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Upper mantle rheology from GRACE and GPS postseismic deformation after the 2004 Sumatra‐Andaman earthquake / Isabelle Panet in Geochemistry, Geophysics, Geosystems, vol 11 n° 6 (June 2010)
[article]
Titre : Upper mantle rheology from GRACE and GPS postseismic deformation after the 2004 Sumatra‐Andaman earthquake Type de document : Article/Communication Auteurs : Isabelle Panet , Auteur ; Fred Pollitz, Auteur ; Valentin O. Mikhailov, Auteur ; Michel Diament , Auteur ; P. Banerjee, Auteur ; K. Grijalva, Auteur Année de publication : 2010 Article en page(s) : 20 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données GPS
[Termes IGN] données GRACE
[Termes IGN] manteau terrestre
[Termes IGN] rhéologie
[Termes IGN] séisme
[Termes IGN] SumatraRésumé : (auteur) Mantle rheology is one of the essential, yet least understood, material properties of our planet, controlling the dynamic processes inside the Earth's mantle and the Earth's response to various forces. With the advent of GRACE satellite gravity, measurements of mass displacements associated with many processes are now available. In the case of mass displacements related to postseismic deformation, these data may provide new constraints on the mantle rheology. We consider the postseismic deformation due to the Mw = 9.2 Sumatra 26 December 2004 and Mw = 8.7 Nias 28 March 2005 earthquakes. Applying wavelet analyses to enhance those local signals in the GRACE time varying geoids up to September 2007, we detect a clear postseismic gravity signal. We supplement these gravity variations with GPS measurements of postseismic crustal displacements to constrain postseismic relaxation processes throughout the upper mantle. The observed GPS displacements and gravity variations are well explained by a model of viscoelastic relaxation plus a small amount of afterslip at the downdip extension of the coseismically ruptured fault planes. Our model uses a 60 km thick elastic layer above a viscoelastic asthenosphere with Burgers body rheology. The mantle below depth 220 km has a Maxwell rheology. Assuming a low transient viscosity in the 60–220 km depth range, the GRACE data are best explained by a constant steady state viscosity throughout the ductile portion of the upper mantle (e.g., 60–660 km). This suggests that the localization of relatively low viscosity in the asthenosphere is chiefly in the transient viscosity rather than the steady state viscosity. We find a 8.1018 Pa s mantle viscosity in the 220–660 km depth range. This may indicate a transient response of the upper mantle to the high amount of stress released by the earthquakes. To fit the remaining misfit to the GRACE data, larger at the smaller spatial scales, cumulative afterslip of about 75 cm at depth should be added over the period spanned by the GRACE models. It produces only small crustal displacements. Our results confirm that satellite gravity data are an essential complement to ground geodetic and geophysical networks in order to understand the seismic cycle and the Earth's inner structure. Numéro de notice : A2010-655 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2009GC002905 Date de publication en ligne : 19/06/2010 En ligne : https://doi.org/10.1029/2009GC002905 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91728
in Geochemistry, Geophysics, Geosystems > vol 11 n° 6 (June 2010) . - 20 p.[article]Documents numériques
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Upper mantle rheology from GRACE and GPS ... - pdf éditeurAdobe Acrobat PDF Ocean loading effects on the prediction of Antarctic glacial isostatic uplift and gravity rates / K. Simon in Journal of geodesy, vol 84 n° 5 (May 2010)
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Titre : Ocean loading effects on the prediction of Antarctic glacial isostatic uplift and gravity rates Type de document : Article/Communication Auteurs : K. Simon, Auteur ; T. James, Auteur ; Eric Ivins, Auteur Année de publication : 2010 Article en page(s) : pp 305 - 317 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Antarctique
[Termes IGN] champ de pesanteur local
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données GRACE
[Termes IGN] isostasie
[Termes IGN] positionnement par GPS
