Person:
Muñoz Martín, Alfonso

First Name

Alfonso

Last Name

Muñoz Martín

URI

https://hdl.handle.net/20.500.14352/75220

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

Department

Geodinámica, Estratigrafía y Paleontología

Area

Geodinámica Interna

Identifiers

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Now showing 1 - 10 of 30

Análisis de nuevos datos gravimétricos marinos en el entorno de la Isla Decepción (Islas Shetland del Sur, Antártida)
(Revista de la Sociedad Geológica de España, 2001) Carbo Gorosabel, Andrés; Muñoz Martín, Alfonso; Martín Dávila, José; Catalán, Manuel; García, Alicia
La Isla Decepción es la parte emergida de un volcán muy joven y activo. Se encuentra situada en el SO del Estrecho de Bransfield, que separa la Península Antártica de las islas Shetland del Sur. En este trabajo se muestran los resultados del levantamiento gravimétrico realizado en la campaña de investigación geofísica marina DECVOL99 (Diciembre de 1999). El procesado de los 4906 datos seleccionados, obtenidos a lo largo de 48 líneas de navegación, ha permitido la realización de dos mapas de anomalías de Bouguer en el interior y en el exterior de la Isla Decepción. El tratamiento de los datos gravimétricos ha incluido, además de las correcciones habituales, la corrección topográfica terrestre y del fondo marino utilizando una malla de 1 km de lado. Los mapas de anomalías de Bouguer resultantes muestran una serie de anomalías y gradientes gravimétricos bien definidos que, al integrarlos con el resto de información existente, permiten su interpretación desde el punto de vista estructural y tectónico. De este modo las anomalías gravimétricas en el entorno de la Isla Decepción se encuentran definidas por una serie de mínimos y máximos con dos orientaciones principales NE-SO y NO-SE, que se corresponden bien con rasgos morfoestructurales y geofísicos en otros sectores del Estrecho de Bransfield. La mayor parte de los gradientes gravimétricos alargados y con carácter neto pueden ser interpretados como zonas de fractura NO-SE y NE-SO que limitan áreas de máximos y mínimos gravimétricos. Las anomalías positivas de gran longitud de onda constituyen la continuación hacia el SO de la corteza continental de la Isla Livingston, mientras que los máximos gravimétricos de alta frecuencia están asociados a bloques elevados y de alta densidad. Las zonas de mínimos valores de anomalía de Bouguer coinciden con los principales ejes de extensión y máximo relleno de materiales sedimentarios recientes. Las orientaciones y localizaciones de las bandas de alto gradiente gravimétrico permiten su correlación con zonas de fracturas definidas mediante otros datos geofísicos marinos, así como con la batimetría y los datos estructurales medidos en superficie.
Análisis de Mapas de Anomalías Gravimétricas en el Borde NE de la Placa Caribe
(2006) Granja Bruña, José Luis; Carbo Gorosabel, Andrés; Muñoz Martín, Alfonso
Along the Eastern Greater Antilles (Hispaniola and Puerto Rico area) takes place the interaction between the Caribbean and North-American plates. This interaction produced inside a broad band of deformation with a complex and active tectonics. Here, many tectonic models have been proposed: strain partitioning, microplates tectonics, oblique subduction, opposing subducted slabs, crust arching, and tear fault in the downgoing plate. Except the seismological data that provide a general idea about the disposition of the lithospherics plates in depth, the most of models has been proposed from geodetic data (GPS), geological surface data (onland and onsea) and refection seismic data, so the models are constrained only in the superficial crust. In this survey, an analysis of anomaly gravity maps is presented. Those maps have been realized from the gravity data acquired during the PRICO (1997) and GEOPRICO-DO (2005) marine geophysical surveys, on-land data and satellite gravity data. In the maps analysis we emphasize the extreme values of Bouguer gravity anomaly (-400 mGals) located in the oceanic crust of the North American plate and the maximum free air gravity anomaly of the Earth (-350 mGals) located in the Puerto Rico Trench. This analysis, integrated with geomagnetic, seismologic and deep seismic sounding data is the way to approach the study of deep crust and to can elaborate lithosphere models constrained in depth.
Alboran basin, Southern Spain. Part II: Neogene tectonic implications for the orogenic float model
(Marine and Petroleum Geology, 2008) Gómez Ballesteros, María; Rivera, Jesus; Muñoz, Araceli; Muñoz Martín, Alfonso; Acosta, Juan; Carbo Gorosabel, Andrés; Uchupi, E.
