Una aproximación multidisciplinar al estudio de las fallas activas, los terremotos y el riesgo sísmico : 2ª Reunión Ibérica sobre Fallas Activas y Paleosismología : celebrada del 22 al 24 de octubre de 2014, en Lorca

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Madinat al-Zahra'

Duración 00:10:11. Necesita tener instalado Adobe Flash Player. Instalador incluido en el DVD.Este DVD contiene, en video de formato estandard y en HD, una reconstrucción virtual de la ciudad palatina de Madinat al-Zahra, levantada por los califas omeyas de al-Andalus entre los años 936 y 1010, situada a ocho kilómetros de Córdoba. Esta reconstrucción puede verse tanto a través de la animación con explicación sonora como mediante panoramas esféricos enlazados que permiten un recorrido inter-activo por las zonas hasta ahora descubiertas del alcázar, accesibles a través de la aplicación al-Zahra.exe. El audiovisual ha sido realizado por el Laboratorio de Arqueología y Arquitectura de la Ciudad (LAAC) de la Escuela de Estudios Árabes de Granada, perteneciente al Consejo Superior de Investigaciones Científicas (CSIC), en colaboración con la Fundación El Legado Andalusí.Peer reviewe

Recent consequences of climate change have affected tree growth in distinct Nothofagus macrocarpa (DC.) FM Vaz & Rodr age classes in Central Chile

Forests play an important role in water and carbon cycles in semiarid regions such as the Mediterranean ecosystems. Previous research in the Chilean Mediterranean forests revealed a break point in 1980 in regional tree-ring chronologies linked to climate change. However, it is still unclear which populations and age classes are more affected by recent increases in drought conditions. In this study, we investigated the influence of recent variations in precipitation, temperature, and CO2 concentrations on tree growth of various populations and age classes of Nothofagus macrocarpa trees in Central Chile. We sampled 10 populations from five sites of N. macrocarpa through its whole geographic distribution in both Coastal and Andes ranges. We used standard dendrochronological methods to (i) group populations using principal component analysis, (ii) separate age classes (young, mature, and old trees), (iii) evaluate linear growth trends based on the basal area increment (BAI), and (iv) analyze the link between BAI and atmospheric changes using linear mixed-effects models. Results showed that young trees are more sensitive to climate variability. Regarding population grouping, we observed that all population clusters were sensitive to winter-spring precipitation, but only the Andes and Coastal populations were negatively correlated with temperature. The results of CO2 fertilization analyses were controversial and unclear. Since young trees from all population clusters reacted positively in the phase with an increase of atmospheric CO2 between 1980 and 2014, this behavior was not translated into growth for the last 15 years (2000-2014). However, it should be noted that the young trees of the highest elevation populations did not have a negative growth trend, so it seems that CO2 counteracted the negative effect of recent regional climate change (increase in temperature and precipitation decrease) in these population trees. Further studies are needed to assess the effects of climate variability over other ecological and physiological processes.Fil: Venegas González, Alejandro. Universidad Mayor.; ChileFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Peña Rojas, Karen. Universidad de Chile; ChileFil: Hadad, Martín Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Aguilera Betti, Isabella. Pontificia Universidad Católica de Valparaíso; Chile. Universidad Austral de Chile; ChileFil: Muñoz, Ariel A.. Pontificia Universidad Católica de Valparaíso; Chil

Avances en el estudio de fallas activas, terremotos y peligrosidad sísmica de Iberia.

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Patrones de teleconexión entre circulación atmosférica a gran escala y precipitación en la Península Ibérica

Ponencia presentada en: II Congreso de la Asociación Española de Climatología “El tiempo del clima”, celebrado en Valencia del 7 al 9 de junio de 2001[ES]Un análisis de descomposición singular ha sido realizado a la matriz de croscovarianza de dos Campos para investigar la naturaleza de las interacciones entre la circulación atmosférica a gran escala y la precipitación en la Península Ibérica. Este análisis ha sido aplicado a una base de datos de 30 inviernos consistente en precipitación mensual acumulada en la Península Ibérica y altura geopotencial mensual media en varios niveles atmosféricos sobre la cuenca del Atlántico Norte. El análisis ha dado como resultado 2 pares significativos de patrones de teleconexión que cuentan con más del 86% del total de la covarianza cuadrada entre los dos campos. El primer patrón de geopotencial, el modo dominante, puede ser identificado con la Oscilación del Atlántico Norte y da cuenta del valor más alto de fracción de covarianza cuadrada en todos los niveles atmosféricos. Este modo muestra una distribución espacial que se mantiene en toda la troposfera. El segundo modo muestra altos valores de correlación en varios niveles atmosféricos. Este patrón de teleconexión está caracterizado por un dipolo de anomalías de geopotencial orientado SW-NE acoplado con un patrón de precipitación que presenta fuertes anomalías negativas en el norte de la Península Ibérica y anomalías positivas en el sur y el este. Para una mejor interpretación de los patrones resultantes, se ha complementado la información con un análisis de funciones ortogonales empíricas de los campos individuales.[EN]To investigate the nature of the atmosphere circulation interactions with the rainfall at Iberia a singular value decomposition analysis has been performed to a croscovariance matrix of two fields. This analysis has been applied to a 30-winter dataset consisting of both monthly totals of precipitation in Iberia and monthly mean geopotential height at several levels over North Atlantic Ocean. The analysis has yielded two significant pairs of teleconnection patterns that account for more than 86% of the total square covariance between the two fields. The first geopotential pattern, the dominant mode, has been recognised as the North Atlantic Oscillation with the highest value of square covariance fraction at all atmospheric levels. The mode shows a spatial distribution which is kept on the whole troposphere. The second mode shows high correlation values at the several atmospheric levels. These second teleconnection patterns showed a geopotential anomaly dipole SW-NE pattern that is coupled with strong negative precipitation anomalies at N of the Iberian Península and positive ones at southern and eastern areas. To avoid misinterpretations, the information of these teleconnection patterns has been completed by the empirical orthogonal function analysis of the individual fields.Este trabajo ha sido parcialmente financiado por el proyecto de investigación REN2000-0786/CLI

