Anatomy of a High-Silica Eruption as Observed by a Local Seismic Network: The June 2011 Puyehue-Cordón Caulle Event (Southern Andes, Chile)
Daniel Basualto1,2,Andrés Tassara2,3,4,Jonathan Lazo-Gil5,Luis Franco-Marin6,Carlos Cardona6,Juan Jose San Martín5,Fernando Gil-Cruz6,Marcela Calabi-Floddy7,and Cristian Farías8Daniel Basualto et al.Daniel Basualto1,2,Andrés Tassara2,3,4,Jonathan Lazo-Gil5,Luis Franco-Marin6,Carlos Cardona6,Juan Jose San Martín5,Fernando Gil-Cruz6,Marcela Calabi-Floddy7,and Cristian Farías8
1Universidad de La Frontera (UFRO), Departamento de Ingeniería en Obras Civiles, Facultad de Ingeniería y Ciencias, Francisco Salazar #01145, Temuco, Chile
2Programa de Doctorado en Ciencias Geológicas, Universidad de Concepción, Víctor Lamas #1290, Concepción, Chile
3Universidad de Concepción, Departamento Ciencias de la Tierra, Víctor Lamas #1290, Concepción, Chile
4Núcleo Milenio CYCLO: The Seismic Cycle along Subduction Zones, Chile
5Universidad de La Frontera, Departamento de Ciencias Físicas, Casilla 54-D, Temuco, Chile
6Servicio Nacional de Geología y Minería (SERNAGEOMIN) - Red Nacional de Vigilancia Volcánica (RNVV) - Observatorio Volcanológico de los Andes del Sur, (OVDAS), Rudecindo Ortega #03850, Temuco, Chile
7Universidad de La Frontera, Nano-biotechnology Laboratory, Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Biotechnological Bioresource Nucleus, BIOREN-UFRO, Francisco Salazar #01145, Temuco, Chile
8Universidad Católica de Temuco, Departamento de Geología y Obras Civiles, Facultad de Ingeniería, Rudecindo Ortega 02950, Temuco, Chile
1Universidad de La Frontera (UFRO), Departamento de Ingeniería en Obras Civiles, Facultad de Ingeniería y Ciencias, Francisco Salazar #01145, Temuco, Chile
2Programa de Doctorado en Ciencias Geológicas, Universidad de Concepción, Víctor Lamas #1290, Concepción, Chile
3Universidad de Concepción, Departamento Ciencias de la Tierra, Víctor Lamas #1290, Concepción, Chile
4Núcleo Milenio CYCLO: The Seismic Cycle along Subduction Zones, Chile
5Universidad de La Frontera, Departamento de Ciencias Físicas, Casilla 54-D, Temuco, Chile
6Servicio Nacional de Geología y Minería (SERNAGEOMIN) - Red Nacional de Vigilancia Volcánica (RNVV) - Observatorio Volcanológico de los Andes del Sur, (OVDAS), Rudecindo Ortega #03850, Temuco, Chile
7Universidad de La Frontera, Nano-biotechnology Laboratory, Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Biotechnological Bioresource Nucleus, BIOREN-UFRO, Francisco Salazar #01145, Temuco, Chile
8Universidad Católica de Temuco, Departamento de Geología y Obras Civiles, Facultad de Ingeniería, Rudecindo Ortega 02950, Temuco, Chile
Received: 08 Apr 2022 – Discussion started: 01 Jun 2022
Abstract. High-silica explosive eruptions are one of the most dangerous natural phenomena, yet it is unclear which processes are involved in this infrequent kind of events. We present the first systematic characterization of near-field seismicity associated to a large high-silica eruption analyzing data recorded before, during and after the June 4th 2011 rhyolitic eruption of Puyehue Cordón Caulle Volcanic Complex (PCCVC). Results of a first-level data processing, developed by The Southern Andean Volcano Observatory (OVDAS) to monitor unrest and the evolution of the eruption, are complemented here with the relocation of hypocenters into a local 1D velocity model, time-series of the b-value and the computation of focal mechanism. This information allows us to define several phases before and after the onset of the eruption, describing details of the space-time evolution of seismicity, defining and characterizing the seismic sources, identifying the structural-control of the magmatic intrusion and stress variations during the eruption. Our results illuminate several underlying processes, with emphasis on the possible role that basement structures had on the storage, transport and evacuation of magma. Integrating our results with previous findings based on satellite geodesy and petrology of erupted materials, we discuss general conceptual models regarding destabilization of structurally-controlled acidic magmatic systems, the pass from unrest to eruption, changes in eruptive style and waning phases of eruptions, with broader implications for monitoring and forecast of violent silicic eruptions.
Infrequent eruptions of acidic magma are one of the most dangerous natural phenomena, but almost none of them has been witnessed by modern science. We present the first systematic characterization of seismicity recorded near an erupting acidic volcano (Cordon Caulle 2011). We define different phases of unrest and eruption, which combined with previous findings allows to discuss main processes associated with this type of violent eruptions, with implications to their volcanic hazard.
Infrequent eruptions of acidic magma are one of the most dangerous natural phenomena, but almost...