1,738 research outputs found

    Keeping watch over Colombia’s slumbering volcanoes

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    The Volcanological and Seismological Observatories of Manizales, Pasto and Popayan (Colombian Geological Survey) monitor and study the active volcanoes of Colombia using seismological, geodetic, geochemical and other techniques. Since 2009, permanent GNSS stations have been installed to complement classical geodetic measurements (e.g., tilt, EDM). At the moment, there are a total of 20 GNSS stations installed at Nevado del Ruiz, Cerro Machín, Puracé and Galeras volcanoes. Nevado del Ruiz has remained the most dynamic of the active Colombian volcanoes since its tragic eruption of 13 November 1985. The most significant deformation occurred between 2007 and 2012, when inflation, associated with magma migration and several small to moderate explosive eruptions in 2012 (VEI less or equal to 3), was observed. Galeras has experienced more than 25 moderate Vulcanian eruptions (VEI less or equal to 3) since 1989. In particular, the deformation network detected significant signals associated with magma migration and the extrusion of lava domes in 1991, 2005, 2008 and 2012. Puracé volcano has been the site of more than 10 minor eruptive episodes (VEI=2) in the past century, most recently in 1977. Monitoring of this volcano started in 1994. Unrest at Puracé since that time has been characterized by significant increases in seismic activity but with little or no deformation. We employ GAMIT/GLOBK to process GPS data from the monitoring network with support from the Volcano Disaster Assistance Program (U.S. Geological Survey). Additionally, differential processing is carried out using the commercial package Trimble 4D Control. Preliminary results for 2012 show no significant deformation at Puracé and Galeras volcanoes. On the other hand, the time series from Nevado del Ruiz shows a minor inflation (2-4 cm/yr) associated with the eruptive activity of 2012

    INIA 317: Altiplano, variedad de papa con buena adaptacion en la region altiplanica del Peru.

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    La papa constituye uno de los cultivos alimenticios más importantes en la agricultura familiar de la región andina del Perú. En las condiciones agroecológicas de esta región, uno de los factores más importantes que limita los niveles de producción y productividad de la papa es el clima adverso. Con el objetivo de lograr genotipos de papa; que además, de tener buena capacidad de rendimiento, respondan mejor a los nuevos estreses abióticos y bióticos provocados por el cambio climático, el Centro Internacional de la Papa realizó cruzamientos entre los cultivares nativos pertenecientes a Solanum tuberosum subsp. andigena. La evaluación de los genotipos se realizó a partir del año 2000 en las diferentes localidades de la región andina. Desde del año 2005, la Estación Experimental Illpa-Puno del Instituto Nacional de Innovación Agraria (INIA) y el Centro Internacional de la Papa (CIP) dentro de las actividades del Proyecto ALTAGRO, evaluaron un grupo de estos clones en diversas comunidades de la Región Altiplánica del Perú, a través de la metodología de selección participativa, con el objetivo de obtener una variedad de papa con alta capacidad productiva, adaptada a las condiciones climáticas de la Región Altiplánica y con aptitud para procesamiento en tunta. Como resultado de este trabajo de investigación se ha logrado seleccionar un genotipo de papa adaptada a la Región Altiplánica del Perú, con alto potencial de rendimiento y alto contenido de materia seca. Este genotipo de papa inicialmente identificado como el clon 399085.30 (B1C5041.30), actualmente es denominado variedad INIA 317 – ALTIPLAN

    Estimation of Carbon Content in the Páramo Ecosystem of Pasa Population, Ambato Canton, Tungurahua Province

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    The stored carbon content was determined based on a randomized stratified experimental design by type of vegetation; three sampling units of 400 m2 each were installed, from 3600–4100 m.s.n.m., with intervals of 150 m of altitude. The inventory of herbaceous vegetation was taken using the GLORIA method. For the sampling of the aerial biomass and necromass in the plot, circular subplots were constructed, and the samples were collected in 4 quadrants of 0.25 m2, two in each subplot. Samples of 0–20, 20–40 and 40–60 cm were taken from the soil profile, and the percentage of organic carbon in the soil and the apparent density were evaluated. The results indicate a floristic diversity represented by 44 species, 39 of herbaceous vegetation and 5 of tree vegetation. The carbon content stored in aerial biomass returned a value of 83.88 tC⋅ha−1 for herbaceous vegetation and 158.50 tC⋅ha−1 in tree vegetation, and in terms of necromass, returned values of 0.89 tC-ha−1 and 7.40 tC-ha−1, respectively. The carbon stored in the soil at a depth of 20 cm is 111.84 tC- ha−1 for herbaceous vegetation and 122.45 tC-ha−1 for tree vegetation. Keywords: ecosystem, paramo, tree vegetation, carbon, biomass. Resumen Se determinó el contenido de carbono almacenado en base a un diseño experimental estratificado al azar por tipo de vegetación, se instalaron tres unidades de muestreo de 400 m2 cada una, a partir de 3600–4100 m.s.n.m; con intervalos de 150 m de altitud. El inventario de la vegetación herbácea mediante el método GLORIA, Para el muestreo de la biomasa aérea y necromasa en la parcela se anidaron subparcelas circulares, se recolecto las muestras en 4 cuadrantes de 0.25m2 dos en cada subparcela. En el comportamiento suelo se tomaron muestras de 0–20 cm, 20–40 cm y de 40–60 cm, se evaluó el porcentaje de carbono orgánico en el suelo y la densidad aparente. Los resultados indican una diversidad florística representada por 44 especies, 39 de la vegetación herbácea y 5 de la vegetación arbórea. El contenido de carbono almacenado en la biomasa aérea reporto un valor de 83,88 tC⋅ha−1 para vegetación herbácea y de 158,50 tC⋅ha−1 en la vegetación arbórea, en cuanto a necromasa con valores de 0,89 tC-ha−1 y de 7,40 tC-ha−1 respectivamente. El carbono almacenado en el suelo a 20 cm de profundidad es de 111.84 tC-ha−1 la vegetación herbácea y de 122,45 tC-ha−1 para la vegetación arbórea. Palabras clave: ecosistema, paramo, vegetación arbórea, carbono, biomasa

    Torsion and Gravitation: A new view

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    According to the teleparallel equivalent of general relativity, curvature and torsion are two equivalent ways of describing the same gravitational field. Despite equivalent, however, they act differently: whereas curvature yields a geometric description, in which the concept of gravitational force is absent, torsion acts as a true gravitational force, quite similar to the Lorentz force of electrodynamics. As a consequence, the right-hand side of a spinless-particle equation of motion (which would represent a gravitational force) is always zero in the geometric description, but not in the teleparallel case. This means essentially that the gravitational coupling prescription can be minimal only in the geometric case. Relying on this property, a new gravitational coupling prescription in the presence of curvature and torsion is proposed. It is constructed in such a way to preserve the equivalence between curvature and torsion, and its basic property is to be equivalent with the usual coupling prescription of general relativity. According to this view, no new physics is connected with torsion, which appears as a mere alternative to curvature in the description of gravitation. An application of this formulation to the equations of motion of both a spinless and a spinning particle is madeComment: To appear on IJMP
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