On the use of long-term observation of water level and temperature along the shore for a better understanding of the dynamics: example of Toulon area,France     

Rey  Vincent  Dufresne  Christiane  Fuda  Jean-Luc  Mallarino  Didier  Missamou  Tathy  Paugam  Caroline  Rougier  Gilles  Taupier-Letage  Isabelle 《Ocean Dynamics》2020,70(7):913-933

Ocean Dynamics - A dense network of instruments has been deployed within harbors along the Mediterranean coast, in the Toulon Metropole area, between the Hyères islands and the Sanary Bay in...  相似文献   

A Bayesian method for missing rainfall estimation using a conceptual rainfall–runoff model     

Siao Sun  Günther Leonhardt  Santiago Sandoval  Jean-Luc Bertrand-Krajewski  Wolfgang Rauch 《水文科学杂志》2017,62(15):2456-2468

The estimation of missing rainfall data is an important problem for data analysis and modelling studies in hydrology. This paper develops a Bayesian method to address missing rainfall estimation from runoff measurements based on a pre-calibrated conceptual rainfall–runoff model. The Bayesian method assigns posterior probability of rainfall estimates proportional to the likelihood function of measured runoff flows and prior rainfall information, which is presented by uniform distributions in the absence of rainfall data. The likelihood function of measured runoff can be determined via the test of different residual error models in the calibration phase. The application of this method to a French urban catchment indicates that the proposed Bayesian method is able to assess missing rainfall and its uncertainty based only on runoff measurements, which provides an alternative to the reverse model for missing rainfall estimates.  相似文献   

Apport des isotopes stables dans l'estimation des altitudes de recharge de sources thermales du MarocRecharge altitude estimation of thermal springs using stable isotopes in Morocco     

Anne Winckel  Christelle Marlin  Laurent Dever  Jean-Luc Morel  Karim Morabiti  Mohamed Ben Makhlouf  Ahmed Chalouan 《Comptes Rendus Geoscience》2002,334(7):469-474

The recharge altitude estimation of thermal springs from northern and eastern Morocco using ¹⁸O and ²H contents requires the definition of regional isotopic altitudinal gradients (?0.25‰ for 100 m for the Rif and ?0.30‰ for the East) and the calculation of residence time using ¹⁴C. The altitudes of emergence vary widely between 170 and 1040 m under the altitude of the recharge areas. The ¹⁸O and ²H compositions of palaeowaters ($\text{>10}\text{000}$ yr BP) indicate two effects, altitude and palaeoclimate. To cite this article: A. Winckel et al., C. R. Geoscience 334 (2002) 469–474.  相似文献   

New Image Modeling Approaches     

Fionn Murtagh  Jean-Luc Starck 《Surveys in Geophysics》2000,21(2-3):229-239

Earth observation relies heavily on imaging. Extraction of informationin turn relies on image processing and analysis. A new and powerfulmethodology has come to the fore in recent years, based on the waveletand other multiscale transforms. Of the many possible application areaswe describe in this paper some approaches for object and feature findingin images', noise filtering of synthetic aperture radar (SAR) images, andthe automatic geometrical registration of different images.  相似文献   

The Teggiolo zone: a key to the Helvetic–Penninic connection (stratigraphy and tectonics in the Val Bavona,Ticino, Central Alps)     

Battista Matasci  Jean-Luc Epard  Henri Masson 《Swiss Journal of Geoscience》2011,104(2):257-283

The Teggiolo zone is the sedimentary cover of the Antigorio nappe, one of the lowest tectonic units of the Penninic Central Alps. Detailed mapping, stratigraphic and structural analyses, and comparisons with less metamorphic series in several well-studied domains of the Alps, provide a new stratigraphic interpretation. The Teggiolo zone is comprised of several sedimentary cycles, separated by erosive surfaces and large stratigraphic gaps, which cover the time span from Triassic to Eocene. At Mid-Jurassic times it appears as an uplifted, partially emergent block, marking the southern limit of the main Helvetic basin (the Limiting South-Helvetic Rise LSHR). The main mass of the Teggiolo calcschists, whose base truncates the Triassic–Jurassic cycles and can erode the Antigorio basement, consists of fine-grained clastic sediments analogous to the deep-water flyschoid deposits of Late Cretaceous to Eocene age in the North-Penninic (or Valais s.l.) basins. Thus the Antigorio-Teggiolo domain occupies a crucial paleogeographic position, on the boundary between the Helvetic and Penninic realms: from Triassic to Early Cretaceous its affinity is with the Helvetic; at the end of Cretaceous it is incorporated into the North-Penninic basins. An unexpected result is the discovery of the important role played by complex formations of wildflysch type at the top of the Teggiolo zone. They contain blocks of various sizes. According to their nature, three different associations are distinguished that have specific vertical and lateral distributions. These blocks give clues to the existence of territories that have disappeared from the present-day level of observation and impose constraints on the kinematics of early folding and embryonic nappe emplacement. Tectonics produced several phases of superimposed folds and schistosities, more in the metasediments than in the gneissic basement. Older deformations that predate the amplification of the frontal hinge of the nappe generated the dominant schistosity and the km-wide Vanzèla isoclinal fold.  相似文献   

