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The Quaternary Active Faults Database of Iberia (QAFI) is an initiative lead by the Institute of Geology and Mines of Spain (IGME) for building a public repository of scientific data regarding faults having documented activity during the last 2.59 Ma (Quaternary). QAFI also addresses a need to transfer geologic knowledge to practitioners of seismic hazard and risk in Iberia by identifying and characterizing seismogenic fault-sources. QAFI is populated by the information freely provided by more than 40 Earth science researchers, storing to date a total of 262 records. In this article we describe the development and evolution of the database, as well as its internal architecture. Additionally, a first global analysis of the data is provided with a special focus on length and slip-rate fault parameters. Finally, the database completeness and the internal consistency of the data are discussed. Even though QAFI v.2.0 is the most current resource for calculating fault-related seismic hazard in Iberia, the database is still incomplete and requires further review, Instituto Geológico y Minero de España, España, Departamento de Geodinámica, Universidad Complutense de Madrid, España, Instituto de Hidráulica Ambiental, Universidad de Cantabria, España, Departament de Geodinàmica i Geofísica, Universidad de Barcelona, España, Departamento de Geologia, Universidade de Lisboa, Portugal, Instituto Dom Luiz, Universidade de Lisboa, Portugal, Área de Geología, Universidad Rey Juan Carlos, España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España, Instituto Superior Técnico, Portugal

La Base de Datos de Fallas Activas de Iberia (QAFI) es una iniciativa promovida por el Instituto Geológico y Minero de España (IGME) para construir un repositorio público de información científica sobre fallas con actividad en los últimos 2,59 Ma (Cuaternario). Además, la QAFI persigue establecer una base sobre la que facilitar la transferencia de conocimiento geológico al ámbito tecnológico de la gestión del riesgo sísmico en Iberia, en particular en la identificación y caracterización de fuentes sismogénicas tipo falla. La QAFI se ha construido a partir de la información proporcionada de modo altruista por más de 40 investigadores en ciencias de la Tierra conteniendo actualmente un total de de 262 registros. En este artículo se describe la concepción y evolución de la base de datos, y su arquitectura interna. Además, se ofrece un primer análisis global de los datos que contiene, con especial interés en parámetros tan importantes como la longitud y tasa de deslizamiento de las fallas. Finalmente se discuten dos temas cruciales en cualquier base de datos: su completitud y la homogeneidad de los datos. Se concluye que QAFI v.2.0, pese a ser la fuente más actualizada de información disponible en Iberia sobre peligrosidad sísmica de fallas concretas, dista aun de ser completa, por lo que nuevas revisiones y versiones deberán seguir llevándose a cabo en el futuro.

Con motivo de la ocurrencia de un terremoto catastrófico el 11 de mayo de 2011 de magnitud Mw 5.1, a las 18:47 (hora local), presentamos a continuación un informe geológico preliminar de urgencia. Consta de una descripción de los primeros datos geológicos relacionados con la posible fuente geológica del terremoto, sus características sismotectónicas, y sus efectos superficiales, tanto los relacionados con los daños en edificaciones como con efecto geológicos superficiales. Pocas horas después del evento se desplazó a la zona un grupo de especialistas en geología de terremotos de varias instituciones: Instituto Geológico y Minero de España (IGME), Grupo de Tectónica Activa, Paleosismicidad y Riesgos Asociados de la UCM (UCM), Universidad Autónoma de Madrid (UAM) y la Universidad Rey Juan Carlos de Madrid (URJC), con el fin de recabar todos aquellos datos, tanto de daños como de posibles efectos geológicos superficiales que por su carácter efímero pudieran desaparecen en pocos días tras el evento. Para la realización de este informe se han utilizado los datos obtenidos durante los cuatro días que duró esta campaña de emergencia, así como datos sísmicos del Instituto Geográfico Nacional y datos geológicos de trabajos previos. Los resultados e interpretaciones presentadas son preliminares y responden al análisis de las evidencias con que se cuenta a día de hoy durante la redacción de este informe.

Hecates Tholus is a volcano located at the Elysium volcanic province in the Martian lowlands (32ºN, 210ºW). In addition to several nested calderas, the volcano shows several geological and geomorphological features that could be indicative of a complex volcanic evolution: channels, depressions, pits, faults and ridges, and a complex volcano topography. The processes that can explain the structural evolution of the volcano, include: (1) volcanic spreading, (2) lateral volcanic activity, (3) development of large landslides, (4) hydrothermal activity, and (5) tectonic deformation. We discuss these hypotheses and their implications, in order to establish the most feasible volcanic history of Hecates Tholus

