@article{fdi:010018409,
  title = {{S}eismic source study of the {R}acha-{D}zhava ({G}eorgia) earthquake from aftershocks and broad-band teleseismic body-wave records : an example of active nappe tectonics},
  author = {{F}uenzalida, {H}. and {R}ivera, {L}. and {H}aessler, {H}. and {L}egrand, {D}. and {P}hilip, {H}. and {D}orbath, {L}ouis and {M}c{C}ormack, {D}. and {A}refiev, {S}. and {L}anger, {C}. and {C}isternas, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {R}acha-{D}zhava earthquake ({M}s = 7.0) that occurred on 1991 {A}pril 29 at 09:12:48.1 {GMT} in the southern border of the {G}reat {C}aucasus is the biggest event ever recorded in the region, stronger than the {S}pitak earthquake ({M}s = 6.9) of 1988. {A} field expedition to the epicentral area was organised and a temporary seismic network of 37 stations was deployed to record the aftershock activity. {A} very precise image of the aftershock distribution is obtained, showing an elongated cloud oriented {N}105°, with one branch trending {N}310° in the {W}estern part. {T}he southernmost part extends over 80 km, with the depth ranging from 0 to 15 km, and dips north. {T}he northern branch, which is about 30 km long, shows activity that ranges in depth from 5 to 15 km. {T}he complex thrust dips northwards. {A} stress-tensor inversion from {P}-wave first-motion polarities shows a state of triaxial compression, with the major principal axis oriented roughly {N}-{S}, the minor principal axis being vertical. {B}ody-waveform inversion of teleseismic seismograms was performed for the main shock, which can be divided into four subevents with a total rupture-time duration of 22 s. {T}he most important part of the seismic moment was released by a gentle northerly dipping thrust. {T}he model is consistent with the compressive tectonics of the region and is in agreement with the aftershock distribution and the stress tensor deduced from the aftershocks. {T}he focal mechanisms of the three largest aftershocks were also inverted from body-wave records. {T}he {A}pril 29th ({M}s = 6.1) and {M}ay 5th ({M}s = 5.4) aftershocks have thrust mechanisms on roughly {E}-{W}-oriented planes, similar to the main shock. {S}urprisingly, the {J}une 15th ({M}s = 6.2) aftershock shows a thrust fault striking {N}-{S}. {T}his mechanism is explained by the structural control of the rupture along the east-dipping geometry of the {D}zirula {M}assif close to the {B}orzhomi-{K}azberg strike-slip fault... ({D}'apr{\`e}s r{\'e}sum{\'e} d'auteur)},
  keywords = {{SEISME} ; {ETUDE} {REGIONALE} ; {TECTONIQUE} {DE} {PLAQUES} ; {MODELISATION} ; {ONDE} {SISMIQUE} ; {MESURE} ; {GEORGIE} ; {CAUCASE}},
  booktitle = {},
  journal = {{G}eophysical {J}ournal {I}nternational},
  volume = {130},
  numero = {1},
  pages = {29--46},
  ISSN = {0956-540{X}},
  year = {1997},
  DOI = {10.1111/j.1365-246{X}.1997.tb00985.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010018409},
}