@article{fdi:010068354,
  title = {{S}tructure and evolution of an active resurgent dome evidenced by geophysical investigations : the {Y}enkahe dome-{Y}asur volcano system ({S}iwi caldera, {V}anuatu)},
  author = {{B}rothelande, {E}. and {L}enat, {J}. {F}. and {C}haput, {M}. and {G}ailler, {L}. and {F}inizola, {A}. and {D}umont, {S}. and {P}eltier, {A}. and {B}achelery, {P}. and {B}arde-{C}abusson, {S}. and {B}yrdina, {S}vetlana and {M}enny, {P}. and {C}olonge, {J}. and {D}ouillet, {G}. {A}. and {L}etort, {J}. and {L}etourneur, {L}. and {M}erle, {O}. and {D}i {G}angi, {F}. and {N}akedau, {D}. and {G}araebiti, {E}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n this contribution, we focus on one of the most active resurgences on {E}arth, that of the {Y}enkahe dome in the {S}iwi caldera ({T}anna {I}sland, {V}anuatu), which is associated with the persistently active {Y}asur volcano. {G}ravity and magnetic surveys have been carried out over the past few years in the area, as well as electrical methods including electrical resistivity tomography ({ERT}), time domain electro-magnetics ({TDEM}) and self-potential ({SP}). {T}hese investigations were completed by thermometry, {CO}2 soil gas measurements, field observations and sampling. {T}his multi-method approach allows geological structures within the caldera to be identified, as well as associated hydrothermal features. {T}he global structure of the caldera is deduced from gravity data, which shows the caldera rim as a high density structure. {L}arge lava fields, emplaced before and after the onset of resurgence, are evidenced by combined gravity, magnetic and resistivity signals. {I}n the middle of the caldera, the {Y}enkahe dome apparently results from a combination of volcanic and tectonic events, showing that lava extrusion and resurgence have been operating simultaneously or alternately during the {S}iwi caldera post-collapse history. {T}here is a clear distinction between the western and eastern parts of the dome. {T}he western part is older and records the growth of an initial volcanic cone and the formation of a small caldera. {T}his small caldera (paleo-{Y}asur caldera), partially filled with lava flows, is the present-day focus of volcanic activity and associated fluid circulation and alteration. {T}he eastern part of the dome is presumably younger, and is characterized by intense, extensive hydro thermal alteration and activity. {I}ts northern part is covered by lava flow piles and exhibits a shallow hydrothermal zone in {ERT}. {T}he southern part has hydrothermal alteration and activity extending at least down to the base of the resurgent dome. {T}his part of the dome is built up of low cohesion rock and is thus potentially prone to gravitational landslides. {L}astly, while self-potential and temperature data suggest that widespread hydro thermal circulation occurs throughout almost all of the caldera, and possibly beyond, the most active parts of this hydrothermal system are associated with the dome. {T}he presence of this active hydrothermal system is the clearest indicator that these methods can provide of a potential shallow magmatic body underneath the dome.},
  keywords = {{C}aldera ; {R}esurgent dome ; {Y}enkahe ; {Y}asur ; {H}ydrothermal system ; {G}eophysics ; {VANUATU} ; {YASUR} {VOLCAN}},
  booktitle = {{U}nderstanding volcanoes in the {V}anuatu arc},
  journal = {{J}ournal of {V}olcanology and {G}eothermal {R}esearch},
  volume = {322},
  numero = {{N}o {S}p{\'e}cial},
  pages = {241--262},
  ISSN = {0377-0273},
  year = {2016},
  DOI = {10.1016/j.jvolgeores.2015.08.021},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068354},
}