Search results for "Bas"
showing 10 items of 28787 documents
Chlorine Partitioning Between a Basaltic Melt and H2O-CO2 Fluids at Mount Etna
2009
Partitioning experiments between a basaltic melt from Mt. Etna and a low-density hydrous fluid or vapor containing H(2)O or H(2)O-CO(2) were performed at 1200-1260 degrees C, at pressures between 1 and 200 MPa, either near the nickel-nickel oxide (NNO) buffer or at two log units above it (NNO + 2), and with different chloride concentrations. Most of the experiments were done at chloride-brine-undersaturated conditions, although at the highest Cl concentrations explored brine saturation might have been reached. The average partition coefficients (D(Cl)(fluid/melt)) over the range of Cl concentrations were derived on a weight basis by plotting the calculated concentrations of Cl in the fluid …
Simulating future trends in hydrological regime of a large Sudano-Sahelian catchment under climate change
2012
Summary This paper assesses the future variability of water resources in the short, medium and long terms over a large Sudano-Sahelian catchment in West Africa. Flow simulations were performed with a daily conceptual model. A period of nearly 50 years (1952–2000) was chosen to capture long-term hydro-climatic variability. Calibration and validation were performed on the basis of a multi-objective function that aggregates a variety of goodness-of-fit indices. The climate models HadCM3 and MPI-M under SRES-A2 were used to provide future climate scenarios over the catchment. Outputs from these models were used to generate daily rainfall and temperature series for the 21st century according to:…
Soil moisture modelling of a SMOS pixel: interest of using the PERSIANN database over the Valencia Anchor Station
2010
In the framework of Soil Moisture and Ocean Salinity (SMOS) Calibration/Validation (Cal/Val) activities, this study addresses the use of the PERSIANN-CCS<sup>1</sup>database in hydrological applications to accurately simulate a whole SMOS pixel by representing the spatial and temporal heterogeneity of the soil moisture fields over a wide area (50×50 km<sup>2</sup>). The study focuses on the Valencia Anchor Station (VAS) experimental site, in Spain, which is one of the main SMOS Cal/Val sites in Europe. <br><br> A faithful representation of the soil moisture distribution at SMOS pixel scale (50×50 km<sup>2</sup>) requires an accurate estimation…
Hydrostratigraphic characterization of glaciofluvial deposits underlying an infiltration basin using ground penetrating radar.
2008
14 pages; International audience; An understanding of the heterogeneity of quaternary gravelly deposits is required to predict flow and contaminant transfer through these formations. In such deposits, preferential flow paths can lead to contamination at depths greater than predicted under the assumption of a homogeneous medium. The difficulties in characterizing their complex structure with conventional methods represent an obstacle for this prediction. In this study, we developed an approach relying on the use of ground penetrating radar (GPR) for the detection of sedimentary depositional units. A genetic interpretation of the radar stratigraphy allowed us to construct a distribution model…
Influence of microporosity distribution on the mechanical behavior of oolithic carbonate rocks.
2015
Abstract The mechanical behavior of oolithic carbonate rocks was investigated for selected rocks with two different microstructural attributes: uniform (UP) and rimmed (RP) distribution of microporosity within ooids. These oolithic carbonate rocks are from the Oolithe Blanche formation, a deep saline aquifer in the Paris Basin, and a possible target for CO2 sequestration and geothermal production. Samples of similar physical properties (porosity, grain diameter, cement content) but different microporosity textures were deformed under triaxial configuration, in water saturated conditions, at 28 MPa of confining pressure, 5 MPa of pore pressure and at a temperature of 55 °C. During the experi…
Progress on bringing together raptor collections in Europe for contaminant research and monitoring in relation to chemicals regulation.
2019
Paola Movalli et al.
The key role played by the Augusta basin (southern Italy) in the mercury contamination of the Mediterranean Sea.
2011
The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of ∼0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y(-1) to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing …
GRB 050904 at redshift 6.3: observations of the oldest cosmic explosion after the Big Bang
2005
We present optical and near-infrared observations of the afterglow of the gamma-ray burst GRB 050904. We derive a photometric redshift z = 6.3, estimated from the presence of the Lyman break falling between the I and J filters. This is by far the most distant GRB known to date. Its isotropic-equivalent energy is 3.4x10^53 erg in the rest-frame 110-1100 keV energy band. Despite the high redshift, both the prompt and the afterglow emission are not peculiar with respect to other GRBs. We find a break in the J-band light curve at t_b = 2.6 +- 1.0 d (observer frame). If we assume this is the jet break, we derive a beaming-corrected energy E_gamma = (4-12)x10^51 erg. This limit shows that GRB 050…
First M87 Event Horizon Telescope Results. II. Array and Instrumentation
2019
The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of ~1.3 mm, EHT angular resolution (λ/D) is ~25 μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of th…
Thermal and structural modeling of the Scillato wedge-top basin source-to-sink system. Insights into the Sicilian fold-and-thrust belt evolution (Ita…
2019
AbstractTemperature-dependent clay mineral assemblages, vitrinite reflectance, and one-dimensional (1-D) thermal and three-dimensional (3-D) geological modeling of a Neogene wedge-top basin in the Sicilian fold-and-thrust belt and its pre-orogenic substratum allowed us to: (1) define the burial history of the sedimentary succession filling the wedge-top basin and its substratum, (2) reconstruct the wedge-top basin geometry, depocenter migration, and sediment provenance through time in the framework of a source-to-sink system, and (3) shed new light into the kinematic evolution of the Apennine-Maghrebian fold-and-thrust belt.The pre-orogenic substratum of the Scillato basin shows an increase…