We infer that the Alboran Basin, the first western Mediterranean Basin found after crossing Gibraltar, is an orogenic float underlained by a de´ collement system, a multi-layered ductile shear extending from 10km to between 30 and 40km below sea level. This float was formed as consequence of the collision of the African–Eurasian plates in the Oligocene–late Miocene. Synchronous with this compression the float experienced basin wide crustal thinning and subsidence about 25 m/year ago by subcrustal processes. Since latest Miocene the float has undergone compression due to the continuous convergence of Eurasia and Africa. The faults created as a result of this compression are dominated by a conjugate system of northeast trending left-lateral and northwest right-lateral strike–slip faults. This deformation is taking place under a simple shear mechanism. Associated with the northwest and northeast lateral faults are zones of compression trending west and east of north extending from the base of the basin’s north upper slope to the Alboran Ridge. The initial morphology of the Alboran Ridge on the southern side of the Alboran Basin was due to the construction of a volcanic edifice at the northeast end of the ridge and igneous activity along northeast trending fractures southwest of the edifice. At the northeast end of the Alboran Ridge motion along a right-lateral fault cutting across the ridge led to sediment collapse and the creation of a prominent embayment on the ridge’s northwest flank. Deformation is more subdued in the western than in the eastern part of the Alboran Basin, a tectonic style due either to differences in sediment rheology or that the accommodation of the convergence of Africa and Iberia is more diffused and attenuated in the west than in the east.
Cinturón Deformado de Los Muertos (Noreste de la Placa Caribe): Análisis Morfotectónico y Procesos Activos.
(2006) Granja Bruña, José Luis; Carbo Gorosabel, Andrés; Muñoz Martín, Alfonso; Gómez Ballesteros, María
The Muertos Deformed Belt (MDB) is a tectonic feature located within the Northeastern Caribbean Plate Boundary Zone. This deformed belt is occupying a broad band of active compression regime with an east-west trend along the south of Hispaniola and Puerto Rico islands. In our survey area, the deformed belt is limited to the south by the Muertos Trough (>5500 m depth), where the Venezuelan Basin oceanic crust is being underthrusted beneath western Puerto Rico and eastern Hispaniola areas. Here, we present the morphotectonic interpretation from the multibeam systematic survey in Muertos Deformed Belt area (from GEOPRICO-DO marine geophysical survey (2005)) and the relationship with seismicity and kinematic data (GPS). Active deformation features have been widely found in the area from bathymetry model and Chirp sub-bottom seismic profiles (TOPAS). These features include: folded and faulted recent sediments (Holocene), submarine landslides scars associated with faults (tsunamogenic potential) and submarine canyons deflected by fault traces. All these features are well preserved and show a little erosion. Future works will integrate potential field data and deep seismic data, which will allow us to elaborate complete tectonic models for this active and complex plate boundary.
Comparación entre las técnicas AEOS, Re-Mi y PS-logging aplicadas en un terreno de estructura profunda conocida
(Geotemas, 2008) García Mayordomo, Julián; Pérez Santisteban, Itziar; Pantín, V.; Muñoz Martín, Alfonso; Carbo Gorosabel, Andrés
En este estudio se contrastan los resultados que ofrecen dos técnicas de uso habitual en el Laboratorio de Geotecnia del CEDEX, el AEOS y el PS-logging, con los de una técnica relativamente novedosa, el Re-Mi (o sísmica pasiva). Para ello se emplean los resultados obtenidos por las tres técnicas en un emplazamiento común de estructura profunda conocida: un tramo de terraplén ferroviario recién construido. La técnica más precisa en la identificación de las diferentes partes de la estructura de tierras (terraplén, cimiento y contacto con el terreno natural) es el PS-logging, seguido por el AEOS y Re-Mi. Los valores de Vs promedio proporcionados por cada técnica presentan importantes diferencias, obteniéndose los más altos con el PS-logging, seguido por AEOS y Re-Mi. La desviación de los valores Vs promedio obtenidos por una técnica en particular, en comparación con las otras, es similar. Respecto a la técnica Re-Mi, cabe destacar que, si bien no se ha mostrado muy precisa en este estudio, presenta un alto grado de operatividad en cuanto a implantación, ejecución y procesado de datos.
Comparison among SASW, ReMi and PS-logging techniques: Application to a railway embankment
(Journal of applied geophysics, 2011) Pérez Santisteban , Itziar; García Mayordomo, Julián; Muñoz Martín, Alfonso; Carbo Gorosabel, Andrés
Results obtained by SASW and PS-logging (in-hole) seismic techniques are compared with the relatively new ReMi (Refraction microtremor) method at a common site with a well-known soil profile: a recently constructed high-speed railway embankment. PS-logging is the most accurate technique in identifying the soil profile of the embankment followed by Re-Mi and SASW. Mean shear wave velocity estimations are also higher for PS-logging, followed by SASW and ReMi, while mean deviation is similar in each technique. The ReMi technique has provided very accurate results in the study of the embankment profile, which in addition to its high operability and its fast data processing, makes it a very convenient technique for extensive geotechnical surveys
