Seismicity and Volcanic Activity of Ceboruco Volcano (Mexico): Insights from Historical and Recent Studies

The Ceboruco Volcano, located in the western portion of the Trans-Mexican Volcanic Belt, is classified as one of Mexico’s most dangerous volcanic systems. Consequently, effective monitoring is essential; however, seismic observations at Ceboruco have been inconsistent over the past quarter-century. Initial temporary monitoring networks, comprising one to four stations, provided only a general overview of the seismic activity in the area surrounding the volcano. During the preliminary observation phase with a single station, volcano-tectonic, low-frequency, and hybrid seismic events were recorded, exhibiting a seemingly random spatial distribution. In 2012, the deployment of a four-station seismic network yielded data that enhanced understanding of the structural characteristics of the volcanic edifice and its reactivated ENE–WSW-oriented geological structures. Nevertheless, a discernible hypocentral location pattern remained unresolved. This limited dataset was insufficient to establish a baseline of the volcano’s current status, prompting the deployment of a dense, temporary seismic network comprising 25 stations covering an area of 16 × 16 km around the volcano. This enhanced network identified 81 seismic events, with depths ranging from 4 to 8 km. A significant portion of this recent seismic activity manifested in swarms, leading to the identification of four distinct sequences. The findings indicate a shift in the distribution of local seismicity relative to earlier reports, which had linked seismic events near the volcanic edifice to fluid migration within structural weaknesses associated with the extensional stresses of the Tepic-Zacoalco Rift. The observed alterations in seismic patterns align with fluid-dynamics observations at various geothermal sites worldwide and may also indicate a potential resurgence of volcanic activity.