[Termes IGN] surcharge océaniqueRésumé : (Auteur) The effect of regional ocean loading on predicted rates of crustal uplift and gravitational change due to glacial isostatic adjustment (GIA) is determined for Antarctica. The effect is found to be significant for the ICE-3G and ICE-5G loading histories (up to -8 mm/year and -3 mm/year change in uplift rate and -3 cm/year and -1 cm/year equivalent water height change (EWHC) of surface mass, respectively). The effect is smaller (+1 mm/year; +0.25 cm/year) for the IJ05 loading history. The impact of ocean loading on the rate of change of the long-wavelength zonal harmonics of the Earth’s gravitational field is also significantly smaller for IJ05 than ICE-3G. A simple analytical formula is derived that is accurate to about 3% in a root-mean-square sense that relates predicted or observed gravitational change at the surface of the Earth (r = a) to the EWHC. A fundamental difference in the definition of the load histories accounts for the differing sensitivities to ocean loading. IJ05 defines its surface load history relative to the present-day surface load, rather than specifying an absolute loading history, and thus implicitly approximates the temporal and spatial mass exchange between grounded ice and open ocean. In contrast, ICE-3G and ICE-5G specify an absolute load history and explicit regional ocean loading substantially perturbs predicted GIA rates. Conclusions of previous studies that used IJ05 predictions without ocean loading are relatively robust. Numéro de notice : A2010-183 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0368-4 Date de publication en ligne : 12/02/2010 En ligne : https://doi.org/10.1007/s00190-010-0368-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30378
in Journal of geodesy > vol 84 n° 5 (May 2010) . - pp 305 - 317[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2010051 SL Revue Centre de documentation Revues en salle Disponible Mantle dynamics, geoid, inertia and TPW since 120 Myr / Hélène Rouby in Earth and planetary science letters, vol 292 n° 3-4 (April 2010)
[article]
Titre : Mantle dynamics, geoid, inertia and TPW since 120 Myr Type de document : Article/Communication Auteurs : Hélène Rouby , Auteur Année de publication : 2010 Article en page(s) : pp 301 - 311 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] géoïde terrestre
[Termes IGN] manteau terrestre
[Termes IGN] moment d'inertie
[Termes IGN] oscillation
[Termes IGN] rotation de la TerreRésumé : (auteur) We investigate the effect of internal masses redistributions on the position of the Earth rotational pole for the last 120 Myr. We use a geodynamic model based on plate reconstructions that estimates the location and rate of subducted slabs under the assumption that they sink vertically into the mantle (Ricard et al., 1993b). Our model also takes into account the effect of large-scale upwellings (domes) derived from an analysis of seismic tomography. Their location is assumed to remain stable with time. We then compute the geoid associated with the time-dependent mantle density heterogeneities. In order to reconcile the computed and observed geoids, we investigate the influence of the depth down to which the subducted Pacific plates beneath the Americas present a significant density contrast with respect to the surrounding mantle on the present-day geoid, and propose a plate model in which we obtain a variance reduction greater than 0.9 for the degree 2. We show that the vertical oscillation of domes within mantle only modulates the amplitude of the associated geoid. The temporal variation of the mantle density heterogeneities is consequently essentially due to changes in the subduction history. The temporal evolution of the Principal Inertia Axis (PIA) of the Earth derived from our model (the rotational axis is aligned to the maximum PIA) is then investigated, and finally compared to estimations of TPW. Both the maximum and intermediate PIAs have moved in a plane perpendicular to Africa, along a circle corresponding to the low of geoid induced by subduction around the Pacific. The minimum PIA seems to be relatively stable since 120 Myr, and close to the maximum degree 2 geoid high under Africa. This can account for observed TPW or African APW in the last 200 Myr. Numéro de notice : A2010-697 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.epsl.2010.01.033 En ligne : https://doi.org/10.1016/j.epsl.2010.01.033 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102049
in Earth and planetary science letters > vol 292 n° 3-4 (April 2010) . - pp 301 - 311[article]Les marées terrestres, la dynamique du manteau et la sismicité / Laurent Métivier in Géomatique expert, n° 67 (01/02/2009)
[article]
Titre : Les marées terrestres, la dynamique du manteau et la sismicité Type de document : Article/Communication Auteurs : Laurent Métivier , Auteur Année de publication : 2009 Article en page(s) : pp 36 - 39 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] géoïde altimétrique