Radar detection of Asteroid 2002 AA29     

Steven J Ostro  Jon D Giorgini  Alice A Hine  Jean-Luc Margot  Christian Veillet 《Icarus》2003,166(2):271-275

Radar echoes from Earth co-orbital Asteroid 2002 AA29 yield a total-power radar cross section of 2.9×10⁻⁵ km² ±25%, a circular polarization ratio of SC/OC=0.26±0.07, and an echo bandwidth of at least 1.5 Hz. Combining these results with the estimate of its visual absolute magnitude, H_V=25.23±0.24, from reported Spacewatch photometry indicates an effective diameter of 25±5 m, a rotation period no longer than 33 min, and an average surface bulk density no larger than 2.0 g cm⁻³; the asteroid is radar dark and optically bright, and its statistically most likely spectral class is S. The H_V estimate from LINEAR photometry (23.58±0.38) is not compatible with either Spacewatch's H_V or our radar results. If a bias this large were generally present in LINEAR's estimates of H_V for asteroids it has discovered or observed, then estimates of the current completeness of the Spaceguard Survey would have to be revised downward.  相似文献   

Radar and photometric observations and shape modeling of contact binary near-Earth Asteroid (8567) 1996 HW1     

Christopher Magri  Ellen S. Howell  Patrick A. Taylor  Michael Mueller  Lance A.M. Benner  Steven J. Ostro  Michael D. Hicks  James M. Somers  Vladimir V. Kouprianov  Igor E. Molotov  Jean-Luc Margot  Vojislava Protitch-Benishek  David Higgins  Donald P. Pray 《Icarus》2011,214(1):210-227

We observed near-Earth Asteroid (8567) 1996 HW1 at the Arecibo Observatory on six dates in September 2008, obtaining radar images and spectra. By combining these data with an extensive set of new lightcurves taken during 2008-2009 and with previously published lightcurves from 2005, we were able to reconstruct the object’s shape and spin state. 1996 HW1 is an elongated, bifurcated object with maximum diameters of 3.8 × 1.6 × 1.5 km and a contact-binary shape. It is the most bifurcated near-Earth asteroid yet studied and one of the most elongated as well. The sidereal rotation period is 8.76243 ± 0.00004 h and the pole direction is within 5° of ecliptic longitude and latitude (281°, −31°). Radar astrometry has reduced the orbital element uncertainties by 27% relative to the a priori orbit solution that was based on a half-century of optical data. Simple dynamical arguments are used to demonstrate that this asteroid could have originated as a binary system that tidally decayed and merged.  相似文献   

The 2010 European Venus Explorer (EVE) mission proposal     

Colin Frank Wilson  Eric Chassefière  Emmanuel Hinglais  Kevin H. Baines  Tibor S. Balint  Jean-Jacques Berthelier  Jacques Blamont  Georges Durry  Csaba S. Ferencz  Robert E. Grimm  Takeshi Imamura  Jean-Luc Josset  Fran?ois Leblanc  Sebastien Lebonnois  Johannes J. Leitner  Sanjay S. Limaye  Bernard Marty  Ernesto Palomba  Sergei V. Pogrebenko  Scot C. R. Rafkin  Dean L. Talboys  Rainer Wieler  Liudmila V. Zasova  Cyrill Szopa 《Experimental Astronomy》2012,33(2-3):305-335

