SciELO - Scientific Electronic Library Online

 
vol.43 número1Tefrocronología holocénica cerca de Cochrane (~47° S), Chile AustralAdelgazamiento del glaciar cubierto Horcones Inferior, derivado de mediciones geodésicas mediante el uso de estaciones semicontinuas GNSS, durante un período de cinco estaciones de verano (C° Aconcagua, Argentina) índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Revista

Articulo

Indicadores

Links relacionados

  • En proceso de indezaciónCitado por Google
  • No hay articulos similaresSimilares en SciELO
  • En proceso de indezaciónSimilares en Google

Compartir


Andean geology

versión On-line ISSN 0718-7106

Resumen

AGUILERA, Felipe et al. Eruptive activity of Planchón-Peteroa volcano for period 2010-2011, Southern Andean Volcanic Zone, Chile. AndGeo [online]. 2016, vol.43, n.1, pp.20-46. ISSN 0718-7106.  http://dx.doi.org/10.5027/andgeoV43n1-a02.

Planchon-Peteroa volcano started a renewed eruptive period between January 2010 and July 2011. This eruptive period was characterized by the occurrence of 4 explosive eruptive phases, dominated by low-intensity phreatic activity, which produced almost permanent gas/steam columns (200-800 m height over the active crater). Those columns presented frequently scarce ash, and were interrupted by phreatic explosions that produced ash columns 1,000-3,000 m height in the more intense periods. Eruptive plumes were transported in several directions (NW, N, NE, E and SE), but more than half of the time the plume axis was 130-150° E, and reached a distance up to 638 km from the active crater. Tephra fall deposits identified in the NW, N, NE, E and SE flanks covered an area of 1,265 km2, thickness variable from 4 m (SE border of active crater) to ~0.5 cm 36.8 km SE and ~8 km NW from active crater, respectively, corresponding to a minimum volume of 0.0088 km3. Tephra fall deposit is exclusively constituted of no juvenile fragments including: lithics fragments as main component, quartz and plagioclase crystals, some oxidized lithics, and occasional presence of Fe oxide, and less frequently Cu minerals, as single fragments. We present new field-based measurements data of the geochemistry of gas/water from fumaroles and acid crater lakes, and fall deposit analysis, that integrated with the eruptive record and GOES satellite data, suggests that the eruptive period 2010-2011 has been related to an increasing of heat and mass transfer from hydrothermal-magmatic reservoirs, which would have been favoured by the formation and/or reactivation of cracks after 8.8 Mw Maule earthquake in February 2010. This process also allowed the ascent of fluids from a shallow hydrothermal source, dominated by reduced species as H2S and CH4, during the entire eruptive period, and the release of more oxidizing fluids from a deep magmatic reservoir, dominated by acid species as SO2, HCl and HF, increasing strongly after the end of the eruptive period, probably since October 2011. The eruptive period was scored with a magnitude of 3.36, corresponding to a VEI 1-2.

Palabras clave : Phreatic explosions; Fluid geochemistry; Planchón-Peteroa volcano.

        · resumen en Español     · texto en Inglés     · Inglés ( pdf )

 

Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons