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X Congreso Geológico de España, 5-7 Julio 2021, Vitoria - Gasteiz, La región Cantábrica, al tratarse de una zona tradicionalmente considerada de baja sismicidad, ha suscitado menor atención que otras regiones sísmicamente más activas. Los nuevos datos recogidos por las redes sísmicas temporales implantadas en el marco de los proyectos SISCAN y MISTERIOS (2014-2020) han permitido mejorar el conocimiento acerca de la actividad sísmica de la zona. Durante el periodo del estudio, de casi seis años, se desplegaron más de 50 estaciones en la Región Cantábrica y norte de la Cordillera Ibérica. La densidad de estaciones y la geometría regular de estas redes han permitido registrar una sismicidad significativa. Se han localizado más de más de 1200 terremotos y se han calculado más de 60 mecanismos focales, en una región dónde apenas existían este tipo de datos. Los eventos localizados con mayor precisión y los mecanismos focales calculados se utilizaron para avanzar en la interpretación sismotectónica, con la identificación de las principales fallas activas. Por último, se ha llevado a cabo una evaluación de la peligrosidad sísmica de la región cantábrica y del Pirineo occidental. Para ello se ha abordado una modelización probabilista de la peligrosidad sísmica en términos de aceleración pico (PGA) y de aceleraciones espectrales (SA (T)) para un periodo de retorno de 475 años., The present-day seismicity in the Cantabrian region (North of Iberia) is not well known due to the limited coverage of stations from permanent seismic network in the area. Being an area traditionally considered of low seismicity, it has attracted less attention than other seismically more active regions, such as the southeast and northwest of the Iberian Peninsula, or the Pyrenean area. The new data collected by the temporary seismic networks implemented during the SISCAN and MISTERIOS projects (2014-2020) have allowed us to improve our knowledge about the seismic activity in the area. During the study period, for almost six years, a seismic network of more than 50 stations was deployed in the Cantabrian Region and the northern Iberian Chain. The density of stations and the regular geometry of these seismic net-works have allowed us to register a significant seismic activity. More than 1200 earthquakes have been located and more than 60 focal mechanisms have been calculated in a region where such data was hard-ly available. The events located with the greatest precision and the calculated focal mechanisms were used to improve the seismotectonic interpretation, with the identification of the main active faults. Final-ly, an evaluation of the seismic hazard in the Cantabrian region and the western Pyrenees has been carried out. To this end, a probabilistic modeling of the seismic hazard in terms of peak ground acceleration (PGA) and spectral acceleration (SA (T)) has been addressed for a return period of 475 years.

12th International Conference of the ERCIM WG on Computational and Methodological Statistics (CMStatistics 2019) in London, UK ,14-16 december 2019, Seismic data are typically employed to monitor earthquake activity, but they can also be exploited in order to investigate the existing links between the seismic signal and a broad range of physical processes occurring in the nearby rivers. For instance, the noise related to water turbulence during high discharges has a clear impact on the seismic signal. Concurrently, high-flows in gravel-bed rivers involve the displacement of large volumes of coarse sediment particles, travelling as bedload, which in turn should be the source of an additional and non-negligible amount of seismic noise. Data derived from the 3-years seismic monitoring of a gravel-bed river located in NW of Spain are considered. First, we have accomplished spectral analysis over the seismic noise generated by more than 10 river flow events with high discharge. Then, we have applied several statistical analysis not only for calibrating the functions describing the links between seismic noise and fluvial discharge but also in order to identify the thresholds for detection of incipient bedload transport and geomorphic change in the seismic signal.

