Geophysical Study of a Large Landslide Affecting the Urban Area of Albuñuelas (S Spain)

The urban area of Albuñuelas, a small town located to the south of Granada (S Spain), has been developed in terrain affected by a large-scale rotational landslide with very slow rate of movement. Despite this situation, the internal structure of the landslide and how it has evolved to its present state has not been analyzed in depth up to now. In this paper, we present the first study performed on this landslide to define its configuration and characteristics. For this purpose, ambient noise single-station and array measurements were carried out along several cross-sections of the landslide. The inversion of the measurements has allowed for the estimation of the soil stratigraphy at each site of measurement. These geophysical results have been constrained by data from a borehole drilled in the zone and from field observations of the local geology, allowing for the reduction in uncertainties in the results. A geological–geophysical model of the landslide has been built from these data, showing that the landslide thicknesses is greater than 50 m in its central parts and above 60 m in the upper ones. This model reveals that the evolution of the landslide was complex, with several dislodged elements (blocks) that moved in sequence (retrogression) and were partially eroded in order to explain present morphology. The future evolution of this landslide will be controlled by the composition of the materials surveyed along the foot of the valley, being the western part where there are more erodible materials according to the obtained results.This study was partially funded by the EU (FEDER), by the Secretaría de Estado de Investigación, Desarrollo e Innovación of the Spanish government (projects CGL2015-65602-R, CGL2016-77688-R), by the Spanish Investigation Agency (project PID2022-136678NB-I00 AEI/FEDER), by the Conselleria de Innovación, Universidades, Ciencia y Sociedad Digital de la Generalitat Valenciana (project CIAICO/2022/038), and by the Junta de Andalucía (project GGI3002IDIN)

Aprendizaje a través de aplicaciones en titulaciones de Ciencias e Ingeniería

En estos años de impartición de los grados, todos los miembros de la red docente hemos comprobado cómo, curso a curso, el nivel del alumnado, sobre todo en áreas como Física, Química y Matemáticas iba disminuyendo y cada vez era más difícil conseguir que asimilaran conceptos complejos y que mantuvieran un alto nivel de motivación para el aprendizaje si se utilizaban mecanismos tradicionales de enseñanza-aprendizaje. La realidad observada es que, en la mayoría de los casos, el alumnado trataba de memorizar el concepto sin entenderlo y, por lo tanto, su aplicación práctica le resultaba casi imposible si los parámetros iniciales del problema a resolver se apartaban ligeramente de los que se resolvían en clase. Esta red docente ha servido para diseñar aplicaciones/instrumentos que permitirán no sólo motivar al alumnado mediante experiencias que le permiten demostrar su competencia en el concepto aprendido sino también a que estas se realicen en un entorno diferente y se pueda evaluar el grado de satisfacción con la metodología aplicada. Las asignaturas seleccionadas pertenecen a los grados en Ciencias del Mar, Geología, Ingeniería Química e Ingeniería en Sonido e Imagen en Telecomunicación

Diseño de instrumentos y aplicaciones para la mejora del aprendizaje en asignaturas de titulaciones de Ciencias e Ingeniería

Actualmente, el alumnado de titulaciones de Ciencias e Ingeniería (Grado en Ciencias del Mar, Grado en Geología, Grado en Ingeniería Química y Grado en Ingeniería en Sonido e Imagen) muestra una gran dificultad para el aprendizaje de determinados conceptos teóricos, que no pueden observarse mediante aplicaciones prácticas durante las sesiones de teoría o de laboratorio, sobre todo en el caso de conceptos relacionados con fenómenos a gran escala, como por ejemplo el movimiento de las corrientes oceánicas, las ondas planetarias, la generación y registro de terremotos, la geología marina, etc. El objetivo de este trabajo ha sido el diseño de aplicaciones y/o instrumentos para algunas asignaturas de los grados anteriores. Como resultado se han desarrollado diferentes esquemas de trabajo colaborativo basado, generalmente, en aplicaciones de software libre y/o de bajo coste así como un vehículo remotamente operado (ROV) de bajo coste que han permitido diseñar guiones de trabajo para el aprendizaje de determinados conceptos complejos en el alumnado de Ciencias e Ingeniería y mejorar, de esta forma, su interés por las asignaturas y el grado de aprendizaje. Aunque en esta fase no se ha podido evaluar completamente su utilidad en el aula esperamos poder continuar este proceso en una futura red