Hecates Tholus is a volcano located at the Elysium volcanic province in the Martian lowlands (32ºN, 210ºW). In addition to several nested calderas, the volcano shows several geological and geomorphological features that could be indicative of a complex volcanic evolution: channels, depressions, pits, faults and ridges, and a complex volcano topography. The processes that can explain the structural evolution of the volcano, include: (1) volcanic spreading, (2) lateral volcanic activity, (3) development of large landslides, (4) hydrothermal activity, and (5) tectonic deformation. We discuss these hypotheses and their implications, in order to establish the most feasible volcanic history of Hecates Tholus

The Northwest of the Iberian Peninsula is characterised by the absence of Mesozoic sedimentary deposits, the Cenozoic sediments being scarce. Due to that, the chronology of the geological events in the area is difficult to establish. Nevertheless, in the absence of deposits during a certain time span, the thermal history a particular area during that time-elapse could have been recorded in previous materials. Modelling of the apatite fission-track (AFT) data is a powerful tool to infer geological information in this kind of regions. The tectonothermal history observed in the AFT models begins with the intrusion of the late Variscan granitic plutons and their cooling in the upper crustal levels. After this initial event, three main episodes have been identified. The first involves an important heating during the Upper Jurassic and Earlier Cretaceous, which can be related to the evolution of the Atlantic passive margin. The second heating episode can be connected to the beginning of the Europe-Africa collision during the Upper Cretaceous and the Earlier Palaeogene. Finally, a cooling episode is observed during the Paleogene, which can reflect exhumation processes according with the tectonic structures and the development of the present day topography

The Northwest of the Iberian Peninsula is characterised by the absence of Mesozoic sedimentary deposits, the Cenozoic sediments being scarce. Due to that, the chronology of the geological events in the area is difficult to establish. Nevertheless, in the absence of deposits during a certain time span, the thermal history a particular area during that time-elapse could have been recorded in previous materials. Modelling of the apatite fission-track (AFT) data is a powerful tool to infer geological information in this kind of regions. The tectonothermal history observed in the AFT models begins with the intrusion of the late Variscan granitic plutons and their cooling in the upper crustal levels. After this initial event, three main episodes have been identified. The first involves an important heating during the Upper Jurassic and Earlier Cretaceous, which can be related to the evolution of the Atlantic passive margin. The second heating episode can be connected to the beginning of the Europe-Africa collision during the Upper Cretaceous and the Earlier Palaeogene. Finally, a cooling episode is observed during the Paleogene, which can reflect exhumation processes according with the tectonic structures and the development of the present day topography

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 (

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.

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.

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 fault

The illite crystallinity index of Kubler (1C) has been studied to establish the conditions of the last deformation stages in the Santa María de la Alameda shear zone. For this study, it has been used mainly the fine grained fraction of the samples (less than 2 mm) which is concentrated along small brittle fractures and zones of protocataclasitic material. The studied rocks give "illite crystallinity index" values between 0.35 D°2q and 0.25 D°2q, pointing to deformation conditions at temperatures which denotes a retrograde metamorphismo zone belonging to the epizone and anquizone. These results indicate a a rétrogradation condition for the late brittle deformation stage of the Santa Maria de alameda fault, in temperatures range between 255 and 200° C

Principles of fractal geometry have been applied to the description of quartz grain borders and to the assessment of deformation temperature in milonitic rocks at the Santa Maria de la Alameda Ductile Shear Zone (Central System). This shear zone have evolved during late variscan tectonic period in a large temperature range, which goes from regional metamorphic pick conditions (Amphibolite facies) to temperatures lower than for Greenschists facies. Using fractal dimension analysis techniques and the temperature calibration performed by Kruhl y Nega (1996), have been established a temperature sequence, diminishing from around 490°C to 325°C during the simultaneous processes of milonitization and retrogressive metamorphism. These results are in agreement with temperatures obtained from deformation mechanisms in quartz and potassium feldspar showming the validity of fractal geometry method to deformation temperature assessment

Principles of fractal geometry have been applied to the description of quartz grain borders and to the assessment of deformation temperature in milonitic rocks at the Santa Maria de la Alameda Ductile Shear Zone (Central System). This shear zone have evolved during late variscan tectonic period in a large temperature range, which goes from regional metamorphic pick conditions (Amphibolite facies) to temperatures lower than for Greenschists facies. Using fractal dimension analysis techniques and the temperature calibration performed by Kruhl y Nega (1996), have been established a temperature sequence, diminishing from around 490°C to 325°C during the simultaneous processes of milonitization and retrogressive metamorphism. These results are in agreement with temperatures obtained from deformation mechanisms in quartz and potassium feldspar showming the validity of fractal geometry method to deformation temperature assessment

In this work is shown how an active fold (the Sierra de Cartama fault) is marked by the drainage pattern and topography, besides of structural data. The Sierra de Cartama fold is an asymmetric fold with double plunge and determines the shape of an elongated saw in the Western Betic Chains (South of Spain). Watching the drainage patterns, it can be noticed how streams and creeks round the saw. The uplift of the saw raise the valleys steeply, even leaving a hanging valley ("wind gap ") at the western part of the structure. Regarding to these observations, the lateral propagation of the fold seems to be toward the west. The proposed structure implies the existence of a compressive neotectonic activity in the zone. The compressive horizontal direction is N10e-30eW, perpendicular to the fold axis. In this tectonic environment it could be possible to interpret a reverse fault in deep associated with the fold growth

The Santa Maria de Alameda (Madrid) Ductile Shear Zone is a complex mylonitic belt trending east -West and dipping 30°-60° southward. The hanging wall block sinks towards the South-Southeast. Its kinematics is in relation to an extensional tectonic regime with North-south stretching direction. This large structure belongs to the early stages of the Malagon tectonic period, where important faulting and dike emplacement were produced. The shearing process was developed in retrograde metamorphic conditions in a wide range of temperature, which goes from 400° C to 150° C. The age of this deformation is constrained by the variscan regional metamorphic peak and the intrusion of late variscan granitoids (Las Navas del Marques adamellites), being therefore, between early Namurian and Stephanian

The Santa Maria de Alameda (Madrid) Ductile Shear Zone is a complex mylonitic belt trending east -West and dipping 30°-60° southward. The hanging wall block sinks towards the South-Southeast. Its kinematics is in relation to an extensional tectonic regime with North-south stretching direction. This large structure belongs to the early stages of the Malagon tectonic period, where important faulting and dike emplacement were produced. The shearing process was developed in retrograde metamorphic conditions in a wide range of temperature, which goes from 400° C to 150° C. The age of this deformation is constrained by the variscan regional metamorphic peak and the intrusion of late variscan granitoids (Las Navas del Marques adamellites), being therefore, between early Namurian and Stephanian

La determinación de las fallas capaces de disparar terremotos en zonas adyacentes con formaciones geológicas aptas para el almacenamiento profundo de gas, es una tarea que mitiga la ocurrencia de sismicidad inducida por operaciones subterráneas y movimiento de fluidos. Para ello, la determinación del campo de esfuerzos/deformación tectónicos activo ayuda a entender los patrones tridimensionales de fracturación cartografiados no solo en la zona, sino también en la propia roca almacén. Por este motivo, se presenta un protocolo de trabajo para la obtención del campo de deformación (σHmax, σhmin) que ayude a entender el papel de cada conjunto de fallas cartografiado. Para ello, aplicamos el Análisis Poblacional de fallas en dos zonas de influencia: 1) Campo cercano: 10 km de diámetro del almacenamiento y 2) Campo Lejano: 20 km de diámetro. Sobre estas zonas calculamos las trayectorias de deformación y llevamos a cabo una cartografía sistemática de fallas. Se presentan los resultados preliminares de Hontomín.

Reunión Ibérica sobre Fallas Activas y Paleosismología (3ª. 2018. Alicante). - Texto en inglés con resumen y palabras claves en inglés y español, Se han analizado 682 mecanismos focales de terremotos localizados en la Península Ibérica y zonas próximas. Aplicando métodos de determinación del tensor de deformación (Modelo de Deslizamiento), se han obtenido diferentes resultados para cada uno de los mecanismos focales: (1) plano de falla entre los dos planos nodales del mecanismo, (2) orientación de máximo acortamiento horizontal (ey), (3) factor de forma de tensor de deformación (k’) y (4) tipo de falla. Con estos datos se pueden realizar análisis regionales y locales de las características de la fracturación activa en el área considerada: (a) caracterización de la fracturación, (b) orientación de máximo acortamiento horizontal, (c) zonación en función del tipo de falla y del factor de forma del tensor de deformación. Este tipo de información puede ser muy útil a la hora de realizar tanto diferentes análisis locales de la peligrosidad sísmica, como para incorporar a los catálogos sísmicos terremotos históricos destructivos sin información de la fuente sísmica. = We analysed 682 earthquake focal mechanism solutions located in the Iberian Peninsula and nearby areas. We have obtained different parameters applying methods of determination of the strain tensor (Slip Model): (1) the fault plane between the nodal planes of the focal mechanism, (2) the orientation of the maximum horizontal shortening (ey), (3) the strain shape factor (k`) and (4) the type of fault. With these data, regional and local analysis of active faulting can be carried out in Spain: (a) fracture characterization, (b) the orientation of maximum horizontal shortening, (c) spatial zonation according to the type of fault and (d) the strain shape factor. These results can be useful for seismic hazards studies of local zones and for including destructive historical earthquakes in the seismic catalogs., Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España, Instituto Geológico y Minero de España, España, Departamento de Geología, Universidad de Salamanca, España, Departamento de Geología, Geografía y Medio Ambiente, Universidad de Alcalá, España, Departamento de Edafología, Universidad Politécnica de Madrid, España