EGU General Assembly 2019, in Viena, Austria, 7–12 April 2019, Many ambient noise tomography applications are based on measuring surface wave group velocities from timedomain cross-correlations. This approach has several downsides, among them being: (A) reliable group velocity measurements require at least an inter-station distance of 3 wavelengths, (B) usually, only the fundamental mode of Rayleigh wave propagation is considered, disregarding the possible contribution to the observed group/phase velocity of higher modes, and (C) surface wave dispersion measurements only offer weak constraints for the very shallow and the very deep shear-wave velocity structure at the periods used in most regional studies. To overcome these limitations, we propose an inversion scheme based on Aki’s spectral formulation. First, we measured Rayleigh wave phase velocities by fitting Bessel functions to the observed cross-correlation spectra, and used these measurements in a tomographic inversion to produce a set of phase velocity maps. Then, we defined a grid of regularly spaced nodes on the phase velocity maps, and used the dispersion information on a non-linear inversion to obtain a 1D shear-wave velocity profile at each node. Our inversion scheme considers the influence of higher modes in the observed phase velocities. The same noise recordings used for measuring surface wave dispersion can be used to determine the H/V spectral ratios at the receivers. The fundamental frequency and the shape of the peaks in the H/V ratios can be related to the thickness of the sediment layers and the impedance contrasts between the sediments and the basement, thus providing additional constraints for the deep shear-wave velocity structure in the vicinity of the receivers. Therefore, for the nodes closer to the receivers, we performed a joint inversion of the Rayleigh wave phase velocities and the H/V spectral ratios. We applied this methodology to the data provided by the SISCAN-MISTERIOS network, a regularlyspaced grid of 40 broad-band stations with inter-station distances ranging from 27 to 440 km, deployed in the Basque-Cantabrian basin (N Spain) during the period 2014-2018. The Basque-Cantabrian basin (N Spain) is one of the major Mesozoic extensional basins developed during the opening of the Bay of Biscay. In Cenozoic times, the Alpine collision between the European plate and Iberian sub-plate caused the inversion of the normal faults, the reactivation of older (Variscan) thrusts and the creation of new structures. As a consequence, both the depth to the Paleozoic basement and the velocity structure vary greatly across the area, providing a challenging scenario to test the proposed methodology. In spite of some difficulties (i.e. weak impedance contrasts between the Mesozoic sediments and the Paleozoic basement in parts of the basin, problems to retrieve accurate spectral ratios for some stations at the considered frequencies, etc), the application of the methodology described above provided good results in areas where the structure was known in detail, and allowed us to achieve a better constrained image of the 3D shear-wave velocity structure across the whole basin.

AGU Fall Meeting 2019, in San Francisco, 9-13 december 2019, Surface waves in seismic noise correlation functions are routinely exploited to image structures at a broad range of scales and resolutions. In most applications, the correlation functions are considered (1) to be estimates of the Green¿s function between pairs of receivers and (2) to be composed mainly of fundamental-mode surface waves. This approach requires at least an inter-station distance of 3 wavelengths to produce reliable phase/group velocity measurements, which can be a limiting factor when working at local or regional scales. Additionally, as shown by many previous studies, the presence of superficial low-velocity layers may cause a dominance of higher modes over certain frequency ranges, which means that only considering the fundamental mode may not be enough to accurately model the observed dispersion curves. In this work, we overcome the limitations by measuring Rayleigh wave phase velocities directly from the cross-correlation spectra. This approach does not depend on the far-field approximation and is, therefore, not subject to the three-wavelength rule. We use these measurements to produce a set of phase velocity maps using a standard tomographic algorithm. Finally, for a set of regularly spaced nodes, dispersion curves are compiled from the phase velocity maps and used in a non-linear inversion to obtain the 1D shear-wave velocity structure. Previous geological and geophysical studies are used to place constraints on the non-linear inversion. We apply this methodology to seismic data acquired in the Basque-Cantabrian region (N Spain) between 2014 and 2018 (by the SISCAN-MISTERIOS network, with inter-station distances ranging from 7 to 400 km) and obtain a 3D model of this structurally complex area (a thick Mesozoic basin inverted and incorporated into the Pyrenean-Cantabrian mountain belt in the Cenozoic) which agrees with the existing geological knowledge but significantly extends the area for which high-resolution information is available.

International audience; The Alpine Pyrenean-Cantabrian orogen developed along the plate boundary between Iberia and Europe, involving the inversion of Mesozoic hyperextended basins along the southern Biscay margin. Thus, this margin represents a natural laboratory to analyze the control of structural rift inheritance on the compressional reactivation of a continental margin. With the aim to identify former rift domains and investigate their role during the subsequent compression, we performed a structural analysis of the central and western North Iberian margin, based on the interpretation of seismic reflection profiles and local constraints from drill-hole data. Seismic interpretations and published seismic velocity models enabled the development of crustal thickness maps that helped to constrain further the offshore and onshore segmentation. Based on all these constraints, we present a rift domain map across the central and western North Iberian margin, as far as the adjacent western Cantabrian Mountains. Furthermore, we provide a first-order description of the margin segmentation resulting from its polyphase tectonic evolution. The most striking result is the presence of a hyperthinned domain (e.g., Asturian Basin) along the central continental platform that is bounded to the north by the Le Danois High, interpreted as a rift-related continental block separating two distinctive hyperextended domains. From the analysis of the rift domain map and the distribution of reactivation structures, we conclude that the landward limit of the necking domain and the hyperextended domains, respectively, guide and localize the compressional overprint. The Le Danois block acted as a local buttress, conditioning the inversion of the Asturian Basin.