Aspectos tectónicos del estudio gravimétrico de la Cuenca de Málaga

This work shows the results o f a gravimetric survey carried out in the Malaga Basin (sited on the Internal Zone o f the Western Betic Chain, southern Spain). Three anomalies maps are exposed and interpreted, focusing on neotectonic aspects. In order to avoid the influence of peridotitic bodies which outcrop in the studied area, and the southward thinning of the crust, a regional anomaly map has been processed and subtracted to the Bouguer anomaly. So, a residual anomaly map has been reached, where neotectonic interpretation has been done. The main tectonic feature evidenced by gravimetric data is the Albornoque Fault. It represents the southern boundary o f the Malaga Basin with a noticeable vertical component, according to its high gradient. By other hand, the fold o f Sierra de Cartama is marked by a maximum axis. This axis continues westward giving a duplicated depocenter of the basin. It is interpreted as a reverse fault, related in depth with the folding o f Sierra de Cartama, and which affects the basement o f the basin. According with the current stress field in the zone (NNW-SSE), the proposed structures imply the existence o f a compressive neotectonic activity, where the Albornoque fault is interpreted as a high angle reverse fault o f a reverse faul

Análisis de la sinuosidad del bajo Guadalhorce y sus implicaciones en la actividad tectónica reciente en la Cuenca de Málaga

The sinuosity of the Cuadalhorce River in the Malaga Basin is studied in this paper. The Malaga Basin is located in the Internal Zone of the Western Betic Chain, southern Spain. The river channel is divided into 5 reaches from the mouth, according to the strike variations of the valley. The sinuosity decreases dramatically in reach 2 in comparison to the sinuosity in reaches 5, 4, and 3. We interpret this lower sinuosity in reach 2 as a decrease in the slope of the valley. This fact is also observed in the longitudinal profile of the river channel along reach 2. We conclude that the anomalies observed in reach 2 are due to a gentle syncline related to the active anticline of Sierra de Cártama

Movimientos verticales de las fallas alpinas NE-SO del Macizo Ibérico en la región de Lugo

The vertical component of the movement associated to a fault system striking NE-SW has been determine using geomorphic and structural observations. These faults are located in the Iberian Massif in the Lugo region. The results of both kind o f observations have coincided in characterising these faults as hinge and pivotal faults. Moreover, considering the different periods of time recorded by these methods, we can establish that these faults are Tertiary and it is very difficult to explain a previous origin because of the structure complexity and the coincidence of the measures. In addition, and according to the results obtained from this area, we believe that the measures taken from the geomorphic markers, can be used alone as reliable indicators of the vertical component in this kind of faults, especially in areas where there are no others indicators

Evolución del basamento paleozoico de los Andes Norpatagónicos en el área de San Martín de los Andes (Neuquén, Argentina): petrología, edad y correlaciones

