Éditeur(s) : Auxerre : Gilles Bouquet
Siècle(s) traité(s) : 17
Droits : Domaine public
Provenance : Communauté d'agglomération de La Rochelle. Médiathèque Michel-Crépeau
Permalien : http://www.manioc.org/patrimon/MMC16001-2
MMC16001-2

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
We report measurements of long-period P wave polarization (P pol) in Australia and Tahiti made by combining modeling of the polarization deviation and harmonic analysis. The analysis of the deviation of the horizontal polarization of the P wave as a function of event back azimuth may be used to obtain information about (1) sensor misorientation, (2) dipping discontinuities, (3) seismic anisotropy, and (4) velocity heterogeneities beneath a seismic station. The results from harmonic analysis and a grid search using Snell's law suggest the presence of a dipping seismic discontinuity beneath stations CTAO and CAN in Australia. These results are consistent with published receiver function studies for these stations. The P pol fast axis orientation is close to the N–S absolute plate motion direction at station TAU (Tasmania), which may be due to plate-motion-driven alignment of olivine crystals in the asthenosphere. Interestingly, measurements of SKS splitting at Tahiti (French Polynesia) show an apparent isotropy, whereas an inversion of P pol observations at PPTL seismic station located in Tahiti suggests the presence of two anisotropic layers. The fast axis azimuth is oriented E–W in the upper layer, and it is close to the NW–SE orientation in the lower layer. Since P pol orientations are used for real-time earthquake locations, especially in poorly instrumented areas such as the South Pacific, we show that the bias from anisotropy and sensor misorientation determined here can be corrected to improve the location accuracy, which yields fundamental data for rapid location necessary for effective tsunami warning.
ISSN: 2169-9313

hal-01389113
http://hal.univ-reunion.fr/hal-01389113
http://hal.univ-reunion.fr/hal-01389113/document
http://hal.univ-reunion.fr/hal-01389113/file/Fontaine_Ppol_JGR2009.pdf
DOI : 10.1029/2008JB005709

Éditeur(s) : Macon : Protat frères
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Martinique. Bibliothèque Schoelcher
Permalien : http://www.manioc.org/patrimon/SCH13269
SCH13269

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
We report measurements of long-period P wave polarization (P-pol) in Australia and Tahiti made by combining modeling of the polarization deviation and harmonic analysis. The analysis of the deviation of the horizontal polarization of the P wave as a function of event back azimuth may be used to obtain information about (1) sensor misorientation, (2) dipping discontinuities, (3) seismic anisotropy, and (4) velocity heterogeneities beneath a seismic station. The results from harmonic analysis and a grid search using Snell's law suggest the presence of a dipping seismic discontinuity beneath stations CTAO and CAN in Australia. These results are consistent with published receiver function studies for these stations. The P-pol fast axis orientation is close to the N-S absolute plate motion direction at station TAU (Tasmania), which may be due to plate-motion-driven alignment of olivine crystals in the asthenosphere. Interestingly, measurements of SKS splitting at Tahiti (French Polynesia) show an apparent isotropy, whereas an inversion of P-pol observations at PPTL seismic station located in Tahiti suggests the presence of two anisotropic layers. The fast axis azimuth is oriented E-Win the upper layer, and it is close to the NW-SE orientation in the lower layer. Since P-pol orientations are used for real-time earthquake locations, especially in poorly instrumented areas such as the South Pacific, we show that the bias from anisotropy and sensor misorientation determined here can be corrected to improve the location accuracy, which yields fundamental data for rapid location necessary for effective tsunami warning.
ISSN: 2169-9313

hal-00413141
https://hal.archives-ouvertes.fr/hal-00413141
https://hal.archives-ouvertes.fr/hal-00413141/document
https://hal.archives-ouvertes.fr/hal-00413141/file/FontaineetalJGR2008.pdf
DOI : 10.1029/2008JB005709

Éditeur(s) : Saint-Pierre, Martinique : Impr. Hte Durieu
Siècle(s) traité(s) : 19
Provenance : Archives départementales de Guadeloupe
Permalien : http://www.manioc.org/patrimon/ADG18183
ADG18183

Éditeur(s) : Paris : Imprimerie royale
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Martinique. Bibliothèque Schoelcher
Permalien : http://www.manioc.org/patrimon/SCH13142
SCH13142

Éditeur(s) : Paris : Impressions Printory et Georges Courville, Libraire
Siècle(s) traité(s) : 20
Droits : Domaine public
Provenance : Ville de Pointe-à-Pitre. Réseau des bibliothèques
Permalien : http://www.manioc.org/patrimon/PAP11055
PAP11055

Éditeur(s) : Madrid : Fernando Fe ; Sevilla : Hijos de Fe ; Lisboa : Bertrand [et al.]
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Université Toulouse - Jean Jaurès. Service Commun de la Documentation
Permalien : http://www.manioc.org/patrimon/TLS17043
TLS17043

Éditeur(s) : Leipzig : in der Weidmannschen Buchhandlung
Siècle(s) traité(s) : 18
Droits : Domaine public
Provenance : Université Toulouse III - Paul Sabatier. Service Commun de la Documentation
Permalien : http://www.manioc.org/patrimon/TLS17115
TLS17115