@article{fdi:010086409,
  title = {{C}onduit processes in crystal-rich dacitic magma and implications for eruptive cycles at {G}uagua {P}ichincha volcano, {E}cuador},
  author = {{C}olombier, {M}. and {B}ernard, {B}. and {W}right, {H}. and {L}e {P}ennec, {J}ean-{L}uc and {C}aceres, {F}. and {C}imarelli, {C}. and {H}eap, {M}. {J}. and {S}amaniego, {P}ablo and {V}asseur, {J}. and {D}ingwell, {D}. {B}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}tratovolcanoes are commonly characterised by cyclic eruptive activity marked by transitions between dome-forming, {V}ulcanian, {S}ubplinian and {P}linian eruptions. {G}uagua {P}ichincha volcano ({E}cuador) has been a location of such cyclicity for the past similar to 2000 years, with {P}linian eruptions in the first and tenth centuries {AD} ({A}nno {D}omini/after {C}hrist), and {CE} ({C}ommon {E}ra) 1660, which were separated by dome-forming to {S}ubplinian eruptions, such as the recent 1999-2001 eruption. {T}hese cycles are therefore a prominent example of effusive-explosive transitions at varying timescales. {H}ere, we investigate the reasons for such shifts in activity by focusing on degassing and outgassing processes within the conduit. {W}e have coupled a petrophysical and textural analysis of dacites from the {CE} 1660 {P}linian eruption and the 1999-2001 dome-forming/{V}ulcanian eruption, with different percolation models in order to better understand the role of degassing on eruptive style. {W}e demonstrate that the transition from dome-forming to {P}linian activity is correlated with differences in phenocryst content and consequently in bulk viscosity. {A} lower initial phenocryst content and viscosity is inferred for the {P}linian case, which promotes faster ascent, closed-system degassing, fragmentation and explosive activity. {I}n contrast, dome-forming phases are promoted by a higher magma viscosity due to higher phenocryst content, with slower ascent enhancing gas escape and microlite crystallization, decreasing explosivity and yielding effusive activity.},
  keywords = {{G}uagua {P}ichincha ; {E}ruptive cycles ; {T}extural analysis ; {P}linian eruption ; {D}ome-forming eruption ; {E}ffusive-explosive transition ; {D}egassing ; {P}ercolation model ; {EQUATEUR}},
  booktitle = {},
  journal = {{B}ulletin of {V}olcanology},
  volume = {84},
  numero = {12},
  pages = {105 [23 ]},
  ISSN = {0258-8900},
  year = {2022},
  DOI = {10.1007/s00445-022-01612-1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010086409},
}