[Termes IGN] levé gravimétrique
[Termes IGN] manteau terrestre
[Termes IGN] marée terrestre
[Termes IGN] séisme
[Termes IGN] sismicitéRésumé : (Auteur) Comment les marées solides et la gravimétrie influent sur la sismicité : Compte-rendu d'une conférence de Laurent Métivier, du laboratoire Lareg de l'IGN. Numéro de notice : A2009-062 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29692
in Géomatique expert > n° 67 (01/02/2009) . - pp 36 - 39[article]Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 265-09021 RAB Revue Centre de documentation En réserve L003 Disponible IFN-001-P000319 RAB Revue Nogent-sur-Vernisson En réserve L003 Exclu du prêt Documents numériques
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Les marées terrestres, la dynamique du manteau et la sismicitéAdobe Acrobat PDF A seafloor experiment to monitor vertical deformation at the Lucky Strike volcano, Mid-Atlantic Ridge / Marie-Noëlle Bouin in Journal of geodesy, vol 83 n° 2 (February 2009)
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Titre : A seafloor experiment to monitor vertical deformation at the Lucky Strike volcano, Mid-Atlantic Ridge Type de document : Article/Communication Auteurs : Marie-Noëlle Bouin , Auteur ; V. Ballut, Auteur ; Jérôme Ammann, Auteur ; O. Pot, Auteur ; Olivier de Viron, Auteur ; et al., Auteur Année de publication : 2009 Article en page(s) : pp 147 - 159 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Atlantique (océan)
[Termes IGN] déformation verticale de la croute terrestre
[Termes IGN] dorsale
[Termes IGN] fond marin
[Termes IGN] surveillance géologique
[Termes IGN] volcanRésumé : (Auteur) Decades of cruise-based exploration have provided excellent snapshots of the structure of mid-ocean ridges and have revealed that accretion is a mixture of steady-state and quantum events. Observatory-type studies are now needed to quantify the temporal evolution of these systems. A multi-disciplinary seafloor observatory site is currently being set up at the Lucky Strike volcano, in the axial valley of the slow spreading Mid-Atlantic ridge as a part of the MoMAR (monitoring of the Mid-Atlantic Ridge) initiative. The aim of this observatory is to better understand the dynamics of the volcano and the hydrothermal vents hosted at its summit as well as their plumbing systems. In August 2006, the GRAVILUCK cruise initiated an experiment to monitor the deformation of Lucky Strike volcano. A geodetic network was installed, and seafloor pressure, gravity and magnetic data were collected. In this paper, we present the method used to monitor volcanic deformation, which involves measuring relative depth difference between points within a seafloor geodesy network. We show that, taking into account oceanographic variability and measurement noise, the network should be able to detect vertical deformations of the order of 1 cm. Copyright Springer Numéro de notice : A2009-189 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-008-0248-3 En ligne : https://doi.org/10.1007/s00190-008-0248-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29819
in Journal of geodesy > vol 83 n° 2 (February 2009) . - pp 147 - 159[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-09021 SL Revue Centre de documentation Revues en salle Disponible Effects of topographic-isostatic masses on gravitational functionals at the Earth's surface and at airborne and satellite altitudes / A. Makhloof in Journal of geodesy, vol 82 n° 2 (February 2008)PermalinkGéologie / Pierre Peycru (2008)PermalinkMagnetic satellite missions: where have we been and where are we going? / Mioara Mandea in Comptes rendus : Géoscience, vol 338 n° 14-15 (November 2006)PermalinkNew 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)PermalinkEffet de moyenne par moindres carrés, application à l'analyse des séries temporelles laser / David Coulot in Bulletin d'information scientifique et technique de l'IGN, n° 75 (mars 2006)PermalinkEtude du couplage visqueux entre le noyau et le manteau de la Terre / Charlotte Ducrocq (2006)PermalinkEtude de la structure interne de Mars / T. Rugi (2006)PermalinkMesure de la déformation de l'écorce terrestre par géodésie spatiale [diaporama] / Jérome Verdun (2006)PermalinkMesures GPS continues et tectonique des plaques / Christophe Vigny in Géochronique, n° 94 (juin - août 2005)PermalinkUtilisation des données GPS pour la réalisation de la carte géodynamique de la Méditerranée / Nicolas Chamot-Rooke in Géochronique, n° 94 (juin - août 2005)Permalink