Author Archives: Laurent Longuevergne

IGN : A research position in Physical Geodesy

Context : The French national institute for geographical and forestry information (IGN,Institut National de l’Information Géographique et Forestière) is preparing a major evolution of the French vertical reference system management, in order to decrease the maintenance costs of the leveling network (400,000 bench marks), and to improve the quality of the service to the users. IGN needs notably to improve […]

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Goldschmidt conference: this year in Paris!

  Goldschmidt is the foremost annual, international conference on geochemistry and related subjects, organised by the European Association of Geochemistry and the Geochemical Society. The 2017 edition will take place in Paris, France, from August 13th-18th, 2017. More than 3600 abstracts are expected, with up to 4000 attendees. The 2017 conference will feature sessions on a variety of newsworthy topics, […]

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3rd AGU-SEG Hydrogeophysics Workshop: Imaging the Critical Zone

  The 3rd AGU-SEG Hydrogeophysics Workshop – Imaging the Critical Zone – will be held in Stanford, California, next 24-27 July 2017.   The Critical Zone (CZ) is a dynamic region where rock, soil, water, air, and living biota interact to shape Earth’s surface. The Critical Zone ranges from the tops of the trees to the bottom of groundwater. The field […]

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CRITEX meeting, this year in Grenoble !

The CRITEX annual meeting will take place on the Vectors plateau from May, 10th to 12th 2017 Website:  http://www.ige-grenoble.fr/spip.php?page=article&id_article=324 Organization committee: Marc Descloitres Jean-Martial Cohard Jean Martins Guillaume Nord Cédric Legout Frédéric Cazenave Sylvie Galle Delphine Six

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ENIGMA Innovative Training Network: 15 PhD positions available

The ENIGMA ITN (European training Network for in situ imaGing of dynaMic processes in heterogeneous subsurfAce environments) aims at training a new generation of young researchers in the development of innovative methods for imaging process dynamics in subsurface hydrosystems, in order to enhance understanding and predictive modelling capacities and to transfer these innovations to the economic sector. Scientific and technological […]

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Contribution of the finite volume point dilution method for measurement of groundwater fluxes in a fractured aquifer

Papers - Publications scientifiques

Measurement of groundwater fluxes is the basis of all hydrogeological study, from hydraulic characterization to the most advanced reactive transport modeling. Usual groundwater flux estimation with Darcy’s law may lead to cumulated errors on spatial variability, especially in fractured aquifers where local direct measurement of groundwater fluxes becomes necessary. In the present study, both classical point dilution method (PDM) and […]

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2D characterization of near-surface VP/VS: surface-wave dispersion inversion versus refraction tomography

Papers - Publications scientifiques

The joint study of pressure (P-) and shear (S-) wave velocities (VP and VS), as well as their ratio (VP/VS), has been used for many years at large scales but remains marginal in near-surface applications. For these applications, VP and VS are generally retrieved with seismic refraction tomography combining P and SH (shear-horizontal) waves, thus requiring two separate acquisitions. Surface-wave […]

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Inferring field-scale properties of a fractured aquifer from ground surface deformation during a well test

Papers - Publications scientifiques

Fractured aquifers which bear valuable water resources are often difficult to characterize  with classical hydrogeological tools due to their intrinsic heterogeneities. Here we implement ground surface deformation tools (tiltmetry and optical leveling) to monitor groundwater pressure changes induced by a classical hydraulic test at the Ploemeur observatory. By jointly analyzing complementary time constraining data (tilt) and spatially constraining data (vertical […]

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