Monitoring vertical deformation due to water pumping in the city of Paris (France) with differential interferometry     

Bénédicte Fruneau  Benoît Deffontaines  Jean-Paul Rudant  Anne-Marie Le Parmentier 《Comptes Rendus Geoscience》2005,337(13):1173-1183

The Saint-Lazare area in Paris (France) has undergone important water pumping for the construction of the underground Haussmann–Saint-Lazare station for the EOLE subway line. This paper presents the monitoring of the small surface displacements related to this pumping activity, by classical SAR interferometry. Piezometric measurements provided on 87 piezometers by SNCF and IGC as well as precise levelling data acquired on 626 points by SNCF are also examined. Their comparison with interferometric results shows their good agreement and complementarity, as well as the potential ‘operationality’ of SAR interferometric approach in such a study. To cite this article: B. Fruneau et al., C. R. Geoscience 337 (2005).  相似文献   

Erosion balance in the watersheds of the western Paris Basin by high-frequency monitoring of discharge and suspended sediment in surface water     

Benoît Laignel  Emmanuel Dupuis  Alain Durand  Jean-Paul Dupont  Emmanuel Hauchard  Nicolas Massei 《Comptes Rendus Geoscience》2006,338(8):556-564

An accurate quantification of erosion, based on high-frequency monitoring of river discharge and suspended sediment fluxes is proposed for two watersheds in the western Paris Basin, a sensitive area with respect to erosion phenomena. This continuous monitoring makes it possible to include flood events of short duration, but significant erosion potential. The obtained erosion rate (16 and 21 t?km^?2?yr^?1) is among the weakest of the planet (3.5 to 18?000 t?km^?2?yr^?1). However, this annual balance does not reflect the behaviour of these rivers which can be torrential in certain cases. To cite this article: B. Laignel et al., C. R. Geoscience 338 (2006).  相似文献   

Seasonal effect on vertical positioning by Satellite Laser Ranging and Global Positioning System and on absolute gravity at the OCA geodetic station, Grasse, France     

J. Nicolas  J.-M. Nocquet  M. Van Camp  T. van Dam  J.-P. Boy  J. Hinderer  P. Gegout  E. Calais  M. Amalvict 《Geophysical Journal International》2006,167(3):1127-1137

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Post-collisional melting of crustal sources: constraints from geochronology,petrology and Sr,Nd isotope geochemistry of the Variscan Sichevita and Poniasca granitoid plutons (South Carpathians,Romania)   总被引：1，自引：1，他引：0  

Jean-Clair Duchesne  Jean-Paul Liègeois  Viorica Iancu  Tudor Berza  Dmitry I. Matukov  Mihai Tatu  Sergei A. Sergeev 《International Journal of Earth Sciences》2008,97(4):705-723

The Sichevita and Poniasca plutons belong to an alignment of granites cutting across the metamorphic basement of the Getic Nappe in the South Carpathians. The present work provides SHRIMP age data for the zircon population from a Poniasca biotite diorite and geochemical analyses (major and trace elements, Sr–Nd isotopes) of representative rock types from the two intrusions grading from biotite diorite to biotite K-feldspar porphyritic monzogranite. U–Pb zircon data yielded 311 ± 2 Ma for the intrusion of the biotite diorite. Granites are mostly high-K leucogranites, and biotite diorites are magnesian, and calcic to calc-alkaline. Sr, and Nd isotope and trace element data (REE, Th, Ta, Cr, Ba and Rb) permit distinguishing five different groups of rocks corresponding to several magma batches: the Poniasca biotite diorite (P₁) shows a clear crustal character while the Poniasca granite (P₂) is more juvenile. Conversely, Sichevita biotite diorite (S₁), and a granite (S₂*) are more juvenile than the other Sichevita granites (S₂). Geochemical modelling of major elements and REE suggests that fractional crystallization can account for variations within P₁ and S₁ groups. Dehydration melting of a number of protoliths may be the source of these magma batches. The Variscan basement, a subduction accretion wedge, could correspond to such a heterogeneous source. The intrusion of the Sichevita–Poniasca plutons took place in the final stages of the Variscan orogeny, as is the case for a series of European granites around 310 Ma ago, especially in Bulgaria and in Iberia, no Alleghenian granitoids (late Carboniferous—early Permian times) being known in the Getic nappe. The geodynamical environment of Sichevita–Poniasca was typically post-collisional of the Variscan orogenic phase.  相似文献   

Star Formation in Accretion Disks Around Massive Black Holes and Pregalactic Enrichment     

Suzy Collin  Jean-Paul Zahn 《Astrophysics and Space Science》1999,265(1-4):501-505

Broad Absorption Lines (BALs) prove the existence of a high velocity outflowing gas with metallicities larger than solar in the central few parsecs of high redshift quasars. At the same distance from the black hole, accretion disks in quasars and Active Galactic Nuclei (AGN) are locally gravitationally unstable, and clumps must form with a size of the order of the scale height of the disk. This is hardly a coincidence, and we have tried to link these two facts. We have assumed that the unstable clumps give rise to protostars, which become massive stars after a rapid stage of accretion, and explode as supernovae, producing strong outflows perpendicular to the disk and inducing outward transfer of angular momentum in the plane of the disk. As a consequence a self-regulated disk made of gas and stars where supernovae sustain the inflow mass rate required by the AGN is a viable solution in this region of the disk. This model could explain the BALs, and could also account for a pregalactic enrichment of the intergalactic medium and of the Galaxy, if massive black holes formed early in the Universe. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

SCUBA's first-born: SMM J02399-0136     

Rob Ivison  Ian Smail  Andrew Blain  Jean-Paul Kneib  David Frayer 《Astrophysics and Space Science》1999,266(1-2):285-290

We discuss observations of the submm-selected galaxy,SMM J02399-0136, and what has been learnt about it during the yearfollowing its discovery. SMM J02399-0136 was the first distantgalaxy detected in surveys with the Submm Common-User Bolometer Array(SCUBA). Its association with a massive, gas-rich starburst/AGN atz = 2.8 has lead to suggestions that the prevalence of AGN in theearly Universe may be high (Ivison et al. 1998) and that these AGNmay account for a significant fraction of the far-IR background (e.g.Fixsen et al. 1998).  相似文献