Eruptive parameters and dynamics of the April 2015 sub-Plinian eruptions of Calbuco volcano (southern Chile) - Archive ouverte HAL Access content directly
Journal Articles Bulletin of Volcanology Year : 2016

Eruptive parameters and dynamics of the April 2015 sub-Plinian eruptions of Calbuco volcano (southern Chile)

, , , (1) , (1) , (1) ,
1
Angelo Castruccio
  • Function : Author
Jorge Clavero
  • Function : Author
Andrea Segura
  • Function : Author
Pablo Samaniego
Olivier Roche
Jean-Luc Le Pennec
  • Function : Author
  • PersonId : 855480
Bárbara Droguett
  • Function : Author

Abstract

We conducted geological and petrological analyses of the tephra fallout and pyroclastic density current (PDC) products of the 22-23 April 2015 Calbuco eruptions. The eruptive cycle consisted of two sub-Plinian phases that generated > 15 km height columns and PDCs that travelled up to 6 km from the vent. The erupted volume is estimated at 0.38 km3 (non-DRE), with approximately 90% corresponding to tephra fall deposits and the other 10% to PDC deposits. The erupted products are basaltic-andesite, 54-55 wt.% SiO2, with minor amounts of andesite (58 wt.% SiO2). Despite the uniform composition of the products, there are at least four types of textures in juvenile clasts, with different degrees of vesicularity and types and content of crystals. We propose that the eruption triggering mechanism was either exsolution of volatiles due to crystallization, or a small intrusion into the base of the magma chamber, without significant magma mixing or with a magma compositionally similar to that of the residing magma. In either case the triggering mechanism generated convection and sufficient overpressure to promote the first eruptive phase. The start of the eruption decompressed the chamber, promoting intense vesiculation of the remaining magma and an increase in eruption rate towards the end of the eruption.
Not file

Dates and versions

hal-01637081 , version 1 (17-11-2017)

Identifiers

Cite

Angelo Castruccio, Jorge Clavero, Andrea Segura, Pablo Samaniego, Olivier Roche, et al.. Eruptive parameters and dynamics of the April 2015 sub-Plinian eruptions of Calbuco volcano (southern Chile). Bulletin of Volcanology, 2016, 78 (9), ⟨10.1007/s00445-016-1058-8⟩. ⟨hal-01637081⟩
46 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More