179 research outputs found

    On weighted compositions preserving the Carathéodory class

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    This is a post-peer-review, pre-copyedit version of an article published in Monatshefte für Mathematik. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00605-017-1093-3We characterize in various ways the weighted composition transformations which preserve the class P of normalized analytic functions in the disk with positive real part. We analyze the meaning of the criteria obtained for various special cases of symbols and identify the fixed points of such transformationsArévalo, Martín, and Vukotić are supported by MTM2015-65792-P from MINECO and FEDER/EU and partially by the Thematic Research Network MTM2015-69323-REDT, MINECO, Spain. Hernández and Martín are supported by FONDECYT 1150284, Chile. Martín is also supported by Academy of Finland Grant 26800

    Tectónica activa de la Cuenca de Málaga: evidencias en marcadores morfotectónicos (Cordillera Bética Occidental, España)

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    The Malaga Basin is located in the westernmost part of the Betic Cordillera. This alpine cordillera in the south of Spain is the most active region of the Iberian Peninsula. Some of the most destructive earthquakes occurred historically in Spain took place within the Malaga Basin. In this work we focus on geomorphic and morphotectonic observations in the aim of finding active tectonic structures that could be seismogenic sources. First, we study the spatial arrangement and age of the Quaternary alluvial fan system as well as the drainage pattern of the basin, followed by the analysis of the distribution of regional markers like marine erosive surfaces and the extend of Pliocene marine deposits in the Malaga Basin. The tectonic structures inferred as active by the morphotectonic analysis are grouped into four main families: N60º-85ºE folds associated with blind thrust faults, N20º-30ºE and N40º-50ºE high angle dip-slip faults, and N165º-170ºE tear faults. Finally, their seismic potential in terms of maximum moment magnitude (Mw) is assessed by means of empirical relationships, varying between 6.0 and 7.0 depending on the hypothesis considered.La cuenca de Málaga se sitúa en la parte más occidental de la cordillera Bética. En esta cordillera alpina del sur de España se han localizado algunos de los terremotos más destructivos ocurridos históricamente en la península Ibérica. En este trabajo se estudian algunos de los aspectos geomorfológicos de la cuenca del Málaga con el fin de identificar las estructuras tectónicas activas que pudiesen ser fuentes sismogénicas. Se estudia la distribución y edad del sistema de abanicos aluviales de la cuenca, así como la red de drenaje. También se analiza la distribución regional de marcadores tectónicos pliocenos, como superficies de erosión marina y los depósitos sedimentarios de este periodo transgresivo. Se han identificado varias estructuras tectónicas activas que han sido agrupadas en cuatro familias: pliegues N60º-85ºE asociados con falla inversas ciegas, fallas de alto buzamiento con salto en la vertical N20º-30ºE y N40º-50ºE, y fallas de transferencia N165º-170ºE. En base a relaciones empíricas se ha estimado un potencial sísmico para las fallas identificadas, obteniéndose valores de magnitud momento (Mw) entre 6,0 y 7,0

    Active fault databases and seismic hazard calculations: a compromise between science and practice. Review of case studies from Spain

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    Since the Quaternary Active Faults Database of Iberia (QAFI) was released in February 2012 a number of studies aimed at producing seismic hazard assessments have made use of it. We will present a summary of the shortcomings and advantages that were faced when QAFI was considered in different seismic hazard studies. These include the production of the new official seismic hazard map of Spain, performed in the view of the foreseen adoption of Eurocode-8 throughout 2017. The QAFI database was considered as a complementary source of information for designing the seismogenic source-zone models used in the calculations, and particularly for the estimation of maximum magnitude distribution in each zone, as well as for assigning the predominant rupture mechanism based on style of faulting. We will also review the different results obtained by other studies that considered QAFI faults as independent seismogenic-sources in opposition to source-zones, revealing, on one hand, the crucial importance of data-reliability and, on the other, the very much influence that ground motion attenuation models have on the actual impact of fault-sources on hazard results. Finally, we will present briefly the updated version of the database (QAFI v.3, 2015), which includes an original scheme for evaluating the reliability of fault seismic parameters specifically devised to facilitate decision-making to seismic hazard practitioners

    Experimental and theoretical investigations on a CVD grown thin film of polymeric carbon nitride and its structure

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    A polymeric carbon nitride thin film has been grown using chemical vapor deposition. The characterization of the material shows that it has the same molecular composition as a formerly synthesized graphitic carbon nitride powder but both substances differ widely in their structural organization. In particular, our analyses reveal a paradoxical character in which the thin film sample exhibits simultaneously a high degree of organization in the stacking of the polymer sheets with strong inter-layer interactions, as expected from the growth technique, and a complete lack of crystallinity. A comprehensive theoretical study based on massive semi-empirical quantum chemistry computations has permitted to explain the properties of the material and to elucidate fundamental issues regarding the structural conformation of graphitic carbon nitride

    Tectonic analysis of the gravimetric anomaly maps in the Málaga Basin (Western Betic Chain)

