Valorisation

Evaluation and localization of an artificial drainage network by 3D time-lapse electrical resistivity tomography

Papers - Publications scientifiques

In France, 10 % of total arable land is equipped with subsurface drainage systems, to control winter and spring waterlogging due to a temporary perched water table. Most of these systems were installed in the 1980s and have aged since then and may now need maintenance. Sometimes, the location of the systems is known, but the standard situation in France […]

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CRITEX, Guide de la R&D, 2016

CRITEX est un projet financé par le Programme d’Investissements d’Avenir visant le développement de capteurs pour l’étude de la zone critique de la Terre, c’est à dire cette zone comprise entre le ciel et les profondeurs de la Terre sur laquelle l’humanité vit, dont elle se nourrit et où elle stocke ses déchets. Ce programme associe plusieurs organismes de recherche […]

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Une zone si critique

L’humanité se rassemble sur une fine pellicule de la planète qui va des sols à la basse atmosphère et inclut tout le vivant : un espace pour notre survie qui ne se laisse pas étudier si facilement. Spécialistes en géosciences, Nicolas Arnaud et Jérôme Gaillardet nous en disent plus sur ce que l’on appelle la « zone critique ». Copyright […]

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Small-Scale Seismic Monitoring of Varying Water Levels in Granular Media

Papers - Publications scientifiques

Physical properties of soils in the vadose zone, and especially their water content, are characterized by strong spatial and temporal variations mostly driven by weather and anthropogenic activities. To understand this variability and help water resource management, seismic methods have been recently suggested as a complement to electrical and electromagnetic techniques. The simultaneous in situ estimation of pressure (P) 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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Integrated Workflow for Surface-wave Dispersion Inversion and Profiling

Papers - Publications scientifiques

While surface-wave prospecting methods are classically applied for the one-dimensional (1D) estimation of shear (S-) wave velocities (Vs), two-dimensional (2D) profiling still requires implementing specific processing and inversion tools that are not yet widely available in the community. We present here a free and open-source tool performing surface-wave inversion and profiling (SWIP) in order to retrieve 2D lateral variations of […]

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Interpretation of magnetic resonance measurements in the varying earth’s magnetic field

Papers - Publications scientifiques

At the scale of a magnetic resonance sounding (MRS) field setup, the earth’s magnetic field in the subsurface may vary laterally with depth and over time. These variations can be caused by different natural factors and generally cannot be compensated for by accurate tuning of the measuring device. The varying geomagnetic field (GMF) causes nonresonance conditions of excitation that affect […]

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Distributed Temperature Sensing as a down-hole tool in hydrogeology

Papers - Publications scientifiques

Distributed Temperature Sensing (DTS) technology enables down-hole temperature monitoring to study hydrogeological processes at unprecedentedly high frequency and spatial resolution. DTS has been widely applied in passive mode in site investigations of groundwater ow, in-well flow, and subsurface thermal property estimation. However, recent years have seen the further development of the use of DTS in an active mode (A-DTS) for which heat sources are deployed. […]

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Using DGT passive samplers and MC-ICPMS to determine Pb and Zn isotopic signature of natural water

Papers - Publications scientifiques

Increasing numbers of studies use zinc (Zn) and lead (Pb) isotopic compositions to track anthropogenic pollutions in surface water and groundwater. However, given the low content in Pb and Zn in natural waters, we are often restricted for analysis by MC-ICPMS. One solution is to use passive Diffusive Gradients in Thin films (DGT) samplers for in-situ preconcentration of these metals. […]

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Newsletter 3 : Mars 2016

Editorial Bonjour Bienvenue sur la newsletter 2015 de CRITEX. Comme en témoignent ces quelques pages, CRITEX prend de l’ampleur. A quelques mois de la fin des dépenses de la tranche d’Investissement, les différents instruments sont quasiment tous acquis, opérationnels ou en phase de test sur le terrain. Les premières résultats de notre programme ont été publiés dans des revues internationales […]

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