The European Venus Explorer (EVE) mission described in this paper was proposed in December 2010 to ESA as an ‘M-class’ mission under the Cosmic Vision programme. It consists of a single balloon platform floating in the middle of the main convective cloud layer of Venus at an altitude of 55?km, where temperatures and pressures are benign (～25°C and ～0.5 bar). The balloon float lifetime would be at least 10 Earth days, long enough to guarantee at least one full circumnavigation of the planet. This offers an ideal platform for the two main science goals of the mission: study of the current climate through detailed characterization of cloud-level atmosphere, and investigation of the formation and evolution of Venus, through careful measurement of noble gas isotopic abundances. These investigations would provide key data for comparative planetology of terrestrial planets in our solar system and beyond.  相似文献   

Experimental determination of F and Cl partitioning between lherzolite and basaltic melt     

Célia Dalou  Kenneth T. Koga  Nobumichi Shimizu  Julien Boulon  Jean-Luc Devidal 《Contributions to Mineralogy and Petrology》2012,163(4):591-609

We experimentally determined F and Cl partition coefficients together with that of 19 trace elements (including REE, U-Th, HFSE and LILE) between basaltic melt and lherzolite minerals: olivine, orthopyroxene, clinopyroxene, plagioclase and garnet. Under conditions from 8 to 25 kbars and from 1,265 to 1,430°C, compatibilities of F and Cl are globally ordered as D ^Cpx/melt > D ^Opx/melt > D ^Grt/melt > D ^Ol/melt > D ^Plag/melt, and D _F ^mineral/melt is larger than D _Cl^mineral/melt. Four other major results were brought to light. (1) Chlorine partition coefficients positively correlate with the jadeite component in orthopyroxene, and increase of the CaTs component promotes Cl incorporation in clinopyroxene. (2) Variations of fluorine partition coefficients correlate strongly with melt viscosity. (3) F and Cl partition coefficients correlate with the Young’s modulus (E ₀) of pyroxene octahedral sites (M sites) and with Raman vibrational modes of pyroxenes. This demonstrates a fundamental interaction between the M site of pyroxenes and the incorporation of F and Cl. (4) We also determined the parameters of the lattice-strain model applied to 3+ cation trace elements for the two M sites in orthopyroxene and clinopyroxene: D ₀^M1, D ₀^M2, r ₀^M1, r ₀^M2, E ₀^M1 and E ₀^M2.  相似文献   

Pyroclastic flow erosion and bulking processes: comparing field-based vs. modeling results at Tungurahua volcano,Ecuador     

Julien Bernard  Karim Kelfoun  Jean-Luc Le Pennec  Silvia Vallejo Vargas 《Bulletin of Volcanology》2014,76(9):1-16

Pyroclastic density currents (PDCs) are high-temperature and high-velocity mixtures that threaten populations in the vicinity of many active volcanoes. Deciphering the cause of their remarkable mobility is essential for volcanic hazard analysis, but remains difficult because of the complex processes occurring within the flows. Here, we investigate the effect of bulking on dense PDC mobility by means of a double approach. First, we estimate the amount of material incorporated into scoria flows emplaced during the August 2006 eruption of Tungurahua volcano, Ecuador. For this, we carry out a detailed analysis of 3D-corrected digital images of well-exposed scoria flow deposits. Componentry analysis indicates that PDC bulking occurs principally on the steep (>25°) upper slope of the volcano, and the deposits typically comprise 40–50 wt% of non-juvenile (i.e., accessory and accidental) material. Secondly, we develop a simple stress-related grain-by-grain equation of erosion combined with two simple depth-averaged geophysical mass-flow models that compare the bulking mechanism to a non-fluidized and a fluidized flow. Two behaviors based on Coulomb and plastic rheologies are used to reproduce, on a first order basis, the 2006 Tungurahua PDCs. Cross-check comparisons between these modeled cases and the erosion pattern inferred from field-based data allow us to evaluate the accuracy of our modeling assumptions. Regardless of the rheological regime, the PDC-induced erosion pattern of the 2006 Tungurahua eruption can only be reproduced by fluctuations of the flow’s basal shear stress during emplacement. Such variations are controlled by flow thinning-thickening processes, notably through the formation of a thick non-erosive flow body that pushes a thin frictional erosive front during PDC emplacement. The input volume of juvenile material, as well as the thickness of the erodible layer available prior to the eruption, are additional key parameters. Our work highlights complexities in PDC erosion and bulking processes that deserve further study. In terms of hazard assessment, our findings reveal that incorporation and bulking translate into increased flow mobility, i.e., the augmented flow mass enhances both flow velocity and runout distance (up to 20 %). These outcomes should be considered closely for hazard analysis at many other andesitic volcanoes worldwide where similar PDC events are common.  相似文献