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    En el presente trabajo se muestra el análisis tectónico de los mapas de anomalía gravimétrica resultado de una campaña gravimétrica llevada a cabo en la Cuenca de Málaga, situada en la Cordillera Bética Occidental. En los mapas realizados se interpreta la presencia significativa de cuerpos peridotíticos en profundidad, entre los que destaca el que se encuentra bajo los Montes de Málaga, con gran continuidad lateral. Además, queda reflejado el fuerte control estructural con dirección E-O que presenta la cuenca, que estuvo condicionada por un corredor de fallas dextrales desde el Burdigaliense Inferior hasta el Tortoniense Inferior. A favor de este corredor se desplazó hacia el Oeste un segmento cortical que incluía gran parte de la masa de peridotitas existentes en la zona y que ahora quedan marcadas por dos máximos gravimétricos en los mapas de anomalía de carácter más regional. Posteriormente, con el cambio en la dirección de esfuerzos máximos horizontales a NNO-SSE, el movimiento en dirección de las fallas de este corredor quedó prácticamente bloqueado, y la falla del límite sur de la Cuenca de Málaga empezó a actuar como una falla inversa de alto ángulo controlando la sedimentación de la cuenca. Bajo estas condiciones de compresión NNO-SSE se desarrolla la actividad post-miocena del pliegue de la Sierra de Cártama.The tectonic analysis of the gravimetric anomalies maps resulting from the gravimetric survey carried out in the Malaga Basin (located on the Internal Zone of the Western Betic Chain, southern Spain) are shown in this paper. In these maps it can be observed the remarkable presence of peridotites in deep. The most important ultramafic body is sited under the Montes de Malaga with wide lateral continuity. A strong structural control in E-W direction is marked in the maps for the basin. This basin was controled by a dextral faults corridor from the Lower Budigalian until the Lower Tortonian. A crustal segment, which included the main part of the peridotites body was displaced westward by these corridor, as it can be deduced from the maximum gravimetric anomalies map of the whole region. After the Tortonian, with the change in the regional shotening direction to NNW-SSE, the strike-slip became progresivelly blocked, with an increasing of the reverse component of the existing faults. Under this stress field, the main fault bounding the southern border of the Malaga Basin works as a reverse fault and controls the sedimentation in the basin.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

    Active fault databases: building a bridge between earthquake geologists and seismic hazard practitioners, the case of the QAFI v.3 database

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    Active fault databases are a very powerful and useful tool in seismic hazard assessment, particularly when singular faults are considered seismogenic sources. Active fault databases are also a very relevant source of information for earth scientists, earthquake engineers and even teachers or journalists. Hence, active fault databases should be updated and thoroughly reviewed on a regular basis in order to keep a standard quality and uniformed criteria. Desirably, active fault databases should somehow indicate the quality of the geological data and, particularly, the reliability attributed to crucial fault-seismic parameters, such as maximum magnitude and recurrence interval. In this paper we explain how we tackled these issues during the process of updating and reviewing the Quaternary Active Fault Database of Iberia (QAFI) to its current version 3. We devote particular attention to describing the scheme devised for classifying the quality and representativeness of the geological evidence of Quaternary activity and the accuracy of the slip rate estimation in the database. Subsequently, we use this information as input for a straightforward rating of the level of reliability of maximum magnitude and recurrence interval fault seismic parameters. We conclude that QAFI v.3 is a much better database than version 2 either for proper use in seismic hazard applications or as an informative source for non-specialized users. However, we already envision new improvements for a future update

    New insights on the seismogenic potential of the Eastern Betic Shear Zone (SE Iberia): Quaternary activity and paleoseismicity of the SW segment of the Carrascoy Fault Zone

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    The Carrascoy Fault (CAF) is one of the main active faults that form part of the Eastern Betic Shear Zone, a 450 km fault system that accommodates most of the convergence between the Eurasian (Iberia) and Nubian plates in the Betic Cordillera, south Spain. Although the CAF represents a major earthquake threat to the nearby City of Murcia, studies on its Quaternary tectonics and seismogenic potential are scarce to date. We present evidence that supports the division of the CAF into two overlapping segments with contrasting tectonic structure, Quaternary activity, and landform control: a SW segment, characterized by a broad fold-and-thrust zone similar to the forebergs defined in the Gobi-Altai region, and a NE segment, characterized by a sharp mountain front controlled by strike-slip tectonics. We attribute the differentiation into these two segments to the stresses associated with topography, which in turn is a consequence of the shortening component, at the middle Pleistocene, after circa 217.4 ka. For the SW segment we infer the occurrence of 9 to 11, Mw 6.7 paleoearthquakes in the last 30.2 kyr, and a slip rate of 0.37 ± 0.08 m/kyr. We date the occurrence of the last surface rupture event after 2750 B.P., and we estimate an average recurrence period of major events of 3.3 ± 0.7 kyrThis work was supported by SISMOGEN (IGME, 2279) and FASEGEO (CGL2009-09726) research projects and a technical assistance of the Civil Protection Service of Murci
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