Reunión Ibérica sobre Fallas Activas y Paleosismología (3ª. 2018. Alicante). - Texto en inglés con resumen y palabras claves en inglés y español, Se ha realizado un mapa de intensidad macrosísmica y aceleración del terreno (ShakeMap) de un terremoto SIMULADO, dentro de un macro ejercicio de emergencias Nivel III, propuesto por la Unidad Militar de Emergencias (UME), junto con Protección Civil y demás autoridades. El terremoto SIMULADO se localiza en la región de Murcia, con una magnitud de Mw 6.5, a 11 km de profundidad y asociado a un segmento activo de la Falla de Alhama de Murcia (FAM). El principal objetivo en este trabajo, es la génesis de mapas científicos útiles para las autoridades durante la gestión de la emergencia, mostrando las capacidades reales de gestión de un desastre natural de esta magnitud. = We have developed a ShakeMap (macroseismic intensity map and ground acceleration) for a SIMULATED earthquake, to be used into a large Emergency exercise of the highest level (Level III), and proposed by the Spanish Military Emergency Unit (UME), plus the Spanish Civil Protection and other local organisms. The SIMULATED earthquake is located within the Murcia province (SE of Spain), with a magnitude Mw 6.5 and 11 km depth. Moreover, this SIMULATED earthquake was assigned to the Alhama de Murcia Fault. The main goal of this work is the generation of scientific maps to be used by civil and military authorities during the management of great natural disasters as earthquakes, giving a real vision about what we can expect in a large earthquake affecting a wide area of Spain., Área de Riesgos Geológicos, Instituto Geológico y Minero de España, España, Departamento de Geología, Universidad de Salamanca, España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España, Departamento de Edafología, Universidad Politécnica de Madrid, España, Departamento de Geología, Geografía y Medio Ambiente, Universidad de Alcalá, España

La planta piloto de inyección de CO2 de Hontomín (Burgos) es la única planta de inyección en tierra en Europa. Para el desarrollo de este tipo de plantas de inyección son necesarios los estudios de los posibles efectos de terremotos que puedan afectarles. La falta de estudios de neotectónica en esta zona de la meseta norte de España hace necesario obtener datos sobre terremotos antiguos en esta zona. Los efectos de campo lejano del terremoto de Lisboa en Burgos pueden contribuir al conocimiento del comportamiento sísmico del terreno en caso de la ocurrencia de eventos similares. Hemos seleccionado principalmente construcciones románicas para obtener la dirección media de movimiento del sustrato generada por el terremoto de Lisboa en esta zona. Los resultados preliminares indican una dirección media de movimiento NE-SO. Las trayectorias de deformación obtenidas son refractadas por las fallas principales de la zona, variando su orientación para disponerse perpendiculares a estas.

Reunión Ibérica sobre Fallas Activas y Paleosismología (3ª. 2018. Alicante). - Texto en inglés con resumen y palabras claves en inglés y español, El yacimiento de gas de Poseidón constituye uno de los campos de extracción de gas el cual se localiza en el Golfo de Cádiz. Esta zona presenta fallas sismogénicas con capacidad de generar terremotos. Es por ello que un estudio exhaustivo de la potencial sismicidad inducida por operaciones de extracción de gas permitirá avanzar en el estudio de potenciales terremotos que afecten a la zona de Huelva, Cádiz y extremo suroeste de Portugal. La energía sísmica anual liberada en el entorno cercano al almacenamiento (50 km) presenta una correlación positiva con la cantidad de gas producida según datos oficiales del Ministerio de Energía, Turismo y Agenda Digital. También se observa que dicha correlación depende de la cantidad producida al año. Con estos datos, es importante hacer un seguimiento al ser una de las zonas de mayor actividad sísmica de la Península Ibérica, con capacidad de disparar terremotos destructivos. = The offshore field gas of Poseidon is located within the Gulf of Cadiz. This area is prone to large earthquakes, including the estimated epicentre of the great earthquake of Lisbon of 1755. In this sense, the study of the potential induced seismicity in this area is a key point to be addressed plus the role of induced earthquakes and large tectonic faults. We have found a positive correlation between the annual seismic energy released 50 km away of the gas field with the gas production (data provided by the Spanish Ministry of Energy).The long-term behaviour of the seismic energy and gas production indicates that induced seismicity was present during the period of extraction and reservoir depletion., Instituto Geológico y Minero de España, España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España