@article{PAR00003855,
  title = {{H}orizontal and vertical interseismic velocity fields in the {V}anuatu subduction zone from {GPS} measurements : evidence for a central {V}anuatu locked zone},
  author = {{B}ergeot, {N}. and {B}ouin, {M}. {N}. and {D}iament, {M}. and {P}elletier, {B}ernard and {R}{\'e}gnier, {M}arc and {C}almant, {S}t{\'e}phane and {B}allu, {V}al{\'e}rie},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e analyzed interseismic velocity fields along the {V}anuatu arc subduction zone from more than 45 {GPS} station measurements spanning 15 years. {C}onvergence with respect to the {A}ustralian plate ({AP}) is normal to the trench, with amplitudes that vary greatly from a maximum of 170 mm a(-1) at {V}anikoro to 27 mm a(-1) facing the {D}'{E}ntrecasteaux {R}idge ({DER}). {M}otions expressed relative to the {P}acific plate ({PP}) highlight arc segmentation. {B}oth the northern and southern segments undergo back-arc spreading in a roughly {NE}-{SW} direction, rotating anticlockwise and clockwise, respectively, while the central block moves eastward at a faster rate with respect to the {PP} than to the {AP}. {M}ore convergence is therefore accommodated at the eastern bound of the arc than at the {V}anuatu trench. {A} right lateral strike-slip movement (26 +/- 1 mm a(-1)) along a zone normal to the trench (direction {N}70 degrees) is necessary to accommodate the rate variation between the central and southern parts of the arc. {H}orizontal and vertical rates indicate partitioning between {M}alekula-southernmost {S}anto and central-northern {S}anto blocks. {S}imple elastic modeling of the interseismic stage deformation gives locked zone characteristics (25 degrees dip and 50 km width) and a 54 mm a(-1) long-term convergence rate between the {AP} and the central part of the {V}anuatu arc from {GPS} horizontal and vertical velocities estimated south of the {DER}. {T}he modeling does not fit the observed velocities facing the {DER}, probably because it does not account for the inelastic deformation associated with buoyant ridge subduction and back-arc thrusting.},
  keywords = {{VANUATU}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch - {S}olid {E}arth},
  volume = {114},
  numero = {},
  pages = {{B}06405},
  ISSN = {0148-0227},
  year = {2009},
  DOI = {10.1029/2007jb005249},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00003855},
}