@article{fdi:010087284,
  title = {{P}ermanent tremor of {M}asaya {V}olcano, {N}icaragua: {W}ave field analysis and source location},
  author = {{M}{\'e}taxian, {J}ean-{P}hilippe and {L}esage, {P}. and {D}orel, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {M}asaya {V}olcano, {N}icaragua, is a basaltic caldera in a subduction zone. {T}he permanent source of the volcanic tremor was located inside {S}antiago crater, at the lava lake's position and 400 m below the {NE} rim, and therefore corresponds to superficial magma activity. {W}e used two tripartite arrays (90 m side), one semicircular array (r=120 m) in 1992, and two semicircular arrays (r=60 m) and a 2500 m long linear array radiating out from the source and on the flank of the crater in 1993. {W}e used both a cross-spectrum method and a correlation method to determine the wave delay time between the reference station and the other stations of an array and to quantify the wave field. {U}sing the delays therefore by intersecting the back azimuth wave directions from the arrays, we could pinpoint the source. {A}dditionally, the correlation coefficients obtained as functions of frequency for the three components of motion confirm the inferred position of the source of tremor. {T}he tremor's wave field is composed of comparable quantities of dispersed {R}ayleigh and {L}ove surface waves, whose phase velocities lie in the ranges 730-1240 m/s at 2 {H}z and 330-550 m/s at 6 {H}z. {T}he dispersive phase velocities were inverted to obtain crustal structures with a minimal number of layers. {T}he resulting velocity models are similar for the northern and southern parts of the volcano. {A}fter geometrical spreading corrections, {Q}2{H}z=14 and {Q}3{H}z=31 were determined along the northern linear array. {T}he typical low velocities and low {Q} corresponding to the cone structure and are similar to those of other basaltic volcanoes like {P}uu {O}o, {H}awaii, and {K}lyuchevskoy, {K}amchatka.},
  keywords = {{NICARAGUA}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {S}olid {E}arth},
  volume = {102},
  numero = {{B}10},
  pages = {22529--22545},
  ISSN = {2169-9313},
  year = {1997},
  DOI = {10.1029/97{JB}01141},
  URL = {https://www.documentation.ird.fr/hor/fdi:010087284},
}