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New insights on intraplate volcanism in French Polynesia from wavelet analysis of GRACE, CHAMP, and sea surface data / Isabelle Panet in Journal of geophysical research : Solid Earth, vol 111 n° B9 (September 2006)  

Public [article]  inJournal of geophysical research : Solid Earth > vol 111 n° B9 (September 2006) . - 17 p. Titre : New insights on intraplate volcanism in French Polynesia from wavelet analysis of GRACE, CHAMP, and sea surface data Type de document : Article/Communication Auteurs : Isabelle Panet , Auteur ; Aude Chambodut, Auteur ; Michel Diament , Auteur ; Matthias Holschneider, Auteur ; Olivier Jamet , Auteur Année de publication : 2006 Article en page(s) : 17 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] anomalie de pesanteur [Termes IGN] champ de pesanteur local [Termes IGN] Cook (îles) [Termes IGN] croute océanique [Termes IGN] données CHAMP [Termes IGN] données GRACE [Termes IGN] fond marin [Termes IGN] Marquises, îles [Termes IGN] ondelette [Termes IGN] Polynésie française [Termes IGN] Société, archipel de la (Polynésie française) [Termes IGN] surface de la mer [Termes IGN] Tuamotu, îles [Termes IGN] volcan Résumé : (auteur) In this paper, we discuss the origin of superswell volcanism on the basis of representation and analysis of recent gravity and magnetic satellite data with wavelets in spherical geometry. We computed a refined gravity field in the south central Pacific based on the GRACE satellite GGM02S global gravity field and the KMS02 altimetric grid, and a magnetic anomaly field based on CHAMP data. The magnetic anomalies are marked by the magnetic lineation of the seafloor spreading and by a strong anomaly in the Tuamotu region, which we interpret as evidence for crustal thickening. We interpret our gravity field through a continuous wavelet analysis that allows to get a first idea of the internal density distribution. We also compute the continuous wavelet analysis of the bathymetric contribution to discriminate between deep and superficial sources. According to the gravity signature of the different chains as revealed by our analysis, various processes are at the origin of the volcanism in French Polynesia. As evidence, we show a large-scale anomaly over the Society Islands that we interpret as the gravity signature of a deeply anchored mantle plume. The gravity signature of the Cook-Austral chain indicates a complex origin which may involve deep processes. Finally, we discuss the particular location of the Marquesas chain as suggesting that the origin of the volcanism may interfere with secondary convection rolls or may be controlled by lithospheric weakness due to the regional stress field, or else related to the presence of the nearby Tuamotu plateau. Numéro de notice : A2006-305 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2005JB004141 Date de publication en ligne : 23/09/2006 En ligne : https://doi.org/10.1029/2005JB004141 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96656 [article]