We present a new crustal-scale transect of the eastern Basque-Cantabrian Zone, through the Cinco Villas Massif, the Leiza-Aralar Thrust System and the South-Pyrenean Zone. The restoration of this transect to its pre-shortening stage allows us to assess the architecture of the hyperextended domain and the style of the Alpine contractional deformation. During the Cretaceous, extension led to a hyperthinned crust with local mantle unroofing to the base of the eastern Basque-Cantabrian Basin. The mantle unroofing process was driven by a complex system of detachments putting into contact Mesozoic sediments in the hanging wall with mantle rocks in the footwall. At this stage, extensive fluid circulation caused serpentinization of the uppermost mantle body. Furthermore, the thermal anomaly created during the unroofing caused high temperature metamorphism of the overlying sediments of the Leiza detachment system and hydrothermalism in further basins. The Alpine convergence gave rise to the tectonic inversion of the Mesozoic basins. Tectonic structures inherited from the Cretaceous hyperextension played a major role in mountain building. The southward indentation of the European crust forced the northwards subduction of the Iberian crust and the basement-cover decoupling along the Triassic evaporites. Restoration of this section to the end of the extensional period enabled us to estimate a shortening of~90 km., En este trabajo se presenta un nuevo modelo de estructura cortical en el borde oriental de la Zona Vasco-Cantábrica, atravesando el Macizo de Cinco Villas, el sistema de cabalgamientos de Leiza-Aralar y la Zona Surpirenaica. La restauración de esta sección al estadio previo a la convergencia alpina permite establecer la arquitectura del dominio cortical hiperextendido Mesozoico y el estilo de la deformación compresiva posterior. Durante el Mesozoico, la deformación extensional asociada a la apertura del Golfo de Vizcaya dio lugar a la formación de dominios de corteza hiperextendida y a la exhumación parcial del manto bajo la Cuenca Vasco-Cantábrica oriental. El proceso de exhumación del manto se produjo por la acción de un complejo sistema de detachments extensionales que pusieron en contacto la cuenca cretácica en el bloque superior con el manto en su bloque inferior. En este estadio, la intensa circulación de fluidos a lo largo de estos detachments causó la serpentinización de la parte superior del cuerpo mantélico. Además, la anomalía térmica creada en este proceso, generó un metamorfismo de alta temperatura que afectó a los materiales mesozoicos localizados inmediatamente sobre el manto exhumado, así como hidrotermalismo en cuencas más alejadas de la aureola metamórfica. La orogenia Alpina dio lugar a la inversión de las cuencas mesozoicas, y las estructuras tectónicas heredadas de la etapa de hiperextensión cortical jugaron un papel determinante en la configuración de la estructura orogénica. La indentación hacia el sur de la corteza Europea en la corteza Ibérica forzó la subducción de esta última hacia el norte y el desacoplamiento del basamento con respecto a la cobertera sedimentaria mesozoico-terciaria a lo largo del nivel de despegue de las evaporitas del Triásico superior. La restauración de esta sección cortical al final del periodo extensional indica un acortamiento cenozoico de aproximadamente 90 km., We thank the PhD financial support for IDF given by the University of Oviedo-Banco Santander, Government of the Principality of Asturias and the FPU grant of the Spanish Ministry of Education. This is a contribution of the ESF TopoEurope Project PYRTEC (SV-PA-10-03-IP2- PYRTEC), the Consolider-Ingenio 2010 Project TOPOIBERIA (CSD2006-00041) and the Ministry of Economy and Competitiveness Project MISTERIOS (CGL2013-48601-C2-2-R).

