Multidisciplinary observations of the 2011 explosive eruption of Telica volcano, Nicaragua: Implications for the dynamics of low-explosivity ash eruptions

作者:Geirsson Halldor*; Rodgers Mel; LaFemina Peter; Witter Molly; Roman Diana; Munoz Angelica; Tenorio Virginia; Alvarez Julio; Jacobo Vladimir Conde; Nilsson Daniel; Galle Bo; Feineman Maureen D; Furman Tanya; Morales Allan
来源:Journal of Volcanology and Geothermal Research, 2014, 271: 55-69.
DOI:10.1016/j.jvolgeores.2013.11.009

摘要

We present multidisciplinary observations of the March-June 2011 VEI 2 eruptive episode of the basalticandesite Telica volcano, Nicaragua, which allow for a comprehensive study of the eruption mechanics of low-explosivity eruptions at persistently active volcanoes. The observations are from a dense network of seismic and GPS instrumentation augmented by visual observations of the eruptive episode, geochemical and petrologic analysis of eruptive products, plume SO2 measurements, and temperature measurements of fumaroles inside and outside the active vent. The 2011 eruptive episode was Telica's most explosive since 1999 and consisted of numerous vulcanian explosions, with maximum column heights of 1.5-2 km above the crater rim, depositing a low volume of dominantly hydrothermally altered ash. Based on observed variations in seismicity, temperature, and SO2 flux, the lack of deformation of the edifice, the non-juvenile origin of and predominance of accretionary lapilli in the ash, we propose that temporary sealing of the hydrothermal system between similar to 0.5 and 2 km depth, allowed pressure to build up prior to vulcanian explosions, making this a phreatic eruptive episode.

  • 出版日期2014-2-1