Person: Muñoz Martín, Alfonso
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First Name
Alfonso
Last Name
Muñoz Martín
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Geodinámica Interna
Identifiers
4 results
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Item El terremoto de Haití(Enseñanza de las ciencias de la tierra, 2011) Granja Bruña, José Luis; Carbo Gorosabel, Andrés; Hernáiz-Huerta, Pedro Pablo; Llanes Estrada, María Pilar; Muñoz Martín, Alfonso; Olaiz Campos, Antonio JoséItem Exploring active tectonics in the Dominican Republic(Eos, Transactions American Geophysical Union, 2010) Carbo Gorosabel, Andrés; Córdoba Barba, Diego; Martín Dávila, José; Granja Bruña, José Luis; Llanes Estrada, María Pilar; Muñoz Martín, Alfonso; Ten Brink, Uri S.One recent project, Caribbean–North American Plate Boundary Analysis: From Beata Ridge (Dominican Republic) to Anegada Passage (Lesser Antilles) (CARIBENORTE), has conducted onshore and offshore surveys in the Dominican Republic region to study subduction, strike- slip, and collision processes in this area. This survey included a cruise aboard the Spanish R/V Hespérides in April 2009 and simultaneous fieldwork onshore. The CARIBE NORTE project complements the study of the northeastern Caribbean plate boundary carried out during the Structure and Geodynamics of the Northeastern Boundary of the Caribbean Plate: Puerto Rico (GEOPRICO- DO) project in 2005 [Carbó et al., 2005].Item Gravity modeling of the Muertos Trough and tectonic implications (north-eastern Caribbean)(Marine Geophysical researches, 2010) Granja Bruña, José Luis; Muñoz Martín, Alfonso; Ten Brink, Uri S.; Carbo Gorosabel, Andrés; Llanes Estrada, María Pilar; Martín Dávila, José; Córdoba Barba, Diego; Catalán, ManuelThe Muertos Trough in the northeast Caribbean has been interpreted as a subduction zone from seismicity, leading to infer a possible reversal subduction polarity. However, the distribution of the seismicity is very diffuse and makes definition of the plate geometry difficult. In addition, the compressive deformational features observed in the upper crust and sandbox kinematic modeling do not necessarily suggest a subduction process. We tested the hypothesized subduction of the Caribbean plate’s interior beneath the eastern Greater Antilles island arc using gravity modeling. Gravity models simulating a subduction process yield a regional mass deficit beneath the island arc independently of the geometry and depth of the subducted slab used in the models. This mass deficit results from sinking of the less dense Caribbean slab beneath the lithospheric mantle replacing denser mantle materials and suggests that there is not a subducted Caribbean plateau beneath the island arc. The geologically more realistic gravity model which would explain the N–S shortening observed in the upper crust requires an overthrusted Caribbean slab extending at least 60 km northward from the deformation front, a progressive increase in the thrusting angle from 8 to 30 reaching a maximum depth of 22 km beneath the insular slope. This new tectonic model for the Muertos Margin, defined as a retroarc thrusting, will help to assess the seismic and tsunami hazard in the region. The use of gravity modeling has provided targets for future wide-angle seismic surveys in the Muertos Margin.Item Mapa de esfuerzos activos en línea de la Península Ibérica a partir de Mecanismos Focales calculados desde el Tensor de Momento Sísmico(Geotemas, 2012) Muñoz Martín, Alfonso; De Vicente Muñoz, Gerardo; Olaiz Campos, Antonio José; Antón López, Loreto; Vegas Martínez, Ramón; Granja Bruña, José LuisThis work shows a new on-line stress map for Iberian Peninsula obtained from the inversion of earthquakes focal mechanisms calculated with the centroid moment tensor. An amount of 299 focal mechanisms have been selected with several quality criteria from different catalogues (CMT Harvard, ETH, Med-Net, I.G.N. and I.A.G.) from 1973 to January 2012. Values for the maximum horizontal stress and the shape factor of the ellipsoid (horizontal/vertical stress) have been calculated following De Vicente et al. (2008).. The local results have been interpolated to a 10’ regular grid in which the relation between tectonic horizontal stress and vertical load has been taken into account. The final map shows a good correlation with the primary tectonic forces generated in the plate boundaries and the local perturbations related with main crustal heterogeneities. Both the maps and data are free for download from http://www.ucm.es/info/lta/lta.html Applied Tectonophysics Group WebSite). [RESUMEN]Este trabajo muestra el nuevo mapa en línea de esfuerzos activos para la Península Ibérica obtenido a partir de la inversión de mecanismos focales de terremotos (MF) calculados con Tensor de Momento Sísmico (TMS). Un total de 299 MF han sido seleccionados con varios criterios de calidad de diferentes catálogos (CMT Harvard, ETH, Med-Net, I.G.N. e I.A.G.), para un periodo comprendido entre 1973 y enero de 2012 y profundidades menores de 60 km. Los valores de la dirección de máximo acortamiento horizontal (Dey) y el factor de forma (carga horizontal/vertical) han sido calculados siguiendo a De Vicente et al. (2008). Los resultados obtenidos se han interpolado a una malla regular de 10’, teniendo en cuenta las orientaciones de las componentes horizontales de esfuerzo, y el factor de forma. Los mapas finales muestran una buena correlación con indicadores geológicos y cinemáticos. Las orientaciones de los esfuerzos horizontales se relacionan con las fuerzas primarias provenientes de los límites de placas, y con perturbaciones locales relacionadas con heterogeneidades de primer orden a nivel cortical. Tanto los mapas, como los datos procesados son accesibles a través de la Web del Grupo de Tectonofísica Aplicada de la UCM http://www.ucm.es/info/lta/lta.html.