Manioc : Portail | resultats 1 - 20 pour la recherche: Van Dam, Tonie

Histoire de la navigation de Jean Hugues de Linschot Hollandois, aux Indes Orientales

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Cuba por fuera (apuntes del natural)
Auteur(s) : Gallego Garcia, Tesifonte
Année de publication :

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La France équinoxiale. [Tome second], Voyage à travers les Guyanes et l'Amazonie
Auteur(s) : Coudreau, Henri Anatole (1859-1899)
Année de publication :

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An estimate of the influence of loading effects on tectonic velocities in the Pyrenees
Auteur(s) : Ferenc, Marcell Nicolas, Joelle Van Dam, Tonie Polidori, Laurent Rigo, Alexis Vernant, Philippe
Auteurs secondaires : Laboratoire de Géodésie et de Géomatique (L2G ESGT CNAM) ; École Supérieure des Géomètres et Topographes (ESGT CNAM) ; Conservatoire National des Arts et Métiers [CNAM] (CNAM) - Conservatoire National des Arts et Métiers [CNAM] (CNAM) - Conservatoire National des Arts et Métiers [CNAM] (CNAM) Université du Luxembourg (Uni.lu) Institut de recherche en astrophysique et planétologie (IRAP) ; Université Paul Sabatier - Toulouse 3 (UPS) - Observatoire Midi-Pyrénées (OMP) - Centre National de la Recherche Scientifique (CNRS) Risques ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS)

Éditeur(s) : HAL CCSD Springer Verlag (Germany)
Résumé : International audience
Surface displacements due to temporal changes in environmental mass redistributions are observable in the coordinate time series of many Global Navigation Satellite System (GNSS) sites. In this study, we investigated the effect of loading on estimates of tectonic velocity computed from campaign-style GNSS observations. The study region is in the Pyrenees mountain range between France and Spain (ResPyr campaigns). In this area, seismic activity is continuous and moderate and the expected amplitude of the horizontal tectonic velocity is less than 0.5 mm/yr. In order to determine the velocity, 4 sparse GNSS campaigns were carried out from 1995 to 2010. Considering this small rate of deformation, loading phenomena can contribute a non-negligible artifact to the velocity computation that could affect our geodynamical interpretation. In this investigation, we specifically considered the atmospheric, hydrological, and non-tidal ocean loading phenomena. The computed loading deformations for this region show the horizontal displacements are dominated by the non-tidal ocean loading (maximum 4 mm for the North and 3.1 mm for the East components); the main vertical contributions are due to the atmospheric and continental water storage loading (maximum 14.3 for the atmosphere and 8.1 mm for the hydrology, respectively). We have found that the dominant loading effect on the horizontal velocity is the non-tidal ocean loading (mean of 0.11 mm/yr), whereas the vertical component is dominated by the hydrological loading (mean of 0.21 mm/yr). Since the study area is in a mountainous region, we also analyzed the difference between the atmospheric and the topography dependent atmospheric loading models at our GNSS campaign sites. We did not find any significant difference between the two atmospheric loading models in terms of horizontal velocity. Finally, we performed simulations to identify the optimum timing and frequency of future GNSS campaigns in this area that would minimize the loading effects on tectonic velocity estimates.
ISSN: 0039-3169

hal-00963629
https://hal.archives-ouvertes.fr/hal-00963629
DOI : 10.1007/s11200-012-0458-2

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