@article{PAR00008058,
  title = {{I}dentifying potentially active volcanoes in the {A}ndes : radiometric evidence for late {P}leistocene-early {H}olocene eruptions at {V}olcan {I}mbabura, {E}cuador},
  author = {{L}e {P}ennec, {J}ean-{L}uc and {R}uiz, {A}.{G}. and {E}issen, {J}ean-{P}hilippe and {H}all, {M}.{L}. and {F}ornari, {M}ichel},
  editor = {},
  language = {{ENG}},
  abstract = {{R}ecent eruptions from volcanoes with no previously known historical activity in {C}hile and {I}ndonesia have raised the importance of the early identification of potentially active centers for the purpose of hazard assessment. {H}ere we bring radiometric evidence ({C}-14,{A}r-39-{A}r-40) of previously unrecognized but significant magmatic activity at partly eroded {I}mbabura volcano ({E}cuador) in late {P}leistocene to early {H}olocene times, on whose perimeter live more than 300,000 persons. {F}ollowing an effusive stage from 50 to 30 ka with the emplacement of andesitic lava flows on different flanks of its edifice, the activity became explosive with the generation of andesitic block-and-ash flows on its eastern side, beginning at similar to 35 ka cal {BP}. {S}ubsequently a flank collapse associated with a volcanic blast occurred on the volcano's {SW} flank at similar to 30 ka cal {BP}. {T}he resulting debris avalanche and blast breccias cover an area now heavily populated around {S}an {P}ablo {L}ake and its source was later concealed by successive dome building episodes at {H}uarmi which produced similar to 2.8 km(3) of silicic andesite. {R}enewed dome activity at the edifice's {T}aita summit occurred at similar to 17 ka cal {BP} and continued intermittently into early {H}olocene times, as indicated by pyroclastic flow deposits overlying a palaeosoil dated at similar to 9 ka cal {BP}. {I}n summary, this study reveals an eruptive behavior characterized by a low recurrence rate but with quite large eruptions, a pattern which is also observed at other silicic volcanoes of {E}cuador's {W}estern {C}ordillera. {I}t is now imperative to reconsider the origin and source of the many tephra layers catalogued in {H}olocene lacustrine sediments in the {I}mbabura area. {T}ephra and lava volume estimates for {I}mbabura volcano converted to {D}ense {R}ock {E}quivalent values yield a minimum magmatic output rate of 0.13 km(3)/ka in the past 35,000 years, which argues for sustained magma production for this volcano in recent geological times. {T}he lmbabura example thus raises the question of how to improve population preparedness for volcanoes with infrequent eruptions, and how to guide authorities' decisions concerning the development of urban areas and infrastructures near presently inactive but potentially highly dangerous volcanoes.},
  keywords = {{A}ctive volcanoes ; {R}adiometric dating ; {I}mbabura volcano ; {E}cuador},
  booktitle = {},
  journal = {{J}ournal of {V}olcanology and {G}eothermal {R}esearch},
  volume = {206},
  numero = {3-4},
  pages = {121--135},
  ISSN = {0377-0273},
  year = {2011},
  DOI = {10.1016/j.jvolgeores.2011.06.002},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00008058},
}