At the end of March 2006, Ubinas volcano (16.355º S, 70.903º W, 5672 m) considered the most active volcano of Peru during the last 450 years begun a new eruption process which is lasting until present. The Geophysical Institute of Peru (IGP) with the cooperation of the Institut de Recherche pour le Developpement (IRD-France) has carried out the monitoring and surveillance of seismic activity associated to this eruptive process, at the beginning by 2 digital broadband portable seismic stations and later by a network of 3 digital 1Hz stations which data is transmitted by radio telemetry to Cayma Volcanological Observatory at Arequipa city. Here we present the main characteristics about the evolution of the seismicity during this eruptive process that permitted to us to distinguish, considering also the terrain observations, that there were 4 stages during the process: (1) From March 25th...

Resumen de artículo presentado en el EGU General Assembly 2012. Disponible en: Geophysical Research Abstracts,v. 14, EGU2012-9359, 2012.

Seismo-volcano source localization is essential to improve our understanding of eruptive dynamics and of magmatic systems. The lack of clear seismic wave phases prohibits the use of classical location methods. Seismic antennas composed of one-component (1C) seismometers provide a good estimate of the backazimuth of the wavefield. The depth estimation, on the other hand, is difficult or impossible to determine. As in classical seismology, the use of three-component (3C) seismometers is now common in volcano studies. To determine the source location parameters (backazimuth and depth), we extend the 1C seismic antenna approach to 3Cs. This paper discusses a high-resolution location method using a 3C array survey (3C-MUSIC algorithm) with data from two seismic antennas installed on an andesitic volcano in Peru (Ubinas volcano). One of the main scientific questions related to the eruptive pro...

Resumen de artículo presentado en el EGU General Assembly 2008. Disponible en: Geophysical Research Abstracts,v. 10, EGU2008-A-04275, 2008.

Most seismic eruption forerunners are described using Volcano‐Tectonic earthquakes, seismic energy release, deformation rates or seismic noise analyses. Using the seismic data recorded at Ubinas volcano (Perú) between 2006 and 2008, we explore the time evolution of the Long Period (LP) seismicity rate prior to 143 explosions. We resolve an average acceleration of the LP rate above the background level during the 2–3 hours preceding the explosion onset. Such an average pattern, which emerges when stacking over LP time series, is robust and stable over all the 2006–2008 period, for which data is available. This accelerating pattern is also recovered when conditioning the LP rate on the occurrence of an other LP event, rather than on the explosion time. It supports a common mechanism for the generation of explosions and LP events, the magma conduit pressure increase being the most pr...