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 Survey explores active tectonics in Northeastern Caribbean(Eos, Transactions American Geophysical Union, 2005) Carbó Gorosabel, Andrés; Córdoba Barba, Diego; Martín Dávila, José; Ten Brink, Uri S.; Herranz Araújo, Pedro; Von Hilldebrant, Christa; Payero, Juan; Muñoz Martín, Alfonso; Pazos, Antonio; Catalán, Manuel; Granja Bruña, José Luis; Gómez Ballesteros, MaríaThere is renewed interest in studying the active and complex northeastern Caribbean plate boundary to better understand subduction zone processes and for earthquake and tsunami hazard assessments [e.g., ten Brink and Lin, 2004; ten Brink et al., 2004; Grindlay et al, 2005]. To study the active tectonics of this plate boundary, the GEOPRICO-DO (Geological, Puerto Rico-Dominican) marine geophysical cruise, carried out between 28 March and 17 April 2005 (Figure 1), studied the active tectonics of this plate boundary. Initial findings from the cruise have revealed a large underwater landslide, and active faults on the seafloor (Figures 2a and 2c). These findings indicate that the islands within this region face a high risk from tsunami hazards, and that local governments should be alerted in order to develop and coordinate possible mitigation strategies. The cruise collected multibeam bathymetry, gravity, magnetic, high-resolution seismic, deep seismic sounding, and multichannel seismic reflection data, which are currently being processed and interpreted (Table 1). In early November 2005, 10 ocean-bottom seismometers (OBS) that had been deployed northeast of Puerto Rico and the Virgin Islands (Figure 1) during the cruise were recovered. These OBS recorded data during the cruise and the local seismicity between April and October 2005.Item Cinturón Deformado de Los Muertos (Noreste de la Placa Caribe): Análisis Morfotectónico y Procesos Activos.(2006) Granja Bruña, José Luis; Carbó Gorosabel, Andrés; Muñoz Martín, Alfonso; Gómez Ballesteros, MaríaThe 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.Item Análisis de Mapas de Anomalías Gravimétricas en el Borde NE de la Placa Caribe(2006) Granja Bruña, José Luis; Carbó Gorosabel, Andrés; Muñoz Martín, AlfonsoAlong 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.Item Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)(Marine Geology, 2009) Granja Bruña, José Luis; Ten Brink, Uri S.; Carbó Gorosabel, Andrés; Muñoz Martín, Alfonso; Gómez Ballesteros, MaríaMultibeam 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.