The presence of ophicalcites in serpentinized peridotites together with fragments of these rocks in Cretaceous breccias along several North‐Pyrenean basins led to the interpretation of complete mantle exhumation to the seafloor. The westernmost outcrop of peridotites in the Pyrenean‐Cantabrian belt is located in Ziga (eastern Basque‐Cantabrian Basin), associated to a band of HT metamorphism related to the Leiza fault (Marble Unit). We present a petrological and geochemical study of the marbles and Ziga peridotite‐hosted calcite, including standard stable isotope composition and clumped isotope geothermometry. These isotopic techniques allow the determination of different types of formational fluids and crystallization temperatures, and are a useful tool for studying carbonation processes in hyperextended basins. Fieldwork and analytical studies lead us to conclude that during the opening of the Bay of Biscay, mantle rocks were unroofed at the base of the sedimentary pile of the eastern Basque‐Cantabrian Basin. However, the ophicalcite veins were recrystallized from meteoric fluids at low temperatures (≤49°C). The primary carbonate phase may have been formed either during the mid‐Cretaceous unroofing of the mantle or in a post‐exhumation stage. The process of mantle exhumation was accompanied with HT‐LP metamorphism and fluid circulation along major faults that reset the marine isotopic signature in the nearest marbles. For comparison, ophicalcites from Urdach and Lherz (North‐Pyrenean Zone) were included in the clumped isotope study. Results show that they were recrystallized from hot (∼200–230°C), saline fluids, and from meteoric fluids at near ambient temperatures (∼32–42°C), respectively., We thank the PhD financial support for IDF, given by the University of Oviedo‐Banco Santander, Government of the Principality of Asturias and the FPU grant of the Spanish Ministry of Education, Culture and Sport. This is a contribution of the Ministry of Economy and Competitiveness Project MISTERIOS (CGL2013‐48601‐C2‐2‐R), the Consolider‐Ingenio 2010 Project TOPO‐IBERIA (CSD2006‐00041), and the ESF TopoEurope Project PYRTEC (SV‐PA‐10‐03‐IP2‐PYRTEC).

The knowledge of the anisotropic properties beneath the Iberian Peninsula and Northern Morocco has been dramatically improved since late 2007 with the analysis of the data provided by the dense IberArray broad-band seismic network deployed in the Topo-Iberia project, the increasing number of permanent stations operating in Morocco, Portugal and Spain, and the contribution of smaller scale/higher resolution experiments. The first Topo-Iberia de-ployment in the Betics-Alboran zone has evidenced a spectacular rotation of the fast polarization direction (FPD) along the Gibraltar arc following the curvature of the Rif-Betic chain. This result has been interpreted as an evidence of mantle flow deflected around the high velocity slab beneath the Alboran Sea Arc. Data from the second Topo-Iberia deployment and from additional deployments in the Moroccan Meseta and the western High Atlas have shown a rather uniform N100ºE FPD beneath the Variscan Central Iberian Massif, consistent with global mantle flow models taking into account contributions of surface plate motion, density variations and net lithosphere rotation. The results from the last deployment of the IberArray network presented here cover the northern part of the Iberian Peninsula and also show a rather uniform FPD orientation close to N100ºE, confirming the previous interpretation. However, the degree of anisotropy changes significantly, from delay times values around 0.5 s beneath NW Iberia to values reaching 2.0s in its NE corner. The anisotropic parameters retrieved from single events providing high quality data also show significant differences for stations located in the Variscan units of NW Iberia, suggesting that the region includes multiple anisotropic layers or complex anisotropy systems.

Host plant quality can influence insect larval performance and subsequent adult fitness. Advanced hybrid potato clones (donor species: Solanum berthaultii Hawkes) and their parents were evaluated for resistance to the potato tuber moth (PTM) and examined for several biochemical, molecular and physical traits in order to investigate the mechanisms which underlie PTM-resistance. Resistant parent recorded 57% of mortality of pupae in comparison to the 23% observed in the susceptible parent. Expression patterns of specific genes involved in the phenolic biosynthetic pathway show that hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) and cinnamate-4-hydroxylase (C4H) reflect chlorogenic and caffeic acid levels in the skin of all the genotypes (0.7 ≤ r ≤ 1.0). Skin α-chaconine and skin caffeic acid strongly and significantly related with PTM larval mortality (r2 = 0.99 and r = 0.90, respectively). This study suggests that skin α-chaconine and skin caffeic acid could play a defensive role against PTM and proposes a PTM resistant clone with high level of these bio-compounds, useful in breeding projects for plant defense and nutritional value purposes.