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Investigating tropospheric effects and seasonal position variations in GPS and DORIS time-series from the Nepal Himalaya / Mireille Flouzat in Geophysical journal international, vol 178 n° 3 (September 2009)  

Public [article]  inGeophysical journal international > vol 178 n° 3 (September 2009) . - pp 1246 - 1259 Titre : Investigating tropospheric effects and seasonal position variations in GPS and DORIS time-series from the Nepal Himalaya Type de document : Article/Communication Auteurs : Mireille Flouzat, Auteur ; Pierre Bettinelli, Auteur ; Pascal Willis , Auteur ; Jean-Philippe Avouac, Auteur ; Thierry Héritier, Auteur ; Umesh Gautam, Auteur Année de publication : 2009 Projets : 1-Pas de projet / Article en page(s) : pp 1246 - 1259 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] données DORIS [Termes IGN] données GPS [Termes IGN] Himalaya [Termes IGN] propagation troposphérique [Termes IGN] série temporelle [Termes IGN] variation saisonnière Résumé : (auteur) Geodetic time-series from continuous GPS (cGPS) and 1 DORIS stations across the Himalaya of central Nepal show strong seasonal fluctuations observed on the horizontal and vertical components. Because the fluctuations determined at the different stations have similar phase but different amplitudes, these observations would imply that the secular shortening across the range is modulated by a seasonal strain. Given the geographic and climatic setting, there is however a possibility that the GPS positions be biased by tropospheric effects. We process these data using two different software packages and two different analysis strategies. Our analysis shows evidence for 1-strong seasonal fluctuation of zenithal delays consistent with in situ meteorological data and two strong horizontal tropospheric gradients in particular in the EW direction, that is, parallel to the mountain front at Gumba, also detected in DORIS results. We show that the tropospheric effects cannot however be the source of the observed seasonality of horizontal strain. This study supports the view that the seasonal strain in the Himalaya is real and probably driven by seasonal surface load variations. Our study adds support to the view that seasonal variations of seismicity in the Himalaya reflects seasonal variations of geodetic strain. Numéro de notice : A2009-604 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1365-246X.2009.04252.x En ligne : https://doi.org/10.1111/j.1365-246X.2009.04252.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95755 [article]