Study of seismic activity at Ceboruco Volcano (Nayarit, Mexico) in the period 2012 to 2014

摘要

Ceboruco volcano is a stratovolcano located in western central Mexico within the state of Nayarit. Ceboruco volcano is one of the active volcanoes of the Trans-Mexican Volcanic Belt and lies within the Tepic-Zacoalco Rift structure. Eruptions at Ceboruco volcano have been reported over the last 1000 years with eruptions every 126 years on average, with the most recent eruption occurring in 1870. Current activity at Ceboruco volcano is primarily fumarolic emissions. Continued population and socio-economic growth around the volcano over the last 20 years, make urgent the need to study Ceboruco volcano. Previous investigations of seismicity classified the recorded earthquakes into four families using waveform and spectral features. In this paper, we present a seismicity study from March 2012 to July 2014 using four portable seismic stations within the context of the regional stress and structures near Ceboruco volcano. Of the 489 volcanic earthquakes recorded during this time period, only 33 could be located using P- and S-wave arrivals registered at least three stations. The P- and S-phase arrival times were obtained using particle motion. The epicentral distribution of these earthquakes is around the volcanic edifice along three structural lineaments with preferred ENE-WSW orientations, roughly perpendicular to Tepic-Zacoalco Rift and, following the youngest deformation pattern. Hypocentral depths locate within first 10 km, indicating the earthquakes are a result of local tectonic stresses, intrusions into the magma chamber, or both.