@article{fdi:010092614,
  title = {{M}odeling magma recharge dynamics during the 2016 {N}evados de {C}hillan eruption : an interacting two-chamber system evidenced by petrology and geodesy},
  author = {{L}izama, {C}. {N}. and {R}{\'e}my, {D}ominique and {B}aez, {J}. {C}. and {O}yarzun, {A}. and {B}onvalot, {S}ylvain and {H}ooper, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {N}evados de {C}hillan is a large composite stratovolcanic complex located in the {S}outhern {A}ndean {V}olcanic {Z}one, at the south of {C}hile. {I}ts last eruption spanned six years from {J}anuary 8, 2016 until {J}anuary 2023. {A}fter three years without any deformation, exhibiting phreatic and phreatomagmatic activity, an uplift episode was reported in {J}une 2019, marking the start of its magmatic phase. {H}ow this geodetic activity evolved in the following three years is still not clear, neither how it correlates with its superficial activity. {H}ere we analyze {I}n{SAR} time series, as well as daily {GNSS} time series from 2015 to early 2022, highlighting the wide range of ground surface displacements observed during the eruption. {I}n-depth analysis of these displacements together with recent petrological and geochemical results leads us to consider a recharge mechanism involving a double-reservoir model to explain the observed geodetic activity. {W}e develop an analytical model of dynamic magma flow, which we coupled with a boundary element method to account for any geometry of the reservoirs and the topography of the volcano. {T}he model consists of a shallow elongated source located at 5.8 km depth below the volcanic edifice connected by an incompressible magma-filled hydraulic pipe to a deeper sill like source centered at 15 km depth. {W}e propose that the activation of the system started with a small magma intrusion of one month of duration, which was sufficient to overheat the hydrothermal system and re-mobilize magma in the shallow chamber, thus explaining the non-deformation during its phreatic phase and the slight subsidence observed during its phreato-magmatic stage. {T}hen, we propose that a new and larger magma intrusion occurred in {J}une 2019, explaining the uplift episode observed, which continued for the following three years of the eruption, decaying exponentially. {O}ur model indicates that this intrusion was triggered by magma coming from the crust-mantle boundary to the deep reservoir at constant rate of 0.016 km(3)y(-1) from {J}une 2019 to {J}an. 2022, with small changes to this rate that would explain the small fluctuations observed during this uplift episode. {W}e show that the conduit-dominated magma transfer between both reservoirs controls the dynamics of the system. {A} deep mafic reservoir recharging an evolved shallow reservoir would explain the mafic enclaves found in the dacites in the latter eruption and thus offers a physical model to jointly explain the observations we get from petrology, geochemistry and geophysics, bridging the disciplines. {T}he model presented here can be used to study potential recharge mechanism occurring in the different stages of an eruptive cycle including pre-eruptive, co-eruptive and post-eruptive stages.},
  keywords = {{I}n{SAR} and {GNSS} ; {E}xplosive and effusive eruption phases ; {S}outhern {V}olcanic {Z}one ; {D}ouble reservoir modeling ; {U}plift episode ; {P}hreatomagmatic eruption ; {CHILI} ; {ANDES}},
  booktitle = {},
  journal = {{J}ournal of {V}olcanology and {G}eothermal {R}esearch},
  volume = {458},
  numero = {},
  pages = {108253 [14 p.]},
  ISSN = {0377-0273},
  year = {2025},
  DOI = {10.1016/j.jvolgeores.2024.108253},
  URL = {https://www.documentation.ird.fr/hor/fdi:010092614},
}