In San Martín de los Andes area (Argentinian Patagonia) the Palaeozoic basement consists of metamorphic and plutonic rocks. The metamorphic rocks include strongly deformed schists, gneisses and migmatites. Their geochemical and petrographic characteristics suggest that the protholith could have been a sequence of pelites and greywackes. Detrital zircon analysis (U-Pb Q-ICP-LA-MS) yielded a maximum depositional age of 501±14 Ma (Series 3 Cambrian) for this sedimentary protolith. Metasedimentary rocks are affected by a regional foliation defined by the minerals of the metamorphic peak. This is a S2 foliation, since relics of a former foliation are present in some samples. This regional foliation is locally affected by open folds that develop an incipient crenulation cleavage (S3). The high-grade metamorphism includes partial melting processes, where the incipient segregates intrude parallel to the regional foliation and also cut it in presence of abundant melt. Zircons from anatectic granites formed during this partial melting process yielded a U-Pb Concordia age of 434.1±4.5 Ma (Llandovery-Wenlock, Silurian). The age of maximum sedimentation and the anatectic age constrain the metamorphic evolution of the basement into the lower Palaeozoic (between upper Cambrian and lower Silurian). The igneous rocks of the basement are granodiorites, tonalities, and some gabbros that cut the metamorphic basement and contain xenoliths and roof pendants from the country rocks. These plutonic rocks are affected by low-grade metamorphism, with the development of discrete, centimetric to hectometric, brittle-ductile shear zones. The age of these igneous rocks has been constrained through U-Pb zircons analysis, carried out by several authors between ca. 370 and 400 Ma (Devonian). The maximum sedimentation age for the protolith and its metamorphic evolution seems to be related to an early Palaeozoic orogenic event, probably the Patagonian Famatinian orogeny. In contrast, the Devonian igneous rocks of San Martín de los Andes could represent a Devonian magmatic arc, related to subduction processes developed at the beginning of the Gondwanan orogenic cycle, which culminates with the Gondwanan orogeny.En el entorno de San Martín de los Andes (Patagonia argentina), el basamento Paleozoico está constituido por rocas metamórficas e ígneas. Las rocas metamórficas de esta área incluyen esquistos, gneises y migmatitas intensamente deformadas. Según sus características geoquímicas y petrográficas, el protolito de las mismas es considerado una alternancia de pelitas y grauvacas. Análisis de circones detríticos (U-Pb Q-ICP-LA-MS) permiten definir una edad máxima de sedimentación de 501±14 Ma (Series 3, Cámbrico) para este protolito sedimentario. Las rocas metasedimentarias se encuentran afectadas por una foliación regional definida por la asociación principal del pico metamórfico. Esta es una foliación de tipo S2, ya que se encuentran relictos de una foliación anterior en algunas muestras. Esta foliación regional, está localmente afectada por pliegues abiertos donde se desarrolla un clivaje de crenulación incipiente (S3). El metamorfismo de alto grado incluye un evento de fusión parcial, donde los primeros segregados se introducen a favor de la foliación S2 y la cortan en presencia de abundante fundido. Circones obtenidos de un granito anatéctico producido durante este evento de fusión parcial arrojaron una edad Concordia U-Pb de 434.1±4.5 Ma (Llandovery-Wenlock, Silúrico). La edad máxima de sedimentación y la edad de anatexis permiten acotar la evolución de las rocas metamórficas del basamento al Paleozoico inferior (entre el Cámbrico tardío y el Silúrico temprano). Las rocas ígneas del basamento son granodioritas y tonalitas, con menor proporción de gabros, las cuales cortan las rocas metamórficas y contienen xenolitos y roof pendants de las mismas. Por otra parte, estas rocas plutónicas fueron afectadas por un metamorfismo de bajo grado que llevan asociadas zonas de cizalla frágil-dúctil centimétricas a hectométricas. Edades U-Pb SHRIMP en circones restringe la edad de estas rocas entre 370 y 400 Ma (Devónico). La edad máxima de sedimentación de los protolitos de las rocas metamórficas y su evolución metamórfica podría estar relacionada a un evento orogénico del Paleozoico temprano, probablemente a la orogenia Famatiniana Patagónica. En contraste, las rocas plutónicas de San Martín de los Andes representarían un arco magmático, relacionado a una subducción que se habría producido al comienzo del ciclo orogénico Gondwánico, el cual culmina con la orogenia Gondwánica.Centro de Investigaciones Geológica

Análisis paleopiezométrico y tasas de deformación de la zona de cizalla dúctil extensional de Santa María de la Alameda (Sistema Central)

The differential stress that caused the extensional ductile shear o f Santa Ma de la Alameda during the collapse of the Variscan orogen in the Sistema Central (central Iberia) has been estimated using the dynamically recrystallized grain size of quartz. An estimate of the strain rate has been calculated by the flow laws for ductile strain of quartz knowing the deformation temperature. The stress history obtained for this shear band features 3 stages of 22-31 MPa, 34-65 MPa and 53-67 MPa. The increase o f the differential stress is caused by the concentration of the strain in smaller bands during mylonitization. The first stage can be correlated to the initial deformation of a wide shear band, the second stage can be related to the formation of two main mylonitic shears, and finally the third stage correspond to the deformation of thin (<1 mm) shear bands between grains in granitic synkinematic dikes. The strain rate deduced for the temperature interval of 300-350Q C ranges from 10-11 s-1 to 10-13 s-1. An small fault displacement can be assumed based on the low difference of the metamorphic grade, this allows us to discuss different duration for mylonitization according to different strain rates. The strain rates more successful range from 10-12 s-1 to 10-13 s-1 giving respectively a mylonitization period o f 1,6 ma. and 16 ma. for the observed thickness ot 280 m of mylonites