Search results for "Planetary Science"
showing 10 items of 4367 documents
Tree rings and volcanic cooling
2012
Biocénoses à triopsidés(Crustacea, Branchiopoda) du Permien du bassin de Lodève (France)
1997
Resume Nous decrivons les triopsides (Crustacea, Branchiopoda) qui abondent dans les facies “saxoniens” de la Formation du Salagou du bassin de Lodeve date “Thuringien” ou “Saxonien” selon les auteurs. A partir de milliers de debris de carapaces, d'axes thoraco-abdominaux et plus rarement a partir d'animaux entiers, nous avons identifie et decrit deux especes nouvelles: Triops cancriformis permiensis nov. ssp. et Lepidurus occitaniacus nov. sp., morphologiquement proches d' especes actuelles. En se basant sur les preferences ecologiques des triopsides actuels et les caracteristiques sedimentologiques de leur milieu de vie au Permien, nous avons confirme l'existence d'etendues d'eau, peu pro…
Column-integrated aerosol optical properties in the free troposphere: case study-Sierra Nevada, Spain
2004
From spectral solar irradiance extinction measurements in the visible range carried out at Sierra Nevada (2950 m a.s.l.) during July 1998, the characteristics of the aerosol column in the free troposphere have been measured. The results show that in stable atmospheric conditions, the column-integrated aerosol takes an optical depth (AOD) at 500 nm of 0.02 /spl plusmn/ 0.02, and an average radius in the accumulation mode of 0.15 /spl mu/m, with a likely Atlantic origin. In unstable situations, the AOD at 500 nm can increase by more than an order of magnitude, and the aerosols' origin is uncertain, since air masses can arrive from different sources at different altitudes.
Dolomitization as an eventualdetermining factor in the colour alteration index (CAI)
1993
Abstract The Colour Alteration Index of conodonts (CAI) is indicative of the degree of alteration of organic material that exists in the interior of the conodonts. This CAI is used ordinarily in the determination of paleotemperatures. More frequent findings of abnormally high CAI values, equivalent to paleotemperatures that are not compatible with temperatures obtained by other more trustworthy methods, has taken us to use values not superior to 6 for the establishment of paleotemperatures. The CAI values measured in specimens proceding from dolostones in the Iberian Range (Spain) show in this way a certain degree of incompatibility with geological data. These anomalous values are the conse…
Turbidez y profundidad de disco de Secchi con Sentinel-2 en embalses con diferente estado trófico en la Comunidad Valenciana
2019
[ES] En los estudios de calidad de aguas por teledetección, uno de los principales indicadores es la transparencia o turbidez del agua. La transparencia puede ser medida in situ mediante la profundidad del disco de Secchi (SD), y la turbidez con un turbidímetro. En las últimas décadas se han utilizado diferentes relaciones entre bandas de diferentes sensores obtenidas por teledetección para la estimación de estos parámetros. En este trabajo, a partir de datos de campo obtenidos a lo largo de 2017 y 2018 en embalses de la cuenca del Júcar con gran variedad de estados tróficos, se han calibrado diferentes índices y bandas para poder estimar la transparencia a partir de imágenes Sentinel-2 (S2…
Multitemporal water quality study in Sitjar (Castelló, Spain) reservoir using Sentinel-2 images
2020
[EN] Water quality is a subject of intense scientific inquiry because of its repercussion in human’s life, agriculture or even energy generation. Remote sensing can be used to control water masses by analyzing biophysical variables. Chlorophyll-a (Chl-a) and Total Suspended Solids (SS) are a well-known feature of water quality. These variables have been measured in Sitjar reservoir (Castelló, Spain) as a part of the project Ecological Status of Aquatic Systems with Sentinel Satellites (ESAQS), in order to compare the results with satellite reflectance data. Two processes were compared to correct atmospherically the level 1C Sentinel 2 (S2) images. The results show that Case 2 Regional Coast…
Miniatures from domestic contexts in Iron age Iberia
2015
AbstractThis article reviews a set of miniatures from domestic contexts in Iron Age eastern Iberia, and interprets them in terms of their role in forging social personae. After an introduction to the historical case under consideration, the miniatures are described in terms of their typology and their contexts of provenance are outlined. Though not abundant, they tend to occur in central places in the landscape; specifically, they are often found in houses of the powerful. The vast majority are miniatures of pottery and tools, though some miniature weapons are recorded. We contend that these objects were used as a means of enculturation and for the learning of values and norms. It is no coi…
Sicilian transitional waters: Current status and future development
2010
To appraise the current knowledge of Sicilian transitional waters (TWs), a review was undertaken of the information available on these ecosystems. In detail, a synthesis of the current status is reported, highlighting for each area the ecological features and status, historical data, conservation regime, environmental emergencies and anthropic pressures to which they are subject. The Sicilian TWs reviewed include coastal ponds and lakes, mires and areas with active and nonactive saltworks. Almost all of these ecosystems are affected by several protection regimes because of their high naturalistic value, although current knowledge is limited and fragmented. A few areas have received more att…
Modelling regional-scale attenuation across Italy and the Tyrrhenian Sea
2021
Abstract Modelling regional-scale attenuation of seismic waves at ~1 Hz is challenging, especially when these waves propagate across both continental and oceanic crust. Recent developments in seismic imaging and modelling have provided us with the computational tools necessary to reconstruct these mixed settings using deterministic (coherent) and stochastic (coda) information. Here, we present new tomographic maps of coda-attenuation for both the Italian peninsula and the Tyrrhenian Sea. Kernel-based coda attenuation imaging in the diffusive approximation is tested in the oceanic environment, highlighting a non-diffusive behaviour across the Southern Tyrrhenian Sea. Joint deterministic and …
The southern Tyrrhenian Sea margin an example of lithospheric scale strike-slip duplex
2010
The southern Tyrrhenian Sea margin is dominated by deformations whose kinematics are relatively poorly constrained, and different models have been proposed to account for its recent evolution. Analysis of new structural and space geodesy data, combined with available geophysical information, reveal a deformation field characterised by subhorizontal NW-SE directed shortening and SW-NE directed extension. The main recognised regional-scale structure comprises E-W trending fault zones, namely the Ustica-Eolie Line and the Mt. Kumeta-Alcantara Line, connected by the NW-SE trending Marettimo, Trapani, San Vito, Palermo, Gratteri-Mt. Mufara and Eolie faults. This fault network displays a remarkab…