Las prácticas de Geofísica marina en los grados de la Universidad de Alicante

En las asignaturas de “Geología marina”, del grado de Ciencias del Mar, y “Geofísica y prospección geofísica” del grado de Geología de la Universidad de Alicante se realizan prácticas de geofísica marina. Las prácticas suelen realizarse con un equipo boomer de sísmica de alta resolución desde barco. Durante los últimos 4 cursos se han realizado dichas prácticas, resultando muy problemáticas cuando hay mal tiempo, ya que obliga a hacerlas dentro del puerto. Por ello, se ha buscado la alternativa de hacer las prácticas desde tierra firme, con los equipos en el muelle, complementándola con la utilización de un ROV (Remote Operated Vehicle). Para ello se ha fabricado un ROV adaptando un diseño previo, al que se le acopla una cámara sumergible para realizar inmersiones en diferentes zonas de los muelles. De esta forma se consigue una práctica no dependiente del tiempo atmosférico, adecuada a unos horarios cada vez menos flexibles, y mucho más barata, ya que no se necesita alquilar un barco.Marine Geophysics practices are performed in the subjects of “Marine Geology”, of the Marine Sciences degree, and “Geophysics and Geophysical Prospecting” of the Geology degree in the University of Alicante. The practices are carried out with a-high-resolution seismic boomer equipment carried on a ship. During the last 4 courses the practices have been conducted, being very problematic in bad weather days. Therefore, we have thought the alternative of doing practices onshore, releasing the equipment from the dock, supplemented by the use of an ROV (Remote Operated Vehicle). For this we have built our ROV, adapting a previous design, to which is attached an underwater camera for diving in different areas of the docks. Thus a non-dependent on the weather, more adequate to increasingly less flexible schedules, and much cheaper practice is achieved, since there is no need to rent a boat

Assessment of CO2 dynamics in subsurface atmospheres using the wavelet approach: from cavity–atmosphere exchange to anthropogenic impacts in Rull cave (Vall d′Ebo, Spain)

Subsurface environments are non-negligible contributors to the net carbon balance because they act as natural sinks of CO2 and are responsible for the efflux to the Earth’s atmosphere during their ventilation states. In this way, the characterization of the CO2 dynamics in these underground environments is essential to determine the gas exchange between both atmospheres. A complete microclimatic analysis and trace gas (CO2 and 222Rn) monitoring of Rull cave (southeast Spain) were conducted to characterize the natural dynamics and anthropogenic influence on the cavity. The analysis was accomplished by implementing wavelet analysis and resemblance techniques. This study enhances wavelet analysis as an efficient tool to analyse microclimatic time series, as it allows for the detection of the main periodicities of signals located in the time domain and the prevailing relationships between them. The analysis indicates that the low-frequency components of the signals were close to the identified annual natural cycles. For a 1-year cycle, the ventilation of the cavity causes the CO2 concentration to decrease from 3569 to 932 ppm in nearly 1 month, highlighting the existence of an output efflux from the cavity. On the contrary, the high-frequency components are linked to human perturbations caused by visitors in the cavity.This research was funded by the Spanish Ministry of Economy and Competitiveness Projects CGL2011-25162 and CGL2013-43324-R, and its programme Torres Quevedo (PTQ 13-06296 and PTQ 12-05601). A pre-doctoral research fellowship (BES-2012-053468) was awarded to C. Pla for the Project CGL2011-25162. Funding was also provided by the People Programme (Marie Curie Actions—Intra-European Fellowships, call 2013) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA Grant Agreement No. 624204.Peer Reviewe

Las prácticas de Geofísica marina en los grados de la Universidad de Alicante

En las asignaturas de “Geología marina”, del grado de Ciencias del Mar, y “Geofísica y prospección geofísica” del grado de Geología de la Universidad de Alicante se realizan prácticas de geofísica marina. Las prácticas suelen realizarse con un equipo boomer de sísmica de alta resolución desde barco. Durante los últimos 4 cursos se han realizado dichas prácticas, resultando muy problemáticas cuando hay mal tiempo, ya que obliga a hacerlas dentro del puerto. Por ello, se ha buscado la alternativa de hacer las prácticas desde tierra firme, con los equipos en el muelle, complementándola con la utilización de un ROV (Remote Operated Vehicle). Para ello se ha fabricado un ROV adaptando un diseño previo, al que se le acopla una cámara sumergible para realizar inmersiones en diferentes zonas de los muelles. De esta forma se consigue una práctica no dependiente del tiempo atmosférico, adecuada a unos horarios cada vez menos flexibles, y mucho más barata, ya que no se necesita alquilar un barco.Marine Geophysics practices are performed in the subjects of “Marine Geology”, of the Marine Sciences degree, and “Geophysics and Geophysical Prospecting” of the Geology degree in the University of Alicante. The practices are carried out with a-high-resolution seismic boomer equipment carried on a ship. During the last 4 courses the practices have been conducted, being very problematic in bad weather days. Therefore, we have thought the alternative of doing practices onshore, releasing the equipment from the dock, supplemented by the use of an ROV (Remote Operated Vehicle). For this we have built our ROV, adapting a previous design, to which is attached an underwater camera for diving in different areas of the docks. Thus a non-dependent on the weather, more adequate to increasingly less flexible schedules, and much cheaper practice is achieved, since there is no need to rent a boat

