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Interseismic and coseismic motions in GPS series related to the Ms 7.3 July 13, 1994, Malekula Earthquake, Central New Hebrides Subduction Zone / Stéphane Calmant in Geophysical research letters, vol 24 n° 23 (December 1997)  

Public [article]  inGeophysical research letters > vol 24 n° 23 (December 1997) . - pp 3077 - 3080 Titre : Interseismic and coseismic motions in GPS series related to the Ms 7.3 July 13, 1994, Malekula Earthquake, Central New Hebrides Subduction Zone Type de document : Article/Communication Auteurs : Stéphane Calmant, Auteur ; Bernard Pelletier, Auteur ; Robert Pillet, Auteur ; M. Régnier, Auteur ; Pierre Lebellegard, Auteur ; Didier Maillard, Auteur ; Fred Taylor, Auteur ; Michael Bevis, Auteur ; Jacques Récy, Auteur Année de publication : 1997 Article en page(s) : pp 3077 - 3080 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] déformation de la croute terrestre [Termes IGN] Nouvelles-Hébrides [Termes IGN] séisme [Termes IGN] subduction [Termes IGN] tectonique des plaques Résumé : (auteur) On July 13, 1994, an earthquake Ms=7.3 occurred at Malekula, in the New Hebrides archipelago. The GPS data collected across the New Hebrides trench between 1990 and 1996 were processed in order to separate the interseismic and coseismic motions from the drifts related to the convergence with the Australian plate. The GPS-derived coseismic displacements at the GPS site in Malekula are 49 ± 15 mm southward, 230 ± 30 mm westward and 170 ± 37 mm downward, when the CMT-derived displacements are 50 mm southward, 210 mm westward and 150 mm downward. Taking into account the interseismic strain accumulation (25 mm/yr at the source established from historical seismicity, 7.5 mm/yr at the GPS site), the strain-free convergence rate at Malekula is 49 ± 3 mm/yr. Other GPS-derived convergence rates are 95 ± 1 mm/yr at Efate and 37 ± 2 mm/yr at Santo. These rates imply a regional right-lateral motion between the Efate and the Santo-Malekula segments. In contrast, the focal mechanism of the earthquake mostly indicates a left-lateral motion. Therefore, we hypothesize that the earthquake is related to variations in the interplate coupling along the converging boundary of the Santo-Malekula segment. Numéro de notice : A1997-124 Affiliation des auteurs : IGN+Ext (1940-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/97GL02962 En ligne : https://doi.org/10.1029/97GL02962 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102941 [article]

Geodetic measurements of convergence across the New Hebrides Subduction Zone / Stéphane Calmant in Geophysical research letters, vol 22 n° 19 (octobre 1995)  

Public [article]  inGeophysical research letters > vol 22 n° 19 (octobre 1995) . - pp 2573 - 2576 Titre : Geodetic measurements of convergence across the New Hebrides Subduction Zone Type de document : Article/Communication Auteurs : Stéphane Calmant, Auteur ; Pierre Lebellegard, Auteur ; Fred Taylor, Auteur ; Michael Bavis, Auteur ; Didier Maillard, Auteur ; Jacques Récy, Auteur ; Jocelyne Bonneau, Auteur Année de publication : 1995 Article en page(s) : pp 2573 - 2576 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Australie [Termes IGN] données GPS [Termes IGN] Nouvelles-Hébrides [Termes IGN] subduction [Termes IGN] tectonique des plaques Résumé : (auteur) Between 1990 and 1994, geodetic measurements (GPS observations) have been conducted across the New Hebrides subduction zone where the Australia plate subducts under the New Hebrides Arc. This paper establishes convergence rate variations along the trench. In the South, at Tanna, the relative motion is oriented N244 ±4 and has a uniform rate of 11.7±0.8 cm/yr. The rate at Efaté is 10.3±0.9 cm/yr, oriented N242 ±4. Both azimuths very well compare with slip vectors of the last major earthquakes. In the North, the rate at Santo is only 3.6 ±1.2 cm/yr, oriented N253 ± 26. The difference in the convergence rates between Santo on the one hand and Efaté and Tanna in the other hand points to a right lateral shear zone between Santo and Efaté. At Santo where the plate coupling is very high, the very low convergence rate might be related to the absence of recent strong earthquakes. No significant variations are detected for the baselines within the Australia plate. Numéro de notice : A1995-070 Affiliation des auteurs : IGN+Ext (1940-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/95GL01780 Date de publication en ligne : 01/10/1995 En ligne : https://doi.org/10.1029/95GL01780 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102937 [article]