Empirical correlation of shear wave velocity (Vs) with spt of soils in Madrid
(first break, 2016) Pérez Santisteban, Itziar; Muñoz Martín, Alfonso; Carbo Gorosabel, Andrés; Ruiz Fonticiella, J.M.
Empirical correlations are usually used as a predictive tool in geotechnical engineering. However, equations calculated for soils very different to the ones to be characterized are frequently used, and so they are not representative of their mechanical properties. This fact, added to the increasing interest of civil engineering in knowing the shear wave velocity (Vs) of the ground, has led to the calculation of different empirical equations to predict the Vs value of the soils of Madrid. In this study this has been achieved by calculating the empirical correlations between the Vs value obtained through the ReMi (Refraction Microtremor) technique and the Standard Penetration Test (500 NSPT values). The empirical correlations proposed are applicable to the whole metropolitan area of Madrid, and have an excellent predictive capability owing to the incorporation of the measurement depth to the equations, which has an important influence in the resistance properties of soils.
Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)
(Marine Geology, 2009) Granja Bruña, José Luis; Ten Brink, Uri S.; Carbo Gorosabel, Andrés; Muñoz Martín, Alfonso; Gómez Ballesteros, María
Multibeam bathymetry data acquired during the 2005 Spanish R/V Hespérides cruise and reprocessed multichannel seismic profiles provide the basis for the analysis of the morphology and deformation in the central Muertos Trough and Muertos thrust belt. The Muertos Trough is an elongated basin developed where the Venezuelan Basin crust is thrusted under the Muertos fold-and-thrust belt. Structural variations along the Muertos Trough are suggested to be a consequence of the overburden of the asymmetrical thrust belt and by the variable nature of the Venezuelan Basin crust along the margin. The insular slope can be divided into three east–west trending slope provinces with high lateral variability which correspond to different accretion stages: 1) The lower slope is composed of an active sequence of imbricate thrust slices and closed fold axes, which form short and narrow accretionary ridges and elongated slope basins; 2) The middle slope shows a less active imbricate structure resulting in lower superficial deformation and bigger slope basins; 3) The upper slope comprises the talus region and extended terraces burying an island arc basement and an inactive imbricate structure. The talus region is characterized by a dense drainage network that transports turbidite flows from the islands and their surrounding carbonate platform areas to the slope basins and sometimes to the trough. In the survey area the accommodation of the ongoing east–west differential motion between the Hispaniola and the Puerto Rico–Virgin Islands blocks takes place by means of diffuse deformation. The asymmetrical development of the thrust belt is not related to the geological conditions in the foreland, but rather may be caused by variations in the geometry and movement of the backstop. The map-view curves of the thrust belt and the symmetry of the recesses suggest a main north–south convergence along the Muertos margin. The western end of the Investigator Fault Zone comprises a broad band of active normal faults which result in high instability of the upper insular slope.
Zona económica exclusiva española (ZEEE): Mar Balear y Golfo de Valencia. Mapas generales de batimetría, geomorfología, anomalías geomagnéticas, gravimétricas de arie libre y de Bouguer
(2015) Martín Dávila, José; Catalán Morollón, Manuel; Larrán, ALFONSO; Carbo Gorosabel, Andrés; Muñoz Martín, Alfonso; Granja Bruña, José Luis; Gómez Ballesteros, M.P.; Acosta Yepes, Juan; Tello, O.; Maestro, Adolfo; LLavé, E.
Resultados y experiencias de aplicación del método de Refracción por Microtremor (Sísmica Pasiva) para la investigación geofísica de las nuevas líneas de metro en Madrid (España)
(Geogaceta, 2006) Muñoz Martín, Alfonso; Carbo Gorosabel, Andrés
Geophysical exploration with seismic methods in urban zones presents several disadvantages: the presence of numerous sources of seismic noise, the scanty penetration when the seismic source is a hammer and the disability to detect buried low-velocity beds. Recently (Louie, 2001) a new method of seismic investigation has been developed, which allows vertical modeling of Raleygh waves from spectral analysis (Vphase/frequency) using the seismic signal registered with conventional seismographs and geophones. This method allows to detect low-velocity buried beds of great interest in tunneling, and to reach depths below 50 meters. In this work we discuss the conditions of application and experiences obtained during the 2005 geophysical surveys carried out in Madrid before the excavation of the new subway tunnels.