Las fallas del recinto de la Alhambra : Faults in the Alhambra area

The Alhambra is built on a conglomeratic formation, known as the Alhambra Formation, whose age is Pliocene to Lower Pleistocene and has a visible thickness of 200 metres. The western part of the San Pedro escarpment corresponds to a fault-scarp with some retreat; the fault-plane outcrops in the innermost part of the escarpment, showing normal displacement and NW-SE strike with NE steep dip. This fault is the most important one of a set that outcrops along the northern hillslope of the Alhambra. Several topographic steps with NW-SE orientation are interpreted as retreated fault-scarps. In some cases, the activity of these faults seems to be very recent and maybe related to earthquakes. The seismic risk associated with these faults (and maybe some not-outcropping ones) can be taken to be moderate, as some historical damages have been reported concerning the Alhambra walls and the fence. In this respect, the Alhambra fence has numerous cracks geometrically related to fault planes outcropping in the Alhambra Formation, i.e. faults and cracks are continuous and have similar strike and dip. We hypothesize that these cracks are due to small displacements along the faults, occurred during recent earthquakes in the region. These faults constitute mechanical discontinuities, which represent a supplementary risk, because they contribute to reduce the stability of the entire rock massif

Spatial and temporal facies evolution of a Lower Jurassic carbonate platform, NW Tethyan margin (Mallorca, Spain)

The variety of depositional facies of a Lower Jurassic carbonate platform has been investigated on the island of Mallorca along a transect comprising six stratigraphic profiles. Twenty-nine facies and sub-facies have been recognized, grouped into seven facies associations, ranging in depositional environment from supratidal/terrestrial and peritidal to outer platform. Spatial and temporal (2D) facies distribution along the transect reflects the evolution of the carbonate platform with time showing different facies associations, from a broad peritidal platform (stage 1) to a muddy open platform (stage 2), and finally to a peritidal to outer carbonate platform (stage 3). Stage 1 (early Sinemurian to earliest late Sinemurian) corresponds to a nearly-flat peritidal-shallow subtidal epicontinental platform with facies belts that shifted far and fast over the whole study area. The evolution from stage 1 to stage 2 (late Sinemurian) represents a rapid flooding of the epicontinental shallow platform, with more open-marine conditions, and the onset of differential subsidence. During stage 3 (latest Sinemurian), peritidal and shallow-platform environments preferentially developed to the northeast (Llevant Mountains domain) with a rapid transition to middle-outer platform environments toward the northwest (Tramuntana Range domain). Stages 1 and 3 present facies associations typical of Bahamian-type carbonates, whereas stage 2 represents the demise of the Bahamian-type carbonate factory and proliferation of muddy substrates with suspension-feeders. The described platform evolution responded to the interplay between the initial extensional tectonic phases related to Early Jurassic Tethyan rifting, contemporaneous environmental perturbations, and progressive platform flooding related to the Late Triassic–Early Jurassic worldwide marine transgression and associated accommodation changes

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

¿Existe una relación entre sismicidad, fallas, grietas y roturas de muros en la Alhambra?

Actas del primer centenario del Observatorio de Cartuja [Archivo de ordenador] : 100 años de sismología en Granada. -- Granada : Universidad de Granada, 200

Las fallas del recinto de la Alhambra = Faults in the Alhambra area

Publicado en revista Geogaceta nº 34 (2003) p. 159-16

Targeting sources of drought tolerance within an Avena spp. collection through multivariate approaches

In this study, we find and characterize the sources of tolerance to drought amongst an oat (Avena sativa L.) germplasm collection of 174 landraces and cultivars. We used multivariate analysis, non-supervised principal component analyses (PCA) and supervised discriminant function analyses (DFA) to suggest the key mechanism/s responsible for coping with drought stress. Following initial assessment of drought symptoms and area under the drought progress curve, a subset of 14 accessions were selected for further analysis. The collection was assessed for relative water content (RWC), cell membrane stability, stomatal conductance (g 1), leaf temperature, water use efficiency (WUE), lipid peroxidation, lipoxygenase activity, chlorophyll levels and antioxidant capacity during a drought time course experiment. Without the use of multivariate approaches, it proved difficult to unequivocally link drought tolerance to specific physiological processes in the different resistant oat accessions. These approaches allowed the ranking of many supposed drought tolerance traits in the order of degree of importance within this crop, thereby highlighting those with a causal relationship to drought stress tolerance. Analyses of the loading vectors used to derive the PCA and DFA models indicated that two traits involved in water relations, temperature and RWC together with the area of drought curves, were important indicators of drought tolerance. However, other parameters involved in water use such as g 1 and WUE were less able to discriminate between the accessions. These observations validate our approach which should be seen as representing a cost-effective initial screen that could be subsequently employed to target drought tolerance in segregating populations. © 2012 Springer-Verlag.This work was supported by the Spanish Min- istry of Science and Innovation (AGL2010-15936/AGR) and the regional government through the AGR-253 group, the European Regional and Social Development Funds and an FPU fellowship from the Spanish Ministry of Science and Innovation to (JSM).Peer reviewe