araucana. Chilean historiography states Araucanian territory kept its pristine conditions until the republican period beginning. However, the presence of border military enclaves would have produced an early environmental disturbance in the Araucania. To validate this hypothesis, a study of the Spanish chronicles, old documents and historiographical studies was done. Results indicate there was significant environmental disturbance on the Araucanian ecological system, as a result of the intercultural contact during the Arauco war and the Spanish-Creole settlement. Native species extinction, exotic species introduction, Mapuche crops substitution, natural resources mistreatment, land use changes, Mapuche culture modification, and Araucanian mortality and migration rising are among the environmental effects occurred under the area influenced by the forts.
Alteraciones del paisaje ecológico araucano por la asimilación mapuche de la agroganadería hispano-mediterránea (siglos XVI y XVII)
TORREJóN,FERNANDO; CISTERNAS,MARCO;
Revista chilena de historia natural , 2002, DOI: 10.4067/S0716-078X2002000400008
Abstract: the bio-geographic characteristics of the temperate america favored the introduction and spreading of exotic plant and animal species that supported the hispanic-mediterranean farming model. the effects of this situation produced ecological alterations on the territories inhabited by indians without intense productive systems; as the araucanía case. through a historical and documental analysis this paper reports the main characteristics of the araucanian ecological landscape disruption process during the 16th and 17th centuries: (i) during the 16th century, the introduction of exotic species dislocated the mapuche economic system, (ii) both the relative araucanía pristine conditions and the warlike process, occurred between the 16th and 17th centuries, favored the introduction and spreading of the new species, (iii) during the 16th century, both natives and exotic species coexisted, but during the next century the exotic species predominated, and (iv) this preponderance would have produced a local extinction of native plants and animals, disrupting definitively the araucanian ecological landscape.
Alteraciones del paisaje ecológico araucano por la asimilación mapuche de la agroganadería hispano-mediterránea (siglos XVI y XVII) Araucanian ecological landscape disturbances by the mapuche assimilation of the Hispanic-Mediterranean farming (16th and 17th centuries)
FERNANDO TORREJóN,MARCO CISTERNAS
Revista chilena de historia natural , 2002,
Abstract: Las características biogeográficas de la América templada favorecieron la introducción y propagación de especies animales y vegetales que sustentaron al modelo agroganadero hispano-mediterráneo. Los efectos de este fenómeno generaron alteraciones ecológicas, especialmente en los territorios habitados por aborígenes carentes de actividades productivas intensivas, como fue el caso de la Araucanía. Mediante un análisis histórico documental, la presente investigación reconoció las principales características del proceso de alteración del paisaje ecológico araucano entre los siglos XVI y XVII: (i) en el siglo XVI, la introducción de especies exóticas desarticuló el sistema económico mapuche, (ii) tanto la relativa pristinidad de la Araucanía como el proceso bélico de los siglos XVI y XVII, favorecieron la introducción y propagación de las nuevas especies, (iii) durante el siglo XVI coexistieron especies nativas e introducidas, sin embargo, durante el siglo XVII preponderaron las exóticas, y (iv) este predominio habría generado la extinción local de especies animales y vegetales nativas, alterando definitivamente el paisaje ecológico araucano The bio-geographic characteristics of the temperate America favored the introduction and spreading of exotic plant and animal species that supported the Hispanic-Mediterranean farming model. The effects of this situation produced ecological alterations on the territories inhabited by Indians without intense productive systems; as the Araucanía case. Through a historical and documental analysis this paper reports the main characteristics of the Araucanian ecological landscape disruption process during the 16th and 17th centuries: (i) during the 16th century, the introduction of exotic species dislocated the Mapuche economic system, (ii) both the relative Araucanía pristine conditions and the warlike process, occurred between the 16th and 17th centuries, favored the introduction and spreading of the new species, (iii) during the 16th century, both natives and exotic species coexisted, but during the next century the exotic species predominated, and (iv) this preponderance would have produced a local extinction of native plants and animals, disrupting definitively the Araucanian ecological landscape.
Uso de parámetros sedimentológicos en el reconocimiento de ambientes hidrodinámicos en los canales y fiordos adyacentes a "Campos de Hielo Sur"
Ríos R.,Felipe; Cisternas V.,Marco;
Investigaciones marinas , 1998, DOI: 10.4067/S0717-71781998002600003
Abstract: seventeen soft bottom sediment samples taken from the fjord inlets adjacent to the glacial system of "campos de hielo sur", with a box-corer, from the research vessel agor "vidal gormaz", are analysed. a sedimentological characterization was conducted, resulting in the recognition of the main factors controlling the sedimentary process through the use of textural and grain-size parameters. it was found that most of the area is covered by silty sediments. they are moderately sorted, negatively skewed and leptokurtic. the spatial distribution of these parameters point out to the existence of two sedimentary environments with different levels of energy (sheltered heads and exposed inlets). the total organic matter and color of the sediments show that the area is subjected to periodic renewals of the bottom waters and that the organic matter is been supplied from the marine environment. canal messier, paso del indio, the mouth of the penguin and europe bays are recognized as being part of one sedimentary unit, probably regulated by the action of tidal currents
Efectos ambientales de la colonización espa?ola desde el río Maullín al archipiélago de Chiloé, sur de Chile
TORREJóN,FERNANDO; CISTERNAS,MARCO; ARANEDA,ALBERTO;
Revista chilena de historia natural , 2004, DOI: 10.4067/S0716-078X2004000400009
Abstract: the biogeographical characteristics of chiloé limited the introduction and propagation of exotic plants and animals that supported the subsistence and economy of spanish colonies. this in turn limited the rate of occupation and the scarce economic return of land reduced the extent and severity of environmental disturbances produced during the colonisation period. the present investigation analysed historic documentation from xvi, xvii and xviii centuries in order to characterise pre-hispanic environmental conditions and the environmental problems created by the colonist settlement. the adaptation of land-use practices to the region and the evolution of agricultural and forestry bring it by the colonists are described. the principal finding of this research indicates that the environmental impacts generated by the early spanish settlement were primarily at a local level, which meant that the ecological landscape of chiloé during the xviii century retained several of its pristine characteristics
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