Seismological investigation on the recent unrest of Tenerife (Canary Islands)

Tenerife is an active volcanic island belonging to the Canary Islands Archipelago. After its last eruption in 1909, the only visible volcanic manifestations consisted of weak fumaroles from the summit crater of Teide volcano, the most prominent geographic feature of the island. Tenerife has been monitored since 2016 by a seismic network consisting currently of 21 broadband stations. Since October 2016, the seismic activity has shown an increase, corresponding to a relevant growth of the diffuse degassing from the summit of Teide. This has been interpreted as the effect of pressurization of the hydrothermal system triggered by repeated injections of fluids of magmatic origin. Here, we present different analyses realized on the seismic catalogue of the island. First, we show the spatio-temporal variation in the hypocenter distribution, highlighting the temporal evolution of seismicity clusters. Then, we discuss the spatial and temporal variations of the Gutenberg-Richter b-value, which shows a remarkable increase and, in general, higher values around the central part of the island. We also highlight the presence of a significant long-period seismic activity, consisting of both isolated events and dense swarms. Finally, we discuss the relationship between the seismicity and the internal structure of the island, inferred by recent seismic tomography studies, as well as the temporal correlation with other geophysical and geochemical parameters measured on the island.