Shear wave velocity estimation in the metropolitan area of Málaga (S Spain)

We carry out a seismic noise study based on array measurements at three sites in the Málaga basin, South Spain, for the further estimation of shear wave velocity profiles. For this purpose, we use both the H/V method and the f–k technique in order to characterize the different materials present in the zone, i.e., Quaternary sediments and Pliocene sedimentary rocks above the bedrock. The H/V analysis shows frequency peaks going from 1 Hz, in areas close to the border of the basin, to 0.3 Hz in places located toward the center of the formation. The f–k analysis allows obtaining the dispersion curves associated with each site and subsequently, estimating the Vs profiles by inversion of the respective group velocities. In this way, the basin basement can be characterized by S-wave velocities greater than 2000 m/s. Regarding the basin fill, it is divided into three layers defined by different wave velocity intervals. The shallowest one is featured by velocities ranging from 150 to 400 m/s and comprises the Quaternary sediments, while velocities going from 550–700 to1200–1600 m/s characterize the two underlying layers composed by Pliocene sediments. Finally, the information provided by the three Vs profiles is integrated in a 2D cross-section of the basin to have a spatial view of its sedimentary structure. The results obtained here, in addition to providing useful information about the infill of the basin near the metropolitan area of Málaga, will be very helpful for future seismic zonation studies in the region.This work has been partially funded by the Research GroupVIGROB-184 (University of Alicante) and by the Spanish Government (grants CGL2011-30153-C02-02/BTE and CGL2011-25162), FPU program of the Ministry of Science and Innovation (AP2008-04686) and Instituto Alicantino de Cultura Juan Gil-Albert

Insights on Climate-Driven Fluctuations of Cave 222Rn and CO2Concentrations Using Statistical and Wavelet Analyses

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Understanding the fluctuations in cave air concentrations and their climatic control is substantial not only to preserve the quality of indoor atmospheres but also to avoid the risk related to the presence of hazardous substances. In this study, we investigated the most influential factors affecting 222Rn and CO2 concentrations, the nature of their dynamics, and their coupling with climatic variations. For this purpose, we combined a set of mathematical methods that included a statistical and wavelet analysis of a 6-year time series in Rull Cave (Spain). Generally, the 222Rn and CO2 dynamic in cave air showed similar patterns. However, the obtained results show that these gases have a different frequency response. Thus, the annual component of 222Rn and CO2 is controlled by the relationship between external and internal temperatures. At low frequencies, both gases are affected by the same variables when the cave atmosphere reaches a minimum concentration. However, when the cave atmosphere is isolated from the outdoors, 222Rn and CO2 behave differently and disturbance caused by the visitors is evidenced in terms of the CO2 concentration; the latter observation was confirmed by the wavelet analysis at high frequencies. In contrast, the 222Rn concentration shows important variations following rainfall, which was weakly identified in the CO2 concentration.This research was funded by the Spanish Ministry of Science, Innovation and Universities (projects CGL2016-78318-C2-1-R, CGL2016-78318-C2-2-R, and RTI2018-099052-B-I00) and the University of Alicante (project GRE17-12)

Ambient noise measurements in Albunyuelas (Granada, Spain)

Raw data corresponding to the paper "Geophysical Study of a Large Landslide Affecting the Urban Area of Albuñuelas (S Spain)

Implementación de estrategias basadas en instrumentos y aplicaciones para la mejora del aprendizaje en asignaturas de ciencias e ingeniería. Detección de debilidades y fortalezas

Actualmente, el alumnado de titulaciones de Ciencias e Ingeniería muestra una gran dificultad para el aprendizaje de determinados conceptos teóricos, que no pueden observarse mediante aplicaciones prácticas durante las sesiones de teoría o de laboratorio. En este trabajo profundizamos la investigación realizada durante el curso 2015-16 (Molina et al., 2016a), en la que se diseñaron instrumentos y aplicaciones, usando TIC, para poder introducir experimentos prácticos dentro de un aula de teoría (o un laboratorio) y con los que el alumnado pudiera interactuar, reforzando el aprendizaje teórico. Para ello se han seleccionados conceptos complejos en varias asignaturas y el proceso de aprendizaje se ha llevado a cabo comparando los resultados antes y después del uso de las TIC y analizando las debilidades y fortalezas asociadas al proceso. Los resultados demuestran las ventajas de su uso puesto que los resultados del aprendizaje y el interés del alumnado mejoran notablemente, así como su actitud hacia la utilidad del concepto. Sin embargo, también se observan debilidades importantes relacionadas fundamentalmente con las dificultades que el alumnado presenta al usar aplicaciones informáticas, la dificultad de mantener la atención y la motivación en el aula y con la falta de base en Física, Química y Matemáticas