@article{fdi:010082300,
  title = {{W}hat triggers caldera ring-fault subsidence at {A}mbrym volcano ? {I}nsights from the 2015 dike intrusion and eruption},
  author = {{S}hreve, {T}. and {G}randin, {R}. and {S}mittarello, {D}. and {C}ayol, {V}. and {P}inel, {V}irginie and {B}oichu, {M}. and {M}orishita, {Y}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}urface deformation accompanying dike intrusions is dominated by uplift and horizontal motion directly related to the intrusions. {I}n some cases, it includes subsidence due to associated magma reservoir deflation. {W}hen reservoir deflation is large enough, it can form, or reactivate preexisting, caldera ring-faults. {R}ing-fault reactivation, however, is rarely observed during moderate-sized eruptions. {O}n {F}ebruary 21, 2015 at {A}mbrym volcano in {V}anuatu, a basaltic dike intrusion produced more than 1 m of coeruptive uplift, as measured by {I}n{SAR}, synthetic aperture radar correlation, and {M}ultiple {A}perture {I}nterferometry. {H}ere, we show that an average of similar to 40 cm of slip occurred on a normal caldera ring-fault during this moderate-sized ({VEI} < 3) event, which intruded a volume of similar to 24 x 10(6) m(3) and erupted similar to 9.3 x 10(6) m(3) of lava ({DRE}). {U}sing the 3{D} {M}ixed {B}oundary {E}lement {M}ethod, we explore the stress change imposed by the opening dike and the depressurizing reservoir on a passive, frictionless fault. {N}ormal fault slip is promoted when stress is transferred from a depressurizing reservoir beneath one of {A}mbrym's main craters. {A}fter estimating magma compressibility, we provide an upper bound on the critical fraction (f = 7%) of magma extracted from the reservoir to trigger fault slip. {W}e infer that broad basaltic calderas may form in part by hundreds of subsidence episodes no greater than a few meters, as a result of magma extraction from the reservoir during moderate-sized dike intrusions.},
  keywords = {basaltic volcanism ; calderas ; rift zones ; ring-faults ; stress transfer ; {VANUATU} ; {AMBRYM} {VOLCAN}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {S}olid {E}arth},
  volume = {126},
  numero = {6},
  pages = {e2020{JB}020277 [26 p.]},
  ISSN = {2169-9313},
  year = {2021},
  DOI = {10.1029/2020jb020277},
  URL = {https://www.documentation.ird.fr/hor/fdi:010082300},
}